diff --git a/g10/tofu.c b/g10/tofu.c index 6eb7f5e99..d7730a360 100644 --- a/g10/tofu.c +++ b/g10/tofu.c @@ -1,3736 +1,3885 @@ /* tofu.c - TOFU trust model. * Copyright (C) 2015, 2016 g10 Code GmbH * * This file is part of GnuPG. * * GnuPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * GnuPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ /* TODO: - Format the fingerprints nicely when printing (similar to gpg --list-keys) */ #include #include #include #include #include #include #include #include #include #include "gpg.h" #include "types.h" #include "logging.h" #include "stringhelp.h" #include "options.h" #include "mbox-util.h" #include "i18n.h" #include "ttyio.h" #include "trustdb.h" #include "mkdir_p.h" #include "gpgsql.h" #include "status.h" #include "sqrtu32.h" #include "tofu.h" #define CONTROL_L ('L' - 'A' + 1) /* Number of signed messages required to indicate that enough history * is available for basic trust. */ #define BASIC_TRUST_THRESHOLD 10 /* Number of signed messages required to indicate that a lot of * history is available. */ #define FULL_TRUST_THRESHOLD 100 /* An struct with data pertaining to the tofu DB. To initialize this data structure, call opendbs(). Cleanup is done when the CTRL object is released. To get a handle to a database, use the getdb() function. This will either return an existing handle or open a new DB connection, as appropriate. */ struct tofu_dbs_s { sqlite3 *db; char *want_lock_file; time_t want_lock_file_ctime; struct { sqlite3_stmt *savepoint_batch; sqlite3_stmt *savepoint_batch_commit; sqlite3_stmt *record_binding_get_old_policy; sqlite3_stmt *record_binding_update; sqlite3_stmt *get_policy_select_policy_and_conflict; sqlite3_stmt *get_trust_bindings_with_this_email; sqlite3_stmt *get_trust_gather_other_user_ids; sqlite3_stmt *get_trust_gather_signature_stats; sqlite3_stmt *get_trust_gather_encryption_stats; sqlite3_stmt *register_already_seen; sqlite3_stmt *register_signature; sqlite3_stmt *register_encryption; } s; int in_batch_transaction; int in_transaction; time_t batch_update_started; }; #define STRINGIFY(s) STRINGIFY2(s) #define STRINGIFY2(s) #s /* The grouping parameters when collecting signature statistics. */ /* If a message is signed a couple of hours in the future, just assume some clock skew. */ #define TIME_AGO_FUTURE_IGNORE (2 * 60 * 60) /* Days. */ #define TIME_AGO_UNIT_SMALL (24 * 60 * 60) #define TIME_AGO_SMALL_THRESHOLD (7 * TIME_AGO_UNIT_SMALL) /* Months. */ #define TIME_AGO_UNIT_MEDIUM (30 * 24 * 60 * 60) #define TIME_AGO_MEDIUM_THRESHOLD (2 * TIME_AGO_UNIT_MEDIUM) /* Years. */ #define TIME_AGO_UNIT_LARGE (365 * 24 * 60 * 60) #define TIME_AGO_LARGE_THRESHOLD (2 * TIME_AGO_UNIT_LARGE) /* Local prototypes. */ static gpg_error_t end_transaction (ctrl_t ctrl, int only_batch); static char *email_from_user_id (const char *user_id); const char * tofu_policy_str (enum tofu_policy policy) { switch (policy) { case TOFU_POLICY_NONE: return "none"; case TOFU_POLICY_AUTO: return "auto"; case TOFU_POLICY_GOOD: return "good"; case TOFU_POLICY_UNKNOWN: return "unknown"; case TOFU_POLICY_BAD: return "bad"; case TOFU_POLICY_ASK: return "ask"; default: return "???"; } } /* Convert a binding policy (e.g., TOFU_POLICY_BAD) to a trust level (e.g., TRUST_BAD) in light of the current configuration. */ int tofu_policy_to_trust_level (enum tofu_policy policy) { if (policy == TOFU_POLICY_AUTO) /* If POLICY is AUTO, fallback to OPT.TOFU_DEFAULT_POLICY. */ policy = opt.tofu_default_policy; switch (policy) { case TOFU_POLICY_AUTO: /* If POLICY and OPT.TOFU_DEFAULT_POLICY are both AUTO, default to marginal trust. */ return TRUST_MARGINAL; case TOFU_POLICY_GOOD: return TRUST_FULLY; case TOFU_POLICY_UNKNOWN: return TRUST_UNKNOWN; case TOFU_POLICY_BAD: return TRUST_NEVER; case TOFU_POLICY_ASK: return TRUST_UNKNOWN; default: log_bug ("Bad value for trust policy: %d\n", opt.tofu_default_policy); return 0; } } /* Start a transaction on DB. If ONLY_BATCH is set, then this will start a batch transaction if we haven't started a batch transaction and one has been requested. */ static gpg_error_t begin_transaction (ctrl_t ctrl, int only_batch) { tofu_dbs_t dbs = ctrl->tofu.dbs; int rc; char *err = NULL; log_assert (dbs); /* If we've been in batch update mode for a while (on average, more * than 500 ms), to prevent starving other gpg processes, we drop * and retake the batch lock. * * Note: if we wanted higher resolution, we could use * npth_clock_gettime. */ if (/* No real transactions. */ dbs->in_transaction == 0 /* There is an open batch transaction. */ && dbs->in_batch_transaction /* And some time has gone by since it was started. */ && dbs->batch_update_started != gnupg_get_time ()) { struct stat statbuf; /* If we are in a batch update, then batch updates better have been enabled. */ log_assert (ctrl->tofu.batch_updated_wanted); /* Check if another process wants to run. (We just ignore any * stat failure. A waiter might have to wait a bit longer, but * otherwise there should be no impact.) */ if (stat (dbs->want_lock_file, &statbuf) == 0 && statbuf.st_ctime != dbs->want_lock_file_ctime) { end_transaction (ctrl, 2); /* Yield to allow another process a chance to run. Note: * testing suggests that anything less than a 100ms tends to * not result in the other process getting the lock. */ gnupg_usleep (100000); } else dbs->batch_update_started = gnupg_get_time (); } if (/* We don't have an open batch transaction. */ !dbs->in_batch_transaction && (/* Batch mode is enabled or we are starting a new transaction. */ ctrl->tofu.batch_updated_wanted || dbs->in_transaction == 0)) { struct stat statbuf; /* We are in batch mode, but we don't have an open batch * transaction. Since the batch save point must be the outer * save point, it must be taken before the inner save point. */ log_assert (dbs->in_transaction == 0); rc = gpgsql_stepx (dbs->db, &dbs->s.savepoint_batch, NULL, NULL, &err, "begin immediate transaction;", GPGSQL_ARG_END); if (rc) { log_error (_("error beginning transaction on TOFU database: %s\n"), err); sqlite3_free (err); return gpg_error (GPG_ERR_GENERAL); } dbs->in_batch_transaction = 1; dbs->batch_update_started = gnupg_get_time (); if (stat (dbs->want_lock_file, &statbuf) == 0) dbs->want_lock_file_ctime = statbuf.st_ctime; } if (only_batch) return 0; log_assert (dbs->in_transaction >= 0); dbs->in_transaction ++; rc = gpgsql_exec_printf (dbs->db, NULL, NULL, &err, "savepoint inner%d;", dbs->in_transaction); if (rc) { log_error (_("error beginning transaction on TOFU database: %s\n"), err); sqlite3_free (err); return gpg_error (GPG_ERR_GENERAL); } return 0; } /* Commit a transaction. If ONLY_BATCH is 1, then this only ends the * batch transaction if we have left batch mode. If ONLY_BATCH is 2, * this ends any open batch transaction even if we are still in batch * mode. */ static gpg_error_t end_transaction (ctrl_t ctrl, int only_batch) { tofu_dbs_t dbs = ctrl->tofu.dbs; int rc; char *err = NULL; if (only_batch || (! only_batch && dbs->in_transaction == 1)) { if (!dbs) return 0; /* Shortcut to allow for easier cleanup code. */ /* If we are releasing the batch transaction, then we better not be in a normal transaction. */ if (only_batch) log_assert (dbs->in_transaction == 0); if (/* Batch mode disabled? */ (!ctrl->tofu.batch_updated_wanted || only_batch == 2) /* But, we still have an open batch transaction? */ && dbs->in_batch_transaction) { /* The batch transaction is still in open, but we've left * batch mode. */ dbs->in_batch_transaction = 0; dbs->in_transaction = 0; rc = gpgsql_stepx (dbs->db, &dbs->s.savepoint_batch_commit, NULL, NULL, &err, "commit transaction;", GPGSQL_ARG_END); if (rc) { log_error (_("error committing transaction on TOFU database: %s\n"), err); sqlite3_free (err); return gpg_error (GPG_ERR_GENERAL); } return 0; } if (only_batch) return 0; } log_assert (dbs); log_assert (dbs->in_transaction > 0); rc = gpgsql_exec_printf (dbs->db, NULL, NULL, &err, "release inner%d;", dbs->in_transaction); dbs->in_transaction --; if (rc) { log_error (_("error committing transaction on TOFU database: %s\n"), err); sqlite3_free (err); return gpg_error (GPG_ERR_GENERAL); } return 0; } static gpg_error_t rollback_transaction (ctrl_t ctrl) { tofu_dbs_t dbs = ctrl->tofu.dbs; int rc; char *err = NULL; log_assert (dbs); log_assert (dbs->in_transaction > 0); /* Be careful to not any progress made by closed transactions in batch mode. */ rc = gpgsql_exec_printf (dbs->db, NULL, NULL, &err, "rollback to inner%d;", dbs->in_transaction); dbs->in_transaction --; if (rc) { log_error (_("error rolling back transaction on TOFU database: %s\n"), err); sqlite3_free (err); return gpg_error (GPG_ERR_GENERAL); } return 0; } void tofu_begin_batch_update (ctrl_t ctrl) { ctrl->tofu.batch_updated_wanted ++; } void tofu_end_batch_update (ctrl_t ctrl) { log_assert (ctrl->tofu.batch_updated_wanted > 0); ctrl->tofu.batch_updated_wanted --; end_transaction (ctrl, 1); } /* Suspend any extant batch transaction (it is safe to call this even no batch transaction has been started). Note: you cannot suspend a batch transaction if you are in a normal transaction. The batch transaction can be resumed explicitly by calling tofu_resume_batch_transaction or implicitly by starting a normal transaction. */ static void tofu_suspend_batch_transaction (ctrl_t ctrl) { end_transaction (ctrl, 2); } /* Resume a batch transaction if there is no extant batch transaction and one has been requested using tofu_begin_batch_transaction. */ static void tofu_resume_batch_transaction (ctrl_t ctrl) { begin_transaction (ctrl, 1); } /* Wrapper around strtol which prints a warning in case of a * conversion error. On success the converted value is stored at * R_VALUE and 0 is returned; on error FALLBACK is stored at R_VALUE * and an error code is returned. */ static gpg_error_t string_to_long (long *r_value, const char *string, long fallback, int line) { gpg_error_t err; char *tail = NULL; gpg_err_set_errno (0); *r_value = strtol (string, &tail, 0); if (errno || !(!strcmp (tail, ".0") || !*tail)) { err = errno? gpg_error_from_errno (errno) : gpg_error (GPG_ERR_BAD_DATA); log_debug ("%s:%d: " "strtol failed for DB returned string (tail=%.10s): %s\n", __FILE__, line, tail, gpg_strerror (err)); *r_value = fallback; } else err = 0; return err; } /* Wrapper around strtoul which prints a warning in case of a * conversion error. On success the converted value is stored at * R_VALUE and 0 is returned; on error FALLBACK is stored at R_VALUE * and an error code is returned. */ static gpg_error_t string_to_ulong (unsigned long *r_value, const char *string, unsigned long fallback, int line) { gpg_error_t err; char *tail = NULL; gpg_err_set_errno (0); *r_value = strtoul (string, &tail, 0); if (errno || !(!strcmp (tail, ".0") || !*tail)) { err = errno? gpg_error_from_errno (errno) : gpg_error (GPG_ERR_BAD_DATA); log_debug ("%s:%d: " "strtoul failed for DB returned string (tail=%.10s): %s\n", __FILE__, line, tail, gpg_strerror (err)); *r_value = fallback; } else err = 0; return err; } /* Collect results of a select count (*) ...; style query. Aborts if the argument is not a valid integer (or real of the form X.0). */ static int get_single_unsigned_long_cb (void *cookie, int argc, char **argv, char **azColName) { unsigned long int *count = cookie; (void) azColName; log_assert (argc == 1); if (string_to_ulong (count, argv[0], 0, __LINE__)) return 1; /* Abort. */ return 0; } static int get_single_unsigned_long_cb2 (void *cookie, int argc, char **argv, char **azColName, sqlite3_stmt *stmt) { (void) stmt; return get_single_unsigned_long_cb (cookie, argc, argv, azColName); } /* We expect a single integer column whose name is "version". COOKIE must point to an int. This function always aborts. On error or a if the version is bad, sets *VERSION to -1. */ static int version_check_cb (void *cookie, int argc, char **argv, char **azColName) { int *version = cookie; if (argc != 1 || strcmp (azColName[0], "version") != 0) { *version = -1; return 1; } if (strcmp (argv[0], "1") == 0) *version = 1; else { log_error (_("unsupported TOFU database version: %s\n"), argv[0]); *version = -1; } /* Don't run again. */ return 1; } +static int +check_utks (sqlite3 *db) +{ + int rc; + char *err = NULL; + struct key_item *utks; + struct key_item *ki; + int utk_count; + char *utks_string = NULL; + char keyid_str[16+1]; + long utks_unchanged = 0; + + /* An early version of the v1 format did not include the list of + * known ultimately trusted keys. + * + * This list is used to detect when the set of ultimately trusted + * keys changes. We need to detect this to invalidate the effective + * policy, which can change if an ultimately trusted key is added or + * removed. */ + rc = sqlite3_exec (db, + "create table if not exists ultimately_trusted_keys" + " (keyid);\n", + NULL, NULL, &err); + if (rc) + { + log_error (_("error creating 'ultimately_trusted_keys' TOFU table: %s\n"), + err); + sqlite3_free (err); + goto out; + } + + + utks = tdb_utks (); + for (ki = utks, utk_count = 0; ki; ki = ki->next, utk_count ++) + ; + + if (utk_count) + { + /* Build a list of keyids of the form "XXX","YYY","ZZZ". */ + int len = (1 + 16 + 1 + 1) * utk_count; + int o = 0; + + utks_string = xmalloc (len); + *utks_string = 0; + for (ki = utks, utk_count = 0; ki; ki = ki->next, utk_count ++) + { + utks_string[o ++] = '\''; + format_keyid (ki->kid, KF_LONG, + keyid_str, sizeof (keyid_str)); + memcpy (&utks_string[o], keyid_str, 16); + o += 16; + utks_string[o ++] = '\''; + utks_string[o ++] = ','; + } + utks_string[o - 1] = 0; + log_assert (o == len); + } + + rc = gpgsql_exec_printf + (db, get_single_unsigned_long_cb, &utks_unchanged, &err, + "select" + /* Removed UTKs? (Known UTKs in current UTKs.) */ + " ((select count(*) from ultimately_trusted_keys" + " where (keyid in (%s))) == %d)" + " and" + /* New UTKs? */ + " ((select count(*) from ultimately_trusted_keys" + " where keyid not in (%s)) == 0);", + utks_string ? utks_string : "", + utk_count, + utks_string ? utks_string : ""); + xfree (utks_string); + if (rc) + { + log_error (_("TOFU DB error")); + print_further_info ("checking if ultimately trusted keys changed: %s", + err); + sqlite3_free (err); + goto out; + } + + if (utks_unchanged) + goto out; + + if (DBG_TRUST) + log_debug ("TOFU: ultimately trusted keys changed.\n"); + + /* Given that the set of ultimately trusted keys + * changed, clear any cached policies. */ + rc = gpgsql_exec_printf + (db, NULL, NULL, &err, + "update bindings set effective_policy = %d;", + TOFU_POLICY_NONE); + if (rc) + { + log_error (_("TOFU DB error")); + print_further_info ("clearing cached policies: %s", err); + sqlite3_free (err); + goto out; + } + + /* Now, update the UTK table. */ + rc = sqlite3_exec (db, + "drop table ultimately_trusted_keys;", + NULL, NULL, &err); + if (rc) + { + log_error (_("TOFU DB error")); + print_further_info ("dropping ultimately_trusted_keys: %s", err); + sqlite3_free (err); + goto out; + } + + rc = sqlite3_exec (db, + "create table if not exists" + " ultimately_trusted_keys (keyid);\n", + NULL, NULL, &err); + if (rc) + { + log_error (_("TOFU DB error")); + print_further_info ("creating ultimately_trusted_keys: %s", err); + sqlite3_free (err); + goto out; + } + + for (ki = utks; ki; ki = ki->next) + { + format_keyid (ki->kid, KF_LONG, + keyid_str, sizeof (keyid_str)); + rc = gpgsql_exec_printf + (db, NULL, NULL, &err, + "insert into ultimately_trusted_keys values ('%s');", + keyid_str); + if (rc) + { + log_error (_("TOFU DB error")); + print_further_info ("updating ultimately_trusted_keys: %s", + err); + sqlite3_free (err); + goto out; + } + } + + out: + return rc; +} /* If the DB is new, initialize it. Otherwise, check the DB's version. Return 0 if the database is okay and 1 otherwise. */ static int initdb (sqlite3 *db) { char *err = NULL; int rc; unsigned long int count; int version = -1; rc = sqlite3_exec (db, "begin transaction;", NULL, NULL, &err); if (rc) { log_error (_("error beginning transaction on TOFU database: %s\n"), err); sqlite3_free (err); return 1; } /* If the DB has no tables, then assume this is a new DB that needs to be initialized. */ rc = sqlite3_exec (db, "select count(*) from sqlite_master where type='table';", get_single_unsigned_long_cb, &count, &err); if (rc) { log_error (_("error reading TOFU database: %s\n"), err); print_further_info ("query available tables"); sqlite3_free (err); goto out; } else if (count != 0) /* Assume that the DB is already initialized. Make sure the version is okay. */ { rc = sqlite3_exec (db, "select version from version;", version_check_cb, &version, &err); if (rc == SQLITE_ABORT && version == 1) /* Happy, happy, joy, joy. */ { sqlite3_free (err); rc = 0; goto out; } else if (rc == SQLITE_ABORT && version == -1) /* Unsupported version. */ { /* An error message was already displayed. */ sqlite3_free (err); goto out; } else if (rc) /* Some error. */ { log_error (_("error determining TOFU database's version: %s\n"), err); sqlite3_free (err); goto out; } else { /* Unexpected success. This can only happen if there are no rows. (select returned 0, but expected ABORT.) */ log_error (_("error determining TOFU database's version: %s\n"), gpg_strerror (GPG_ERR_NO_DATA)); rc = 1; goto out; } } /* Create the version table. */ rc = sqlite3_exec (db, "create table version (version INTEGER);", NULL, NULL, &err); if (rc) { log_error (_("error initializing TOFU database: %s\n"), err); print_further_info ("create version"); sqlite3_free (err); goto out; } /* Initialize the version table, which contains a single integer value. */ rc = sqlite3_exec (db, "insert into version values (1);", NULL, NULL, &err); if (rc) { log_error (_("error initializing TOFU database: %s\n"), err); print_further_info ("insert version"); sqlite3_free (err); goto out; } /* The list of bindings and auxiliary data. * * OID is a unique ID identifying this binding (and used by the * signatures table, see below). Note: OIDs will never be * reused. * * FINGERPRINT: The key's fingerprint. * * EMAIL: The normalized email address. * * USER_ID: The unmodified user id from which EMAIL was extracted. * * TIME: The time this binding was first observed. * * POLICY: The trust policy (TOFU_POLICY_BAD, etc. as an integer). * * CONFLICT is either NULL or a fingerprint. Assume that we have * a binding <0xdeadbeef, foo@example.com> and then we observe * <0xbaddecaf, foo@example.com>. There two bindings conflict * (they have the same email address). When we observe the * latter binding, we warn the user about the conflict and ask * for a policy decision about the new binding. We also change * the old binding's policy to ask if it was auto. So that we * know why this occurred, we also set conflict to 0xbaddecaf. */ rc = gpgsql_exec_printf (db, NULL, NULL, &err, "create table bindings\n" " (oid INTEGER PRIMARY KEY AUTOINCREMENT,\n" " fingerprint TEXT, email TEXT, user_id TEXT, time INTEGER,\n" " policy INTEGER CHECK (policy in (%d, %d, %d, %d, %d)),\n" " conflict STRING,\n" " unique (fingerprint, email));\n" "create index bindings_fingerprint_email\n" " on bindings (fingerprint, email);\n" "create index bindings_email on bindings (email);\n", TOFU_POLICY_AUTO, TOFU_POLICY_GOOD, TOFU_POLICY_UNKNOWN, TOFU_POLICY_BAD, TOFU_POLICY_ASK); if (rc) { log_error (_("error initializing TOFU database: %s\n"), err); print_further_info ("create bindings"); sqlite3_free (err); goto out; } /* The signatures that we have observed. * * BINDING refers to a record in the bindings table, which * describes the binding (i.e., this is a foreign key that * references bindings.oid). * * SIG_DIGEST is the digest