sign.c
No OneTemporary
Actions

Size

11 KB

Subscribers

None

sign.c
View Options

	/* sign.c - Sign a message
	* Copyright (C) 2001 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 2 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
	*/

	#include <config.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>
	#include <unistd.h>
	#include <time.h>
	#include <assert.h>

	#include <gcrypt.h>
	#include <ksba.h>

	#include "gpgsm.h"
	#include "keydb.h"
	#include "i18n.h"


	static void
	hash_data (int fd, GCRY_MD_HD md)
	{
	FILE *fp;
	char buffer[4096];
	int nread;

	fp = fdopen ( dup (fd), "rb");
	if (!fp)
	{
	log_error ("fdopen(%d) failed: %s\n", fd, strerror (errno));
	return;
	}

	do
	{
	nread = fread (buffer, 1, DIM(buffer), fp);
	gcry_md_write (md, buffer, nread);
	}
	while (nread);
	if (ferror (fp))
	log_error ("read error on fd %d: %s\n", fd, strerror (errno));
	fclose (fp);
	}


	static KsbaCert
	get_default_signer (void)
	{
	// const char key[] = "1.2.840.113549.1.9.1=#7472757374407765622E6465#,CN=WEB.DE TrustCenter,OU=TrustCenter,O=WEB.DE AG,L=D-76227 Karlsruhe,C=DE";
	const char key[] =
	"/CN=test cert 1,OU=Aegypten Project,O=g10 Code GmbH,L=Düsseldorf,C=DE";

	KEYDB_SEARCH_DESC desc;
	KsbaCert cert = NULL;
	KEYDB_HANDLE kh = NULL;
	int rc;

	rc = keydb_classify_name (key, &desc);
	if (rc)
	{
	log_error ("failed to find default signer: %s\n", gnupg_strerror (rc));
	return NULL;
	}

	kh = keydb_new (0);
	if (!kh)
	return NULL;

	rc = keydb_search (kh, &desc, 1);
	if (rc)
	{
	log_debug ("failed to find default certificate: rc=%d\n", rc);
	}
	else
	{
	rc = keydb_get_cert (kh, &cert);
	if (rc)
	{
	log_debug ("failed to get cert: rc=%d\n", rc);
	}
	}

	keydb_release (kh);
	return cert;
	}


	/* Depending on the options in CTRL add the certifcate CERT as well as
	other certificate up in the chain to the Root-CA to the CMS
	object. */
	static int
	add_certificate_list (CTRL ctrl, KsbaCMS cms, KsbaCert cert)
	{
	KsbaError err;
	int rc = 0;
	KsbaCert next = NULL;
	int n;

	ksba_cert_ref (cert);

	n = ctrl->include_certs;
	if (n < 0 \|\| n > 50)
	n = 50; /* We better apply an upper bound */

	if (n)
	{
	err = ksba_cms_add_cert (cms, cert);
	if (err)
	goto ksba_failure;
	}
	while ( n-- && !(rc = gpgsm_walk_cert_chain (cert, &next)) )
	{
	err = ksba_cms_add_cert (cms, next);
	ksba_cert_release (cert);
	cert = next; next = NULL;
	if (err)
	goto ksba_failure;
	}
	ksba_cert_release (cert);

	return rc == -1? 0: rc;

	ksba_failure:
	ksba_cert_release (cert);
	log_error ("ksba_cms_add_cert failed: %s\n", ksba_strerror (err));
	return map_ksba_err (err);
	}




	/* Perform a sign operation.

	Sign the data received on DATA-FD in embedded mode or in deatched
	mode when DETACHED is true. Write the signature to OUT_FP The key
	used to sign is the default - we will extend the fucntion to take a
	list of fingerprints in the future. */
	int
	gpgsm_sign (CTRL ctrl, int data_fd, int detached, FILE *out_fp)
	{
	int i, rc;
	KsbaError err;
	Base64Context b64writer = NULL;
	KsbaWriter writer;
	KsbaCMS cms = NULL;
	KsbaStopReason stopreason;
	KsbaCert cert = NULL;
	KEYDB_HANDLE kh = NULL;
	GCRY_MD_HD data_md = NULL;
	int signer;
	const char *algoid;
	int algo;
	time_t signed_at;

	if (!detached)
	{
	rc = seterr (Not_Implemented);
	goto leave;
	}


	kh = keydb_new (0);
	if (!kh)
	{
	log_error (_("failed to allocated keyDB handle\n"));
	rc = GNUPG_General_Error;
	goto leave;
	}

	ctrl->pem_name = "SIGNED MESSAGE";
	rc = gpgsm_create_writer (&b64writer, ctrl, out_fp, &writer);
	if (rc)
	{
	log_error ("can't create writer: %s\n", gnupg_strerror (rc));
	goto leave;
	}

	cms = ksba_cms_new ();
	if (!cms)
	{
	rc = seterr (Out_Of_Core);
	goto leave;
	}

	err = ksba_cms_set_reader_writer (cms, NULL, writer);
	if (err)
	{
	log_debug ("ksba_cms_set_reader_writer failed: %s\n",
	ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}

	/* We are going to create signed data with data as encap. content */
	err = ksba_cms_set_content_type (cms, 0, KSBA_CT_SIGNED_DATA);
	if (!err)
	err = ksba_cms_set_content_type (cms, 1, KSBA_CT_DATA);
	if (err)
	{
	log_debug ("ksba_cms_set_content_type failed: %s\n",
	ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}


