mirror of
git://git.gnupg.org/gnupg.git
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7e07a397a0
(gpgsm_cert_use_sign_p,gpgsm_cert_use_encrypt_p): New. (gpgsm_cert_use_verify_p,gpgsm_cert_use_decrypt_p): New. (gpgsm_add_to_certlist): Check the key usage. * sign.c (gpgsm_sign): Ditto. * verify.c (gpgsm_verify): Print a message wehn an unsuitable certificate was used. * decrypt.c (gpgsm_decrypt): Ditto * keylist.c (print_capabilities): Determine values from the cert.
522 lines
13 KiB
C
522 lines
13 KiB
C
/* sign.c - Sign a message
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* Copyright (C) 2001 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#include <config.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <time.h>
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#include <assert.h>
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#include <gcrypt.h>
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#include <ksba.h>
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#include "gpgsm.h"
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#include "keydb.h"
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#include "i18n.h"
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static void
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hash_data (int fd, GCRY_MD_HD md)
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{
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FILE *fp;
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char buffer[4096];
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int nread;
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fp = fdopen ( dup (fd), "rb");
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if (!fp)
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{
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log_error ("fdopen(%d) failed: %s\n", fd, strerror (errno));
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return;
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}
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do
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{
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nread = fread (buffer, 1, DIM(buffer), fp);
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gcry_md_write (md, buffer, nread);
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}
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while (nread);
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if (ferror (fp))
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log_error ("read error on fd %d: %s\n", fd, strerror (errno));
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fclose (fp);
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}
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/* Get the default certificate which is defined as the first one our
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keyDB retruns and has a secret key available */
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int
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gpgsm_get_default_cert (KsbaCert *r_cert)
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{
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KEYDB_HANDLE hd;
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KsbaCert cert = NULL;
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int rc;
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char *p;
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hd = keydb_new (0);
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if (!hd)
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return GNUPG_General_Error;
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rc = keydb_search_first (hd);
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if (rc)
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{
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keydb_release (hd);
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return rc;
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}
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do
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{
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rc = keydb_get_cert (hd, &cert);
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if (rc)
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{
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log_error ("keydb_get_cert failed: %s\n", gnupg_strerror (rc));
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keydb_release (hd);
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return rc;
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}
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p = gpgsm_get_keygrip_hexstring (cert);
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if (p)
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{
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if (!gpgsm_agent_havekey (p))
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{
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xfree (p);
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keydb_release (hd);
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*r_cert = cert;
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return 0; /* got it */
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}
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xfree (p);
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}
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ksba_cert_release (cert);
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cert = NULL;
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}
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while (!(rc = keydb_search_next (hd)));
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if (rc && rc != -1)
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log_error ("keydb_search_next failed: %s\n", gnupg_strerror (rc));
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ksba_cert_release (cert);
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keydb_release (hd);
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return rc;
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}
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static KsbaCert
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get_default_signer (void)
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{
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KEYDB_SEARCH_DESC desc;
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KsbaCert cert = NULL;
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KEYDB_HANDLE kh = NULL;
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int rc;
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if (!opt.local_user)
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{
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rc = gpgsm_get_default_cert (&cert);
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if (rc)
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{
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if (rc != -1)
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log_debug ("failed to find default certificate: %s\n",
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gnupg_strerror (rc));
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return NULL;
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}
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return cert;
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}
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rc = keydb_classify_name (opt.local_user, &desc);
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if (rc)
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{
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log_error ("failed to find default signer: %s\n", gnupg_strerror (rc));
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return NULL;
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}
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kh = keydb_new (0);
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if (!kh)
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return NULL;
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rc = keydb_search (kh, &desc, 1);
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if (rc)
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{
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log_debug ("failed to find default certificate: rc=%d\n", rc);
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}
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else
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{
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rc = keydb_get_cert (kh, &cert);
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if (rc)
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{
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log_debug ("failed to get cert: rc=%d\n", rc);
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}
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}
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keydb_release (kh);
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return cert;
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}
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/* Depending on the options in CTRL add the certificate CERT as well as
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other certificate up in the chain to the Root-CA to the CMS
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object. */
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static int
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add_certificate_list (CTRL ctrl, KsbaCMS cms, KsbaCert cert)
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{
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KsbaError err;
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int rc = 0;
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KsbaCert next = NULL;
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int n;
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int not_root = 0;
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ksba_cert_ref (cert);
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n = ctrl->include_certs;
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if (n == -2)
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{
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not_root = 1;
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n = -1;
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}
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if (n < 0 || n > 50)
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n = 50; /* We better apply an upper bound */
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if (n)
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{
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if (not_root && gpgsm_is_root_cert (cert))
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err = 0;
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else
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err = ksba_cms_add_cert (cms, cert);
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if (err)
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goto ksba_failure;
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}
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while ( n-- && !(rc = gpgsm_walk_cert_chain (cert, &next)) )
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{
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if (not_root && gpgsm_is_root_cert (next))
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err = 0;
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else
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err = ksba_cms_add_cert (cms, next);
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ksba_cert_release (cert);
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cert = next; next = NULL;
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if (err)
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goto ksba_failure;
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}
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ksba_cert_release (cert);
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return rc == -1? 0: rc;
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ksba_failure:
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ksba_cert_release (cert);
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log_error ("ksba_cms_add_cert failed: %s\n", ksba_strerror (err));
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return map_ksba_err (err);
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}
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/* Perform a sign operation.