stored in the signature. * * SIG_TIME is the timestamp stored in the signature. * * ORIGIN is a free-form string that describes who fed this * signature to GnuPG (e.g., email:claws). * * TIME is the time this signature was registered. */ rc = sqlite3_exec (db, "create table signatures " " (binding INTEGER NOT NULL, sig_digest TEXT," " origin TEXT, sig_time INTEGER, time INTEGER," " primary key (binding, sig_digest, origin));", NULL, NULL, &err); if (rc) { log_error (_("error initializing TOFU database: %s\n"), err); print_further_info ("create signatures"); sqlite3_free (err); goto out; } out: if (! rc) { /* Early version of the v1 format did not include the encryption table. Add it. */ rc = sqlite3_exec (db, "create table if not exists encryptions" " (binding INTEGER NOT NULL," " time INTEGER);" "create index if not exists encryptions_binding" " on encryptions (binding);\n", NULL, NULL, &err); if (rc) { log_error (_("error creating 'encryptions' TOFU table: %s\n"), err); sqlite3_free (err); } } if (! rc) { /* The effective policy for a binding. If a key is ultimately * trusted, then the effective policy of all of its bindings is * good. Likewise if a key is signed by an ultimately trusted * key, etc. If the effective policy is NONE, then we need to * recompute the effective policy. Otherwise, the effective * policy is considered to be up to date, i.e., effective_policy * is a cache of the computed policy. */ rc = gpgsql_exec_printf (db, NULL, NULL, &err, "alter table bindings" " add column effective_policy INTEGER" " DEFAULT %d" " CHECK (effective_policy in (%d, %d, %d, %d, %d, %d));", TOFU_POLICY_NONE, TOFU_POLICY_NONE, TOFU_POLICY_AUTO, TOFU_POLICY_GOOD, TOFU_POLICY_UNKNOWN, TOFU_POLICY_BAD, TOFU_POLICY_ASK); if (rc) { if (rc == SQLITE_ERROR) /* Almost certainly "duplicate column name", which we can * safely ignore. */ rc = 0; else log_error (_("adding column effective_policy to bindings DB: %s\n"), err); sqlite3_free (err); } } + if (! rc) + rc = check_utks (db); + if (rc) { rc = sqlite3_exec (db, "rollback;", NULL, NULL, &err); if (rc) { log_error (_("error rolling back transaction on TOFU database: %s\n"), err); sqlite3_free (err); } return 1; } else { rc = sqlite3_exec (db, "end transaction;", NULL, NULL, &err); if (rc) { log_error (_("error committing transaction on TOFU database: %s\n"), err); sqlite3_free (err); return 1; } return 0; } } static int busy_handler (void *cookie, int call_count) { ctrl_t ctrl = cookie; tofu_dbs_t dbs = ctrl->tofu.dbs; (void) call_count; /* Update the lock file time stamp so that the current owner knows that we want the lock. */ if (dbs) { /* Note: we don't fail if we can't create the lock file: this process will have to wait a bit longer, but otherwise nothing horrible should happen. */ int fd = open (dbs->want_lock_file, O_CREAT|O_WRONLY|O_TRUNC, S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR); if (fd == -1) log_debug ("TOFU: Error opening '%s': %s\n", dbs->want_lock_file, strerror (errno)); else close (fd); } /* Call again. */ return 1; } /* Create a new DB handle. Returns NULL on error. */ /* FIXME: Change to return an error code for better reporting by the caller. */ static tofu_dbs_t opendbs (ctrl_t ctrl) { char *filename; sqlite3 *db; int rc; if (!ctrl->tofu.dbs) { filename = make_filename (gnupg_homedir (), "tofu.db", NULL); rc = sqlite3_open (filename, &db); if (rc) { log_error (_("error opening TOFU database '%s': %s\n"), filename, sqlite3_errmsg (db)); /* Even if an error occurs, DB is guaranteed to be valid. */ sqlite3_close (db); db = NULL; } /* If a DB is locked wait up to 5 seconds for the lock to be cleared before failing. */ if (db) { sqlite3_busy_timeout (db, 5 * 1000); sqlite3_busy_handler (db, busy_handler, ctrl); } if (db && initdb (db)) { sqlite3_close (db); db = NULL; } if (db) { ctrl->tofu.dbs = xmalloc_clear (sizeof *ctrl->tofu.dbs); ctrl->tofu.dbs->db = db; ctrl->tofu.dbs->want_lock_file = xasprintf ("%s-want-lock", filename); } xfree (filename); } else log_assert (ctrl->tofu.dbs->db); return ctrl->tofu.dbs; } /* Release all of the resources associated with the DB handle. */ void tofu_closedbs (ctrl_t ctrl) { tofu_dbs_t dbs; sqlite3_stmt **statements; dbs = ctrl->tofu.dbs; if (!dbs) return; /* Not initialized. */ log_assert (dbs->in_transaction == 0); end_transaction (ctrl, 2); /* Arghh, that is a surprising use of the struct. */ for (statements = (void *) &dbs->s; (void *) statements < (void *) &(&dbs->s)[1]; statements ++) sqlite3_finalize (*statements); sqlite3_close (dbs->db); xfree (dbs->want_lock_file); xfree (dbs); ctrl->tofu.dbs = NULL; } /* Collect results of a select min (foo) ...; style query. Aborts if the argument is not a valid integer (or real of the form X.0). */ static int get_single_long_cb (void *cookie, int argc, char **argv, char **azColName) { long *count = cookie; (void) azColName; log_assert (argc == 1); if (string_to_long (count, argv[0], 0, __LINE__)) return 1; /* Abort. */ return 0; } static int get_single_long_cb2 (void *cookie, int argc, char **argv, char **azColName, sqlite3_stmt *stmt) { (void) stmt; return get_single_long_cb (cookie, argc, argv, azColName); } /* Record (or update) a trust policy about a (possibly new) binding. If SHOW_OLD is set, the binding's old policy is displayed. */ static gpg_error_t record_binding (tofu_dbs_t dbs, const char *fingerprint, const char *email, const char *user_id, enum tofu_policy policy, enum tofu_policy effective_policy, const char *conflict, int set_conflict, int show_old, time_t now) { char *fingerprint_pp = format_hexfingerprint (fingerprint, NULL, 0); gpg_error_t rc; char *err = NULL; if (! (policy == TOFU_POLICY_AUTO || policy == TOFU_POLICY_GOOD || policy == TOFU_POLICY_UNKNOWN || policy == TOFU_POLICY_BAD || policy == TOFU_POLICY_ASK)) log_bug ("%s: Bad value for policy (%d)!\n", __func__, policy); if (DBG_TRUST || show_old) { /* Get the old policy. Since this is just for informational * purposes, there is no need to start a transaction or to die * if there is a failure. */ /* policy_old needs to be a long and not an enum tofu_policy, because we pass it by reference to get_single_long_cb2, which expects a long. */ long policy_old = TOFU_POLICY_NONE; rc = gpgsql_stepx (dbs->db, &dbs->s.record_binding_get_old_policy, get_single_long_cb2, &policy_old, &err, "select policy from bindings where fingerprint = ? and email = ?", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_END); if (rc) { log_debug ("TOFU: Error reading from binding database" " (reading policy for ): %s\n", fingerprint, email, err); sqlite3_free (err); } if (policy_old != TOFU_POLICY_NONE) (show_old ? log_info : log_debug) ("Changing TOFU trust policy for binding" " from %s to %s.\n", fingerprint, show_old ? user_id : email, tofu_policy_str (policy_old), tofu_policy_str (policy)); else (show_old ? log_info : log_debug) ("Setting TOFU trust policy for new binding" " to %s.\n", fingerprint, show_old ? user_id : email, tofu_policy_str (policy)); } if (opt.dry_run) { log_info ("TOFU database update skipped due to --dry-run\n"); rc = 0; goto leave; } rc = gpgsql_stepx (dbs->db, &dbs->s.record_binding_update, NULL, NULL, &err, "insert or replace into bindings\n" " (oid, fingerprint, email, user_id, time," " policy, conflict, effective_policy)\n" " values (\n" /* If we don't explicitly reuse the OID, then SQLite will * reallocate a new one. We just need to search for the OID * based on the fingerprint and email since they are unique. */ " (select oid from bindings where fingerprint = ? and email = ?),\n" " ?, ?, ?, ?, ?," /* If SET_CONFLICT is 0, then preserve conflict's current value. */ " case ?" " when 0 then" " (select conflict from bindings where fingerprint = ? and email = ?)" " else ?" " end," " ?);", /* oid subquery. */ GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, /* values 2 through 6. */ GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, user_id, GPGSQL_ARG_LONG_LONG, (long long) now, GPGSQL_ARG_INT, (int) policy, /* conflict subquery. */ GPGSQL_ARG_INT, set_conflict ? 1 : 0, GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, conflict ? conflict : "", GPGSQL_ARG_INT, (int) effective_policy, GPGSQL_ARG_END); if (rc) { log_error (_("error updating TOFU database: %s\n"), err); print_further_info (" insert bindings = %s", fingerprint, email, tofu_policy_str (policy)); sqlite3_free (err); goto leave; } leave: xfree (fingerprint_pp); return rc; } /* Collect the strings returned by a query in a simply string list. Any NULL values are converted to the empty string. If a result has 3 rows and each row contains two columns, then the results are added to the list as follows (the value is parentheses is the 1-based index in the final list): row 1, col 2 (6) row 1, col 1 (5) row 2, col 2 (4) row 2, col 1 (3) row 3, col 2 (2) row 3, col 1 (1) This is because add_to_strlist pushes the results onto the front of the list. The end result is that the rows are backwards, but the columns are in the expected order. */ static int strings_collect_cb (void *cookie, int argc, char **argv, char **azColName) { int i; strlist_t *strlist = cookie; (void) azColName; for (i = argc - 1; i >= 0; i --) add_to_strlist (strlist, argv[i] ? argv[i] : ""); return 0; } static int strings_collect_cb2 (void *cookie, int argc, char **argv, char **azColName, sqlite3_stmt *stmt) { (void) stmt; return strings_collect_cb (cookie, argc, argv, azColName); } /* Auxiliary data structure to collect statistics about signatures. */ struct signature_stats { struct signature_stats *next; /* The user-assigned policy for this binding. */ enum tofu_policy policy; /* How long ago the signature was created (rounded to a multiple of TIME_AGO_UNIT_SMALL, etc.). */ long time_ago; /* Number of signatures during this time. */ unsigned long count; /* If the corresponding key/user id has been expired / revoked. */ int is_expired; int is_revoked; /* The key that generated this signature. */ char fingerprint[1]; }; static void signature_stats_free (struct signature_stats *stats) { while (stats) { struct signature_stats *next = stats->next; xfree (stats); stats = next; } } static void signature_stats_prepend (struct signature_stats **statsp, const char *fingerprint, enum tofu_policy policy, long time_ago, unsigned long count) { struct signature_stats *stats = xmalloc_clear (sizeof (*stats) + strlen (fingerprint)); stats->next = *statsp; *statsp = stats; strcpy (stats->fingerprint, fingerprint); stats->policy = policy; stats->time_ago = time_ago; stats->count = count; } /* Process rows that contain the four columns: . */ static int signature_stats_collect_cb (void *cookie, int argc, char **argv, char **azColName, sqlite3_stmt *stmt) { struct signature_stats **statsp = cookie; int i = 0; enum tofu_policy policy; long time_ago; unsigned long count; long along; (void) azColName; (void) stmt; i ++; if (string_to_long (&along, argv[i], 0, __LINE__)) return 1; /* Abort */ policy = along; i ++; if (! argv[i]) time_ago = 0; else { if (string_to_long (&time_ago, argv[i], 0, __LINE__)) return 1; /* Abort. */ } i ++; /* If time_ago is NULL, then we had no messages, but we still have a single row, which count(*) turns into 1. */ if (! argv[i - 1]) count = 0; else { if (string_to_ulong (&count, argv[i], 0, __LINE__)) return 1; /* Abort */ } i ++; log_assert (argc == i); signature_stats_prepend (statsp, argv[0], policy, time_ago, count); return 0; } /* Convert from seconds to time units. Note: T should already be a multiple of TIME_AGO_UNIT_SMALL or TIME_AGO_UNIT_MEDIUM or TIME_AGO_UNIT_LARGE. */ signed long time_ago_scale (signed long t) { if (t < TIME_AGO_UNIT_MEDIUM) return t / TIME_AGO_UNIT_SMALL; if (t < TIME_AGO_UNIT_LARGE) return t / TIME_AGO_UNIT_MEDIUM; return t / TIME_AGO_UNIT_LARGE; } /* Format the first part of a conflict message and return that as a * malloced string. */ static char * format_conflict_msg_part1 (int policy, strlist_t conflict_set, const char *email) { estream_t fp; char *fingerprint; char *tmpstr, *text; log_assert (conflict_set); fingerprint = conflict_set->d; fp = es_fopenmem (0, "rw,samethread"); if (!fp) log_fatal ("error creating memory stream: %s\n", gpg_strerror (gpg_error_from_syserror())); if (policy == TOFU_POLICY_NONE) { es_fprintf (fp, _("This is the first time the email address \"%s\" is " "being used with key %s."), email, fingerprint); es_fputs (" ", fp); } else if (policy == TOFU_POLICY_ASK && conflict_set->next) { int conflicts = strlist_length (conflict_set); es_fprintf (fp, _("The email address \"%s\" is associated with %d keys!"), email, conflicts); if (opt.verbose) es_fprintf (fp, _(" Since this binding's policy was 'auto', it has been " "changed to 'ask'.")); es_fputs (" ", fp); } es_fprintf (fp, _("Please indicate whether this email address should" " be associated with key %s or whether you think someone" " is impersonating \"%s\"."), fingerprint, email); es_fputc ('\n', fp); es_fputc (0, fp); if (es_fclose_snatch (fp, (void **)&tmpstr, NULL)) log_fatal ("error snatching memory stream\n"); text = format_text (tmpstr, 0, 72, 80); es_free (tmpstr); return text; } /* Return 1 if A signed B and B signed A. */ static int cross_sigs (const char *email, kbnode_t a, kbnode_t b) { int i; PKT_public_key *a_pk = a->pkt->pkt.public_key; PKT_public_key *b_pk = b->pkt->pkt.public_key; char a_keyid[33]; char b_keyid[33]; if (DBG_TRUST) { format_keyid (pk_main_keyid (a_pk), KF_LONG, a_keyid, sizeof (a_keyid)); format_keyid (pk_main_keyid (b_pk), KF_LONG, b_keyid, sizeof (b_keyid)); } for (i = 0; i < 2; i ++) { /* See if SIGNER signed SIGNEE. */ kbnode_t signer = i == 0 ? a : b; kbnode_t signee = i == 0 ? b : a; PKT_public_key *signer_pk = signer->pkt->pkt.public_key; u32 *signer_kid = pk_main_keyid (signer_pk); kbnode_t n; int saw_email = 0; /* Iterate over SIGNEE's keyblock and see if there is a valid signature from SIGNER. */ for (n = signee; n; n = n->next) { PKT_signature *sig; if (n->pkt->pkttype == PKT_USER_ID) { if (saw_email) /* We're done: we've processed all signatures on the user id. */ break; else { /* See if this is the matching user id. */ PKT_user_id *user_id = n->pkt->pkt.user_id; char *email2 = email_from_user_id (user_id->name); if (strcmp (email, email2) == 0) saw_email = 1; xfree (email2); } } if (! saw_email) continue; if (n->pkt->pkttype != PKT_SIGNATURE) continue; sig = n->pkt->pkt.signature; if (! (sig->sig_class == 0x10 || sig->sig_class == 0x11 || sig->sig_class == 0x12 || sig->sig_class == 0x13)) /* Not a signature over a user id. */ continue; /* SIG is on SIGNEE's keyblock. If SIG was generated by the signer, then it's a match. */ if (keyid_cmp (sig->keyid, signer_kid) == 0) /* Match! */ break; } if (! n) /* We didn't find a signature from signer over signee. */ { if (DBG_TRUST) log_debug ("No cross sig between %s and %s\n", a_keyid, b_keyid); return 0; } } /* A signed B and B signed A. */ if (DBG_TRUST) log_debug ("Cross sig between %s and %s\n", a_keyid, b_keyid); return 1; } /* Return whether the key was signed by an ultimately trusted key. */ static int signed_by_utk (const char *email, kbnode_t a) { kbnode_t n; int saw_email = 0; for (n = a; n; n = n->next) { PKT_signature *sig; if (n->pkt->pkttype == PKT_USER_ID) { if (saw_email) /* We're done: we've processed all signatures on the user id. */ break; else { /* See if this is the matching user id. */ PKT_user_id *user_id = n->pkt->pkt.user_id; char *email2 = email_from_user_id (user_id->name); if (strcmp (email, email2) == 0) saw_email = 1; xfree (email2); } } if (! saw_email) continue; if (n->pkt->pkttype != PKT_SIGNATURE) continue; sig = n->pkt->pkt.signature; if (! (sig->sig_class == 0x10 || sig->sig_class == 0x11 || sig->sig_class == 0x12 || sig->sig_class == 0x13)) /* Not a signature over a user id. */ continue; /* SIG is on SIGNEE's keyblock. If SIG was generated by the signer, then it's a match. */ if (tdb_keyid_is_utk (sig->keyid)) { /* Match! */ if (DBG_TRUST) log_debug ("TOFU: %s is signed by an ultimately trusted key.\n", pk_keyid_str (a->pkt->pkt.public_key)); return 1; } } if (DBG_TRUST) log_debug ("TOFU: %s is NOT signed by an ultimately trusted key.\n", pk_keyid_str (a->pkt->pkt.public_key)); return 0; } enum { BINDING_NEW = 1 << 0, BINDING_CONFLICT = 1 << 1, BINDING_EXPIRED = 1 << 2, BINDING_REVOKED = 1 << 3 }; /* Ask the user about the binding. There are three ways we could end * up here: * * - This is a new binding and there is a conflict * (policy == TOFU_POLICY_NONE && conflict_set_count > 1), * * - This is a new binding and opt.tofu_default_policy is set to * ask. (policy == TOFU_POLICY_NONE && opt.tofu_default_policy == * TOFU_POLICY_ASK), or, * * - The policy is ask (the user deferred last time) (policy == * TOFU_POLICY_ASK). * * Note: this function must not be called while in a transaction! * * CONFLICT_SET includes all of the conflicting bindings * with FINGERPRINT first. FLAGS is a bit-wise or of * BINDING_NEW, etc. */ static void ask_about_binding (ctrl_t ctrl, enum tofu_policy *policy, int *trust_level, strlist_t conflict_set, const char *fingerprint, const char *email, const char *user_id, time_t now) { tofu_dbs_t dbs; strlist_t iter; int conflict_set_count = strlist_length (conflict_set); char *sqerr = NULL; int rc; estream_t fp; strlist_t other_user_ids = NULL; struct signature_stats *stats = NULL; struct signature_stats *stats_iter = NULL; char *prompt = NULL; char *choices; dbs = ctrl->tofu.dbs; log_assert (dbs); log_assert (dbs->in_transaction == 0); fp = es_fopenmem (0, "rw,samethread"); if (!fp) log_fatal ("error creating memory stream: %s\n", gpg_strerror (gpg_error_from_syserror())); { char *text = format_conflict_msg_part1 (*policy, conflict_set, email); es_fputs (text, fp); es_fputc ('\n', fp); xfree (text); } begin_transaction (ctrl, 0); /* Find other user ids associated with this key and whether the * bindings are marked as good or bad. */ rc = gpgsql_stepx (dbs->db, &dbs->s.get_trust_gather_other_user_ids, strings_collect_cb2, &other_user_ids, &sqerr, "select user_id, policy from bindings where fingerprint = ?;", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_END); if (rc) { log_error (_("error gathering other user IDs: %s\n"), sqerr); sqlite3_free (sqerr); sqerr = NULL; rc = gpg_error (GPG_ERR_GENERAL); } if (other_user_ids) { strlist_t strlist_iter; es_fprintf (fp, _("This key's user IDs:\n")); for (strlist_iter = other_user_ids; strlist_iter; strlist_iter = strlist_iter->next) { char *other_user_id = strlist_iter->d; char *other_thing; enum tofu_policy other_policy; log_assert (strlist_iter->next); strlist_iter = strlist_iter->next; other_thing = strlist_iter->d; other_policy = atoi (other_thing); es_fprintf (fp, " %s (", other_user_id); es_fprintf (fp, _("policy: %s"), tofu_policy_str (other_policy)); es_fprintf (fp, ")\n"); } es_fprintf (fp, "\n"); free_strlist (other_user_ids); } /* Get the stats for all the keys in CONFLICT_SET. */ strlist_rev (&conflict_set); for (iter = conflict_set; iter && ! rc; iter = iter->next) { #define STATS_SQL(table, time, sign) \ "select fingerprint, policy, time_ago, count(*)\n" \ " from\n" \ " (select bindings.*,\n" \ " "sign" case\n" \ " when delta ISNULL then 1\n" \ /* From the future (but if its just a couple of hours in the \ * future don't turn it into a warning)? Or should we use \ * small, medium or large units? (Note: whatever we do, we \ * keep the value in seconds. Then when we group, everything \ * that rounds to the same number of seconds is grouped.) */ \ " when delta < -("STRINGIFY (TIME_AGO_FUTURE_IGNORE)") then 2\n" \ " when delta < ("STRINGIFY (TIME_AGO_SMALL_THRESHOLD)")\n" \ " then 3\n" \ " when delta < ("STRINGIFY (TIME_AGO_MEDIUM_THRESHOLD)")\n" \ " then 4\n" \ " when delta < ("STRINGIFY (TIME_AGO_LARGE_THRESHOLD)")\n" \ " then 5\n" \ " else 6\n" \ " end time_ago,\n" \ " delta time_ago_raw\n" \ " from bindings\n" \ " left join\n" \ " (select *,\n" \ " cast(? - " time " as real) delta\n" \ " from " table ") ss\n" \ " on ss.binding = bindings.oid)\n" \ " where email = ? and fingerprint = ?