diff --git a/sm/verify.c b/sm/verify.c index 6d2f11055..ecc3a7c1f 100644 --- a/sm/verify.c +++ b/sm/verify.c @@ -1,696 +1,727 @@ /* verify.c - Verify a messages signature * Copyright (C) 2001, 2002, 2003, 2007, * 2010 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 #include #include #include #include #include "gpgsm.h" #include #include #include "keydb.h" #include "../common/i18n.h" #include "../common/compliance.h" static char * strtimestamp_r (ksba_isotime_t atime) { char *buffer = xmalloc (15); if (!atime || !*atime) strcpy (buffer, "none"); else sprintf (buffer, "%.4s-%.2s-%.2s", atime, atime+4, atime+6); return buffer; } /* Hash the data for a detached signature. Returns 0 on success. */ static gpg_error_t hash_data (int fd, gcry_md_hd_t md) { gpg_error_t err = 0; estream_t fp; char buffer[4096]; int nread; fp = es_fdopen_nc (fd, "rb"); if (!fp) { err = gpg_error_from_syserror (); log_error ("fdopen(%d) failed: %s\n", fd, gpg_strerror (err)); return err; } do { nread = es_fread (buffer, 1, DIM(buffer), fp); gcry_md_write (md, buffer, nread); } while (nread); if (es_ferror (fp)) { err = gpg_error_from_syserror (); log_error ("read error on fd %d: %s\n", fd, gpg_strerror (err)); } es_fclose (fp); return err; } /* Perform a verify operation. To verify detached signatures, DATA_FD must be different than -1. With OUT_FP given and a non-detached signature, the signed material is written to that stream. */ int gpgsm_verify (ctrl_t ctrl, int in_fd, int data_fd, estream_t out_fp) { int i, rc; gnupg_ksba_io_t b64reader = NULL; gnupg_ksba_io_t b64writer = NULL; ksba_reader_t reader; ksba_writer_t writer = NULL; ksba_cms_t cms = NULL; ksba_stop_reason_t stopreason; ksba_cert_t cert; KEYDB_HANDLE kh; gcry_md_hd_t data_md = NULL; int signer; const char *algoid; int algo; int is_detached; estream_t in_fp = NULL; char *p; audit_set_type (ctrl->audit, AUDIT_TYPE_VERIFY); kh = keydb_new (); if (!kh) { log_error (_("failed to allocate keyDB handle\n")); rc = gpg_error (GPG_ERR_GENERAL); goto leave; } in_fp = es_fdopen_nc (in_fd, "rb"); if (!in_fp) { rc = gpg_error_from_syserror (); log_error ("fdopen() failed: %s\n", strerror (errno)); goto leave; } rc = gnupg_ksba_create_reader (&b64reader, ((ctrl->is_pem? GNUPG_KSBA_IO_PEM : 0) | (ctrl->is_base64? GNUPG_KSBA_IO_BASE64 : 0) | (ctrl->autodetect_encoding? GNUPG_KSBA_IO_AUTODETECT : 0)), in_fp, &reader); if (rc) { log_error ("can't create reader: %s\n", gpg_strerror (rc)); goto leave; } if (out_fp) { rc = gnupg_ksba_create_writer (&b64writer, ((ctrl->create_pem? GNUPG_KSBA_IO_PEM : 0) | (ctrl->create_base64? GNUPG_KSBA_IO_BASE64 : 0)), ctrl->pem_name, out_fp, &writer); if (rc) { log_error ("can't create writer: %s\n", gpg_strerror (rc)); goto leave; } } rc = ksba_cms_new (&cms); if (rc) goto leave; rc = ksba_cms_set_reader_writer (cms, reader, writer); if (rc) { log_error ("ksba_cms_set_reader_writer failed: %s\n", gpg_strerror (rc)); goto leave; } rc = gcry_md_open (&data_md, 0, 0); if (rc) { log_error ("md_open failed: %s\n", gpg_strerror (rc)); goto leave; } if (DBG_HASHING) gcry_md_debug (data_md, "vrfy.data"); audit_log (ctrl->audit, AUDIT_SETUP_READY); is_detached = 0; do { rc = ksba_cms_parse (cms, &stopreason); if (rc) { log_error ("ksba_cms_parse failed: %s\n", gpg_strerror (rc)); goto leave; } if (stopreason == KSBA_SR_NEED_HASH) { is_detached = 1; audit_log (ctrl->audit, AUDIT_DETACHED_SIGNATURE); if (opt.verbose) log_info ("detached signature\n"); } if (stopreason == KSBA_SR_NEED_HASH || stopreason == KSBA_SR_BEGIN_DATA) { audit_log (ctrl->audit, AUDIT_GOT_DATA); /* We are now able to enable the hash algorithms */ for (i=0; (algoid=ksba_cms_get_digest_algo_list (cms, i)); i++) { algo = gcry_md_map_name (algoid); if (!algo) { log_error ("unknown hash algorithm '%s'\n", algoid? algoid:"?"); if (algoid && ( !strcmp (algoid, "1.2.840.113549.1.1.2") ||!strcmp (algoid, "1.2.840.113549.2.2"))) log_info (_("(this is the MD2 algorithm)\n")); audit_log_s (ctrl->audit, AUDIT_BAD_DATA_HASH_ALGO, algoid); } else { if (DBG_X509) log_debug ("enabling hash algorithm %d (%s)\n", algo, algoid? algoid:""); gcry_md_enable (data_md, algo); audit_log_i (ctrl->audit, AUDIT_DATA_HASH_ALGO, algo); } } if (opt.extra_digest_algo) { if (DBG_X509) log_debug ("enabling extra hash algorithm %d\n", opt.extra_digest_algo); gcry_md_enable (data_md, opt.extra_digest_algo); audit_log_i (ctrl->audit, AUDIT_DATA_HASH_ALGO, opt.extra_digest_algo); } if (is_detached) { if (data_fd == -1) { log_info ("detached signature w/o data " "- assuming certs-only\n"); audit_log (ctrl->audit, AUDIT_CERT_ONLY_SIG); } else audit_log_ok (ctrl->audit, AUDIT_DATA_HASHING, hash_data (data_fd, data_md)); } else { ksba_cms_set_hash_function (cms, HASH_FNC, data_md); } } else if (stopreason == KSBA_SR_END_DATA) { /* The data bas been hashed */ audit_log_ok (ctrl->audit, AUDIT_DATA_HASHING, 0); } } while (stopreason != KSBA_SR_READY); if (b64writer) { rc = gnupg_ksba_finish_writer (b64writer); if (rc) { log_error ("write failed: %s\n", gpg_strerror (rc)); audit_log_ok (ctrl->audit, AUDIT_WRITE_ERROR, rc); goto leave; } } if (data_fd != -1 && !is_detached) { log_error ("data given for a non-detached signature\n"); rc = gpg_error (GPG_ERR_CONFLICT); audit_log (ctrl->audit, AUDIT_USAGE_ERROR); goto leave; } for (i=0; (cert=ksba_cms_get_cert (cms, i)); i++) { /* Fixme: it might be better to check the validity of the certificate first before entering it into the DB. This way we would avoid cluttering the DB with invalid certificates. */ audit_log_cert (ctrl->audit, AUDIT_SAVE_CERT, cert, keydb_store_cert (ctrl, cert, 0, NULL)); ksba_cert_release (cert); } cert = NULL; for (signer=0; ; signer++) { char *issuer = NULL; ksba_sexp_t sigval = NULL; ksba_isotime_t sigtime, keyexptime; ksba_sexp_t serial; char *msgdigest = NULL; size_t msgdigestlen; char *ctattr; int sigval_hash_algo; int info_pkalgo; + unsigned int nbits; + int pkalgo; + char *pkalgostr = NULL; + char *pkfpr = NULL; unsigned int verifyflags; rc = ksba_cms_get_issuer_serial (cms, signer, &issuer, &serial); if (!signer && gpg_err_code (rc) == GPG_ERR_NO_DATA && data_fd == -1 && is_detached) { log_info ("certs-only message accepted\n"); rc = 0; break; } if (rc) { if (signer && rc == -1) rc = 0; break; } gpgsm_status (ctrl, STATUS_NEWSIG, NULL); audit_log_i (ctrl->audit, AUDIT_NEW_SIG, signer); if (DBG_X509) { log_debug ("signer %d - issuer: '%s'\n", signer, issuer? issuer:"[NONE]"); log_debug ("signer %d - serial: ", signer); gpgsm_dump_serial (serial); log_printf ("\n"); } if (ctrl->audit) { char *tmpstr = gpgsm_format_sn_issuer (serial, issuer); audit_log_s (ctrl->audit, AUDIT_SIG_NAME, tmpstr); xfree (tmpstr); } rc = ksba_cms_get_signing_time (cms, signer, sigtime); if (gpg_err_code (rc) == GPG_ERR_NO_DATA) *sigtime = 0; else if (rc) { log_error ("error getting signing time: %s\n", gpg_strerror (rc)); *sigtime = 0; /* (we can't encode an error in the time string.) */ } rc = ksba_cms_get_message_digest (cms, signer, &msgdigest, &msgdigestlen); if (!rc) { algoid = ksba_cms_get_digest_algo (cms, signer); algo = gcry_md_map_name (algoid); if (DBG_X509) log_debug ("signer %d - digest algo: %d\n", signer, algo); if (! gcry_md_is_enabled (data_md, algo)) { log_error ("digest algo %d (%s) has not been enabled\n", algo, algoid?algoid:""); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "unsupported"); goto next_signer; } } else if (gpg_err_code (rc) == GPG_ERR_NO_DATA) { assert (!msgdigest); rc = 0; algoid = NULL; algo = 0; } else /* real error */ { audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "error"); break; } rc = ksba_cms_get_sigattr_oids (cms, signer, "1.2.840.113549.1.9.3", &ctattr); if (!rc) { const char *s; if (DBG_X509) log_debug ("signer %d - content-type attribute: %s", signer, ctattr); s = ksba_cms_get_content_oid (cms, 1); if (!s || strcmp (ctattr, s)) { log_error ("content-type attribute does not match " "actual content-type\n"); ksba_free (ctattr); ctattr = NULL; audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } ksba_free (ctattr); ctattr = NULL; } else if (rc != -1) { log_error ("error getting content-type attribute: %s\n", gpg_strerror (rc)); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } rc = 0; sigval = ksba_cms_get_sig_val (cms, signer); if (!sigval) { log_error ("no signature value available\n"); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } sigval_hash_algo = hash_algo_from_sigval (sigval); if (DBG_X509) { log_debug ("signer %d - signature available (sigval hash=%d)", signer, sigval_hash_algo); /*log_printhex(sigval, gcry_sexp_canon_len (sigval, 0, NULL, NULL),*/ /* "sigval "); */ } if (!sigval_hash_algo) sigval_hash_algo = algo; /* Fallback used e.g. with old libksba. */ /* Find the certificate of the signer */ keydb_search_reset (kh); rc = keydb_search_issuer_sn (ctrl, kh, issuer, serial); if (rc) { if (rc == -1) { log_error ("certificate not found\n"); rc = gpg_error (GPG_ERR_NO_PUBKEY); } else log_error ("failed to find the certificate: %s\n", gpg_strerror(rc)); { char numbuf[50]; sprintf (numbuf, "%d", rc); gpgsm_status2 (ctrl, STATUS_ERROR, "verify.findkey", numbuf, NULL); } audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "no-cert"); goto next_signer; } rc = keydb_get_cert (kh, &cert); if (rc) { log_error ("failed to get cert: %s\n", gpg_strerror (rc)); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "error"); goto next_signer; } - /* Check compliance. */ - { - unsigned int nbits; - int pk_algo = gpgsm_get_key_algo_info (cert, &nbits); - - if (! gnupg_pk_is_allowed (opt.compliance, PK_USE_VERIFICATION, - pk_algo, NULL, nbits, NULL)) - { - char kidstr[10+1]; - - snprintf (kidstr, sizeof kidstr, "0x%08lX", - gpgsm_get_short_fingerprint (cert, NULL)); - log_error (_("key %s may not be used for signing in %s mode\n"), - kidstr, - gnupg_compliance_option_string (opt.compliance)); - goto next_signer; - } - - if (! gnupg_digest_is_allowed (opt.compliance, 0, sigval_hash_algo)) - { - log_error (_("digest algorithm '%s' may not be used in %s mode\n"), - gcry_md_algo_name (sigval_hash_algo), - gnupg_compliance_option_string (opt.compliance)); - goto next_signer; - } - - /* Check compliance with CO_DE_VS. */ - if (gnupg_pk_is_compliant (CO_DE_VS, pk_algo, NULL, nbits, NULL) - && gnupg_digest_is_compliant (CO_DE_VS, sigval_hash_algo)) - gpgsm_status (ctrl, STATUS_VERIFICATION_COMPLIANCE_MODE, - gnupg_status_compliance_flag (CO_DE_VS)); - } + pkfpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1); + pkalgostr = gpgsm_pubkey_algo_string (cert, NULL); + pkalgo = gpgsm_get_key_algo_info (cert, &nbits); + /* Print infos about the signature. */ log_info (_("Signature made ")); if (*sigtime) - dump_isotime (sigtime); + { + /* We take the freedom as noted in RFC3339 to use a space + * instead of the :T" delimiter between date and time.. We + * also append a separate UTC instead of a "Z" or "+00:00" + * suffix because that makes it clear to everyone what kind + * of time this is. */ + dump_isotime (sigtime); + log_printf (" UTC"); + } else log_printf (_("[date not given]")); - log_printf (_(" using certificate ID 0x%08lX\n"), - gpgsm_get_short_fingerprint (cert, NULL)); + log_info (_(" using %s key %s\n"), pkalgostr, pkfpr); + if (opt.verbose) + { + log_info (_("algorithm:")); + log_printf (" %s + %s", + gcry_pk_algo_name (pkalgo), + gcry_md_algo_name (sigval_hash_algo)); + if (algo != sigval_hash_algo) + log_printf (" (%s)", gcry_md_algo_name (algo)); + log_printf ("\n"); + } audit_log_i (ctrl->audit, AUDIT_DATA_HASH_ALGO, algo); + /* Check compliance. */ + if (! gnupg_pk_is_allowed (opt.compliance, PK_USE_VERIFICATION, + pkalgo, NULL, nbits, NULL)) + { + char kidstr[10+1]; + + snprintf (kidstr, sizeof kidstr, "0x%08lX", + gpgsm_get_short_fingerprint (cert, NULL)); + log_error (_("key %s may not be used for signing in %s mode\n"), + kidstr, + gnupg_compliance_option_string (opt.compliance)); + goto next_signer; + } + + if (! gnupg_digest_is_allowed (opt.compliance, 0, sigval_hash_algo)) + { + log_error (_("digest algorithm '%s' may not be used in %s mode\n"), + gcry_md_algo_name (sigval_hash_algo), + gnupg_compliance_option_string (opt.compliance)); + goto next_signer; + } + + /* Check compliance with CO_DE_VS. */ + if (gnupg_pk_is_compliant (CO_DE_VS, pkalgo, NULL, nbits, NULL) + && gnupg_digest_is_compliant (CO_DE_VS, sigval_hash_algo)) + gpgsm_status (ctrl, STATUS_VERIFICATION_COMPLIANCE_MODE, + gnupg_status_compliance_flag (CO_DE_VS)); + + + /* Now we can check the signature. */ if (msgdigest) { /* Signed attributes are available. */ gcry_md_hd_t md; unsigned char *s; /* Check that the message digest in the signed attributes matches the one we calculated on the data. */ s = gcry_md_read (data_md, algo); if ( !s || !msgdigestlen || gcry_md_get_algo_dlen (algo) != msgdigestlen || memcmp (s, msgdigest, msgdigestlen) ) { char *fpr; log_error (_("invalid signature: message digest attribute " "does not match computed one\n")); if (DBG_X509) { if (msgdigest) log_printhex (msgdigest, msgdigestlen, "message: "); if (s) log_printhex (s, gcry_md_get_algo_dlen (algo), "computed: "); } fpr = gpgsm_fpr_and_name_for_status (cert); gpgsm_status (ctrl, STATUS_BADSIG, fpr); xfree (fpr); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } audit_log_i (ctrl->audit, AUDIT_ATTR_HASH_ALGO, sigval_hash_algo); rc = gcry_md_open (&md, sigval_hash_algo, 0); if (rc) { log_error ("md_open failed: %s\n", gpg_strerror (rc)); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "error"); goto next_signer; } if (DBG_HASHING) gcry_md_debug (md, "vrfy.attr"); ksba_cms_set_hash_function (cms, HASH_FNC, md); rc = ksba_cms_hash_signed_attrs (cms, signer); if (rc) { log_error ("hashing signed attrs failed: %s\n", gpg_strerror (rc)); gcry_md_close (md); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "error"); goto next_signer; } rc = gpgsm_check_cms_signature (cert, sigval, md, sigval_hash_algo, &info_pkalgo); gcry_md_close (md); } else { rc = gpgsm_check_cms_signature (cert, sigval, data_md, algo, &info_pkalgo); } if (rc) { char *fpr; log_error ("invalid signature: %s\n", gpg_strerror (rc)); fpr = gpgsm_fpr_and_name_for_status (cert); gpgsm_status (ctrl, STATUS_BADSIG, fpr); xfree (fpr); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } rc = gpgsm_cert_use_verify_p (cert); /*(this displays an info message)*/ if (rc) { gpgsm_status_with_err_code (ctrl, STATUS_ERROR, "verify.keyusage", gpg_err_code (rc)); rc = 0; } if (DBG_X509) log_debug ("signature okay - checking certs\n"); audit_log (ctrl->audit, AUDIT_VALIDATE_CHAIN); rc = gpgsm_validate_chain (ctrl, cert, *sigtime? sigtime : "19700101T000000", keyexptime, 0, NULL, 0, &verifyflags); { char *fpr, *buf, *tstr; fpr = gpgsm_fpr_and_name_for_status (cert); if (gpg_err_code (rc) == GPG_ERR_CERT_EXPIRED) { gpgsm_status (ctrl, STATUS_EXPKEYSIG, fpr); rc = 0; } else gpgsm_status (ctrl, STATUS_GOODSIG, fpr); xfree (fpr); + /* FIXME: INFO_PKALGO correctly shows ECDSA but PKALGO is then + * ECC. We should use the ECDS here and need to find a way to + * figure this oult without using the bodus assumtion in + * gpgsm_check_cms_signature that ECC is alwas ECDSA. */ + fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1); tstr = strtimestamp_r (sigtime); buf = xasprintf ("%s %s %s %s 0 0 %d %d 00", fpr, tstr, *sigtime? sigtime : "0", *keyexptime? keyexptime : "0", info_pkalgo, algo); xfree (tstr); xfree (fpr); gpgsm_status (ctrl, STATUS_VALIDSIG, buf); xfree (buf); } audit_log_ok (ctrl->audit, AUDIT_CHAIN_STATUS, rc); if (rc) /* of validate_chain */ { log_error ("invalid certification chain: %s\n", gpg_strerror (rc)); if (gpg_err_code (rc) == GPG_ERR_BAD_CERT_CHAIN || gpg_err_code (rc) == GPG_ERR_BAD_CERT || gpg_err_code (rc) == GPG_ERR_BAD_CA_CERT || gpg_err_code (rc) == GPG_ERR_CERT_REVOKED) gpgsm_status_with_err_code (ctrl, STATUS_TRUST_NEVER, NULL, gpg_err_code (rc)); else gpgsm_status_with_err_code (ctrl, STATUS_TRUST_UNDEFINED, NULL, gpg_err_code (rc)); audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "bad"); goto next_signer; } audit_log_s (ctrl->audit, AUDIT_SIG_STATUS, "good"); for (i=0; (p = ksba_cert_get_subject (cert, i)); i++) { log_info (!i? _("Good signature from") : _(" aka")); log_printf (" \""); gpgsm_es_print_name (log_get_stream (), p); log_printf ("\"\n"); ksba_free (p); } + /* Print a note if this is a qualified signature. */ { size_t qualbuflen; char qualbuffer[1]; rc = ksba_cert_get_user_data (cert, "is_qualified", &qualbuffer, sizeof (qualbuffer), &qualbuflen); if (!rc && qualbuflen) { if (*qualbuffer) { log_info (_("This is a qualified signature\n")); if (!opt.qualsig_approval) log_info (_("Note, that this software is not officially approved " "to create or verify such signatures.\n")); } } else if (gpg_err_code (rc) != GPG_ERR_NOT_FOUND) log_error ("get_user_data(is_qualified) failed: %s\n", gpg_strerror (rc)); } gpgsm_status (ctrl, STATUS_TRUST_FULLY, (verifyflags & VALIDATE_FLAG_STEED)? "0 steed": (verifyflags & VALIDATE_FLAG_CHAIN_MODEL)? "0 chain": "0 shell"); next_signer: rc = 0; xfree (issuer); xfree (serial); xfree (sigval); xfree (msgdigest); + xfree (pkalgostr); + xfree (pkfpr); ksba_cert_release (cert); cert = NULL; } rc = 0; leave: ksba_cms_release (cms); gnupg_ksba_destroy_reader (b64reader); gnupg_ksba_destroy_writer (b64writer); keydb_release (kh); gcry_md_close (data_md); es_fclose (in_fp); if (rc) { char numbuf[50]; sprintf (numbuf, "%d", rc ); gpgsm_status2 (ctrl, STATUS_ERROR, "verify.leave", numbuf, NULL); } return rc; }