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Sign the data received on DATA-FD in embedded mode or in deatched
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mode when DETACHED is true. Write the signature to OUT_FP The key
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used to sign is the default - we will extend the fucntion to take a
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list of fingerprints in the future. */
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int
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gpgsm_sign (CTRL ctrl, int data_fd, int detached, FILE *out_fp)
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{
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int i, rc;
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KsbaError err;
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Base64Context b64writer = NULL;
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KsbaWriter writer;
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KsbaCMS cms = NULL;
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KsbaStopReason stopreason;
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KsbaCert cert = NULL;
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KEYDB_HANDLE kh = NULL;
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GCRY_MD_HD data_md = NULL;
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int signer;
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const char *algoid;
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int algo;
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time_t signed_at;
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if (!detached)
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{
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rc = seterr (Not_Implemented);
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goto leave;
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}
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kh = keydb_new (0);
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if (!kh)
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{
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log_error (_("failed to allocated keyDB handle\n"));
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rc = GNUPG_General_Error;
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goto leave;
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}
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ctrl->pem_name = "SIGNED MESSAGE";
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rc = gpgsm_create_writer (&b64writer, ctrl, out_fp, &writer);
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if (rc)
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{
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log_error ("can't create writer: %s\n", gnupg_strerror (rc));
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goto leave;
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}
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cms = ksba_cms_new ();
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if (!cms)
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{
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rc = seterr (Out_Of_Core);
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goto leave;
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}
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err = ksba_cms_set_reader_writer (cms, NULL, writer);
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if (err)
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{
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log_debug ("ksba_cms_set_reader_writer failed: %s\n",
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ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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/* We are going to create signed data with data as encap. content */
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err = ksba_cms_set_content_type (cms, 0, KSBA_CT_SIGNED_DATA);
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if (!err)
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err = ksba_cms_set_content_type (cms, 1, KSBA_CT_DATA);
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if (err)
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{
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log_debug ("ksba_cms_set_content_type failed: %s\n",
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ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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/* gather certificates of signers and store in theCMS object */
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/* fixme: process a list of fingerprints and store the certificate of
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each given fingerprint */
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cert = get_default_signer ();
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if (!cert)
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{
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log_error ("no default signer found\n");
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rc = seterr (General_Error);
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goto leave;
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}
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rc = gpgsm_cert_use_sign_p (cert);
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if (rc)
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goto leave;
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err = ksba_cms_add_signer (cms, cert);
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if (err)
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{
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log_error ("ksba_cms_add_signer failed: %s\n", ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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rc = add_certificate_list (ctrl, cms, cert);
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if (rc)
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{
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log_error ("failed to store list of certificates: %s\n",
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gnupg_strerror(rc));
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goto leave;
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}
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ksba_cert_release (cert); cert = NULL;
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/* Set the hash algorithm we are going to use */
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err = ksba_cms_add_digest_algo (cms, "1.3.14.3.2.26" /*SHA-1*/);
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if (err)
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{
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log_debug ("ksba_cms_add_digest_algo failed: %s\n", ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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/* Prepare hashing (actually we are figuring out what we have set above)*/
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data_md = gcry_md_open (0, 0);
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if (!data_md)
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{
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rc = map_gcry_err (gcry_errno());
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log_error ("md_open failed: %s\n", gcry_strerror (-1));
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goto leave;
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}
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if (DBG_HASHING)
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gcry_md_start_debug (data_md, "sign.data");
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for (i=0; (algoid=ksba_cms_get_digest_algo_list (cms, i)); i++)
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{
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algo = gcry_md_map_name (algoid);
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if (!algo)
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{
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log_error ("unknown hash algorithm `%s'\n", algoid? algoid:"?");
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rc = GNUPG_Bug;
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goto leave;
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}
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gcry_md_enable (data_md, algo);
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}
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signer = 0;
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if (detached)
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{ /* we hash the data right now so that we can store the message
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digest. ksba_cms_build() takes this as an flag that detached
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data is expected. */
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unsigned char *digest;
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size_t digest_len;
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/* Fixme do this for all signers and get the algo to use from