\n" \ " group by time_ago\n" \ /* Make sure the current key is first. */ \ " order by time_ago desc;\n" /* Use the time when we saw the signature, not when the signature was created as that can be forged. */ rc = gpgsql_stepx (dbs->db, &dbs->s.get_trust_gather_signature_stats, signature_stats_collect_cb, &stats, &sqerr, STATS_SQL ("signatures", "time", ""), GPGSQL_ARG_LONG_LONG, (long long) now, GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, iter->d, GPGSQL_ARG_END); if (rc) { rc = gpg_error (GPG_ERR_GENERAL); break; } if (!stats || strcmp (iter->d, stats->fingerprint) != 0) /* No stats for this binding. Add a dummy entry. */ signature_stats_prepend (&stats, iter->d, TOFU_POLICY_AUTO, 1, 1); rc = gpgsql_stepx (dbs->db, &dbs->s.get_trust_gather_encryption_stats, signature_stats_collect_cb, &stats, &sqerr, STATS_SQL ("encryptions", "time", "-"), GPGSQL_ARG_LONG_LONG, (long long) now, GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, iter->d, GPGSQL_ARG_END); if (rc) { rc = gpg_error (GPG_ERR_GENERAL); break; } #undef STATS_SQL if (!stats || strcmp (iter->d, stats->fingerprint) != 0 || stats->time_ago > 0) /* No stats for this binding. Add a dummy entry. */ signature_stats_prepend (&stats, iter->d, TOFU_POLICY_AUTO, -1, 1); } end_transaction (ctrl, 0); strlist_rev (&conflict_set); if (rc) { strlist_t strlist_iter; log_error (_("error gathering signature stats: %s\n"), sqerr); sqlite3_free (sqerr); sqerr = NULL; es_fprintf (fp, ngettext("The email address \"%s\" is" " associated with %d key:\n", "The email address \"%s\" is" " associated with %d keys:\n", conflict_set_count), email, conflict_set_count); for (strlist_iter = conflict_set; strlist_iter; strlist_iter = strlist_iter->next) es_fprintf (fp, " %s\n", strlist_iter->d); } else { char *key = NULL; strlist_t binding; int seen_in_past = 0; es_fprintf (fp, _("Statistics for keys" " with the email address \"%s\":\n"), email); for (stats_iter = stats; stats_iter; stats_iter = stats_iter->next) { #if 0 log_debug ("%s: time_ago: %ld; count: %ld\n", stats_iter->fingerprint, stats_iter->time_ago, stats_iter->count); #endif if (! key || strcmp (key, stats_iter->fingerprint)) { int this_key; char *key_pp; key = stats_iter->fingerprint; this_key = strcmp (key, fingerprint) == 0; key_pp = format_hexfingerprint (key, NULL, 0); es_fprintf (fp, " %s (", key_pp); /* Find the associated binding. */ for (binding = conflict_set; binding; binding = binding->next) if (strcmp (key, binding->d) == 0) break; log_assert (binding); if ((binding->flags & BINDING_REVOKED)) { es_fprintf (fp, _("revoked")); es_fprintf (fp, _(", ")); } else if ((binding->flags & BINDING_EXPIRED)) { es_fprintf (fp, _("expired")); es_fprintf (fp, _(", ")); } if (this_key) es_fprintf (fp, _("this key")); else es_fprintf (fp, _("policy: %s"), tofu_policy_str (stats_iter->policy)); es_fputs ("):\n", fp); xfree (key_pp); seen_in_past = 0; } if (labs(stats_iter->time_ago) == 1) { /* The 1 in this case is the NULL entry. */ log_assert (stats_iter->count == 1); stats_iter->count = 0; } seen_in_past += stats_iter->count; es_fputs (" ", fp); /* TANSLATORS: This string is concatenated with one of * the day/week/month strings to form one sentence. */ if (stats_iter->time_ago > 0) es_fprintf (fp, ngettext("Verified %d message", "Verified %d messages", seen_in_past), seen_in_past); else es_fprintf (fp, ngettext("Encrypted %d message", "Encrypted %d messages", seen_in_past), seen_in_past); if (!stats_iter->count) es_fputs (".", fp); else if (labs(stats_iter->time_ago) == 2) { es_fprintf (fp, "in the future."); /* Reset it. */ seen_in_past = 0; } else { if (labs(stats_iter->time_ago) == 3) es_fprintf (fp, ngettext(" over the past day.", " over the past %d days.", TIME_AGO_SMALL_THRESHOLD / TIME_AGO_UNIT_SMALL), TIME_AGO_SMALL_THRESHOLD / TIME_AGO_UNIT_SMALL); else if (labs(stats_iter->time_ago) == 4) es_fprintf (fp, ngettext(" over the past month.", " over the past %d months.", TIME_AGO_MEDIUM_THRESHOLD / TIME_AGO_UNIT_MEDIUM), TIME_AGO_MEDIUM_THRESHOLD / TIME_AGO_UNIT_MEDIUM); else if (labs(stats_iter->time_ago) == 5) es_fprintf (fp, ngettext(" over the past year.", " over the past %d years.", TIME_AGO_LARGE_THRESHOLD / TIME_AGO_UNIT_LARGE), TIME_AGO_LARGE_THRESHOLD / TIME_AGO_UNIT_LARGE); else if (labs(stats_iter->time_ago) == 6) es_fprintf (fp, _(" in the past.")); else log_assert (! "Broken SQL.\n"); } es_fputs ("\n", fp); } } if (conflict_set_count > 1 || (conflict_set->flags & BINDING_CONFLICT)) { /* This is a conflict. */ /* TRANSLATORS: Please translate the text found in the source * file below. We don't directly internationalize that text so * that we can tweak it without breaking translations. */ char *text = _("TOFU detected a binding conflict"); char *textbuf; if (!strcmp (text, "TOFU detected a binding conflict")) { /* No translation. Use the English text. */ text = "Normally, an email address is associated with a single key. " "However, people sometimes generate a new key if " "their key is too old or they think it might be compromised. " "Alternatively, a new key may indicate a man-in-the-middle " "attack! Before accepting this association, you should talk to or " "call the person to make sure this new key is legitimate."; } textbuf = format_text (text, 0, 72, 80); es_fprintf (fp, "\n%s\n", textbuf); xfree (textbuf); } es_fputc ('\n', fp); /* Add a NUL terminator. */ es_fputc (0, fp); if (es_fclose_snatch (fp, (void **) &prompt, NULL)) log_fatal ("error snatching memory stream\n"); /* I think showing the large message once is sufficient. If we * would move it right before the cpr_get many lines will scroll * away and the user might not realize that he merely entered a * wrong choise (because he does not see that either). As a small * benefit we allow C-L to redisplay everything. */ tty_printf ("%s", prompt); /* Suspend any transaction: it could take a while until the user responds. */ tofu_suspend_batch_transaction (ctrl); while (1) { char *response; /* TRANSLATORS: Two letters (normally the lower and upper case * version of the hotkey) for each of the five choices. If * there is only one choice in your language, repeat it. */ choices = _("gG" "aA" "uU" "rR" "bB"); if (strlen (choices) != 10) log_bug ("Bad TOFU conflict translation! Please report."); response = cpr_get ("tofu.conflict", _("(G)ood, (A)ccept once, (U)nknown, (R)eject once, (B)ad? ")); trim_spaces (response); cpr_kill_prompt (); if (*response == CONTROL_L) tty_printf ("%s", prompt); else if (!response[0]) /* Default to unknown. Don't save it. */ { tty_printf (_("Defaulting to unknown.")); *policy = TOFU_POLICY_UNKNOWN; break; } else if (!response[1]) { char *choice = strchr (choices, *response); if (choice) { int c = ((size_t) choice - (size_t) choices) / 2; switch (c) { case 0: /* Good. */ *policy = TOFU_POLICY_GOOD; *trust_level = tofu_policy_to_trust_level (*policy); break; case 1: /* Accept once. */ *policy = TOFU_POLICY_ASK; *trust_level = tofu_policy_to_trust_level (TOFU_POLICY_GOOD); break; case 2: /* Unknown. */ *policy = TOFU_POLICY_UNKNOWN; *trust_level = tofu_policy_to_trust_level (*policy); break; case 3: /* Reject once. */ *policy = TOFU_POLICY_ASK; *trust_level = tofu_policy_to_trust_level (TOFU_POLICY_BAD); break; case 4: /* Bad. */ *policy = TOFU_POLICY_BAD; *trust_level = tofu_policy_to_trust_level (*policy); break; default: log_bug ("c should be between 0 and 4 but it is %d!", c); } if (record_binding (dbs, fingerprint, email, user_id, *policy, TOFU_POLICY_NONE, NULL, 0, 0, now)) { /* If there's an error registering the * binding, don't save the signature. */ *trust_level = _tofu_GET_TRUST_ERROR; } break; } } xfree (response); } tofu_resume_batch_transaction (ctrl); xfree (prompt); signature_stats_free (stats); } /* Return the set of keys that conflict with the binding (including the binding itself, which will be first in the list). For each returned key also sets BINDING_NEW, etc. */ static strlist_t build_conflict_set (tofu_dbs_t dbs, PKT_public_key *pk, const char *fingerprint, const char *email) { gpg_error_t rc; char *sqerr; strlist_t conflict_set = NULL; int conflict_set_count; strlist_t iter; kbnode_t *kb_all; KEYDB_HANDLE hd; int i; /* Get the fingerprints of any bindings that share the email address * and whether the bindings have a known conflict. * * Note: if the binding in question is in the DB, it will also be * returned. Thus, if the result set is empty, then is a new binding. */ rc = gpgsql_stepx (dbs->db, &dbs->s.get_trust_bindings_with_this_email, strings_collect_cb2, &conflict_set, &sqerr, "select" /* A binding should only appear once, but try not to break in the * case of corruption. */ " fingerprint || case sum(conflict NOTNULL) when 0 then '' else '!' end" " from bindings where email = ?" " group by fingerprint" /* Make sure the current key comes first in the result list (if it is present). */ " order by fingerprint = ? asc, fingerprint desc;", GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_END); if (rc) { log_error (_("error reading TOFU database: %s\n"), sqerr); print_further_info ("listing fingerprints"); sqlite3_free (sqerr); rc = gpg_error (GPG_ERR_GENERAL); return NULL; } /* Set BINDING_CONFLICT if the binding has a known conflict. This * allows us to distinguish between bindings where the user * explicitly set the policy to ask and bindings where we set the * policy to ask due to a conflict. */ for (iter = conflict_set; iter; iter = iter->next) { int l = strlen (iter->d); if (!(l == 2 * MAX_FINGERPRINT_LEN || l == 2 * MAX_FINGERPRINT_LEN + 1)) { log_error (_("TOFU db corruption detected.\n")); print_further_info ("fingerprint '%s' is not %d characters long", iter->d, 2 * MAX_FINGERPRINT_LEN); } if (l >= 1 && iter->d[l - 1] == '!') { iter->flags |= BINDING_CONFLICT; /* Remove the !. */ iter->d[l - 1] = 0; } } /* If the current binding has not yet been recorded, add it to the * list. (The order by above ensures that if it is present, it will * be first.) */ if (! (conflict_set && strcmp (conflict_set->d, fingerprint) == 0)) { add_to_strlist (&conflict_set, fingerprint); conflict_set->flags |= BINDING_NEW; } conflict_set_count = strlist_length (conflict_set); /* Eliminate false conflicts. */ if (conflict_set_count == 1) /* We only have a single key. There are no false conflicts to eliminate. But, we do need to set the flags. */ { if (pk->has_expired) conflict_set->flags |= BINDING_EXPIRED; if (pk->flags.revoked) conflict_set->flags |= BINDING_REVOKED; return conflict_set; } /* If two keys have cross signatures, then they are controlled by * the same person and thus are not in conflict. */ kb_all = xcalloc (sizeof (kb_all[0]), conflict_set_count); hd = keydb_new (); for (i = 0, iter = conflict_set; i < conflict_set_count; i ++, iter = iter->next) { char *fp = iter->d; KEYDB_SEARCH_DESC desc; kbnode_t kb; PKT_public_key *binding_pk; kbnode_t n; int found_user_id; rc = keydb_search_reset (hd); if (rc) { log_error (_("resetting keydb: %s\n"), gpg_strerror (rc)); continue; } rc = classify_user_id (fp, &desc, 0); if (rc) { log_error (_("error parsing key specification '%s': %s\n"), fp, gpg_strerror (rc)); continue; } rc = keydb_search (hd, &desc, 1, NULL); if (rc) { /* Note: it is entirely possible that we don't have the key corresponding to an entry in the TOFU DB. This can happen if we merge two TOFU DBs, but not the key rings. */ log_info (_("key \"%s\" not found: %s\n"), fp, gpg_strerror (rc)); continue; } rc = keydb_get_keyblock (hd, &kb); if (rc) { log_error (_("error reading keyblock: %s\n"), gpg_strerror (rc)); print_further_info ("fingerprint: %s", fp); continue; } merge_keys_and_selfsig (kb); log_assert (kb->pkt->pkttype == PKT_PUBLIC_KEY); kb_all[i] = kb; /* Since we have the key block, use this opportunity to figure * out if the binding is expired or revoked. */ binding_pk = kb->pkt->pkt.public_key; /* The binding is always expired/revoked if the key is * expired/revoked. */ if (binding_pk->has_expired) iter->flags |= BINDING_EXPIRED; if (binding_pk->flags.revoked) iter->flags |= BINDING_REVOKED; /* The binding is also expired/revoked if the user id is * expired/revoked. */ n = kb; found_user_id = 0; while ((n = find_next_kbnode (n, PKT_USER_ID)) && ! found_user_id) { PKT_user_id *user_id2 = n->pkt->pkt.user_id; char *email2; if (user_id2->attrib_data) continue; email2 = email_from_user_id (user_id2->name); if (strcmp (email, email2) == 0) { found_user_id = 1; if (user_id2->is_revoked) iter->flags |= BINDING_REVOKED; if (user_id2->is_expired) iter->flags |= BINDING_EXPIRED; } xfree (email2); } if (! found_user_id) { log_info (_("TOFU db corruption detected.\n")); print_further_info ("user id '%s' not on key block '%s'", email, fingerprint); } } keydb_release (hd); /* Now that we have the key blocks, check for cross sigs. */ { int j; strlist_t *prevp; strlist_t iter_next; int die[conflict_set_count]; memset (die, 0, sizeof (die)); for (i = 0; i < conflict_set_count; i ++) { /* Look for cross sigs between this key (i == 0) or a key * that has cross sigs with i == 0 (i.e., transitively) */ if (! (i == 0 || die[i])) continue; for (j = i + 1; j < conflict_set_count; j ++) /* Be careful: we might not have a key block for a key. */ if (kb_all[i] && kb_all[j] && cross_sigs (email, kb_all[i], kb_all[j])) die[j] = 1; } /* Free unconflicting bindings (and all of the key blocks). */ for (iter = conflict_set, prevp = &conflict_set, i = 0; iter; iter = iter_next, i ++) { iter_next = iter->next; release_kbnode (kb_all[i]); if (die[i]) { *prevp = iter_next; iter->next = NULL; free_strlist (iter); conflict_set_count --; } else { prevp = &iter->next; } } /* We shouldn't have removed the head. */ log_assert (conflict_set); log_assert (conflict_set_count >= 1); } xfree (kb_all); if (DBG_TRUST) { log_debug ("binding conflicts:\n", fingerprint, email); for (iter = conflict_set; iter; iter = iter->next) { log_debug (" %s:%s%s%s%s\n", iter->d, (iter->flags & BINDING_NEW) ? " new" : "", (iter->flags & BINDING_CONFLICT) ? " known_conflict" : "", (iter->flags & BINDING_EXPIRED) ? " expired" : "", (iter->flags & BINDING_REVOKED) ? " revoked" : ""); } } return conflict_set; } /* Return the effective policy for the binding * (email has already been normalized) and any conflict information in * *CONFLICT_SETP, if CONFLICT_SETP is not NULL. Returns * _tofu_GET_POLICY_ERROR if an error occurs. */ static enum tofu_policy get_policy (tofu_dbs_t dbs, PKT_public_key *pk, const char *fingerprint, const char *user_id, const char *email, strlist_t *conflict_setp, time_t now) { int rc; char *err = NULL; strlist_t results = NULL; enum tofu_policy policy = _tofu_GET_POLICY_ERROR; enum tofu_policy effective_policy_orig = TOFU_POLICY_NONE; enum tofu_policy effective_policy = _tofu_GET_POLICY_ERROR; long along; char *conflict_orig = NULL; char *conflict = NULL; strlist_t conflict_set = NULL; int conflict_set_count; /* Check if the binding is known (TOFU_POLICY_NONE cannot appear in the DB. Thus, if POLICY is still TOFU_POLICY_NONE after executing the query, then the result set was empty.) */ rc = gpgsql_stepx (dbs->db, &dbs->s.get_policy_select_policy_and_conflict, strings_collect_cb2, &results, &err, "select policy, conflict, effective_policy from bindings\n" " where fingerprint = ? and email = ?", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_END); if (rc) { log_error (_("error reading TOFU database: %s\n"), err); print_further_info ("reading the policy"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); goto out; } if (strlist_length (results) == 0) { /* No results. Use the defaults. */ policy = TOFU_POLICY_NONE; effective_policy = TOFU_POLICY_NONE; } else if (strlist_length (results) == 3) { /* Parse and sanity check the results. */ if (string_to_long (&along, results->d, 0, __LINE__)) { log_error (_("error reading TOFU database: %s\n"), gpg_strerror (GPG_ERR_BAD_DATA)); print_further_info ("bad value for policy: %s", results->d); goto out; } policy = along; if (! (policy == TOFU_POLICY_AUTO || policy == TOFU_POLICY_GOOD || policy == TOFU_POLICY_UNKNOWN || policy == TOFU_POLICY_BAD || policy == TOFU_POLICY_ASK)) { log_error (_("error reading TOFU database: %s\n"), gpg_strerror (GPG_ERR_DB_CORRUPTED)); print_further_info ("invalid value for policy (%d)", policy); effective_policy = _tofu_GET_POLICY_ERROR; goto out; } if (*results->next->d) conflict = xstrdup (results->next->d); if (string_to_long (&along, results->next->next->d, 0, __LINE__)) { log_error (_("error reading TOFU database: %s\n"), gpg_strerror (GPG_ERR_BAD_DATA)); print_further_info ("bad value for effective policy: %s", results->next->next->d); goto out; } effective_policy = along; if (! (effective_policy == TOFU_POLICY_NONE || effective_policy == TOFU_POLICY_AUTO || effective_policy == TOFU_POLICY_GOOD || effective_policy == TOFU_POLICY_UNKNOWN || effective_policy == TOFU_POLICY_BAD || effective_policy == TOFU_POLICY_ASK)) { log_error (_("error reading TOFU database: %s\n"), gpg_strerror (GPG_ERR_DB_CORRUPTED)); print_further_info ("invalid value for effective_policy (%d)", effective_policy); effective_policy = _tofu_GET_POLICY_ERROR; goto out; } } else { /* The result has the wrong form. */ log_error (_("error reading TOFU database: %s\n"), gpg_strerror (GPG_ERR_BAD_DATA)); print_further_info ("reading policy: expected 3 columns, got %d\n", strlist_length (results)); goto out; } /* Save the effective policy and conflict so we know if we changed * them. */ effective_policy_orig = effective_policy; conflict_orig = conflict; /* Unless there is a conflict, if the effective policy is cached, * just return it. The reason we don't do this when there is a * conflict is because of the following scenario: assume A and B * conflict and B has signed A's key. Now, later we import A's * signature on B. We need to recheck A, but the signature was on * B, i.e., when B changes, we invalidate B's effective policy, but * we also need to invalidate A's effective policy. Instead, we * assume that conflicts are rare and don't optimize for them, which * would complicate the code. */ if (effective_policy != TOFU_POLICY_NONE && !conflict) goto out; /* If the user explicitly set the policy, then respect that. */ if (policy != TOFU_POLICY_AUTO && policy != TOFU_POLICY_NONE) { effective_policy = policy; goto out; } /* Unless proven wrong, assume the effective policy is 'auto'. */ effective_policy = TOFU_POLICY_AUTO; /* See if the key is ultimately trusted. */ { u32 kid[2]; keyid_from_pk (pk, kid); if (tdb_keyid_is_utk (kid)) { effective_policy = TOFU_POLICY_GOOD; goto out; } } /* See if the key is signed by an ultimately trusted key. */ { int fingerprint_raw_len = strlen (fingerprint) / 2; char fingerprint_raw[fingerprint_raw_len]; int len = 0; if (fingerprint_raw_len != 20 || ((len = hex2bin (fingerprint, fingerprint_raw, fingerprint_raw_len)) != strlen (fingerprint))) { if (DBG_TRUST) log_debug ("TOFU: Bad fingerprint: %s (len: %zd, parsed: %d)\n", fingerprint, strlen (fingerprint), len); } else { int lookup_err; kbnode_t kb; lookup_err = get_pubkey_byfprint (NULL, &kb, fingerprint_raw, fingerprint_raw_len); if (lookup_err) { if (DBG_TRUST) log_debug ("TOFU: Looking up %s: %s\n", fingerprint, gpg_strerror (lookup_err)); } else { int is_signed_by_utk = signed_by_utk (email, kb); release_kbnode (kb); if (is_signed_by_utk) { effective_policy = TOFU_POLICY_GOOD; goto out; } } } } /* Check for any conflicts / see if a previously discovered conflict * disappeared. The latter can happen if the conflicting bindings * are now cross signed, for instance. */ conflict_set = build_conflict_set (dbs, pk, fingerprint, email); conflict_set_count = strlist_length (conflict_set); if (conflict_set_count == 0) { /* build_conflict_set should always at least return the current binding. Something went wrong. */ effective_policy = _tofu_GET_POLICY_ERROR; goto out; } if (conflict_set_count == 1 && (conflict_set->flags & BINDING_NEW)) { /* We've never observed a binding with this email address and we * have a default policy, which is not to ask the user. */ /* If we've seen this binding, then we've seen this email and * policy couldn't possibly be TOFU_POLICY_NONE. */ log_assert (policy == TOFU_POLICY_NONE); if (DBG_TRUST) log_debug ("TOFU: New binding , no conflict.