/* 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 #include #include #include #include #include #include #include #include #include #include "gpgsm.h" #include "keydb.h" #include "i18n.h" struct reader_cb_parm_s { FILE *fp; }; 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"; KsbaCert cert = NULL; KEYDB_HANDLE kh = NULL; int rc; kh = keydb_new (0); if (!kh) return NULL; rc = keydb_search_subject (kh, key); 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; } /* 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; KsbaWriter writer = NULL; KsbaCMS cms = NULL; KsbaStopReason stopreason; KsbaCert cert; KEYDB_HANDLE kh = NULL; GCRY_MD_HD data_md = NULL; struct reader_cb_parm_s rparm; int signer; const char *algoid; int algo; memset (&rparm, 0, sizeof rparm); 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; } rparm.fp = fdopen ( dup (data_fd), "rb"); if (!rparm.fp) { log_error ("fdopen() failed: %s\n", strerror (errno)); rc = seterr (IO_Error); goto leave; } writer = ksba_writer_new (); if (!writer) { rc = seterr (Out_Of_Core); goto leave; } rc = ksba_writer_set_file (writer, out_fp); if (rc) { ksba_writer_release (writer); rc = map_ksba_err (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_debug ("ksba_cms_add_signer failed: %s\n", ksba_strerror (err)); rc = map_ksba_err (err); goto leave; } cert = NULL; /* cms does now own the certificate */ /* fixme: We might want to include a list of certificate which are put as info into the signed data object - maybe we should add a flag to ksba_cms_add_signer to decider whether this cert should be send along with the signature */ /* 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; } 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); } if (detached) { /* we hash the data right now so tha we can store the message digest. ksba_cms_build() takes this as an flag that deatched 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 */ signer = 0; 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; } } 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; } log_debug ("ksba_cms_build - stop reason %d\n", stopreason); 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 (!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; 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) { ksba_cert_release (cert); 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; } } } } while (stopreason != KSBA_SR_READY); log_info ("signature created\n"); leave: ksba_cms_release (cms); ksba_writer_release (writer); keydb_release (kh); gcry_md_close (data_md); if (rparm.fp) fclose (rparm.fp); return rc; }