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the signer's certificate - does not make mich sense, bu we
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should do this consistent as we have already done it above */
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algo = GCRY_MD_SHA1;
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hash_data (data_fd, data_md);
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digest = gcry_md_read (data_md, algo);
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digest_len = gcry_md_get_algo_dlen (algo);
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if ( !digest || !digest_len)
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{
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log_error ("problem getting the hash of the data\n");
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rc = GNUPG_Bug;
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goto leave;
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}
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err = ksba_cms_set_message_digest (cms, signer, digest, digest_len);
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if (err)
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{
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log_error ("ksba_cms_set_message_digest failed: %s\n",
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ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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}
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signed_at = time (NULL);
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err = ksba_cms_set_signing_time (cms, signer, signed_at);
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if (err)
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{
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log_error ("ksba_cms_set_signing_time failed: %s\n",
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ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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do
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{
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err = ksba_cms_build (cms, &stopreason);
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if (err)
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{
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log_debug ("ksba_cms_build failed: %s\n", ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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if (stopreason == KSBA_SR_BEGIN_DATA)
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{ /* hash the data and store the message digest */
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assert (!detached);
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}
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else if (stopreason == KSBA_SR_NEED_SIG)
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{ /* calculate the signature for all signers */
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GCRY_MD_HD md;
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algo = GCRY_MD_SHA1;
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signer = 0;
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md = gcry_md_open (algo, 0);
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if (DBG_HASHING)
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gcry_md_start_debug (md, "sign.attr");
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if (!md)
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{
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log_error ("md_open failed: %s\n", gcry_strerror (-1));
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goto leave;
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}
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ksba_cms_set_hash_function (cms, HASH_FNC, md);
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rc = ksba_cms_hash_signed_attrs (cms, signer);
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if (rc)
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{
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log_debug ("hashing signed attrs failed: %s\n",
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ksba_strerror (rc));
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gcry_md_close (md);
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goto leave;
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}
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{ /* This is all an temporary hack */
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char *sigval;
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ksba_cert_release (cert);
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cert = get_default_signer ();
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if (!cert)
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{
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log_error ("oops - failed to get cert again\n");
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rc = seterr (General_Error);
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goto leave;
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}
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sigval = NULL;
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rc = gpgsm_create_cms_signature (cert, md, algo, &sigval);
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if (rc)
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goto leave;
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err = ksba_cms_set_sig_val (cms, signer, sigval);
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xfree (sigval);
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if (err)
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{
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log_error ("failed to store the signature: %s\n",
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ksba_strerror (err));
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rc = map_ksba_err (err);
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goto leave;
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}
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/* And write a status message */
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{
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char *buf, *fpr;
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fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
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if (!fpr)
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{
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rc = seterr (Out_Of_Core);
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goto leave;
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}
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rc = asprintf (&buf, "%c %d %d 00 %lu %s",
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detached? 'D':'S',
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GCRY_PK_RSA, /* FIXME: get pk algo from cert */
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algo,
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(ulong)signed_at,
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fpr);
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xfree (fpr);
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if (rc < 0)
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{
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rc = seterr (Out_Of_Core);
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goto leave;
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}
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rc = 0;
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gpgsm_status (ctrl, STATUS_SIG_CREATED, buf );
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free (buf); /* yes, we must use the regular free() here */
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}
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}
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}
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}
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while (stopreason != KSBA_SR_READY);
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rc = gpgsm_finish_writer (b64writer);
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if (rc)
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{
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log_error ("write failed: %s\n", gnupg_strerror (rc));
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goto leave;
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}
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log_info ("signature created\n");
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leave:
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ksba_cert_release (cert);
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ksba_cms_release (cms);
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gpgsm_destroy_writer (b64writer);
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keydb_release (kh);
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gcry_md_close (data_md);
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return rc;
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}
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