\n", fingerprint, email); effective_policy = TOFU_POLICY_AUTO; goto out; } if (conflict_set_count == 1 && (conflict_set->flags & BINDING_CONFLICT)) { /* No known conflicts now, but there was a conflict. That is, * at somepoint there was a conflict, but it went away. A * conflict can go away if there is now a cross sig between the * two keys. In this case, we just silently clear the * conflict. */ if (DBG_TRUST) log_debug ("TOFU: binding had a conflict, but it's been resolved (probably via cross sig).\n", fingerprint, email); effective_policy = TOFU_POLICY_AUTO; conflict = NULL; goto out; } if (conflict_set_count == 1) { /* No conflicts and never marked as conflicting. */ log_assert (!conflict); effective_policy = TOFU_POLICY_AUTO; goto out; } /* There is a conflicting key. */ log_assert (conflict_set_count > 1); effective_policy = TOFU_POLICY_ASK; conflict = xstrdup (conflict_set->next->d); out: log_assert (policy == _tofu_GET_POLICY_ERROR || policy == TOFU_POLICY_NONE || policy == TOFU_POLICY_AUTO || policy == TOFU_POLICY_GOOD || policy == TOFU_POLICY_UNKNOWN || policy == TOFU_POLICY_BAD || policy == TOFU_POLICY_ASK); /* Everything but NONE. */ log_assert (effective_policy == _tofu_GET_POLICY_ERROR || effective_policy == TOFU_POLICY_AUTO || effective_policy == TOFU_POLICY_GOOD || effective_policy == TOFU_POLICY_UNKNOWN || effective_policy == TOFU_POLICY_BAD || effective_policy == TOFU_POLICY_ASK); if (effective_policy != TOFU_POLICY_ASK && conflict) conflict = NULL; /* If we don't have a record of this binding, its effective policy * changed, or conflict changed, update the DB. */ if (effective_policy != _tofu_GET_POLICY_ERROR && (/* New binding. */ policy == TOFU_POLICY_NONE /* effective_policy changed. */ || effective_policy != effective_policy_orig /* conflict changed. */ || (conflict != conflict_orig && (!conflict || !conflict_orig || strcmp (conflict, conflict_orig) != 0)))) { if (record_binding (dbs, fingerprint, email, user_id, policy == TOFU_POLICY_NONE ? TOFU_POLICY_AUTO : policy, effective_policy, conflict, 1, 0, now) != 0) log_error (_("error setting TOFU binding's policy" " to %s\n"), tofu_policy_str (policy)); } /* If the caller wants the set of conflicts, return it. */ if (effective_policy == TOFU_POLICY_ASK && conflict_setp) { if (! conflict_set) conflict_set = build_conflict_set (dbs, pk, fingerprint, email); *conflict_setp = conflict_set; } else { free_strlist (conflict_set); if (conflict_setp) *conflict_setp = NULL; } xfree (conflict_orig); if (conflict != conflict_orig) xfree (conflict); free_strlist (results); return effective_policy; } /* Return the trust level (TRUST_NEVER, etc.) for the binding * (email is already normalized). If no policy * is registered, returns TOFU_POLICY_NONE. If an error occurs, * returns _tofu_GET_TRUST_ERROR. * * PK is the public key object for FINGERPRINT. * * USER_ID is the unadulterated user id. * * If MAY_ASK is set, then we may interact with the user. This is * necessary if there is a conflict or the binding's policy is * TOFU_POLICY_ASK. In the case of a conflict, we set the new * conflicting binding's policy to TOFU_POLICY_ASK. In either case, * we return TRUST_UNDEFINED. Note: if MAY_ASK is set, then this * function must not be called while in a transaction! */ static enum tofu_policy get_trust (ctrl_t ctrl, PKT_public_key *pk, const char *fingerprint, const char *email, const char *user_id, int may_ask, time_t now) { tofu_dbs_t dbs = ctrl->tofu.dbs; int in_transaction = 0; enum tofu_policy policy; int rc; char *sqerr = NULL; strlist_t conflict_set = NULL; int trust_level = TRUST_UNKNOWN; strlist_t iter; log_assert (dbs); if (may_ask) log_assert (dbs->in_transaction == 0); if (opt.batch) may_ask = 0; log_assert (pk_is_primary (pk)); /* Make sure _tofu_GET_TRUST_ERROR isn't equal to any of the trust levels. */ log_assert (_tofu_GET_TRUST_ERROR != TRUST_UNKNOWN && _tofu_GET_TRUST_ERROR != TRUST_EXPIRED && _tofu_GET_TRUST_ERROR != TRUST_UNDEFINED && _tofu_GET_TRUST_ERROR != TRUST_NEVER && _tofu_GET_TRUST_ERROR != TRUST_MARGINAL && _tofu_GET_TRUST_ERROR != TRUST_FULLY && _tofu_GET_TRUST_ERROR != TRUST_ULTIMATE); /* If the key is ultimately trusted, there is nothing to do. */ { u32 kid[2]; keyid_from_pk (pk, kid); if (tdb_keyid_is_utk (kid)) { trust_level = TRUST_ULTIMATE; goto out; } } begin_transaction (ctrl, 0); in_transaction = 1; policy = get_policy (dbs, pk, fingerprint, user_id, email, &conflict_set, now); if (policy == TOFU_POLICY_AUTO) { policy = opt.tofu_default_policy; if (DBG_TRUST) log_debug ("TOFU: binding 's policy is" " auto (default: %s).\n", fingerprint, email, tofu_policy_str (opt.tofu_default_policy)); } switch (policy) { case TOFU_POLICY_AUTO: case TOFU_POLICY_GOOD: case TOFU_POLICY_UNKNOWN: case TOFU_POLICY_BAD: /* The saved judgement is auto -> auto, good, unknown or bad. * We don't need to ask the user anything. */ if (DBG_TRUST) log_debug ("TOFU: Known binding 's policy: %s\n", fingerprint, email, tofu_policy_str (policy)); trust_level = tofu_policy_to_trust_level (policy); goto out; case TOFU_POLICY_ASK: /* We need to ask the user what to do. */ break; case _tofu_GET_POLICY_ERROR: trust_level = _tofu_GET_TRUST_ERROR; goto out; default: log_bug ("%s: Impossible value for policy (%d)\n", __func__, policy); } /* We get here if: * * 1. The saved policy is auto and the default policy is ask * (get_policy() == TOFU_POLICY_AUTO * && opt.tofu_default_policy == TOFU_POLICY_ASK) * * 2. The saved policy is ask (either last time the user selected * accept once or reject once or there was a conflict and this * binding's policy was changed from auto to ask) * (policy == TOFU_POLICY_ASK). */ log_assert (policy == TOFU_POLICY_ASK); if (may_ask) { /* We can't be in a normal transaction in ask_about_binding. */ end_transaction (ctrl, 0); in_transaction = 0; /* If we get here, we need to ask the user about the binding. */ ask_about_binding (ctrl, &policy, &trust_level, conflict_set, fingerprint, email, user_id, now); } else trust_level = TRUST_UNDEFINED; /* Mark any conflicting bindings that have an automatic policy as * now requiring confirmation. Note: we do this after we ask for * confirmation so that when the current policy is printed, it is * correct. */ if (! in_transaction) { begin_transaction (ctrl, 0); in_transaction = 1; } /* The conflict set should always contain at least one element: * the current key. */ log_assert (conflict_set); for (iter = conflict_set->next; iter; iter = iter->next) { /* We don't immediately set the effective policy to 'ask, because */ rc = gpgsql_exec_printf (dbs->db, NULL, NULL, &sqerr, "update bindings set effective_policy = %d, conflict = %Q" " where email = %Q and fingerprint = %Q and effective_policy != %d;", TOFU_POLICY_NONE, fingerprint, email, iter->d, TOFU_POLICY_ASK); if (rc) { log_error (_("error changing TOFU policy: %s\n"), sqerr); print_further_info ("binding: ", fingerprint, user_id); sqlite3_free (sqerr); sqerr = NULL; rc = gpg_error (GPG_ERR_GENERAL); } else if (DBG_TRUST) log_debug ("Set %s to conflict with %s\n", iter->d, fingerprint); } out: if (in_transaction) end_transaction (ctrl, 0); free_strlist (conflict_set); return trust_level; } /* Return a malloced string of the form * "7 months, 1 day, 5 minutes, 0 seconds" * The caller should replace all '~' in the returned string by a space * and also free the returned string. * * This is actually a bad hack which may not work correctly with all * languages. */ static char * time_ago_str (long long int t) { estream_t fp; int years = 0; int months = 0; int days = 0; int hours = 0; int minutes = 0; int seconds = 0; /* The number of units that we've printed so far. */ int count = 0; /* The first unit that we printed (year = 0, month = 1, etc.). */ int first = -1; /* The current unit. */ int i = 0; char *str; /* It would be nice to use a macro to do this, but gettext works on the unpreprocessed code. */ #define MIN_SECS (60) #define HOUR_SECS (60 * MIN_SECS) #define DAY_SECS (24 * HOUR_SECS) #define MONTH_SECS (30 * DAY_SECS) #define YEAR_SECS (365 * DAY_SECS) if (t > YEAR_SECS) { years = t / YEAR_SECS; t -= years * YEAR_SECS; } if (t > MONTH_SECS) { months = t / MONTH_SECS; t -= months * MONTH_SECS; } if (t > DAY_SECS) { days = t / DAY_SECS; t -= days * DAY_SECS; } if (t > HOUR_SECS) { hours = t / HOUR_SECS; t -= hours * HOUR_SECS; } if (t > MIN_SECS) { minutes = t / MIN_SECS; t -= minutes * MIN_SECS; } seconds = t; #undef MIN_SECS #undef HOUR_SECS #undef DAY_SECS #undef MONTH_SECS #undef YEAR_SECS fp = es_fopenmem (0, "rw,samethread"); if (! fp) log_fatal ("error creating memory stream: %s\n", gpg_strerror (gpg_error_from_syserror())); if (years) { /* TRANSLATORS: The tilde ('~') is used here to indicate a * non-breakable space */ es_fprintf (fp, ngettext("%d~year", "%d~years", years), years); count ++; first = i; } i ++; if ((first == -1 || i - first <= 3) && count <= 0 && months) { if (count) es_fprintf (fp, ", "); es_fprintf (fp, ngettext("%d~month", "%d~months", months), months); count ++; first = i; } i ++; if ((first == -1 || i - first <= 3) && count <= 0 && days) { if (count) es_fprintf (fp, ", "); es_fprintf (fp, ngettext("%d~day", "%d~days", days), days); count ++; first = i; } i ++; if ((first == -1 || i - first <= 3) && count <= 0 && hours) { if (count) es_fprintf (fp, ", "); es_fprintf (fp, ngettext("%d~hour", "%d~hours", hours), hours); count ++; first = i; } i ++; if ((first == -1 || i - first <= 3) && count <= 0 && minutes) { if (count) es_fprintf (fp, ", "); es_fprintf (fp, ngettext("%d~minute", "%d~minutes", minutes), minutes); count ++; first = i; } i ++; if ((first == -1 || i - first <= 3) && count <= 0) { if (count) es_fprintf (fp, ", "); es_fprintf (fp, ngettext("%d~second", "%d~seconds", seconds), seconds); } es_fputc (0, fp); if (es_fclose_snatch (fp, (void **) &str, NULL)) log_fatal ("error snatching memory stream\n"); return str; } /* If FP is NULL, write TOFU_STATS status line. If FP is not NULL * write a "tfs" record to that stream. */ static void write_stats_status (estream_t fp, enum tofu_policy policy, unsigned long signature_count, unsigned long signature_first_seen, unsigned long signature_most_recent, unsigned long encryption_count, unsigned long encryption_first_done, unsigned long encryption_most_recent) { const char *validity; unsigned long messages; /* Use the euclidean distance (m = sqrt(a^2 + b^2)) rather then the sum of the magnitudes (m = a + b) to ensure a balance between verified signatures and encrypted messages. */ messages = sqrtu32 (signature_count * signature_count + encryption_count * encryption_count); if (messages < 1) validity = "1"; /* Key without history. */ else if (messages < 2 * BASIC_TRUST_THRESHOLD) validity = "2"; /* Key with too little history. */ else if (messages < 2 * FULL_TRUST_THRESHOLD) validity = "3"; /* Key with enough history for basic trust. */ else validity = "4"; /* Key with a lot of history. */ if (fp) { es_fprintf (fp, "tfs:1:%s:%lu:%lu:%s:%lu:%lu:%lu:%lu:\n", validity, signature_count, encryption_count, tofu_policy_str (policy), signature_first_seen, signature_most_recent, encryption_first_done, encryption_most_recent); } else { write_status_printf (STATUS_TOFU_STATS, "%s %lu %lu %s %lu %lu %lu %lu", validity, signature_count, encryption_count, tofu_policy_str (policy), signature_first_seen, signature_most_recent, encryption_first_done, encryption_most_recent); } } /* Note: If OUTFP is not NULL, this function merely prints a "tfs" record * to OUTFP. * * Returns whether the caller should call show_warning after iterating * over all user ids. */ static int show_statistics (tofu_dbs_t dbs, PKT_public_key *pk, const char *fingerprint, const char *email, const char *user_id, estream_t outfp, time_t now) { enum tofu_policy policy = get_policy (dbs, pk, fingerprint, user_id, email, NULL, now); char *fingerprint_pp; int rc; strlist_t strlist = NULL; char *err = NULL; unsigned long signature_first_seen = 0; unsigned long signature_most_recent = 0; unsigned long signature_count = 0; unsigned long encryption_first_done = 0; unsigned long encryption_most_recent = 0; unsigned long encryption_count = 0; int show_warning = 0; (void) user_id; fingerprint_pp = format_hexfingerprint (fingerprint, NULL, 0); /* Get the signature stats. */ rc = gpgsql_exec_printf (dbs->db, strings_collect_cb, &strlist, &err, "select count (*), min (signatures.time), max (signatures.time)\n" " from signatures\n" " left join bindings on signatures.binding = bindings.oid\n" " where fingerprint = %Q and email = %Q;", fingerprint, email); if (rc) { log_error (_("error reading TOFU database: %s\n"), err); print_further_info ("getting signature statistics"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); goto out; } if (strlist) { /* We expect exactly 3 elements. */ log_assert (strlist->next); log_assert (strlist->next->next); log_assert (! strlist->next->next->next); string_to_ulong (&signature_count, strlist->d, -1, __LINE__); string_to_ulong (&signature_first_seen, strlist->next->d, -1, __LINE__); string_to_ulong (&signature_most_recent, strlist->next->next->d, -1, __LINE__); free_strlist (strlist); strlist = NULL; } /* Get the encryption stats. */ rc = gpgsql_exec_printf (dbs->db, strings_collect_cb, &strlist, &err, "select count (*), min (encryptions.time), max (encryptions.time)\n" " from encryptions\n" " left join bindings on encryptions.binding = bindings.oid\n" " where fingerprint = %Q and email = %Q;", fingerprint, email); if (rc) { log_error (_("error reading TOFU database: %s\n"), err); print_further_info ("getting encryption statistics"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); goto out; } if (strlist) { /* We expect exactly 3 elements. */ log_assert (strlist->next); log_assert (strlist->next->next); log_assert (! strlist->next->next->next); string_to_ulong (&encryption_count, strlist->d, -1, __LINE__); string_to_ulong (&encryption_first_done, strlist->next->d, -1, __LINE__); string_to_ulong (&encryption_most_recent, strlist->next->next->d, -1, __LINE__); free_strlist (strlist); strlist = NULL; } if (!outfp) write_status_text_and_buffer (STATUS_TOFU_USER, fingerprint, email, strlen (email), 0); write_stats_status (outfp, policy, signature_count, signature_first_seen, signature_most_recent, encryption_count, encryption_first_done, encryption_most_recent); if (!outfp) { estream_t fp; char *msg; fp = es_fopenmem (0, "rw,samethread"); if (! fp) log_fatal ("error creating memory stream: %s\n", gpg_strerror (gpg_error_from_syserror())); es_fprintf (fp, _("%s: "), email); if (signature_count == 0) { es_fprintf (fp, _("Verified %ld signatures"), 0L); es_fputc ('\n', fp); } else { char *first_seen_ago_str = time_ago_str (now - signature_first_seen); /* TRANSLATORS: The final %s is replaced by a string like "7 months, 1 day, 5 minutes, 0 seconds". */ es_fprintf (fp, ngettext("Verified %ld signature in the past %s", "Verified %ld signatures in the past %s", signature_count), signature_count, first_seen_ago_str); xfree (first_seen_ago_str); } if (encryption_count == 0) { es_fprintf (fp, _(", and encrypted %ld messages"), 0L); } else { char *first_done_ago_str = time_ago_str (now - encryption_first_done); /* TRANSLATORS: The final %s is replaced by a string like "7 months, 1 day, 5 minutes, 0 seconds". */ es_fprintf (fp, ngettext(", and encrypted %ld message in the past %s", ", and encrypted %ld messages in the past %s", encryption_count), encryption_count, first_done_ago_str); xfree (first_done_ago_str); } if (opt.verbose) { es_fputs (" ", fp); es_fputc ('(', fp); es_fprintf (fp, _("policy: %s"), tofu_policy_str (policy)); es_fputs (").\n", fp); } else es_fputs (".\n", fp); { char *tmpmsg, *p; es_fputc (0, fp); if (es_fclose_snatch (fp, (void **) &tmpmsg, NULL)) log_fatal ("error snatching memory stream\n"); msg = format_text (tmpmsg, 0, 72, 80); es_free (tmpmsg); /* Print a status line but suppress the trailing LF. * Spaces are not percent escaped. */ if (*msg) write_status_buffer (STATUS_TOFU_STATS_LONG, msg, strlen (msg)-1, -1); /* Remove the non-breaking space markers. */ for (p=msg; *p; p++) if (*p == '~') *p = ' '; } log_string (GPGRT_LOG_INFO, msg); xfree (msg); if (policy == TOFU_POLICY_AUTO) { if (signature_count == 0) log_info (_("Warning: we have yet to see" " a message signed using this key and user id!\n")); else if (signature_count == 1) log_info (_("Warning: we've only seen one message" " signed using this key and user id!\n")); if (encryption_count == 0) log_info (_("Warning: you have yet to encrypt" " a message to this key!\n")); else if (encryption_count == 1) log_info (_("Warning: you have only encrypted" " one message to this key!\n")); /* Cf. write_stats_status */ if (sqrtu32 (encryption_count * encryption_count + signature_count * signature_count) < 2 * BASIC_TRUST_THRESHOLD) show_warning = 1; } } out: xfree (fingerprint_pp); return show_warning; } static void show_warning (const char *fingerprint, strlist_t user_id_list) { char *set_policy_command; char *text; char *tmpmsg; set_policy_command = xasprintf ("gpg --tofu-policy bad %s", fingerprint); tmpmsg = xasprintf (ngettext ("Warning: if you think you've seen more signatures " "by this key and user id, then this key might be a " "forgery! Carefully examine the email address for small " "variations. If the key is suspect, then use\n" " %s\n" "to mark it as being bad.\n", "Warning: if you think you've seen more signatures " "by this key and these user ids, then this key might be a " "forgery! Carefully examine the email addresses for small " "variations. If the key is suspect, then use\n" " %s\n" "to mark it as being bad.