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Diffstat (limited to '')
| -rw-r--r-- | g10/encrypt.c | 1039 |
1 files changed, 1039 insertions, 0 deletions
diff --git a/g10/encrypt.c b/g10/encrypt.c new file mode 100644 index 0000000..01f32af --- /dev/null +++ b/g10/encrypt.c @@ -0,0 +1,1039 @@ +/* encrypt.c - Main encryption driver + * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, + * 2006, 2009 Free Software Foundation, Inc. + * 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 <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include "gpg.h" +#include "options.h" +#include "packet.h" +#include "../common/status.h" +#include "../common/iobuf.h" +#include "keydb.h" +#include "../common/util.h" +#include "main.h" +#include "filter.h" +#include "trustdb.h" +#include "../common/i18n.h" +#include "../common/status.h" +#include "pkglue.h" +#include "../common/compliance.h" + + +static int encrypt_simple( const char *filename, int mode, int use_seskey ); +static int write_pubkey_enc_from_list (ctrl_t ctrl, + PK_LIST pk_list, DEK *dek, iobuf_t out); + +/**************** + * Encrypt FILENAME with only the symmetric cipher. Take input from + * stdin if FILENAME is NULL. + */ +int +encrypt_symmetric (const char *filename) +{ + return encrypt_simple( filename, 1, 0 ); +} + + +/**************** + * Encrypt FILENAME as a literal data packet only. Take input from + * stdin if FILENAME is NULL. + */ +int +encrypt_store (const char *filename) +{ + return encrypt_simple( filename, 0, 0 ); +} + + +/* *SESKEY contains the unencrypted session key ((*SESKEY)->KEY) and + the algorithm that will be used to encrypt the contents of the SED + packet ((*SESKEY)->ALGO). If *SESKEY is NULL, then a random + session key that is appropriate for DEK->ALGO is generated and + stored there. + + Encrypt that session key using DEK and store the result in ENCKEY, + which must be large enough to hold (*SESKEY)->KEYLEN + 1 bytes. */ +void +encrypt_seskey (DEK *dek, DEK **seskey, byte *enckey) +{ + gcry_cipher_hd_t hd; + byte buf[33]; + + log_assert ( dek->keylen <= 32 ); + if (!*seskey) + { + *seskey=xmalloc_clear(sizeof(DEK)); + (*seskey)->algo=dek->algo; + make_session_key(*seskey); + /*log_hexdump( "thekey", c->key, c->keylen );*/ + } + + /* The encrypted session key is prefixed with a one-octet algorithm id. */ + buf[0] = (*seskey)->algo; + memcpy( buf + 1, (*seskey)->key, (*seskey)->keylen ); + + /* We only pass already checked values to the following function, + thus we consider any failure as fatal. */ + if (openpgp_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1)) + BUG (); + if (gcry_cipher_setkey (hd, dek->key, dek->keylen)) + BUG (); + gcry_cipher_setiv (hd, NULL, 0); + gcry_cipher_encrypt (hd, buf, (*seskey)->keylen + 1, NULL, 0); + gcry_cipher_close (hd); + + memcpy( enckey, buf, (*seskey)->keylen + 1 ); + wipememory( buf, sizeof buf ); /* burn key */ +} + + +/* Shall we use the MDC? Yes - unless rfc-2440 compatibility is + * requested. Must return 1 or 0. */ +int +use_mdc (pk_list_t pk_list,int algo) +{ + (void)pk_list; + (void)algo; + + /* RFC-2440 don't has MDC - this is the only way to create a legacy + * non-MDC encryption packet. */ + if (RFC2440) + return 0; + + return 1; /* In all other cases we use the MDC */ +} + + +/* We don't want to use use_seskey yet because older gnupg versions + can't handle it, and there isn't really