	/* gather certificates of signers and store in theCMS object */
	/* fixme: process a list of fingerprints and store the certificate of
	each given fingerprint */
	cert = get_default_signer ();
	if (!cert)
	{
	log_error ("no default signer found\n");
	rc = seterr (General_Error);
	goto leave;
	}
	err = ksba_cms_add_signer (cms, cert);
	if (err)
	{
	log_error ("ksba_cms_add_signer failed: %s\n", ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}
	rc = add_certificate_list (ctrl, cms, cert);
	if (rc)
	{
	log_error ("failed to store list of certificates: %s\n",
	gnupg_strerror(rc));
	goto leave;
	}
	ksba_cert_release (cert); cert = NULL;


	/* Set the hash algorithm we are going to use */
	err = ksba_cms_add_digest_algo (cms, "1.3.14.3.2.26" /SHA-1/);
	if (err)
	{
	log_debug ("ksba_cms_add_digest_algo failed: %s\n", ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}

	/* Prepare hashing (actually we are figuring out what we have set above)*/
	data_md = gcry_md_open (0, 0);
	if (!data_md)
	{
	rc = map_gcry_err (gcry_errno());
	log_error ("md_open failed: %s\n", gcry_strerror (-1));
	goto leave;
	}
	if (DBG_HASHING)
	gcry_md_start_debug (data_md, "sign.data");

	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:"?");
	rc = GNUPG_Bug;
	goto leave;
	}
	gcry_md_enable (data_md, algo);
	}

	signer = 0;
	if (detached)
	{ /* we hash the data right now so that we can store the message
	digest. ksba_cms_build() takes this as an flag that detached
	data is expected. */
	unsigned char *digest;
	size_t digest_len;
	/* Fixme do this for all signers and get the algo to use from
	the signer's certificate - does not make mich sense, bu we
	should do this consistent as we have already done it above */
	algo = GCRY_MD_SHA1;
	hash_data (data_fd, data_md);
	digest = gcry_md_read (data_md, algo);
	digest_len = gcry_md_get_algo_dlen (algo);
	if ( !digest \|\| !digest_len)
	{
	log_error ("problem getting the hash of the data\n");
	rc = GNUPG_Bug;
	goto leave;
	}
	err = ksba_cms_set_message_digest (cms, signer, digest, digest_len);
	if (err)
	{
	log_error ("ksba_cms_set_message_digest failed: %s\n",
	ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}
	}

	signed_at = time (NULL);
	err = ksba_cms_set_signing_time (cms, signer, signed_at);
	if (err)
	{
	log_error ("ksba_cms_set_signing_time failed: %s\n",
	ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}

	do
	{
	err = ksba_cms_build (cms, &stopreason);
	if (err)
	{
	log_debug ("ksba_cms_build failed: %s\n", ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}

	if (stopreason == KSBA_SR_BEGIN_DATA)
	{ /* hash the data and store the message digest */
	assert (!detached);
	}
	else if (stopreason == KSBA_SR_NEED_SIG)
	{ /* calculate the signature for all signers */
	GCRY_MD_HD md;

	algo = GCRY_MD_SHA1;
	signer = 0;
	md = gcry_md_open (algo, 0);
	if (DBG_HASHING)
	gcry_md_start_debug (md, "sign.attr");

	if (!md)
	{
	log_error ("md_open failed: %s\n", gcry_strerror (-1));
	goto leave;
	}
	ksba_cms_set_hash_function (cms, HASH_FNC, md);
	rc = ksba_cms_hash_signed_attrs (cms, signer);
	if (rc)
	{
	log_debug ("hashing signed attrs failed: %s\n",
	ksba_strerror (rc));
	gcry_md_close (md);
	goto leave;
	}

	{ /* This is all an temporary hack */
	char *sigval;

	ksba_cert_release (cert);
	cert = get_default_signer ();
	if (!cert)
	{
	log_error ("oops - failed to get cert again\n");
	rc = seterr (General_Error);
	goto leave;
	}

	sigval = NULL;
	rc = gpgsm_create_cms_signature (cert, md, algo, &sigval);
	if (rc)
	goto leave;

	err = ksba_cms_set_sig_val (cms, signer, sigval);
	xfree (sigval);
	if (err)
	{
	log_error ("failed to store the signature: %s\n",
	ksba_strerror (err));
	rc = map_ksba_err (err);
	goto leave;
	}

	/* And write a status message */
	{
	char buf, fpr;

	fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
	if (!fpr)
	{
	rc = seterr (Out_Of_Core);
	goto leave;
	}
	rc = asprintf (&buf, "%c %d %d 00 %lu %s",
	detached? 'D':'S',
	GCRY_PK_RSA, /* FIXME: get pk algo from cert */
	algo,
	(ulong)signed_at,
	fpr);
	xfree (fpr);
	if (rc < 0)
	{
	rc = seterr (Out_Of_Core);
	goto leave;
	}
	rc = 0;
	gpgsm_status (ctrl, STATUS_SIG_CREATED, buf );
	free (buf); /* yes, we must use the regular free() here */
	}

	}
	}
	}
	while (stopreason != KSBA_SR_READY);

	rc = gpgsm_finish_writer (b64writer);
	if (rc)
	{
	log_error ("write failed: %s\n", gnupg_strerror (rc));
	goto leave;
	}

	log_info ("signature created\n");


	leave:
	ksba_cert_release (cert);
	ksba_cms_release (cms);
	gpgsm_destroy_writer (b64writer);
	keydb_release (kh);
	gcry_md_close (data_md);
	return rc;
	}

File Metadata

Mime Type: text/x-c
Expires: Sun, Feb 15, 3:45 PM (11 h, 46 m)
Storage Engine: local-disk
Storage Format: Raw Data
Storage Handle: 78/75/adb97b3d3a04609705cc200a3b8b

sign.cNo OneTemporaryActions

sign.cView Options

File Metadata

Event Timeline

sign.c
No OneTemporary
Actions

sign.c
View Options