\n", strlist_length (user_id_list)), set_policy_command); text = format_text (tmpmsg, 0, 72, 80); xfree (tmpmsg); log_string (GPGRT_LOG_INFO, text); xfree (text); es_free (set_policy_command); } /* Extract the email address from a user id and normalize it. If the user id doesn't contain an email address, then we use the whole user_id and normalize that. The returned string must be freed. */ static char * email_from_user_id (const char *user_id) { char *email = mailbox_from_userid (user_id); if (! email) { /* Hmm, no email address was provided or we are out of core. Just take the lower-case version of the whole user id. It could be a hostname, for instance. */ email = ascii_strlwr (xstrdup (user_id)); } return email; } /* Register the signature with the bindings , for each USER_ID in USER_ID_LIST. The fingerprint is taken from the primary key packet PK. SIG_DIGEST_BIN is the binary representation of the message's digest. SIG_DIGEST_BIN_LEN is its length. SIG_TIME is the time that the signature was generated. ORIGIN is a free-formed string describing the origin of the signature. If this was from an email and the Claws MUA was used, then this should be something like: "email:claws". If this is NULL, the default is simply "unknown". If MAY_ASK is 1, then this function may interact with the user. This is necessary if there is a conflict or the binding's policy is TOFU_POLICY_ASK. This function returns 0 on success and an error code if an error occurred. */ gpg_error_t tofu_register_signature (ctrl_t ctrl, PKT_public_key *pk, strlist_t user_id_list, const byte *sig_digest_bin, int sig_digest_bin_len, time_t sig_time, const char *origin) { time_t now = gnupg_get_time (); gpg_error_t rc; tofu_dbs_t dbs; char *fingerprint = NULL; strlist_t user_id; char *email = NULL; char *err = NULL; char *sig_digest; unsigned long c; dbs = opendbs (ctrl); if (! dbs) { rc = gpg_error (GPG_ERR_GENERAL); log_error (_("error opening TOFU database: %s\n"), gpg_strerror (rc)); return rc; } /* We do a query and then an insert. Make sure they are atomic by wrapping them in a transaction. */ rc = begin_transaction (ctrl, 0); if (rc) return rc; log_assert (pk_is_primary (pk)); sig_digest = make_radix64_string (sig_digest_bin, sig_digest_bin_len); fingerprint = hexfingerprint (pk, NULL, 0); if (! origin) /* The default origin is simply "unknown". */ origin = "unknown"; for (user_id = user_id_list; user_id; user_id = user_id->next) { email = email_from_user_id (user_id->d); if (DBG_TRUST) log_debug ("TOFU: Registering signature %s with binding" " \n", sig_digest, fingerprint, email); /* Make sure the binding exists and record any TOFU conflicts. */ if (get_trust (ctrl, pk, fingerprint, email, user_id->d, 0, now) == _tofu_GET_TRUST_ERROR) { rc = gpg_error (GPG_ERR_GENERAL); xfree (email); break; } /* If we've already seen this signature before, then don't add it again. */ rc = gpgsql_stepx (dbs->db, &dbs->s.register_already_seen, get_single_unsigned_long_cb2, &c, &err, "select count (*)\n" " from signatures left join bindings\n" " on signatures.binding = bindings.oid\n" " where fingerprint = ? and email = ? and sig_time = ?\n" " and sig_digest = ?", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_LONG_LONG, (long long) sig_time, GPGSQL_ARG_STRING, sig_digest, GPGSQL_ARG_END); if (rc) { log_error (_("error reading TOFU database: %s\n"), err); print_further_info ("checking existence"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); } else if (c > 1) /* Duplicates! This should not happen. In particular, because is the primary key! */ log_debug ("SIGNATURES DB contains duplicate records" " ." " Please report.\n", fingerprint, email, (unsigned long) sig_time, sig_digest, origin); else if (c == 1) { if (DBG_TRUST) log_debug ("Already observed the signature and binding" " \n", fingerprint, email, (unsigned long) sig_time, sig_digest, origin); } else if (opt.dry_run) { log_info ("TOFU database update skipped due to --dry-run\n"); } else /* This is the first time that we've seen this signature and binding. Record it. */ { if (DBG_TRUST) log_debug ("TOFU: Saving signature" " \n", fingerprint, email, sig_digest); log_assert (c == 0); rc = gpgsql_stepx (dbs->db, &dbs->s.register_signature, NULL, NULL, &err, "insert into signatures\n" " (binding, sig_digest, origin, sig_time, time)\n" " values\n" " ((select oid from bindings\n" " where fingerprint = ? and email = ?),\n" " ?, ?, ?, ?);", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_STRING, sig_digest, GPGSQL_ARG_STRING, origin, GPGSQL_ARG_LONG_LONG, (long long) sig_time, GPGSQL_ARG_LONG_LONG, (long long) now, GPGSQL_ARG_END); if (rc) { log_error (_("error updating TOFU database: %s\n"), err); print_further_info ("insert signatures"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); } } xfree (email); if (rc) break; } if (rc) rollback_transaction (ctrl); else rc = end_transaction (ctrl, 0); xfree (fingerprint); xfree (sig_digest); return rc; } gpg_error_t tofu_register_encryption (ctrl_t ctrl, PKT_public_key *pk, strlist_t user_id_list, int may_ask) { time_t now = gnupg_get_time (); gpg_error_t rc = 0; tofu_dbs_t dbs; kbnode_t kb = NULL; int free_user_id_list = 0; char *fingerprint = NULL; strlist_t user_id; char *err = NULL; dbs = opendbs (ctrl); if (! dbs) { rc = gpg_error (GPG_ERR_GENERAL); log_error (_("error opening TOFU database: %s\n"), gpg_strerror (rc)); return rc; } if (/* We need the key block to find the primary key. */ ! pk_is_primary (pk) /* We need the key block to find all user ids. */ || ! user_id_list) kb = get_pubkeyblock (pk->keyid); /* Make sure PK is a primary key. */ if (! pk_is_primary (pk)) pk = kb->pkt->pkt.public_key; if (! user_id_list) { /* Use all non-revoked user ids. Do use expired user ids. */ kbnode_t n = kb; while ((n = find_next_kbnode (n, PKT_USER_ID))) { PKT_user_id *uid = n->pkt->pkt.user_id; if (uid->is_revoked) continue; add_to_strlist (&user_id_list, uid->name); } free_user_id_list = 1; if (! user_id_list) log_info (_("WARNING: Encrypting to %s, which has no" "non-revoked user ids.\n"), keystr (pk->keyid)); } fingerprint = hexfingerprint (pk, NULL, 0); tofu_begin_batch_update (ctrl); tofu_resume_batch_transaction (ctrl); for (user_id = user_id_list; user_id; user_id = user_id->next) { char *email = email_from_user_id (user_id->d); /* Make sure the binding exists and that we recognize any conflicts. */ int tl = get_trust (ctrl, pk, fingerprint, email, user_id->d, may_ask, now); if (tl == _tofu_GET_TRUST_ERROR) { /* An error. */ rc = gpg_error (GPG_ERR_GENERAL); xfree (email); goto die; } rc = gpgsql_stepx (dbs->db, &dbs->s.register_encryption, NULL, NULL, &err, "insert into encryptions\n" " (binding, time)\n" " values\n" " ((select oid from bindings\n" " where fingerprint = ? and email = ?),\n" " ?);", GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_STRING, email, GPGSQL_ARG_LONG_LONG, (long long) now, GPGSQL_ARG_END); if (rc) { log_error (_("error updating TOFU database: %s\n"), err); print_further_info ("insert encryption"); sqlite3_free (err); rc = gpg_error (GPG_ERR_GENERAL); } xfree (email); } die: tofu_end_batch_update (ctrl); if (kb) release_kbnode (kb); if (free_user_id_list) free_strlist (user_id_list); xfree (fingerprint); return rc; } /* Combine a trust level returned from the TOFU trust model with a trust level returned by the PGP trust model. This is primarily of interest when the trust model is tofu+pgp (TM_TOFU_PGP). This function ors together the upper bits (the values not covered by TRUST_MASK, i.e., TRUST_FLAG_REVOKED, etc.). */ int tofu_wot_trust_combine (int tofu_base, int wot_base) { int tofu = tofu_base & TRUST_MASK; int wot = wot_base & TRUST_MASK; int upper = (tofu_base & ~TRUST_MASK) | (wot_base & ~TRUST_MASK); log_assert (tofu == TRUST_UNKNOWN || tofu == TRUST_EXPIRED || tofu == TRUST_UNDEFINED || tofu == TRUST_NEVER || tofu == TRUST_MARGINAL || tofu == TRUST_FULLY || tofu == TRUST_ULTIMATE); log_assert (wot == TRUST_UNKNOWN || wot == TRUST_EXPIRED || wot == TRUST_UNDEFINED || wot == TRUST_NEVER || wot == TRUST_MARGINAL || wot == TRUST_FULLY || wot == TRUST_ULTIMATE); /* We first consider negative trust policys. These trump positive trust policies. */ if (tofu == TRUST_NEVER || wot == TRUST_NEVER) /* TRUST_NEVER trumps everything else. */ return upper | TRUST_NEVER; if (tofu == TRUST_EXPIRED || wot == TRUST_EXPIRED) /* TRUST_EXPIRED trumps everything but TRUST_NEVER. */ return upper | TRUST_EXPIRED; /* Now we only have positive or neutral trust policies. We take the max. */ if (tofu == TRUST_ULTIMATE) return upper | TRUST_ULTIMATE | TRUST_FLAG_TOFU_BASED; if (wot == TRUST_ULTIMATE) return upper | TRUST_ULTIMATE; if (tofu == TRUST_FULLY) return upper | TRUST_FULLY | TRUST_FLAG_TOFU_BASED; if (wot == TRUST_FULLY) return upper | TRUST_FULLY; if (tofu == TRUST_MARGINAL) return upper | TRUST_MARGINAL | TRUST_FLAG_TOFU_BASED; if (wot == TRUST_MARGINAL) return upper | TRUST_MARGINAL; if (tofu == TRUST_UNDEFINED) return upper | TRUST_UNDEFINED | TRUST_FLAG_TOFU_BASED; if (wot == TRUST_UNDEFINED) return upper | TRUST_UNDEFINED; return upper | TRUST_UNKNOWN; } /* Write a "tfs" record for a --with-colons listing. */ gpg_error_t tofu_write_tfs_record (ctrl_t ctrl, estream_t fp, PKT_public_key *pk, const char *user_id) { time_t now = gnupg_get_time (); gpg_error_t err; tofu_dbs_t dbs; char *fingerprint; char *email; if (!*user_id) return 0; /* No TOFU stats possible for an empty ID. */ dbs = opendbs (ctrl); if (!dbs) { err = gpg_error (GPG_ERR_GENERAL); log_error (_("error opening TOFU database: %s\n"), gpg_strerror (err)); return err; } fingerprint = hexfingerprint (pk, NULL, 0); email = email_from_user_id (user_id); show_statistics (dbs, pk, fingerprint, email, user_id, fp, now); xfree (email); xfree (fingerprint); return 0; } /* Return the validity (TRUST_NEVER, etc.) of the bindings , for each USER_ID in USER_ID_LIST. If USER_ID_LIST->FLAG is set, then the id is considered to be expired. PK is the primary key packet. If MAY_ASK is 1 and the policy is TOFU_POLICY_ASK, then the user will be prompted to choose a policy. If MAY_ASK is 0 and the policy is TOFU_POLICY_ASK, then TRUST_UNKNOWN is returned. Returns TRUST_UNDEFINED if an error occurs. */ int tofu_get_validity (ctrl_t ctrl, PKT_public_key *pk, strlist_t user_id_list, int may_ask) { time_t now = gnupg_get_time (); tofu_dbs_t dbs; char *fingerprint = NULL; strlist_t user_id; int trust_level = TRUST_UNKNOWN; int bindings = 0; int bindings_valid = 0; int need_warning = 0; dbs = opendbs (ctrl); if (! dbs) { log_error (_("error opening TOFU database: %s\n"), gpg_strerror (GPG_ERR_GENERAL)); return TRUST_UNDEFINED; } fingerprint = hexfingerprint (pk, NULL, 0); tofu_begin_batch_update (ctrl); /* Start the batch transaction now. */ tofu_resume_batch_transaction (ctrl); for (user_id = user_id_list; user_id; user_id = user_id->next, bindings ++) { char *email = email_from_user_id (user_id->d); /* Always call get_trust to make sure the binding is registered. */ int tl = get_trust (ctrl, pk, fingerprint, email, user_id->d, may_ask, now); if (tl == _tofu_GET_TRUST_ERROR) { /* An error. */ trust_level = TRUST_UNDEFINED; xfree (email); goto die; } if (DBG_TRUST) log_debug ("TOFU: validity for : %s%s.\n", fingerprint, email, trust_value_to_string (tl), user_id->flags ? " (but expired)" : ""); if (user_id->flags) tl = TRUST_EXPIRED; if (tl != TRUST_EXPIRED) bindings_valid ++; if (may_ask && tl != TRUST_ULTIMATE && tl != TRUST_EXPIRED) need_warning |= show_statistics (dbs, pk, fingerprint, email, user_id->d, NULL, now); if (tl == TRUST_NEVER) trust_level = TRUST_NEVER; else if (tl == TRUST_EXPIRED) /* Ignore expired bindings in the trust calculation. */ ; else if (tl > trust_level) { /* The expected values: */ log_assert (tl == TRUST_UNKNOWN || tl == TRUST_UNDEFINED || tl == TRUST_MARGINAL || tl == TRUST_FULLY || tl == TRUST_ULTIMATE); /* We assume the following ordering: */ log_assert (TRUST_UNKNOWN < TRUST_UNDEFINED); log_assert (TRUST_UNDEFINED < TRUST_MARGINAL); log_assert (TRUST_MARGINAL < TRUST_FULLY); log_assert (TRUST_FULLY < TRUST_ULTIMATE); trust_level = tl; } xfree (email); } if (need_warning) show_warning (fingerprint, user_id_list); die: tofu_end_batch_update (ctrl); xfree (fingerprint); if (bindings_valid == 0) { if (DBG_TRUST) log_debug ("no (of %d) valid bindings." " Can't get TOFU validity for this set of user ids.\n", bindings); return TRUST_NEVER; } return trust_level; } /* Set the policy for all non-revoked user ids in the keyblock KB to POLICY. If no key is available with the specified key id, then this function returns GPG_ERR_NO_PUBKEY. Returns 0 on success and an error code otherwise. */ gpg_error_t tofu_set_policy (ctrl_t ctrl, kbnode_t kb, enum tofu_policy policy) { gpg_error_t err; time_t now = gnupg_get_time (); tofu_dbs_t dbs; PKT_public_key *pk; char *fingerprint = NULL; log_assert (kb->pkt->pkttype == PKT_PUBLIC_KEY); pk = kb->pkt->pkt.public_key; dbs = opendbs (ctrl); if (! dbs) { log_error (_("error opening TOFU database: %s\n"), gpg_strerror (GPG_ERR_GENERAL)); return gpg_error (GPG_ERR_GENERAL); } if (DBG_TRUST) log_debug ("Setting TOFU policy for %s to %s\n", keystr (pk->keyid), tofu_policy_str (policy)); if (! pk_is_primary (pk)) log_bug ("%s: Passed a subkey, but expecting a primary key.\n", __func__); fingerprint = hexfingerprint (pk, NULL, 0); begin_transaction (ctrl, 0); for (; kb; kb = kb->next) { PKT_user_id *user_id; char *email; if (kb->pkt->pkttype != PKT_USER_ID) continue; user_id = kb->pkt->pkt.user_id; if (user_id->is_revoked) /* Skip revoked user ids. (Don't skip expired user ids, the expiry can be changed.) */ continue; email = email_from_user_id (user_id->name); err = record_binding (dbs, fingerprint, email, user_id->name, policy, TOFU_POLICY_NONE, NULL, 0, 1, now); if (err) { log_error (_("error setting policy for key %s, user id \"%s\": %s"), fingerprint, email, gpg_strerror (err)); xfree (email); break; } xfree (email); } if (err) rollback_transaction (ctrl); else end_transaction (ctrl, 0); xfree (fingerprint); return err; } /* Set the TOFU policy for all non-revoked user ids in the KEY with the key id KEYID to POLICY. If no key is available with the specified key id, then this function returns GPG_ERR_NO_PUBKEY. Returns 0 on success and an error code otherwise. */ gpg_error_t tofu_set_policy_by_keyid (ctrl_t ctrl, u32 *keyid, enum tofu_policy policy) { kbnode_t keyblock = get_pubkeyblock (keyid); if (! keyblock) return gpg_error (GPG_ERR_NO_PUBKEY); return tofu_set_policy (ctrl, keyblock, policy); } /* Return the TOFU policy for the specified binding in *POLICY. If no policy has been set for the binding, sets *POLICY to TOFU_POLICY_NONE. PK is a primary public key and USER_ID is a user id. Returns 0 on success and an error code otherwise. */ gpg_error_t tofu_get_policy (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *user_id, enum tofu_policy *policy) { time_t now = gnupg_get_time (); tofu_dbs_t dbs; char *fingerprint; char *email; /* Make sure PK is a primary key. */ log_assert (pk_is_primary (pk)); dbs = opendbs (ctrl); if (! dbs) { log_error (_("error opening TOFU database: %s\n"), gpg_strerror (GPG_ERR_GENERAL)); return gpg_error (GPG_ERR_GENERAL); } fingerprint = hexfingerprint (pk, NULL, 0); email = email_from_user_id (user_id->name); *policy = get_policy (dbs, pk, fingerprint, user_id->name, email, NULL, now); xfree (email); xfree (fingerprint); if (*policy == _tofu_GET_POLICY_ERROR) return gpg_error (GPG_ERR_GENERAL); return 0; } gpg_error_t tofu_notice_key_changed (ctrl_t ctrl, kbnode_t kb) { tofu_dbs_t dbs; PKT_public_key *pk; char *fingerprint; char *sqlerr = NULL; int rc; /* Make sure PK is a primary key. */ setup_main_keyids (kb); pk = kb->pkt->pkt.public_key; log_assert (pk_is_primary (pk)); dbs = opendbs (ctrl); if (! dbs) { log_error (_("error opening TOFU database: %s\n"), gpg_strerror (GPG_ERR_GENERAL)); return gpg_error (GPG_ERR_GENERAL); } fingerprint = hexfingerprint (pk, NULL, 0); rc = gpgsql_stepx (dbs->db, NULL, NULL, NULL, &sqlerr, "update bindings set effective_policy = ?" " where fingerprint = ?;", GPGSQL_ARG_INT, (int) TOFU_POLICY_NONE, GPGSQL_ARG_STRING, fingerprint, GPGSQL_ARG_END); xfree (fingerprint); if (rc == _tofu_GET_POLICY_ERROR) return gpg_error (GPG_ERR_GENERAL); return 0; } diff --git a/g10/trustdb.c b/g10/trustdb.c index edae6ef45..51a8f2217 100644 --- a/g10/trustdb.c +++ b/g10/trustdb.c @@ -1,2177 +1,2184 @@ /* trustdb.c * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, * 2008, 2012 Free Software Foundation, Inc. * * This file is part of GnuPG. * * GnuPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * GnuPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #include #include #include #include #ifndef DISABLE_REGEX #include #include #endif /* !DISABLE_REGEX */ #include "gpg.h" #include "status.h" #include "iobuf.h" #include "keydb.h" #include "util.h" #include "options.h" #include "packet.h" #include "main.h" #include "mbox-util.h" #include "i18n.h" #include "tdbio.h" #include "trustdb.h" #include "tofu.h" typedef struct key_item **KeyHashTable; /* see new_key_hash_table() */ /* * Structure to keep track of keys, this is used as an array wherre * the item right after the last one has a keyblock set to NULL. * Maybe we can drop this thing and replace it by key_item */ struct key_array { KBNODE keyblock; }; /* Control information for the trust DB. */ static struct { int init; int level; char *dbname; int no_trustdb; } trustdb_args; /* Some globals. */ static struct key_item *user_utk_list; /* temp. used to store --trusted-keys */ static struct key_item *utk_list; /* all ultimately trusted keys */ static int pending_check_trustdb; static int validate_keys (ctrl_t ctrl, int interactive); /********************************************** ************* some helpers ******************* **********************************************/ static struct key_item * new_key_item (void) { struct key_item *k; k = xmalloc_clear (sizeof *k); return k; } static void release_key_items (struct key_item *k) { struct key_item *k2; for (; k; k = k2) { k2 = k->next; xfree (k->trust_regexp); xfree (k); } } #define KEY_HASH_TABLE_SIZE 1024 /* * For fast keylook up we need a hash table. Each byte of a KeyID * should be distributed equally over the 256 possible values (except * for v3 keyIDs but we consider them as not important here). So we * can just use 10 bits to index a table of KEY_HASH_TABLE_SIZE key items. * Possible optimization: Do not use key_items but other hash_table when the * duplicates lists get too large. */ static KeyHashTable new_key_hash_table (void) { struct key_item **tbl; tbl = xmalloc_clear (KEY_HASH_TABLE_SIZE * sizeof *tbl); return tbl; } static void release_key_hash_table (KeyHashTable tbl) { int i; if (!tbl) return; for (i=0; i < KEY_HASH_TABLE_SIZE; i++) release_key_items (tbl[i]); xfree (tbl); } /* * Returns: True if the keyID is in the given hash table */ static int test_key_hash_table (KeyHashTable tbl, u32 *kid) { struct key_item *k; for (k = tbl[(kid[1] % KEY_HASH_TABLE_SIZE)]; k; k = k->next) if (k->kid[0] == kid[0] && k->kid[1] == kid[1]) return 1; return 0; } /* * Add a new key to the hash table. The key is identified by its key ID. */ static void add_key_hash_table (KeyHashTable tbl, u32 *kid) { int i = kid[1] % KEY_HASH_TABLE_SIZE; struct key_item *k, *kk; for (k = tbl[i]; k; k = k->next) if (k->kid[0] == kid[0] && k->kid[1] == kid[1]) return; /* already in table */ kk = new_key_item (); kk->kid[0] = kid[0]; kk->kid[1] = kid[1]; kk->next = tbl[i]; tbl[i] = kk; } /* * Release a key_array */ static void release_key_array ( struct key_array *keys ) { struct key_array *k; if (keys) { for (k=keys; k->keyblock; k++) release_kbnode (k->keyblock); xfree (keys); } } /********************************************* ********** Initialization ***************** *********************************************/ /* * Used to register extra ultimately trusted keys - this has to be done * before initializing the validation module. * FIXME: Should be replaced by a function to add those keys to the trustdb. */ void tdb_register_trusted_keyid (u32 *keyid) { struct key_item *k; k = new_key_item (); k->kid[0] = keyid[0]; k->kid[1] = keyid[1]; k->next = user_utk_list; user_utk_list = k; } void tdb_register_trusted_key( const char *string ) { gpg_error_t err; KEYDB_SEARCH_DESC desc; err = classify_user_id (string, &desc, 1); if (err || desc.mode != KEYDB_SEARCH_MODE_LONG_KID ) { log_error(_("'%s' is not a valid long keyID\n"), string ); return; } register_trusted_keyid(desc.u.kid); } /* * Helper to add a key to the global list of ultimately trusted keys. * Retruns: true = inserted, false = already in in list. */ static int add_utk (u32 *kid) { struct key_item *k; if (tdb_keyid_is_utk (kid)) return 0; k = new_key_item (); k->kid[0] = kid[0]; k->kid[1] = kid[1]; k->ownertrust = TRUST_ULTIMATE; k->next = utk_list; utk_list = k; if( opt.verbose > 1 ) log_info(_("key %s: accepted as trusted key\n"), keystr(kid)); return 1; } /**************** * Verify that all our secret keys are usable and put them into the utk_list. */ static void verify_own_keys(void) { TRUSTREC rec; ulong recnum; int rc; struct key_item *k; if (utk_list) return; /* scan the trustdb to find all ultimately trusted keys */ for (recnum=1; !tdbio_read_record (recnum, &rec, 0); recnum++ ) { if ( rec.rectype == RECTYPE_TRUST && (rec.r.trust.ownertrust & TRUST_MASK) == TRUST_ULTIMATE) { byte *fpr = rec.r.trust.fingerprint; int fprlen; u32 kid[2]; /* Problem: We do only use fingerprints in the trustdb but * we need the keyID here to indetify the key; we can only * use that ugly hack to distinguish between 16 and 20 * butes fpr - it does not work always so we better change * the whole validation code to only work with * fingerprints */ fprlen = (!fpr[16] && !fpr[17] && !fpr[18] && !fpr[19])? 