any point unless we're + making a message that can be decrypted by a public key or + passphrase. */ +static int +encrypt_simple (const char *filename, int mode, int use_seskey) +{ + iobuf_t inp, out; + PACKET pkt; + PKT_plaintext *pt = NULL; + STRING2KEY *s2k = NULL; + byte enckey[33]; + int rc = 0; + int seskeylen = 0; + u32 filesize; + cipher_filter_context_t cfx; + armor_filter_context_t *afx = NULL; + compress_filter_context_t zfx; + text_filter_context_t tfx; + progress_filter_context_t *pfx; + int do_compress = !!default_compress_algo(); + + if (!gnupg_rng_is_compliant (opt.compliance)) + { + rc = gpg_error (GPG_ERR_FORBIDDEN); + log_error (_("%s is not compliant with %s mode\n"), + "RNG", + gnupg_compliance_option_string (opt.compliance)); + write_status_error ("random-compliance", rc); + return rc; + } + + pfx = new_progress_context (); + memset( &cfx, 0, sizeof cfx); + memset( &zfx, 0, sizeof zfx); + memset( &tfx, 0, sizeof tfx); + init_packet(&pkt); + + /* Prepare iobufs. */ + inp = iobuf_open(filename); + if (inp) + iobuf_ioctl (inp, IOBUF_IOCTL_NO_CACHE, 1, NULL); + if (inp && is_secured_file (iobuf_get_fd (inp))) + { + iobuf_close (inp); + inp = NULL; + gpg_err_set_errno (EPERM); + } + if (!inp) + { + rc = gpg_error_from_syserror (); + log_error(_("can't open '%s': %s\n"), filename? filename: "[stdin]", + strerror(errno) ); + release_progress_context (pfx); + return rc; + } + + handle_progress (pfx, inp, filename); + + if (opt.textmode) + iobuf_push_filter( inp, text_filter, &tfx ); + + cfx.dek = NULL; + if ( mode ) + { + rc = setup_symkey (&s2k, &cfx.dek); + if (rc) + { + iobuf_close (inp); + if (gpg_err_code (rc) == GPG_ERR_CIPHER_ALGO + || gpg_err_code (rc) == GPG_ERR_DIGEST_ALGO) + ; /* Error has already been printed. */ + else + log_error (_("error creating passphrase: %s\n"), gpg_strerror (rc)); + release_progress_context (pfx); + return rc; + } + if (use_seskey && s2k->mode != 1 && s2k->mode != 3) + { + use_seskey = 0; + log_info (_("can't use a symmetric ESK packet " + "due to the S2K mode\n")); + } + + if ( use_seskey ) + { + DEK *dek = NULL; + + seskeylen = openpgp_cipher_get_algo_keylen (default_cipher_algo ()); + encrypt_seskey( cfx.dek, &dek, enckey ); + xfree( cfx.dek ); cfx.dek = dek; + } + + if (opt.verbose) + log_info(_("using cipher %s\n"), + openpgp_cipher_algo_name (cfx.dek->algo)); + + cfx.dek->use_mdc=use_mdc(NULL,cfx.dek->algo); + } + + if (do_compress && cfx.dek && cfx.dek->use_mdc + && is_file_compressed(filename, &rc)) + { + if (opt.verbose) + log_info(_("'%s' already compressed\n"), filename); + do_compress = 0; + } + + if ( rc || (rc = open_outfile (-1, filename, opt.armor? 1:0, 0, &out ))) + { + iobuf_cancel (inp); + xfree (cfx.dek); + xfree (s2k); + release_progress_context (pfx); + return rc; + } + + if ( opt.armor ) + { + afx = new_armor_context (); + push_armor_filter (afx, out); + } + + if ( s2k ) + { + PKT_symkey_enc *enc = xmalloc_clear( sizeof *enc + seskeylen + 1 ); + enc->version = 4; + enc->cipher_algo = cfx.dek->algo; + enc->s2k = *s2k; + if ( use_seskey && seskeylen ) + { + enc->seskeylen = seskeylen + 1; /* algo id */ + memcpy (enc->seskey, enckey, seskeylen + 1 ); + } + pkt.pkttype = PKT_SYMKEY_ENC; + pkt.pkt.symkey_enc = enc; + if ((rc = build_packet( out, &pkt ))) + log_error("build symkey packet failed: %s\n", gpg_strerror (rc) ); + xfree (enc); + } + + if (!opt.no_literal) + pt = setup_plaintext_name (filename, inp); + + /* Note that PGP 5 has problems decrypting symmetrically encrypted + data if the file length is in the inner packet. It works when + only partial length headers are use. In the past, we always used + partial body length here, but since PGP 2, PGP 6, and PGP 7 need + the file length, and nobody should be using PGP 5 nowadays + anyway, this is now set to the file length. Note also that this + only applies to the RFC-1991 style symmetric messages, and not + the RFC-2440 style. PGP 6 and 7 work with either partial length + or fixed length with the new style messages. */ + + if ( !iobuf_is_pipe_filename (filename) && *filename && !opt.textmode ) + { + off_t tmpsize; + int overflow; + + if ( !(tmpsize = iobuf_get_filelength(inp, &overflow)) + && !overflow && opt.verbose) + log_info(_("WARNING: '%s' is an empty file\n"), filename ); + /* We can't encode the length of very large files because + OpenPGP uses only 32 bit for file sizes. So if the + size of a file is larger than 2^32 minus some bytes for + packet headers, we switch to partial length encoding. */ + if ( tmpsize < (IOBUF_FILELENGTH_LIMIT - 65536) ) + filesize = tmpsize; + else + filesize = 0; + } + else + filesize = opt.set_filesize ? opt.set_filesize : 0; /* stdin */ + + if (!opt.no_literal) + { + /* Note that PT has been initialized above in !no_literal mode. */ + pt->timestamp = make_timestamp(); + pt->mode = opt.mimemode? 'm' : opt.textmode? 't' : 'b'; + pt->len = filesize; + pt->new_ctb = !pt->len; + pt->buf = inp; + pkt.pkttype = PKT_PLAINTEXT; + pkt.pkt.plaintext = pt; + cfx.datalen = filesize && !do_compress ? calc_packet_length( &pkt ) : 0; + } + else + { + cfx.datalen = filesize && !do_compress ? filesize : 0; + pkt.pkttype = 0; + pkt.pkt.generic = NULL; + } + + /* Register the cipher filter. */ + if (mode) + iobuf_push_filter ( out, cipher_filter, &cfx ); + + /* Register the compress filter. */ + if ( do_compress ) + { + if (cfx.dek && cfx.dek->use_mdc) + zfx.new_ctb = 1; + push_compress_filter (out, &zfx, default_compress_algo()); + } + + /* Do the work. */ + if (!opt.no_literal) + { + if ( (rc = build_packet( out, &pkt )) ) + log_error("build_packet failed: %s\n", gpg_strerror (rc) ); + } + else + { + /* User requested not to create a literal packet, so we copy the + plain data. */ + byte copy_buffer[4096]; + int bytes_copied; + while ((bytes_copied = iobuf_read(inp, copy_buffer, 4096)) != -1) + if ( (rc=iobuf_write(out, copy_buffer, bytes_copied)) ) { + log_error ("copying input to output failed: %s\n", + gpg_strerror (rc) ); + break; + } + wipememory (copy_buffer, 4096); /* burn buffer */ + } + + /* Finish the stuff. */ + iobuf_close (inp); + if (rc) + iobuf_cancel(out); + else + { + iobuf_close (out); /* fixme: check returncode */ + if (mode) + write_status ( STATUS_END_ENCRYPTION ); + } + if (pt) + pt->buf = NULL; + free_packet (&pkt, NULL); + xfree (cfx.dek); + xfree (s2k); + release_armor_context (afx); + release_progress_context (pfx); + return rc; +} + + +gpg_error_t +setup_symkey (STRING2KEY **symkey_s2k, DEK **symkey_dek) +{ + int canceled; + int defcipher; + int s2kdigest; + + defcipher = default_cipher_algo (); + if (!gnupg_cipher_is_allowed (opt.compliance, 1, defcipher, + GCRY_CIPHER_MODE_CFB)) + { + log_error (_("cipher algorithm '%s' may not be used in %s mode\n"), + openpgp_cipher_algo_name (defcipher), + gnupg_compliance_option_string (opt.compliance)); + return gpg_error (GPG_ERR_CIPHER_ALGO); + } + + s2kdigest = S2K_DIGEST_ALGO; + if (!gnupg_digest_is_allowed (opt.compliance, 1, s2kdigest)) + { + log_error (_("digest algorithm '%s' may not be used in %s mode\n"), + gcry_md_algo_name (s2kdigest), + gnupg_compliance_option_string (opt.compliance)); + return gpg_error (GPG_ERR_DIGEST_ALGO); + } + + *symkey_s2k = xmalloc_clear (sizeof **symkey_s2k); + (*symkey_s2k)->mode = opt.s2k_mode; + (*symkey_s2k)->hash_algo = s2kdigest; + + *symkey_dek = passphrase_to_dek (defcipher, + *symkey_s2k, 1, 0, NULL, &canceled); + if (!*symkey_dek || !(*symkey_dek)->keylen) + { + xfree(*symkey_dek); + xfree(*symkey_s2k); + return gpg_error (canceled?GPG_ERR_CANCELED:GPG_ERR_INV_PASSPHRASE); + } + + return 0; +} + + +static int +write_symkey_enc (STRING2KEY *symkey_s2k, DEK *symkey_dek, DEK *dek, + iobuf_t out) +{ + int rc, seskeylen = openpgp_cipher_get_algo_keylen (dek->algo); + + PKT_symkey_enc *enc; + byte enckey[33]; + PACKET pkt; + + enc=xmalloc_clear(sizeof(PKT_symkey_enc)+seskeylen+1); + encrypt_seskey(symkey_dek,&dek,enckey); + + enc->version = 4; + enc->cipher_algo = opt.s2k_cipher_algo; + enc->s2k = *symkey_s2k; + enc->seskeylen = seskeylen + 1; /* algo id */ + memcpy( enc->seskey, enckey, seskeylen + 1 ); + + pkt.pkttype = PKT_SYMKEY_ENC; + pkt.pkt.symkey_enc = enc; + + if ((rc=build_packet(out,&pkt))) + log_error("build symkey_enc packet failed: %s\n",gpg_strerror (rc)); + + xfree(enc); + return rc; +} + + +/* + * Encrypt the file with the given userids (or ask if none is + * supplied). Either FILENAME or FILEFD must be given, but not both. + * The caller may provide a checked list of public keys in + * PROVIDED_PKS; if not the function builds a list of keys on its own. + * + * Note that FILEFD is currently only used by cmd_encrypt in the + * not yet finished server.c. + */ +int +encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename, + strlist_t remusr, int use_symkey, pk_list_t provided_keys, + int outputfd) +{ + iobuf_t inp = NULL; + iobuf_t out = NULL; + PACKET pkt; + PKT_plaintext *pt = NULL; + DEK *symkey_dek = NULL; + STRING2KEY *symkey_s2k = NULL; + int rc = 0, rc2 = 0; + u32 filesize; + cipher_filter_context_t cfx; + armor_filter_context_t *afx = NULL; + compress_filter_context_t zfx; + text_filter_context_t tfx; + progress_filter_context_t *pfx; + PK_LIST pk_list; + int do_compress; + int compliant; + + if (filefd != -1 && filename) + return gpg_error (GPG_ERR_INV_ARG); /* Both given. */ + + do_compress = !!opt.compress_algo; + + pfx = new_progress_context (); + memset( &cfx, 0, sizeof cfx); + memset( &zfx, 0, sizeof zfx); + memset( &tfx, 0, sizeof tfx); + init_packet(&pkt); + + if (use_symkey + && (rc=setup_symkey(&symkey_s2k,&symkey_dek))) + { + release_progress_context (pfx); + return rc; + } + + if (provided_keys) + pk_list = provided_keys; + else + { + if ((rc = build_pk_list (ctrl, remusr, &pk_list))) + { + release_progress_context (pfx); + return rc; + } + } + + /* Prepare iobufs. */ +#ifdef HAVE_W32_SYSTEM + if (filefd == -1) + inp = iobuf_open (filename); + else + { + inp = NULL; + gpg_err_set_errno (ENOSYS); + } +#else + if (filefd == GNUPG_INVALID_FD) + inp = iobuf_open (filename); + else + inp = iobuf_fdopen_nc (FD2INT(filefd), "rb"); +#endif + if (inp) + iobuf_ioctl (inp, IOBUF_IOCTL_NO_CACHE, 1, NULL); + if (inp && is_secured_file (iobuf_get_fd (inp))) + { + iobuf_close (inp); + inp = NULL; + gpg_err_set_errno (EPERM); + } + if (!inp) + { + char xname[64]; + + rc = gpg_error_from_syserror (); + if (filefd != -1) + snprintf (xname, sizeof xname, "[fd %d]", filefd); + else if (!filename) + strcpy (xname, "[stdin]"); + else + *xname = 0; + log_error (_("can't open '%s': %s\n"), + *xname? xname : filename, gpg_strerror (rc) ); + goto leave; + } + + if (opt.verbose) + log_info (_("reading from '%s'\n"), iobuf_get_fname_nonnull (inp)); + + handle_progress (pfx, inp, filename); + + if (opt.textmode) + iobuf_push_filter (inp, text_filter, &tfx); + + rc = open_outfile (outputfd, filename, opt.armor? 1:0, 0, &out); + if (rc) + goto leave; + + if (opt.armor) + { + afx = new_armor_context (); + push_armor_filter (afx, out); + } + + /* Create a session key. */ + cfx.dek = xmalloc_secure_clear (sizeof *cfx.dek); + if (!opt.def_cipher_algo) + { + /* Try to get it from the prefs. */ + cfx.dek->algo = select_algo_from_prefs (pk_list, PREFTYPE_SYM, -1, NULL); + /* The only way select_algo_from_prefs can fail here is when + mixing v3 and v4 keys, as v4 keys have an implicit preference + entry for 3DES, and the pk_list cannot be empty. In this + case, use 3DES anyway as it's the safest choice - perhaps the + v3 key is being used in an OpenPGP implementation and we know + that the implementation behind any v4 key can handle 3DES. */ + if (cfx.dek->algo == -1) + { + cfx.dek->algo = CIPHER_ALGO_3DES; + } + + /* In case 3DES has been selected, print a warning if any key + does not have a preference for AES. This should help to + indentify why encrypting to several recipients falls back to + 3DES. */ + if (opt.verbose && cfx.dek->algo == CIPHER_ALGO_3DES) + warn_missing_aes_from_pklist (pk_list); + } + else + { + if (!opt.expert + && (select_algo_from_prefs (pk_list, PREFTYPE_SYM, + opt.def_cipher_algo, NULL) + != opt.def_cipher_algo)) + { + log_info(_("WARNING: forcing symmetric cipher %s (%d)" + " violates recipient preferences\n"), + openpgp_cipher_algo_name (opt.def_cipher_algo), + opt.def_cipher_algo); + } + + cfx.dek->algo = opt.def_cipher_algo; + } + + /* Check compliance. */ + if (! gnupg_cipher_is_allowed (opt.compliance, 1, cfx.dek->algo, + GCRY_CIPHER_MODE_CFB)) + { + log_error (_("cipher algorithm '%s' may not be used in %s mode\n"), + openpgp_cipher_algo_name (cfx.dek->algo), + gnupg_compliance_option_string (opt.compliance)); + rc = gpg_error (GPG_ERR_CIPHER_ALGO); + goto leave; + } + + if (!gnupg_rng_is_compliant (opt.compliance)) + { + rc = gpg_error (GPG_ERR_FORBIDDEN); + log_error (_("%s is not compliant with %s mode\n"), + "RNG", + gnupg_compliance_option_string (opt.compliance)); + write_status_error ("random-compliance", rc); + goto leave; + } + + compliant = gnupg_cipher_is_compliant (CO_DE_VS, cfx.dek->algo, + GCRY_CIPHER_MODE_CFB); + + { + pk_list_t pkr; + + for (pkr = pk_list; pkr; pkr = pkr->next) + { + PKT_public_key *pk = pkr->pk; + unsigned int nbits = nbits_from_pk (pk); + + if (!gnupg_pk_is_compliant (opt.compliance, pk->pubkey_algo, 0, + pk->pkey, nbits, NULL)) + log_info (_("WARNING: key %s is not suitable for encryption" + " in %s mode\n"), + keystr_from_pk (pk), + gnupg_compliance_option_string (opt.compliance)); + + if (compliant + && !gnupg_pk_is_compliant (CO_DE_VS, pk->pubkey_algo, 0, pk->pkey, + nbits, NULL)) + compliant = 0; + } + + } + + if (compliant) + write_status_strings (STATUS_ENCRYPTION_COMPLIANCE_MODE, + gnupg_status_compliance_flag (CO_DE_VS), + NULL); + + cfx.dek->use_mdc = use_mdc (pk_list,cfx.dek->algo); + + /* Only do the is-file-already-compressed check if we are using a + MDC. This forces compressed files to be re-compressed if we do + not have a MDC to give some protection against chosen ciphertext + attacks. */ + + if (do_compress && cfx.dek->use_mdc && is_file_compressed(filename, &rc2)) + { + if (opt.verbose) + log_info(_("'%s' already compressed\n"), filename); + do_compress = 0; + } + if (rc2) + { + rc = rc2; + goto leave; + } + + make_session_key (cfx.dek); + if (DBG_CRYPTO) + log_printhex (cfx.dek->key, cfx.dek->keylen, "DEK is: "); + + rc = write_pubkey_enc_from_list (ctrl, pk_list, cfx.dek, out); + if (rc) + goto leave; + + /* We put the passphrase (if any) after any public keys as this + seems to be the most useful on the recipient side - there is no + point in prompting a user for a passphrase if they have the + secret key needed to decrypt. */ + if(use_symkey && (rc = write_symkey_enc(symkey_s2k,symkey_dek,cfx.dek,out))) + goto leave; + + if (!opt.no_literal) + pt = setup_plaintext_name (filename, inp); + + /* Get the size of the file if possible, i.e., if it is a real file. */ + if (filename && *filename + && !iobuf_is_pipe_filename (filename) && !opt.textmode ) + { + off_t tmpsize; + int overflow; + + if ( !(tmpsize = iobuf_get_filelength(inp, &overflow)) + && !overflow && opt.verbose) + log_info(_("WARNING: '%s' is an empty file\n"), filename ); + /* We can't encode the length of very large files because + OpenPGP uses only 32 bit for file sizes. So if the size + of a file is larger than 2^32 minus some bytes for packet + headers, we switch to partial length encoding. */ + if (tmpsize < (IOBUF_FILELENGTH_LIMIT - 65536) ) + filesize = tmpsize; + else + filesize = 0; + } + else + filesize = opt.set_filesize ? opt.set_filesize : 0; /* stdin */ + + if (!opt.no_literal) + { + pt->timestamp = make_timestamp(); + pt->mode = opt.mimemode? 'm' : opt.textmode ? 't' : 'b'; + pt->len = filesize; + pt->new_ctb = !pt->len; + pt->buf = inp; + pkt.pkttype = PKT_PLAINTEXT; + pkt.pkt.plaintext = pt; + cfx.datalen = filesize && !do_compress? calc_packet_length( &pkt ) : 0; + } + else + cfx.datalen = filesize && !do_compress ? filesize : 0; + + /* Register the cipher filter. */ + iobuf_push_filter (out, cipher_filter, &cfx); + + /* Register the compress filter. */ + if (do_compress) + { + int compr_algo = opt.compress_algo; + + if (compr_algo == -1) + { + compr_algo = select_algo_from_prefs (pk_list, PREFTYPE_ZIP, -1, NULL); + if (compr_algo == -1) + compr_algo = DEFAULT_COMPRESS_ALGO; + /* Theoretically impossible to get here since uncompressed + is implicit. */ + } + else if (!opt.expert + && select_algo_from_prefs(pk_list, PREFTYPE_ZIP, + compr_algo, NULL) != compr_algo) + { + log_info (_("WARNING: forcing compression algorithm %s (%d)" + " violates recipient preferences\n"), + compress_algo_to_string(compr_algo), compr_algo); + } + + /* Algo 0 means no compression. */ + if (compr_algo) + { + if (cfx.dek && cfx.dek->use_mdc) + zfx.new_ctb = 1; + push_compress_filter (out,&zfx,compr_algo); + } + } + + /* Do the work. */ + if (!opt.no_literal) + { + if ((rc = build_packet( out, &pkt ))) + log_error ("build_packet failed: %s\n", gpg_strerror (rc)); + } + else + { + /* User requested not to create a literal packet, so we copy the + plain data. */ + byte copy_buffer[4096]; + int bytes_copied; + while ((bytes_copied = iobuf_read (inp, copy_buffer, 4096)) != -1) + { + rc = iobuf_write (out, copy_buffer, bytes_copied); + if (rc) + { + log_error ("copying input to output failed: %s\n", + gpg_strerror (rc)); + break; + } + } + wipememory (copy_buffer, 4096); /* Burn the buffer. */ + } + + /* Finish the stuff. */ + leave: + iobuf_close (inp); + if (rc) + iobuf_cancel (out); + else + { + iobuf_close (out); /* fixme: check returncode */ + write_status (STATUS_END_ENCRYPTION); + } + if (pt) + pt->buf = NULL; + free_packet (&pkt, NULL); + xfree (cfx.dek); + xfree (symkey_dek); + xfree (symkey_s2k); + if (!provided_keys) + release_pk_list (pk_list); + release_armor_context (afx); + release_progress_context (pfx); + return rc; +} + + +/* + * Filter to do a complete public key encryption. + */ +int +encrypt_filter (void *opaque, int control, + iobuf_t a, byte *buf, size_t *ret_len) +{ + size_t size = *ret_len; + encrypt_filter_context_t *efx = opaque; + int rc = 0; + + if (control == IOBUFCTRL_UNDERFLOW) /* decrypt */ + { + BUG(); /* not used */ + } + else if ( control == IOBUFCTRL_FLUSH ) /* encrypt */ + { + if ( !efx->header_okay ) + { + efx->cfx.dek = xmalloc_secure_clear ( sizeof *efx->cfx.dek ); + if ( !opt.def_cipher_algo ) + { + /* Try to get it from the prefs. */ + efx->cfx.dek->algo = + select_algo_from_prefs (efx->pk_list, PREFTYPE_SYM, -1, NULL); + if (efx->cfx.dek->algo == -1 ) + { + /* Because 3DES is implicitly in the prefs, this can + only happen if we do not have any public keys in + the list. */ + efx->cfx.dek->algo = DEFAULT_CIPHER_ALGO; + } + + /* In case 3DES has been selected, print a warning if + any key does not have a preference for AES. This + should help to indentify why encrypting to several + recipients falls back to 3DES. */ + if (opt.verbose + && efx->cfx.dek->algo == CIPHER_ALGO_3DES) + warn_missing_aes_from_pklist (efx->pk_list); + } + else + { + if (!opt.expert + && select_algo_from_prefs (efx->pk_list,PREFTYPE_SYM, + opt.def_cipher_algo, + NULL) != opt.def_cipher_algo) + log_info(_("forcing symmetric cipher %s (%d) " + "violates recipient preferences\n"), + openpgp_cipher_algo_name (opt.def_cipher_algo), + opt.def_cipher_algo); + + efx->cfx.dek->algo = opt.def_cipher_algo; + } + + efx->cfx.dek->use_mdc = use_mdc (efx->pk_list,efx->cfx.dek->algo); + + make_session_key ( efx->cfx.dek ); + if (DBG_CRYPTO) + log_printhex (efx->cfx.dek->key, efx->cfx.dek->keylen, "DEK is: "); + + rc = write_pubkey_enc_from_list (efx->ctrl, + efx->pk_list, efx->cfx.dek, a); + if (rc) + return rc; + + if(efx->symkey_s2k && efx->symkey_dek) + { + rc=write_symkey_enc(efx->symkey_s2k,efx->symkey_dek, + efx->cfx.dek,a); + if(rc) + return rc; + } + + iobuf_push_filter (a, cipher_filter, &efx->cfx); + + efx->header_okay = 1; + } + rc = iobuf_write (a, buf, size); + + } + else if (control == IOBUFCTRL_FREE) + { + xfree (efx->symkey_dek); + xfree (efx->symkey_s2k); + } + else if ( control == IOBUFCTRL_DESC ) + { + mem2str (buf, "encrypt_filter", *ret_len); + } + return rc; +} + + +/* + * Write a pubkey-enc packet for the public key PK to OUT. + */ +int +write_pubkey_enc (ctrl_t ctrl, + PKT_public_key *pk, int throw_keyid, DEK *dek, iobuf_t out) +{ + PACKET pkt; + PKT_pubkey_enc *enc; + int