16:20; keyid_from_fingerprint (fpr, fprlen, kid); if (!add_utk (kid)) log_info(_("key %s occurs more than once in the trustdb\n"), keystr(kid)); } } /* Put any --trusted-key keys into the trustdb */ for (k = user_utk_list; k; k = k->next) { if ( add_utk (k->kid) ) { /* not yet in trustDB as ultimately trusted */ PKT_public_key pk; memset (&pk, 0, sizeof pk); rc = get_pubkey (&pk, k->kid); if (rc) log_info(_("key %s: no public key for trusted key - skipped\n"), keystr(k->kid)); else { tdb_update_ownertrust (&pk, ((tdb_get_ownertrust (&pk) & ~TRUST_MASK) | TRUST_ULTIMATE )); release_public_key_parts (&pk); } log_info (_("key %s marked as ultimately trusted\n"),keystr(k->kid)); } } /* release the helper table table */ release_key_items (user_utk_list); user_utk_list = NULL; return; } /* Returns whether KID is on the list of ultimately trusted keys. */ int tdb_keyid_is_utk (u32 *kid) { struct key_item *k; for (k = utk_list; k; k = k->next) if (k->kid[0] == kid[0] && k->kid[1] == kid[1]) return 1; return 0; } + +/* Return the list of ultimately trusted keys. */ +struct key_item * +tdb_utks (void) +{ + return utk_list; +} /********************************************* *********** TrustDB stuff ******************* *********************************************/ /* * Read a record but die if it does not exist */ static void read_record (ulong recno, TRUSTREC *rec, int rectype ) { int rc = tdbio_read_record (recno, rec, rectype); if (rc) { log_error(_("trust record %lu, req type %d: read failed: %s\n"), recno, rec->rectype, gpg_strerror (rc) ); tdbio_invalid(); } if (rectype != rec->rectype) { log_error(_("trust record %lu is not of requested type %d\n"), rec->recnum, rectype); tdbio_invalid(); } } /* * Write a record and die on error */ static void write_record (TRUSTREC *rec) { int rc = tdbio_write_record (rec); if (rc) { log_error(_("trust record %lu, type %d: write failed: %s\n"), rec->recnum, rec->rectype, gpg_strerror (rc) ); tdbio_invalid(); } } /* * sync the TrustDb and die on error */ static void do_sync(void) { int rc = tdbio_sync (); if(rc) { log_error (_("trustdb: sync failed: %s\n"), gpg_strerror (rc) ); g10_exit(2); } } const char * trust_model_string (int model) { switch (model) { case TM_CLASSIC: return "classic"; case TM_PGP: return "pgp"; case TM_EXTERNAL: return "external"; case TM_TOFU: return "tofu"; case TM_TOFU_PGP: return "tofu+pgp"; case TM_ALWAYS: return "always"; case TM_DIRECT: return "direct"; default: return "unknown"; } } /**************** * Perform some checks over the trustdb * level 0: only open the db * 1: used for initial program startup */ int setup_trustdb( int level, const char *dbname ) { /* just store the args */ if( trustdb_args.init ) return 0; trustdb_args.level = level; trustdb_args.dbname = dbname? xstrdup(dbname): NULL; return 0; } void how_to_fix_the_trustdb () { const char *name = trustdb_args.dbname; if (!name) name = "trustdb.gpg"; log_info (_("You may try to re-create the trustdb using the commands:\n")); log_info (" cd %s\n", default_homedir ()); log_info (" %s --export-ownertrust > otrust.tmp\n", GPG_NAME); #ifdef HAVE_W32_SYSTEM log_info (" del %s\n", name); #else log_info (" rm %s\n", name); #endif log_info (" %s --import-ownertrust < otrust.tmp\n", GPG_NAME); log_info (_("If that does not work, please consult the manual\n")); } void init_trustdb () { int level = trustdb_args.level; const char* dbname = trustdb_args.dbname; if( trustdb_args.init ) return; trustdb_args.init = 1; if(level==0 || level==1) { int rc = tdbio_set_dbname( dbname, !!level, &trustdb_args.no_trustdb); if( rc ) log_fatal("can't init trustdb: %s\n", gpg_strerror (rc) ); } else BUG(); if(opt.trust_model==TM_AUTO) { /* Try and set the trust model off of whatever the trustdb says it is. */ opt.trust_model=tdbio_read_model(); /* Sanity check this ;) */ if(opt.trust_model != TM_CLASSIC && opt.trust_model != TM_PGP && opt.trust_model != TM_TOFU_PGP && opt.trust_model != TM_TOFU && opt.trust_model != TM_EXTERNAL) { log_info(_("unable to use unknown trust model (%d) - " "assuming %s trust model\n"),opt.trust_model,"pgp"); opt.trust_model = TM_PGP; } if(opt.verbose) log_info(_("using %s trust model\n"), trust_model_string (opt.trust_model)); } if (opt.trust_model==TM_PGP || opt.trust_model==TM_CLASSIC || opt.trust_model == TM_TOFU || opt.trust_model == TM_TOFU_PGP) { /* Verify the list of ultimately trusted keys and move the --trusted-keys list there as well. */ if(level==1) verify_own_keys(); if(!tdbio_db_matches_options()) pending_check_trustdb=1; } } /**************** * Recreate the WoT but do not ask for new ownertrusts. Special * feature: In batch mode and without a forced yes, this is only done * when a check is due. This can be used to run the check from a crontab */ void check_trustdb (ctrl_t ctrl) { init_trustdb(); if (opt.trust_model == TM_PGP || opt.trust_model == TM_CLASSIC || opt.trust_model == TM_TOFU_PGP || opt.trust_model == TM_TOFU) { if (opt.batch && !opt.answer_yes) { ulong scheduled; scheduled = tdbio_read_nextcheck (); if (!scheduled) { log_info (_("no need for a trustdb check\n")); return; } if (scheduled > make_timestamp ()) { log_info (_("next trustdb check due at %s\n"), strtimestamp (scheduled)); return; } } validate_keys (ctrl, 0); } else log_info (_("no need for a trustdb check with '%s' trust model\n"), trust_model_string(opt.trust_model)); } /* * Recreate the WoT. */ void update_trustdb (ctrl_t ctrl) { init_trustdb (); if (opt.trust_model == TM_PGP || opt.trust_model == TM_CLASSIC || opt.trust_model == TM_TOFU_PGP || opt.trust_model == TM_TOFU) validate_keys (ctrl, 1); else log_info (_("no need for a trustdb update with '%s' trust model\n"), trust_model_string(opt.trust_model)); } void tdb_revalidation_mark (void) { init_trustdb(); if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return; /* We simply set the time for the next check to 1 (far back in 1970) so that a --update-trustdb will be scheduled. */ if (tdbio_write_nextcheck (1)) do_sync (); pending_check_trustdb = 1; } int trustdb_pending_check(void) { return pending_check_trustdb; } /* If the trustdb is dirty, and we're interactive, update it. Otherwise, check it unless no-auto-check-trustdb is set. */ void tdb_check_or_update (ctrl_t ctrl) { if (trustdb_pending_check ()) { if (opt.interactive) update_trustdb (ctrl); else if (!opt.no_auto_check_trustdb) check_trustdb (ctrl); } } void read_trust_options(byte *trust_model,ulong *created,ulong *nextcheck, byte *marginals,byte *completes,byte *cert_depth, byte *min_cert_level) { TRUSTREC opts; init_trustdb(); if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) memset (&opts, 0, sizeof opts); else read_record (0, &opts, RECTYPE_VER); if(trust_model) *trust_model=opts.r.ver.trust_model; if(created) *created=opts.r.ver.created; if(nextcheck) *nextcheck=opts.r.ver.nextcheck; if(marginals) *marginals=opts.r.ver.marginals; if(completes) *completes=opts.r.ver.completes; if(cert_depth) *cert_depth=opts.r.ver.cert_depth; if(min_cert_level) *min_cert_level=opts.r.ver.min_cert_level; } /*********************************************** *********** Ownertrust et al. **************** ***********************************************/ static int read_trust_record (PKT_public_key *pk, TRUSTREC *rec) { int rc; init_trustdb(); rc = tdbio_search_trust_bypk (pk, rec); if (rc) { if (gpg_err_code (rc) != GPG_ERR_NOT_FOUND) log_error ("trustdb: searching trust record failed: %s\n", gpg_strerror (rc)); return rc; } if (rec->rectype != RECTYPE_TRUST) { log_error ("trustdb: record %lu is not a trust record\n", rec->recnum); return GPG_ERR_TRUSTDB; } return 0; } /**************** * Return the assigned ownertrust value for the given public key. * The key should be the primary key. */ unsigned int tdb_get_ownertrust ( PKT_public_key *pk) { TRUSTREC rec; gpg_error_t err; if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return TRUST_UNKNOWN; err = read_trust_record (pk, &rec); if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) return TRUST_UNKNOWN; /* no record yet */ if (err) { tdbio_invalid (); return TRUST_UNKNOWN; /* actually never reached */ } return rec.r.trust.ownertrust; } unsigned int tdb_get_min_ownertrust (PKT_public_key *pk) { TRUSTREC rec; gpg_error_t err; if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return TRUST_UNKNOWN; err = read_trust_record (pk, &rec); if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) return TRUST_UNKNOWN; /* no record yet */ if (err) { tdbio_invalid (); return TRUST_UNKNOWN; /* actually never reached */ } return rec.r.trust.min_ownertrust; } /* * Set the trust value of the given public key to the new value. * The key should be a primary one. */ void tdb_update_ownertrust (PKT_public_key *pk, unsigned int new_trust ) { TRUSTREC rec; gpg_error_t err; if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return; err = read_trust_record (pk, &rec); if (!err) { if (DBG_TRUST) log_debug ("update ownertrust from %u to %u\n", (unsigned int)rec.r.trust.ownertrust, new_trust ); if (rec.r.trust.ownertrust != new_trust) { rec.r.trust.ownertrust = new_trust; write_record( &rec ); tdb_revalidation_mark (); do_sync (); } } else if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) { /* no record yet - create a new one */ size_t dummy; if (DBG_TRUST) log_debug ("insert ownertrust %u\n", new_trust ); memset (&rec, 0, sizeof rec); rec.recnum = tdbio_new_recnum (); rec.rectype = RECTYPE_TRUST; fingerprint_from_pk (pk, rec.r.trust.fingerprint, &dummy); rec.r.trust.ownertrust = new_trust; write_record (&rec); tdb_revalidation_mark (); do_sync (); } else { tdbio_invalid (); } } static void update_min_ownertrust (u32 *kid, unsigned int new_trust ) { PKT_public_key *pk; TRUSTREC rec; gpg_error_t err; if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return; pk = xmalloc_clear (sizeof *pk); err = get_pubkey (pk, kid); if (err) { log_error (_("public key %s not found: %s\n"), keystr (kid), gpg_strerror (err)); return; } err = read_trust_record (pk, &rec); if (!err) { if (DBG_TRUST) log_debug ("key %08lX%08lX: update min_ownertrust from %u to %u\n", (ulong)kid[0],(ulong)kid[1], (unsigned int)rec.r.trust.min_ownertrust, new_trust ); if (rec.r.trust.min_ownertrust != new_trust) { rec.r.trust.min_ownertrust = new_trust; write_record( &rec ); tdb_revalidation_mark (); do_sync (); } } else if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) { /* no record yet - create a new one */ size_t dummy; if (DBG_TRUST) log_debug ("insert min_ownertrust %u\n", new_trust ); memset (&rec, 0, sizeof rec); rec.recnum = tdbio_new_recnum (); rec.rectype = RECTYPE_TRUST; fingerprint_from_pk (pk, rec.r.trust.fingerprint, &dummy); rec.r.trust.min_ownertrust = new_trust; write_record (&rec); tdb_revalidation_mark (); do_sync (); } else { tdbio_invalid (); } } /* * Clear the ownertrust and min_ownertrust values. * * Return: True if a change actually happened. */ int tdb_clear_ownertrusts (PKT_public_key *pk) { TRUSTREC rec; gpg_error_t err; init_trustdb (); if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return 0; err = read_trust_record (pk, &rec); if (!err) { if (DBG_TRUST) { log_debug ("clearing ownertrust (old value %u)\n", (unsigned int)rec.r.trust.ownertrust); log_debug ("clearing min_ownertrust (old value %u)\n", (unsigned int)rec.r.trust.min_ownertrust); } if (rec.r.trust.ownertrust || rec.r.trust.min_ownertrust) { rec.r.trust.ownertrust = 0; rec.r.trust.min_ownertrust = 0; write_record( &rec ); tdb_revalidation_mark (); do_sync (); return 1; } } else if (gpg_err_code (err) != GPG_ERR_NOT_FOUND) { tdbio_invalid (); } return 0; } /* * Note: Caller has to do a sync */ static void update_validity (PKT_public_key *pk, PKT_user_id *uid, int depth, int validity) { TRUSTREC trec, vrec; gpg_error_t err; ulong recno; namehash_from_uid(uid); err = read_trust_record (pk, &trec); if (err && gpg_err_code (err) != GPG_ERR_NOT_FOUND) { tdbio_invalid (); return; } if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) { /* No record yet - create a new one. */ size_t dummy; memset (&trec, 0, sizeof trec); trec.recnum = tdbio_new_recnum (); trec.rectype = RECTYPE_TRUST; fingerprint_from_pk (pk, trec.r.trust.fingerprint, &dummy); trec.r.trust.ownertrust = 0; } /* locate an existing one */ recno = trec.r.trust.validlist; while (recno) { read_record (recno, &vrec, RECTYPE_VALID); if ( !memcmp (vrec.r.valid.namehash, uid->namehash, 20) ) break; recno = vrec.r.valid.next; } if (!recno) /* insert a new validity record */ { memset (&vrec, 0, sizeof vrec); vrec.recnum = tdbio_new_recnum (); vrec.rectype = RECTYPE_VALID; memcpy (vrec.r.valid.namehash, uid->namehash, 20); vrec.r.valid.next = trec.r.trust.validlist; trec.r.trust.validlist = vrec.recnum; } vrec.r.valid.validity = validity; vrec.r.valid.full_count = uid->help_full_count; vrec.r.valid.marginal_count = uid->help_marginal_count; write_record (&vrec); trec.r.trust.depth = depth; write_record (&trec); } /*********************************************** ********* Query trustdb values ************** ***********************************************/ /* Return true if key is disabled. Note that this is usually used via the pk_is_disabled macro. */ int tdb_cache_disabled_value (PKT_public_key *pk) { gpg_error_t err; TRUSTREC trec; int disabled = 0; if (pk->flags.disabled_valid) return pk->flags.disabled; init_trustdb(); if (trustdb_args.no_trustdb) return 0; /* No trustdb => not disabled. */ err = read_trust_record (pk, &trec); if (err && gpg_err_code (err) != GPG_ERR_NOT_FOUND) { tdbio_invalid (); goto leave; } if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) { /* No record found, so assume not disabled. */ goto leave; } if ((trec.r.trust.ownertrust & TRUST_FLAG_DISABLED)) disabled = 1; /* Cache it for later so we don't need to look at the trustdb every time */ pk->flags.disabled = disabled; pk->flags.disabled_valid = 1; leave: return disabled; } void tdb_check_trustdb_stale (ctrl_t ctrl) { static int did_nextcheck=0; init_trustdb (); if (trustdb_args.no_trustdb) return; /* No trustdb => can't be stale. */ if (!did_nextcheck && (opt.trust_model == TM_PGP || opt.trust_model == TM_CLASSIC || opt.trust_model == TM_TOFU_PGP || opt.trust_model == TM_TOFU)) { ulong scheduled; did_nextcheck = 1; scheduled = tdbio_read_nextcheck (); if ((scheduled && scheduled <= make_timestamp ()) || pending_check_trustdb) { if (opt.no_auto_check_trustdb) { pending_check_trustdb = 1; if (!opt.quiet) log_info (_("please do a --check-trustdb\n")); } else { if (!opt.quiet) log_info (_("checking the trustdb\n")); validate_keys (ctrl, 0); } } } } /* * Return the validity information for PK. This is the core of * get_validity. If SIG is not NULL, then the trust is being * evaluated in the context of the provided signature. This is used * by the TOFU code to record statistics. */ unsigned int tdb_get_validity_core (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid, PKT_public_key *main_pk, PKT_signature *sig, int may_ask) { TRUSTREC trec, vrec; gpg_error_t err = 0; ulong recno; #ifdef USE_TOFU unsigned int tofu_validity = TRUST_UNKNOWN; #endif unsigned int validity = TRUST_UNKNOWN; #ifndef USE_TOFU (void)sig; (void)may_ask; #endif init_trustdb (); /* If we have no trustdb (which also means it has not been created) and the trust-model is always, we don't know the validity - return immediately. If we won't do that the tdbio code would try to open the trustdb and run into a fatal error. */ if (trustdb_args.no_trustdb && opt.trust_model == TM_ALWAYS) return TRUST_UNKNOWN; check_trustdb_stale (ctrl); if(opt.trust_model==TM_DIRECT) { /* Note that this happens BEFORE any user ID stuff is checked. The direct trust model applies to keys as a whole. */ validity = tdb_get_ownertrust (main_pk); goto leave; } #ifdef USE_TOFU if (opt.trust_model == TM_TOFU || opt.trust_model == TM_TOFU_PGP) { kbnode_t kb = NULL; kbnode_t n = NULL; strlist_t user_id_list = NULL; int done = 0; /* If the caller didn't supply a user id then use all uids. */ if (! uid) kb = n = get_pubkeyblock (main_pk->keyid); if (DBG_TRUST && sig && sig->signers_uid) log_debug ("TOFU: only considering user id: '%s'\n", sig->signers_uid); while (!done && (uid || (n = find_next_kbnode (n, PKT_USER_ID)))) { PKT_user_id *user_id; int expired = 0; if (uid) { user_id = uid; /* If the caller specified a user id, then we only process the specified user id and are done after the first iteration. */ done = 1; } else user_id = n->pkt->pkt.user_id; if (user_id->attrib_data) /* Skip user attributes. */ continue; if (sig && sig->signers_uid) /* Make sure the UID matches. */ { char *email = mailbox_from_userid (user_id->name); if (!email || !