rc; + gcry_mpi_t frame; + + print_pubkey_algo_note ( pk->pubkey_algo ); + enc = xmalloc_clear ( sizeof *enc ); + enc->pubkey_algo = pk->pubkey_algo; + keyid_from_pk( pk, enc->keyid ); + enc->throw_keyid = throw_keyid; + + /* Okay, what's going on: We have the session key somewhere in + * the structure DEK and want to encode this session key in an + * integer value of n bits. pubkey_nbits gives us the number of + * bits we have to use. We then encode the session key in some + * way and we get it back in the big intger value FRAME. Then + * we use FRAME, the public key PK->PKEY and the algorithm + * number PK->PUBKEY_ALGO and pass it to pubkey_encrypt which + * returns the encrypted value in the array ENC->DATA. This + * array has a size which depends on the used algorithm (e.g. 2 + * for Elgamal). We don't need frame anymore because we have + * everything now in enc->data which is the passed to + * build_packet(). */ + frame = encode_session_key (pk->pubkey_algo, dek, + pubkey_nbits (pk->pubkey_algo, pk->pkey)); + rc = pk_encrypt (pk->pubkey_algo, enc->data, frame, pk, pk->pkey); + gcry_mpi_release (frame); + if (rc) + log_error ("pubkey_encrypt failed: %s\n", gpg_strerror (rc) ); + else + { + if ( opt.verbose ) + { + char *ustr = get_user_id_string_native (ctrl, enc->keyid); + log_info (_("%s/%s encrypted for: \"%s\"\n"), + openpgp_pk_algo_name (enc->pubkey_algo), + openpgp_cipher_algo_name (dek->algo), + ustr ); + xfree (ustr); + } + /* And write it. */ + init_packet (&pkt); + pkt.pkttype = PKT_PUBKEY_ENC; + pkt.pkt.pubkey_enc = enc; + rc = build_packet (out, &pkt); + if (rc) + log_error ("build_packet(pubkey_enc) failed: %s\n", + gpg_strerror (rc)); + } + free_pubkey_enc(enc); + return rc; +} + + +/* + * Write pubkey-enc packets from the list of PKs to OUT. + */ +static int +write_pubkey_enc_from_list (ctrl_t ctrl, PK_LIST pk_list, DEK *dek, iobuf_t out) +{ + if (opt.throw_keyids && (PGP6 || PGP7 || PGP8)) + { + log_info(_("option '%s' may not be used in %s mode\n"), + "--throw-keyids", + gnupg_compliance_option_string (opt.compliance)); + compliance_failure(); + } + + for ( ; pk_list; pk_list = pk_list->next ) + { + PKT_public_key *pk = pk_list->pk; + int throw_keyid = (opt.throw_keyids || (pk_list->flags&1)); + int rc = write_pubkey_enc (ctrl, pk, throw_keyid, dek, out); + if (rc) + return rc; + } + + return 0; +} + +void +encrypt_crypt_files (ctrl_t ctrl, int nfiles, char **files, strlist_t remusr) +{ + int rc = 0; + + if (opt.outfile) + { + log_error(_("--output doesn't work for this command\n")); + return; + } + + if (!nfiles) + { + char line[2048]; + unsigned int lno = 0; + while ( fgets(line, DIM(line), stdin) ) + { + lno++; + if (!*line || line[strlen(line)-1] != '\n') + { + log_error("input line %u too long or missing LF\n", lno); + return; + } + line[strlen(line)-1] = '\0'; + print_file_status(STATUS_FILE_START, line, 2); + rc = encrypt_crypt (ctrl, -1, line, remusr, 0, NULL, -1); + if (rc) + log_error ("encryption of '%s' failed: %s\n", + print_fname_stdin(line), gpg_strerror (rc) ); + write_status( STATUS_FILE_DONE ); + } + } + else + { + while (nfiles--) + { + print_file_status(STATUS_FILE_START, *files, 2); + if ( (rc = encrypt_crypt (ctrl, -1, *files, remusr, 0, NULL, -1)) ) + log_error("encryption of '%s' failed: %s\n", + print_fname_stdin(*files), gpg_strerror (rc) ); + write_status( STATUS_FILE_DONE ); + files++; + } + } +} |