*email || strcmp (sig->signers_uid, email) != 0) { if (DBG_TRUST) log_debug ("TOFU: skipping user id '%s', which does" " not match the signer's email ('%s')\n", email, sig->signers_uid); xfree (email); continue; } xfree (email); } /* If the user id is revoked or expired, then skip it. */ if (user_id->is_revoked || user_id->is_expired) { if (DBG_TRUST) { char *s; if (user_id->is_revoked && user_id->is_expired) s = "revoked and expired"; else if (user_id->is_revoked) s = "revoked"; else s = "expire"; log_debug ("TOFU: Ignoring %s user id (%s)\n", s, user_id->name); } if (user_id->is_revoked) continue; expired = 1; } add_to_strlist (&user_id_list, user_id->name); user_id_list->flags = expired; } /* Process the user ids in the order they appear in the key block. */ strlist_rev (&user_id_list); /* It only makes sense to observe any signature before getting the validity. This is because if the current signature results in a conflict, then we damn well want to take that into account. */ if (sig) { err = tofu_register_signature (ctrl, main_pk, user_id_list, sig->digest, sig->digest_len, sig->timestamp, "unknown"); if (err) { log_error ("TOFU: error registering signature: %s\n", gpg_strerror (err)); tofu_validity = TRUST_UNKNOWN; } } if (! err) tofu_validity = tofu_get_validity (ctrl, main_pk, user_id_list, may_ask); free_strlist (user_id_list); release_kbnode (kb); } #endif /*USE_TOFU*/ if (opt.trust_model == TM_TOFU_PGP || opt.trust_model == TM_CLASSIC || opt.trust_model == TM_PGP) { err = read_trust_record (main_pk, &trec); if (err && gpg_err_code (err) != GPG_ERR_NOT_FOUND) { tdbio_invalid (); return 0; } if (gpg_err_code (err) == GPG_ERR_NOT_FOUND) { /* No record found. */ validity = TRUST_UNKNOWN; goto leave; } /* Loop over all user IDs */ recno = trec.r.trust.validlist; validity = 0; while (recno) { read_record (recno, &vrec, RECTYPE_VALID); if(uid) { /* If a user ID is given we return the validity for that user ID ONLY. If the namehash is not found, then there is no validity at all (i.e. the user ID wasn't signed). */ if(memcmp(vrec.r.valid.namehash,uid->namehash,20)==0) { validity=(vrec.r.valid.validity & TRUST_MASK); break; } } else { /* If no user ID is given, we take the maximum validity over all user IDs */ if (validity < (vrec.r.valid.validity & TRUST_MASK)) validity = (vrec.r.valid.validity & TRUST_MASK); } recno = vrec.r.valid.next; } if ((trec.r.trust.ownertrust & TRUST_FLAG_DISABLED)) { validity |= TRUST_FLAG_DISABLED; pk->flags.disabled = 1; } else pk->flags.disabled = 0; pk->flags.disabled_valid = 1; } leave: #ifdef USE_TOFU validity = tofu_wot_trust_combine (tofu_validity, validity); #else /*!USE_TOFU*/ validity &= TRUST_MASK; if (validity == TRUST_NEVER) /* TRUST_NEVER trumps everything else. */ validity |= TRUST_NEVER; if (validity == TRUST_EXPIRED) /* TRUST_EXPIRED trumps everything but TRUST_NEVER. */ validity |= TRUST_EXPIRED; #endif /*!USE_TOFU*/ if (opt.trust_model != TM_TOFU && pending_check_trustdb) validity |= TRUST_FLAG_PENDING_CHECK; return validity; } static void get_validity_counts (PKT_public_key *pk, PKT_user_id *uid) { TRUSTREC trec, vrec; ulong recno; if(pk==NULL || uid==NULL) BUG(); namehash_from_uid(uid); uid->help_marginal_count=uid->help_full_count=0; init_trustdb (); if(read_trust_record (pk, &trec)) return; /* loop over all user IDs */ recno = trec.r.trust.validlist; while (recno) { read_record (recno, &vrec, RECTYPE_VALID); if(memcmp(vrec.r.valid.namehash,uid->namehash,20)==0) { uid->help_marginal_count=vrec.r.valid.marginal_count; uid->help_full_count=vrec.r.valid.full_count; /* es_printf("Fetched marginal %d, full %d\n",uid->help_marginal_count,uid->help_full_count); */ break; } recno = vrec.r.valid.next; } } void list_trust_path( const char *username ) { (void)username; } /**************** * Enumerate all keys, which are needed to build all trust paths for * the given key. This function does not return the key itself or * the ultimate key (the last point in cerificate chain). Only * certificate chains which ends up at an ultimately trusted key * are listed. If ownertrust or validity is not NULL, the corresponding * value for the returned LID is also returned in these variable(s). * * 1) create a void pointer and initialize it to NULL * 2) pass this void pointer by reference to this function. * Set lid to the key you want to enumerate and pass it by reference. * 3) call this function as long as it does not return -1 * to indicate EOF. LID does contain the next key used to build the web * 4) Always call this function a last time with LID set to NULL, * so that it can free its context. * * Returns: -1 on EOF or the level of the returned LID */ int enum_cert_paths( void **context, ulong *lid, unsigned *ownertrust, unsigned *validity ) { (void)context; (void)lid; (void)ownertrust; (void)validity; return -1; } /**************** * Print the current path */ void enum_cert_paths_print (void **context, FILE *fp, int refresh, ulong selected_lid) { (void)context; (void)fp; (void)refresh; (void)selected_lid; } /**************************************** *********** NEW NEW NEW **************** ****************************************/ static int ask_ownertrust (ctrl_t ctrl, u32 *kid, int minimum) { PKT_public_key *pk; int rc; int ot; pk = xmalloc_clear (sizeof *pk); rc = get_pubkey (pk, kid); if (rc) { log_error (_("public key %s not found: %s\n"), keystr(kid), gpg_strerror (rc) ); return TRUST_UNKNOWN; } if(opt.force_ownertrust) { log_info("force trust for key %s to %s\n", keystr(kid),trust_value_to_string(opt.force_ownertrust)); tdb_update_ownertrust (pk, opt.force_ownertrust); ot=opt.force_ownertrust; } else { ot=edit_ownertrust (ctrl, pk, 0); if(ot>0) ot = tdb_get_ownertrust (pk); else if(ot==0) ot = minimum?minimum:TRUST_UNDEFINED; else ot = -1; /* quit */ } free_public_key( pk ); return ot; } static void mark_keyblock_seen (KeyHashTable tbl, KBNODE node) { for ( ;node; node = node->next ) if (node->pkt->pkttype == PKT_PUBLIC_KEY || node->pkt->pkttype == PKT_PUBLIC_SUBKEY) { u32 aki[2]; keyid_from_pk (node->pkt->pkt.public_key, aki); add_key_hash_table (tbl, aki); } } static void dump_key_array (int depth, struct key_array *keys) { struct key_array *kar; for (kar=keys; kar->keyblock; kar++) { KBNODE node = kar->keyblock; u32 kid[2]; keyid_from_pk(node->pkt->pkt.public_key, kid); es_printf ("%d:%08lX%08lX:K::%c::::\n", depth, (ulong)kid[0], (ulong)kid[1], '?'); for (; node; node = node->next) { if (node->pkt->pkttype == PKT_USER_ID) { int len = node->pkt->pkt.user_id->len; if (len > 30) len = 30; es_printf ("%d:%08lX%08lX:U:::%c:::", depth, (ulong)kid[0], (ulong)kid[1], (node->flag & 4)? 'f': (node->flag & 2)? 'm': (node->flag & 1)? 'q':'-'); es_write_sanitized (es_stdout, node->pkt->pkt.user_id->name, len, ":", NULL); es_putc (':', es_stdout); es_putc ('\n', es_stdout); } } } } static void store_validation_status (int depth, KBNODE keyblock, KeyHashTable stored) { KBNODE node; int status; int any = 0; for (node=keyblock; node; node = node->next) { if (node->pkt->pkttype == PKT_USER_ID) { PKT_user_id *uid = node->pkt->pkt.user_id; if (node->flag & 4) status = TRUST_FULLY; else if (node->flag & 2) status = TRUST_MARGINAL; else if (node->flag & 1) status = TRUST_UNDEFINED; else status = 0; if (status) { update_validity (keyblock->pkt->pkt.public_key, uid, depth, status); mark_keyblock_seen(stored,keyblock); any = 1; } } } if (any) do_sync (); } /* Returns a sanitized copy of the regexp (which might be "", but not NULL). */ #ifndef DISABLE_REGEX static char * sanitize_regexp(const char *old) { size_t start=0,len=strlen(old),idx=0; int escaped=0,standard_bracket=0; char *new=xmalloc((len*2)+1); /* enough to \-escape everything if we have to */ /* There are basically two commonly-used regexps here. GPG and most versions of PGP use "<[^>]+[@.]example\.com>$" and PGP (9) command line uses "example.com" (i.e. whatever the user specfies, and we can't expect users know to use "\." instead of "."). So here are the rules: we're allowed to start with "<[^>]+[@.]" and end with ">$" or start and end with nothing. In between, the only legal regex character is ".", and everything else gets escaped. Part of the gotcha here is that some regex packages allow more than RFC-4880 requires. For example, 4880 has no "{}" operator, but GNU regex does. Commenting removes these operators from consideration. A possible future enhancement is to use commenting to effectively back off a given regex to the Henry Spencer syntax in 4880. -dshaw */ /* Are we bracketed between "<[^>]+[@.]" and ">$" ? */ if(len>=12 && strncmp(old,"<[^>]+[@.]",10)==0 && old[len-2]=='>' && old[len-1]=='$') { strcpy(new,"<[^>]+[@.]"); idx=strlen(new); standard_bracket=1; start+=10; len-=2; } /* Walk the remaining characters and ensure that everything that is left is not an operational regex character. */ for(;start$", then it was escaping the ">" and is fine. If the regexp actually ended with the bare "\", then it's an illegal regexp and regcomp should kick it out. */ if(standard_bracket) strcat(new,">$"); return new; } #endif /*!DISABLE_REGEX*/ /* Used by validate_one_keyblock to confirm a regexp within a trust signature. Returns 1 for match, and 0 for no match or regex error. */ static int check_regexp(const char *expr,const char *string) { #ifdef DISABLE_REGEX (void)expr; (void)string; /* When DISABLE_REGEX is defined, assume all regexps do not match. */ return 0; #else int ret; char *regexp; regexp=sanitize_regexp(expr); #ifdef __riscos__ ret=riscos_check_regexp(expr, string, DBG_TRUST); #else { regex_t pat; ret=regcomp(&pat,regexp,REG_ICASE|REG_NOSUB|REG_EXTENDED); if(ret==0) { ret=regexec(&pat,string,0,NULL,0); regfree(&pat); ret=(ret==0); } } #endif if(DBG_TRUST) log_debug("regexp '%s' ('%s') on '%s': %s\n", regexp,expr,string,ret==0?"YES":"NO"); xfree(regexp); return ret; #endif } /* * Return true if the key is signed by one of the keys in the given * key ID list. User IDs with a valid signature are marked by node * flags as follows: * flag bit 0: There is at least one signature * 1: There is marginal confidence that this is a legitimate uid * 2: There is full confidence that this is a legitimate uid. * 8: Used for internal purposes. * 9: Ditto (in mark_usable_uid_certs()) * 10: Ditto (ditto) * This function assumes that all kbnode flags are cleared on entry. */ static int validate_one_keyblock (KBNODE kb, struct key_item *klist, u32 curtime, u32 *next_expire) { struct key_item *kr; KBNODE node, uidnode=NULL; PKT_user_id *uid=NULL; PKT_public_key *pk = kb->pkt->pkt.public_key; u32 main_kid[2]; int issigned=0, any_signed = 0; keyid_from_pk(pk, main_kid); for (node=kb; node; node = node->next) { /* A bit of discussion here: is it better for the web of trust to be built among only self-signed uids? On the one hand, a self-signed uid is a statement that the key owner definitely intended that uid to be there, but on the other hand, a signed (but not self-signed) uid does carry trust, of a sort, even if it is a statement being made by people other than the key owner "through" the uids on the key owner's key. I'm going with the latter. However, if the user ID was explicitly revoked, or passively allowed to expire, that should stop validity through the user ID until it is resigned. -dshaw */ if (node->pkt->pkttype == PKT_USER_ID && !node->pkt->pkt.user_id->is_revoked && !node->pkt->pkt.user_id->is_expired) { if (uidnode && issigned) { if (uid->help_full_count >= opt.completes_needed || uid->help_marginal_count >= opt.marginals_needed ) uidnode->flag |= 4; else if (uid->help_full_count || uid->help_marginal_count) uidnode->flag |= 2; uidnode->flag |= 1; any_signed = 1; } uidnode = node; uid=uidnode->pkt->pkt.user_id; /* If the selfsig is going to expire... */ if(uid->expiredate && uid->expiredate<*next_expire) *next_expire = uid->expiredate; issigned = 0; get_validity_counts(pk,uid); mark_usable_uid_certs (kb, uidnode, main_kid, klist, curtime, next_expire); } else if (node->pkt->pkttype == PKT_SIGNATURE && (node->flag & (1<<8)) && uid) { /* Note that we are only seeing unrevoked sigs here */ PKT_signature *sig = node->pkt->pkt.signature; kr = is_in_klist (klist, sig); /* If the trust_regexp does not match, it's as if the sig did not exist. This is safe for non-trust sigs as well since we don't accept a regexp on the sig unless it's a trust sig. */ if (kr && (!kr->trust_regexp || !(opt.trust_model == TM_PGP || opt.trust_model == TM_TOFU_PGP) || (uidnode && check_regexp(kr->trust_regexp, uidnode->pkt->pkt.user_id->name)))) { /* Are we part of a trust sig chain? We always favor the latest trust sig, rather than the greater or lesser trust sig or value. I could make a decent argument for any of these cases, but this seems to be what PGP does, and I'd like to be compatible. -dms */ if ((opt.trust_model == TM_PGP || opt.trust_model == TM_TOFU_PGP) && sig->trust_depth && pk->trust_timestamp <= sig->timestamp) { unsigned char depth; /* If the depth on the signature is less than the chain currently has, then use the signature depth so we don't increase the depth beyond what the signer wanted. If the depth on the signature is more than the chain currently has, then use the chain depth so we use as much of the signature depth as the chain will permit. An ultimately trusted signature can restart the depth to whatever level it likes. */ if (sig->trust_depth < kr->trust_depth || kr->ownertrust == TRUST_ULTIMATE) depth = sig->trust_depth; else depth = kr->trust_depth; if (depth) { if(DBG_TRUST) log_debug ("trust sig on %s, sig depth is %d," " kr depth is %d\n", uidnode->pkt->pkt.user_id->name, sig->trust_depth, kr->trust_depth); /* If we got here, we know that: this is a trust sig. it's a newer trust sig than any previous trust sig on this key (not uid). it is legal in that it was either generated by an ultimate key, or a key that was part of a trust chain, and the depth does not violate the original trust sig. if there is a regexp attached, it matched successfully. */ if (DBG_TRUST) log_debug ("replacing trust value %d with %d and " "depth %d with %d\n", pk->trust_value,sig->trust_value, pk->trust_depth,depth); pk->trust_value = sig->trust_value; pk->trust_depth = depth-1; /* If the trust sig contains a regexp, record it on the pk for the next round. */ if (sig->trust_regexp) pk->trust_regexp = sig->trust_regexp; } } if (kr->ownertrust == TRUST_ULTIMATE) uid->help_full_count = opt.completes_needed; else if (kr->ownertrust == TRUST_FULLY) uid->help_full_count++; else if (kr->ownertrust == TRUST_MARGINAL) uid->help_marginal_count++; issigned = 1; } } } if (uidnode && issigned) { if (uid->help_full_count >= opt.completes_needed || uid->help_marginal_count >= opt.marginals_needed ) uidnode->flag |= 4; else if (uid->help_full_count || uid->help_marginal_count) uidnode->flag |= 2; uidnode->flag |= 1; any_signed = 1; } return any_signed; } static int search_skipfnc (void *opaque, u32 *kid, int dummy_uid_no) { (void)dummy_uid_no; return test_key_hash_table ((KeyHashTable)opaque, kid); } /* * Scan all keys and return a key_array of all suitable keys from * kllist. The caller has to pass keydb handle so that we don't use * to create our own. Returns either a key_array or NULL in case of * an error. No results found are indicated by an empty array. * Caller hast to release the returned array. */ static struct key_array * validate_key_list (KEYDB_HANDLE hd, KeyHashTable full_trust, struct key_item *klist, u32 curtime, u32 *next_expire) { KBNODE keyblock = NULL; struct key_array *keys = NULL; size_t nkeys, maxkeys; int rc; KEYDB_SEARCH_DESC desc; maxkeys = 1000; keys = xmalloc ((maxkeys+1) * sizeof *keys); nkeys = 0; rc = keydb_search_reset (hd); if (rc) { log_error ("keydb_search_reset failed: %s\n", gpg_strerror (rc)); xfree (keys); return NULL; } memset (&desc, 0, sizeof desc); desc.mode = KEYDB_SEARCH_MODE_FIRST; desc.skipfnc = search_skipfnc; desc.skipfncvalue = full_trust; rc = keydb_search (hd, &desc, 1, NULL); if (gpg_err_code (rc) == GPG_ERR_NOT_FOUND) { keys[nkeys].keyblock = NULL; return keys; } if (rc) { log_error ("keydb_search(first) failed: %s\n", gpg_strerror (rc)); goto die; } desc.mode = KEYDB_SEARCH_MODE_NEXT; /* change mode */ do { PKT_public_key *pk; rc = keydb_get_keyblock (hd, &keyblock); if (rc) { log_error ("keydb_get_keyblock failed: %s\n", gpg_strerror (rc)); goto die; } if ( keyblock->pkt->pkttype != PKT_PUBLIC_KEY) { log_debug ("ooops: invalid pkttype %d encountered\n", keyblock->pkt->pkttype); dump_kbnode (keyblock); release_kbnode(keyblock); continue; } /* prepare the keyblock for further processing */ merge_keys_and_selfsig (keyblock); clear_kbnode_flags (keyblock); pk = keyblock->pkt->pkt.public_key; if (pk->has_expired || pk->flags.revoked) { /* it does not make sense to look further at those keys */ mark_keyblock_seen (full_trust, keyblock); } else if (validate_one_keyblock (keyblock, klist, curtime, next_expire)) { KBNODE node; if (pk->expiredate && pk->expiredate >= curtime && pk->expiredate < *next_expire) *next_expire = pk->expiredate; if (nkeys == maxkeys) { maxkeys += 1000; keys = xrealloc (keys, (maxkeys+1) * sizeof *keys); } keys[nkeys++].keyblock = keyblock; /* Optimization - if all uids are fully trusted, then we never need to consider this key as a candidate again. */ for (node=keyblock; node; node = node->next) if (node->pkt->pkttype == PKT_USER_ID && !(node->flag & 4)) break; if(node==NULL) mark_keyblock_seen (full_trust, keyblock); keyblock = NULL; } release_kbnode (keyblock); keyblock = NULL; } while (!(rc = keydb_search (hd, &desc, 1, NULL))); if (rc && gpg_err_code (rc) != GPG_ERR_NOT_FOUND) { log_error ("keydb_search_next failed: %s\n", gpg_strerror (rc)); goto die; } keys[nkeys].keyblock = NULL; return keys; die: keys[nkeys].keyblock = NULL; release_key_array (keys); return NULL; } /* Caller must sync */ static void reset_trust_records(void) { TRUSTREC rec; ulong recnum; int count = 0, nreset = 0; for (recnum=1; !tdbio_read_record (recnum, &rec, 0); recnum++ ) { if(rec.rectype==RECTYPE_TRUST) { count++; if(rec.r.trust.min_ownertrust) { rec.r.trust.min_ownertrust=0; write_record(&rec); } } else if(rec.rectype==RECTYPE_VALID && ((rec.r.valid.validity&TRUST_MASK) || rec.r.valid.marginal_count || rec.r.valid.full_count)) { rec.r.valid.validity &= ~TRUST_MASK; rec.r.valid.marginal_count=rec.r.valid.full_count=0; nreset++; write_record(&rec); } } if (opt.verbose) { log_info (ngettext("%d key processed", "%d keys processed", count), count); log_printf (ngettext(" (%d validity count cleared)\n", " (%d validity counts cleared)\n", nreset), nreset); } } /* * Run the key validation procedure. * * This works this way: * Step 1: Find all ultimately trusted keys (UTK). * mark them all as seen and put them into klist. * Step 2: loop max_cert_times * Step 3: if OWNERTRUST of any key in klist is undefined * ask user to assign ownertrust * Step 4: Loop over all keys in the keyDB which are not marked seen * Step 5: if key is revoked or expired * mark key as seen * continue loop at Step 4 * Step 6: For each user ID of that key signed by a key in klist * Calculate validity by counting trusted signatures. * Set validity of user ID * Step 7: If any signed user ID was found * mark key as seen * End Loop * Step 8: Build a new klist from all fully trusted keys from step 6 * End Loop * Ready * */ static int validate_keys (ctrl_t ctrl, int interactive) { int rc = 0; int quit=0; struct key_item *klist = NULL; struct key_item *k; struct key_array *keys = NULL; struct key_array *kar; KEYDB_HANDLE kdb = NULL; KBNODE node; int depth; int ot_unknown, ot_undefined, ot_never, ot_marginal, ot_full, ot_ultimate; KeyHashTable stored,used,full_trust; u32 start_time, next_expire; /* Make sure we have all sigs cached. TODO: This is going to require some architectural re-thinking, as it is agonizingly slow. Perhaps combine this with reset_trust_records(), or only check the caches on keys that are actually involved in the web of trust. */ keydb_rebuild_caches(0); kdb = keydb_new (); if (!kdb) return gpg_error_from_syserror (); start_time = make_timestamp (); next_expire = 0xffffffff; /* set next expire to the year 2106 */ stored = new_key_hash_table (); used = new_key_hash_table (); full_trust = new_key_hash_table (); reset_trust_records(); /* Fixme: Instead of always building a UTK list, we could just build it * here when needed */ if (!utk_list) { if (!opt.quiet) log_info (_("no ultimately trusted keys found\n")); goto leave; } /* mark all UTKs as used and fully_trusted and set validity to ultimate */ for (k=utk_list; k; k = k->next) { KBNODE keyblock; PKT_public_key *pk; keyblock = get_pubkeyblock (k->kid); if (!keyblock) { log_error (_("public key of ultimately" " trusted key %s not found\n"), keystr(k->kid)); continue; } mark_keyblock_seen (used, keyblock); mark_keyblock_seen (stored, keyblock); mark_keyblock_seen (full_trust, keyblock); pk = keyblock->pkt->pkt.public_key; for (node=keyblock; node; node = node->next) { if (node->pkt->pkttype == PKT_USER_ID) update_validity (pk, node->pkt->pkt.user_id, 0, TRUST_ULTIMATE); } if ( pk->expiredate && pk->expiredate >= start_time && pk->expiredate < next_expire) next_expire = pk->expiredate; release_kbnode (keyblock); do_sync (); } if (opt.trust_model == TM_TOFU) /* In the TOFU trust model, we only need to save the ultimately trusted keys. */ goto leave; klist = utk_list; if (!opt.quiet) log_info ("marginals needed: %d completes needed: %d trust model: %s\n", opt.marginals_needed, opt.completes_needed, trust_model_string (opt.trust_model)); for (depth=0; depth < opt.max_cert_depth; depth++) { int valids=0,key_count; /* See whether we should assign ownertrust values to the keys in klist. */ ot_unknown = ot_undefined = ot_never = 0; ot_marginal = ot_full = ot_ultimate = 0; for (k=klist; k; k = k->next) { int min=0; /* 120 and 60 are as per RFC2440 */ if(k->trust_value>=120) min=TRUST_FULLY; else if(k->trust_value>=60) min=TRUST_MARGINAL; if(min!=k->min_ownertrust) update_min_ownertrust(k->kid,min); if (interactive && k->ownertrust == TRUST_UNKNOWN) { k->ownertrust = ask_ownertrust (ctrl, k->kid,min); if (k->ownertrust == (unsigned int)(-1)) { quit=1; goto leave; } } /* This can happen during transition from an old trustdb before trust sigs. It can also happen if a user uses two different versions of GnuPG or changes the --trust-model setting. */ if(k->ownertrustkid[0],(ulong)k->kid[1], trust_value_to_string(k->ownertrust), trust_value_to_string(min)); k->ownertrust=min; } if (k->ownertrust == TRUST_UNKNOWN) ot_unknown++; else if (k->ownertrust == TRUST_UNDEFINED) ot_undefined++; else if (k->ownertrust == TRUST_NEVER) ot_never++; else if (k->ownertrust == TRUST_MARGINAL) ot_marginal++; else if (k->ownertrust == TRUST_FULLY) ot_full++; else if (k->ownertrust == TRUST_ULTIMATE) ot_ultimate++; valids++; } /* Find all keys which are signed by a key in kdlist */ keys = validate_key_list (kdb, full_trust, klist, start_time, &next_expire); if (!keys) { log_error ("validate_key_list failed\n"); rc = GPG_ERR_GENERAL; goto leave; } for (key_count=0, kar=keys; kar->keyblock; kar++, key_count++) ; /* Store the calculated valididation status somewhere */ if (opt.verbose > 1 && DBG_TRUST) dump_key_array (depth, keys); for (kar=keys; kar->keyblock; kar++) store_validation_status (depth, kar->keyblock, stored); if (!opt.quiet) log_info (_("depth: %d valid: %3d signed: %3d" " trust: %d-, %dq, %dn, %dm, %df, %du\n"), depth, valids, key_count, ot_unknown, ot_undefined, ot_never, ot_marginal, ot_full, ot_ultimate ); /* Build a new kdlist from all fully valid keys in KEYS */ if (klist != utk_list) release_key_items (klist); klist = NULL; for (kar=keys; kar->keyblock; kar++) { for (node=kar->keyblock; node; node = node->next) { if (node->pkt->pkttype == PKT_USER_ID && (node->flag & 4)) { u32 kid[2]; /* have we used this key already? */ keyid_from_pk (kar->keyblock->pkt->pkt.public_key, kid); if(test_key_hash_table(used,kid)==0) { /* Normally we add both the primary and subkey ids to the hash via mark_keyblock_seen, but since we aren't using this hash as a skipfnc, that doesn't matter here. */ add_key_hash_table (used,kid); k = new_key_item (); k->kid[0]=kid[0]; k->kid[1]=kid[1]; k->ownertrust = (tdb_get_ownertrust (kar->keyblock->pkt->pkt.public_key) & TRUST_MASK); k->min_ownertrust = tdb_get_min_ownertrust (kar->keyblock->pkt->pkt.public_key); k->trust_depth= kar->keyblock->pkt->pkt.public_key->trust_depth; k->trust_value= kar->keyblock->pkt->pkt.public_key->trust_value; if(kar->keyblock->pkt->pkt.public_key->trust_regexp) k->trust_regexp= xstrdup(kar->keyblock->pkt-> pkt.public_key->trust_regexp); k->next = klist; klist = k; break; } } } } release_key_array (keys); keys = NULL; if (!klist) break; /* no need to dive in deeper */ } leave: keydb_release (kdb); release_key_array (keys); if (klist != utk_list) release_key_items (klist); release_key_hash_table (full_trust); release_key_hash_table (used); release_key_hash_table (stored); if (!rc && !quit) /* mark trustDB as checked */ { int rc2; if (next_expire == 0xffffffff || next_expire < start_time ) tdbio_write_nextcheck (0); else { tdbio_write_nextcheck (next_expire); if (!opt.quiet) log_info (_("next trustdb check due at %s\n"), strtimestamp (next_expire)); } rc2 = tdbio_update_version_record (); if (rc2) { log_error (_("unable to update trustdb version record: " "write failed: %s\n"), gpg_strerror (rc2)); tdbio_invalid (); } do_sync (); pending_check_trustdb = 0; } return rc; } diff --git a/g10/trustdb.h b/g10/trustdb.h index 77aa79da6..45ecc56ab 100644 --- a/g10/trustdb.h +++ b/g10/trustdb.h @@ -1,166 +1,169 @@ /* trustdb.h - Trust database * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, * 2005, 2012 Free Software Foundation, Inc. * * This file is part of GnuPG. * * GnuPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * GnuPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #ifndef G10_TRUSTDB_H #define G10_TRUSTDB_H /* Trust values must be sorted in ascending order! */ #define TRUST_MASK 15 #define TRUST_UNKNOWN 0 /* o: not yet calculated/assigned */ #define TRUST_EXPIRED 1 /* e: calculation may be invalid */ #define TRUST_UNDEFINED 2 /* q: not enough information for calculation */ #define TRUST_NEVER 3 /* n: never trust this pubkey */ #define TRUST_MARGINAL 4 /* m: marginally trusted */ #define TRUST_FULLY 5 /* f: fully trusted */ #define TRUST_ULTIMATE 6 /* u: ultimately trusted */ /* Trust values not covered by the mask. */ #define TRUST_FLAG_REVOKED 32 /* r: revoked */ #define TRUST_FLAG_SUB_REVOKED 64 /* r: revoked but for subkeys */ #define TRUST_FLAG_DISABLED 128 /* d: key/uid disabled */ #define TRUST_FLAG_PENDING_CHECK 256 /* a check-trustdb is pending */ #define TRUST_FLAG_TOFU_BASED 512 /* The trust value is based on * the TOFU information. */ /* Private value used in tofu.c - must be different from the trust values. */ #define _tofu_GET_TRUST_ERROR 100 /* Length of the hash used to select UIDs in keyedit.c. */ #define NAMEHASH_LEN 20 /* * A structure to store key identification as well as some stuff needed * for validation */ struct key_item { struct key_item *next; unsigned int ownertrust,min_ownertrust; byte trust_depth; byte trust_value; char *trust_regexp; u32 kid[2]; }; /* * Check whether the signature SIG is in the klist K. */ static inline struct key_item * is_in_klist (struct key_item *k, PKT_signature *sig) { for (; k; k = k->next) { if (k->kid[0] == sig->keyid[0] && k->kid[1] == sig->keyid[1]) return k; } return NULL; } /*-- trust.c --*/ int cache_disabled_value (PKT_public_key *pk); void register_trusted_keyid (u32 *keyid); void register_trusted_key (const char *string); const char *trust_value_to_string (unsigned int value); int string_to_trust_value (const char *str); const char *uid_trust_string_fixed (ctrl_t ctrl, PKT_public_key *key, PKT_user_id *uid); unsigned int get_ownertrust (PKT_public_key *pk); void update_ownertrust (PKT_public_key *pk, unsigned int new_trust); int clear_ownertrusts (PKT_public_key *pk); void revalidation_mark (void); void check_trustdb_stale (ctrl_t ctrl); void check_or_update_trustdb (ctrl_t ctrl); unsigned int get_validity (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid, PKT_signature *sig, int may_ask); int get_validity_info (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid); const char *get_validity_string (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid); void mark_usable_uid_certs (kbnode_t keyblock, kbnode_t uidnode, u32 *main_kid, struct key_item *klist, u32 curtime, u32 *next_expire); void clean_one_uid (kbnode_t keyblock, kbnode_t uidnode, int noisy, int self_only, int *uids_cleaned, int *sigs_cleaned); void clean_key (kbnode_t keyblock, int noisy, int self_only, int *uids_cleaned,int *sigs_cleaned); /*-- trustdb.c --*/ void tdb_register_trusted_keyid (u32 *keyid); void tdb_register_trusted_key (const char *string); /* Returns whether KID is on the list of ultimately trusted keys. */ int tdb_keyid_is_utk (u32 *kid); +/* Return the list of ultimately trusted keys. The caller must not + * modify this list nor must it free the list. */ +struct key_item *tdb_utks (void); void check_trustdb (ctrl_t ctrl); void update_trustdb (ctrl_t ctrl); int setup_trustdb( int level, const char *dbname ); void how_to_fix_the_trustdb (void); const char *trust_model_string (int model); void init_trustdb( void ); void tdb_check_trustdb_stale (ctrl_t ctrl); void sync_trustdb( void ); void tdb_revalidation_mark (void); int trustdb_pending_check(void); void tdb_check_or_update (ctrl_t ctrl); int tdb_cache_disabled_value (PKT_public_key *pk); unsigned int tdb_get_validity_core (ctrl_t ctrl, PKT_public_key *pk, PKT_user_id *uid, PKT_public_key *main_pk, PKT_signature *sig, int may_ask); void list_trust_path( const char *username ); int enum_cert_paths( void **context, ulong *lid, unsigned *ownertrust, unsigned *validity ); void enum_cert_paths_print( void **context, FILE *fp, int refresh, ulong selected_lid ); void read_trust_options(byte *trust_model,ulong *created,ulong *nextcheck, byte *marginals,byte *completes,byte *cert_depth, byte *min_cert_level); unsigned int tdb_get_ownertrust (PKT_public_key *pk); unsigned int tdb_get_min_ownertrust (PKT_public_key *pk); int get_ownertrust_info (PKT_public_key *pk); const char *get_ownertrust_string (PKT_public_key *pk); void tdb_update_ownertrust (PKT_public_key *pk, unsigned int new_trust); int tdb_clear_ownertrusts (PKT_public_key *pk); /*-- tdbdump.c --*/ void list_trustdb (estream_t fp, const char *username); void export_ownertrust(void); void import_ownertrust(const char *fname); /*-- pkclist.c --*/ int edit_ownertrust (ctrl_t ctrl, PKT_public_key *pk, int mode); #endif /*G10_TRUSTDB_H*/ diff --git a/tests/openpgp/tofu.scm b/tests/openpgp/tofu.scm index 2a04d13a2..e1fa00191 100755 --- a/tests/openpgp/tofu.scm +++ b/tests/openpgp/tofu.scm @@ -1,321 +1,342 @@ #!/usr/bin/env gpgscm ;; Copyright (C) 2016 g10 Code GmbH ;; ;; This file is part of GnuPG. ;; ;; GnuPG is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation; either version 3 of the License, or ;; (at your option) any later version. ;; ;; GnuPG is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public License ;; along with this program; if not, see . (load (with-path "defs.scm")) (setup-environment) ;; Redefine GPG without --always-trust and a fixed time. (define GPG `(,(tool 'gpg) --no-permission-warning --faked-system-time=1466684990)) (define GNUPGHOME (getenv "GNUPGHOME")) (if (string=? "" GNUPGHOME) (error "GNUPGHOME not set")) (catch (skip "Tofu not supported") (call-check `(,@GPG --trust-model=tofu --list-config))) (define KEYS '("2183839A" "BC15C85A" "EE37CF96")) ;; Import the test keys. (call-check `(,@GPG --import ,(in-srcdir "tofu-keys.asc"))) ;; Make sure the keys are imported. (for-each (lambda (keyid) (catch (error "Missing key" keyid) (call-check `(,@GPG --list-keys ,keyid)))) KEYS) ;; Get tofu policy for KEYID. Any remaining arguments are simply ;; passed to GPG. ;; ;; This function only supports keys with a single user id. (define (getpolicy keyid . args) (let ((policy (list-ref (assoc "tfs" (gpg-with-colons `(--trust-model=tofu --with-tofu-info ,@args --list-keys ,keyid))) 5))) (unless (member policy '("auto" "good" "unknown" "bad" "ask")) (error "Bad policy:" policy)) policy)) ;; Check that KEYID's tofu policy matches EXPECTED-POLICY. Any ;; remaining arguments are simply passed to GPG. ;; ;; This function only supports keys with a single user id. (define (checkpolicy keyid expected-policy . args) (let ((policy (apply getpolicy `(,keyid ,@args)))) (unless (string=? policy expected-policy) (error keyid ": Expected policy to be" expected-policy "but got" policy)))) ;; Get the trust level for KEYID. Any remaining arguments are simply ;; passed to GPG. ;; ;; This function only supports keys with a single user id. (define (gettrust keyid . args) (let ((trust (list-ref (assoc "pub" (gpg-with-colons `(--trust-model=tofu ,@args --list-keys ,keyid))) 1))) (unless (and (= 1 (string-length trust)) (member (string-ref trust 0) (string->list "oidreqnmfuws-"))) (error "Bad trust value:" trust)) trust)) ;; Check that KEYID's trust level matches EXPECTED-TRUST. Any ;; remaining arguments are simply passed to GPG. ;; ;; This function only supports keys with a single user id. (define (checktrust keyid expected-trust . args) (let ((trust (apply gettrust `(,keyid ,@args)))) (unless (string=? trust expected-trust) (error keyid ": Expected trust to be" expected-trust "but got" trust)))) ;; Set key KEYID's policy to POLICY. Any remaining arguments are ;; passed as options to gpg. (define (setpolicy keyid policy . args) (call-check `(,@GPG --trust-model=tofu ,@args --tofu-policy ,policy ,keyid))) (info "Checking tofu policies and trust...") ;; Carefully remove the TOFU db. (catch '() (unlink (string-append GNUPGHOME "/tofu.db"))) ;; Verify a message. There should be no conflict and the trust ;; policy should be set to auto. (call-check `(,@GPG --trust-model=tofu --verify ,(in-srcdir "tofu-2183839A-1.txt"))) (checkpolicy "2183839A" "auto") ;; Check default trust. (checktrust "2183839A" "m") ;; Trust should be derived lazily. Thus, if the policy is set to ;; auto and we change --tofu-default-policy, then the trust should ;; change as well. Try it. (checktrust "2183839A" "f" '--tofu-default-policy=good) (checktrust "2183839A" "-" '--tofu-default-policy=unknown) (checktrust "2183839A" "n" '--tofu-default-policy=bad) ;; Change the policy to something other than auto and make sure the ;; policy and the trust are correct. (for-each-p "Setting a fixed policy..." (lambda (policy) (let ((expected-trust (cond ((string=? "good" policy) "f") ((string=? "unknown" policy) "-") (else "n")))) (setpolicy "2183839A" policy) ;; Since we have a fixed policy, the trust level shouldn't ;; change if we change the default policy. (for-each-p "" (lambda (default-policy) (checkpolicy "2183839A" policy '--tofu-default-policy default-policy) (checktrust "2183839A" expected-trust '--tofu-default-policy default-policy)) '("auto" "good" "unknown" "bad" "ask")))) '("good" "unknown" "bad")) ;; At the end, 2183839A's policy should be bad. (checkpolicy "2183839A" "bad") ;; BC15C85A and 2183839A conflict. A policy setting of "auto" ;; (BC15C85A's state) will result in an effective policy of ask. But, ;; a policy setting of "bad" will result in an effective policy of ;; bad. (setpolicy "BC15C85A" "auto") (checkpolicy "BC15C85A" "ask") (checkpolicy "2183839A" "bad") ;; EE37CF96, 2183839A, and BC15C85A conflict. We change BC15C85A's ;; policy to auto and leave 2183839A's policy at bad. This conflict ;; should cause BC15C85A's policy to be changed to ask (since it is ;; auto), but not affect 2183839A's policy. (setpolicy "BC15C85A" "auto") (checkpolicy "BC15C85A" "ask") (call-check `(,@GPG --trust-model=tofu --verify ,(in-srcdir "tofu-EE37CF96-1.txt"))) (checkpolicy "BC15C85A" "ask") (checkpolicy "2183839A" "bad") (checkpolicy "EE37CF96" "ask") ;; Check that we detect the following attack: ;; ;; Alice and Bob each have a key and cross sign them. Bob then adds a ;; new user id, "Alice". TOFU should now detect a conflict, because ;; Alice only signed Bob's "Bob" user id. (display "Checking cross sigs...\n") (define GPG `(,(tool 'gpg) --no-permission-warning --faked-system-time=1476304861)) ;; Carefully remove the TOFU db. (catch '() (unlink (string-append GNUPGHOME "/tofu.db"))) (define DIR "tofu/cross-sigs") ;; The test keys. (define KEYA "1938C3A0E4674B6C217AC0B987DB2814EC38277E") (define KEYB "DC463A16E42F03240D76E8BA8B48C6BD871C2247") (define KEYIDA (substring KEYA (- (string-length KEYA) 8))) (define KEYIDB (substring KEYB (- (string-length KEYB) 8))) (define (verify-messages) (for-each (lambda (key) (for-each (lambda (i) (let ((fn (in-srcdir DIR (string-append key "-" i ".txt")))) (call-check `(,@GPG --trust-model=tofu --verify ,fn)))) (list "1" "2"))) (list KEYIDA KEYIDB))) ;; Import the public keys. (display " > Two keys. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDA "-1.gpg")))) (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-1.gpg")))) ;; Make sure the tofu engine registers the keys. (verify-messages) (display "<\n") ;; Since there is no conflict, the policy should be auto. (checkpolicy KEYA "auto") (checkpolicy KEYB "auto") ;; Import the cross sigs. (display " > Adding cross signatures. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDA "-2.gpg")))) (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-2.gpg")))) (verify-messages) (display "<\n") ;; There is still no conflict, so the policy shouldn't have changed. (checkpolicy KEYA "auto") (checkpolicy KEYB "auto") ;; Import the conflicting user id. (display " > Adding conflicting user id. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-3.gpg")))) (verify-messages) (display "<\n") (checkpolicy KEYA "ask") (checkpolicy KEYB "ask") ;; Import Alice's signature on the conflicting user id. Since there ;; is now a cross signature, we should revert to the default policy. (display " > Adding cross signature on user id. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-4.gpg")))) (verify-messages) (display "<\n") (checkpolicy KEYA "auto") (checkpolicy KEYB "auto") ;; Remove the keys. (call-check `(,@GPG --delete-key ,KEYA)) (call-check `(,@GPG --delete-key ,KEYB)) ;; Check that we detect the following attack: ;; ;; Alice has an ultimately trusted key and she signs Bob's key. Then ;; Bob adds a new user id, "Alice". TOFU should now detect a ;; conflict, because Alice only signed Bob's "Bob" user id. +;; +;; +;; The Alice key: +;; pub rsa2048 2016-10-11 [SC] +;; 1938C3A0E4674B6C217AC0B987DB2814EC38277E +;; uid [ultimate] Spy Cow +;; sub rsa2048 2016-10-11 [E] +;; +;; The Bob key: +;; +;; pub rsa2048 2016-10-11 [SC] +;; DC463A16E42F03240D76E8BA8B48C6BD871C2247 +;; uid [ full ] Spy R. Cow +;; uid [ full ] Spy R. Cow +;; sub rsa2048 2016-10-11 [E] (display "Checking UTK sigs...\n") (define GPG `(,(tool 'gpg) --no-permission-warning --faked-system-time=1476304861)) ;; Carefully remove the TOFU db. (catch '() (unlink (string-append GNUPGHOME "/tofu.db"))) (define DIR "tofu/cross-sigs") ;; The test keys. (define KEYA "1938C3A0E4674B6C217AC0B987DB2814EC38277E") (define KEYB "DC463A16E42F03240D76E8BA8B48C6BD871C2247") (define KEYIDA (substring KEYA (- (string-length KEYA) 8))) (define KEYIDB (substring KEYB (- (string-length KEYB) 8))) (define (verify-messages) (for-each (lambda (key) (for-each (lambda (i) (let ((fn (in-srcdir DIR (string-append key "-" i ".txt")))) (call-check `(,@GPG --trust-model=tofu --verify ,fn)))) (list "1" "2"))) (list KEYIDA KEYIDB))) ;; Import the public keys. (display " > Two keys. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDA "-1.gpg")))) (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-1.gpg")))) (display "<\n") +(checkpolicy KEYA "auto") +(checkpolicy KEYB "auto") + ;; Import the cross sigs. (display " > Adding cross signatures. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDA "-2.gpg")))) (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-2.gpg")))) (display "<\n") +(checkpolicy KEYA "auto") +(checkpolicy KEYB "auto") + ;; Make KEYA ultimately trusted. (display (string-append " > Marking " KEYA " as ultimately trusted. ")) (pipe:do (pipe:echo (string-append KEYA ":6:\n")) (pipe:gpg `(--import-ownertrust))) (display "<\n") ;; An ultimately trusted key's policy is good. (checkpolicy KEYA "good") ;; A key signed by a UTK for which there is no policy gets the default ;; policy of good. (checkpolicy KEYB "good") ;; Import the conflicting user id. (display " > Adding conflicting user id. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-3.gpg")))) (verify-messages) (display "<\n") (checkpolicy KEYA "good") (checkpolicy KEYB "ask") ;; Import Alice's signature on the conflicting user id. (display " > Adding cross signature on user id. ") (call-check `(,@GPG --import ,(in-srcdir DIR (string-append KEYIDB "-4.gpg")))) (verify-messages) (display "<\n") (checkpolicy KEYA "good") (checkpolicy KEYB "good") ;; Remove the keys. (call-check `(,@GPG --delete-key ,KEYA)) (call-check `(,@GPG --delete-key ,KEYB))