diff options
Diffstat (limited to 'g10/encode.c')
| -rw-r--r-- | g10/encode.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/g10/encode.c b/g10/encode.c index 825a4c98a..ba97299e2 100644 --- a/g10/encode.c +++ b/g10/encode.c @@ -39,6 +39,7 @@ static int encode_simple( const char *filename, int mode ); +static int encode_crypt_mdc( const char* fname, STRLIST remusr ); static int write_pubkey_enc_from_list( PK_LIST pk_list, DEK *dek, IOBUF out ); @@ -215,6 +216,10 @@ encode_crypt( const char *filename, STRLIST remusr ) PK_LIST pk_list; int do_compress = opt.compress && !opt.rfc1991; + if( opt.force_mdc ) + return encode_crypt_mdc( filename, remusr ); + + memset( &cfx, 0, sizeof cfx); memset( &afx, 0, sizeof afx); memset( &zfx, 0, sizeof zfx); @@ -329,6 +334,193 @@ encode_crypt( const char *filename, STRLIST remusr ) } + +static int +encode_crypt_mdc( const char* fname, STRLIST remusr ) +{ + armor_filter_context_t afx; + compress_filter_context_t zfx; + md_filter_context_t mfx; + text_filter_context_t tfx; + encrypt_filter_context_t efx; + IOBUF inp = NULL, out = NULL; + PACKET pkt; + PKT_plaintext *pt = NULL; + u32 filesize; + int rc = 0; + PK_LIST pk_list = NULL; + int compr_algo = -1; /* unknown */ + + + memset( &afx, 0, sizeof afx); + memset( &zfx, 0, sizeof zfx); + memset( &mfx, 0, sizeof mfx); + memset( &tfx, 0, sizeof tfx); + memset( &efx, 0, sizeof efx); + init_packet( &pkt ); + + if( (rc=build_pk_list( remusr, &pk_list, PUBKEY_USAGE_ENC )) ) + goto leave; + compr_algo = select_algo_from_prefs( pk_list, PREFTYPE_COMPR ); + + /* prepare iobufs */ + if( !(inp = iobuf_open(fname)) ) { + log_error("can't open %s: %s\n", fname? fname: "[stdin]", + strerror(errno) ); + rc = G10ERR_OPEN_FILE; + goto leave; + } + + if( (rc = open_outfile( fname, opt.armor? 1: 0, &out ))) + goto leave; + + /* prepare to calculate the MD over the input */ + mfx.md = md_open( DIGEST_ALGO_SHA1, 0 ); + iobuf_push_filter( inp, md_filter, &mfx ); + + if( opt.armor ) + iobuf_push_filter( out, armor_filter, &afx ); + efx.pk_list = pk_list; + /* fixme: set efx.cfx.datalen if known */ + iobuf_push_filter( out, encrypt_filter, &efx ); + + if( opt.compress ) { + if( !compr_algo ) + ; /* don't use compression */ + else { + if( compr_algo == 1 ) + zfx.algo = 1; + iobuf_push_filter( out, compress_filter, &zfx ); + } + } + + /* build a one pass packet */ + { + PKT_onepass_sig *ops; + + ops = m_alloc_clear( sizeof *ops ); + ops->sig_class = 0x00; + ops->digest_algo = DIGEST_ALGO_SHA1; + ops->pubkey_algo = 0; + ops->keyid[0] = 0; + ops->keyid[1] = 0; + ops->last = 1; + + init_packet(&pkt); + pkt.pkttype = PKT_ONEPASS_SIG; + pkt.pkt.onepass_sig = ops; + rc = build_packet( out, &pkt ); + free_packet( &pkt ); + if( rc ) { + log_error("build onepass_sig packet failed: %s\n", + g10_errstr(rc)); + goto leave; + } + } + + /* setup the inner packet */ + if( fname || opt.set_filename ) { + char *s = make_basename( opt.set_filename ? opt.set_filename : fname ); + pt = m_alloc( sizeof *pt + strlen(s) - 1 ); + pt->namelen = strlen(s); + memcpy(pt->name, s, pt->namelen ); + m_free(s); + } + else { /* no filename */ + pt = m_alloc( sizeof *pt - 1 ); + pt->namelen = 0; + } + if( fname ) { + if( !(filesize = iobuf_get_filelength(inp)) ) + log_info(_("WARNING: `%s' is an empty file\n"), fname ); + + /* because the text_filter modifies the length of the + * data, it is not possible to know the used length + * without a double read of the file - to avoid that + * we simple use partial length packets. + */ + if( opt.textmode ) + filesize = 0; + } + else + filesize = 0; /* stdin */ + pt->timestamp = make_timestamp(); + pt->mode = 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? calc_packet_length( &pkt ) : 0;*/ + if( (rc = build_packet( out, &pkt )) ) + log_error("build_packet(PLAINTEXT) failed: %s\n", g10_errstr(rc) ); + pt->buf = NULL; + + /* build the MDC faked signature packet */ + { + PKT_signature *sig; + MD_HANDLE md; + byte buf[6]; + size_t n; + + sig = m_alloc_clear( sizeof *sig ); + sig->version = 4; + sig->digest_algo = DIGEST_ALGO_SHA1; + md = md_copy( mfx.md ); + + md_putc( md, sig->version ); + md_putc( md, sig->sig_class ); + md_putc( md, sig->pubkey_algo ); + md_putc( md, sig->digest_algo ); + n = 6; + /* add some magic */ + buf[0] = sig->version; + buf[1] = 0xff; buf[2] = 0; buf[3] = 0; buf[4] = 0; buf[5] = 6; + md_write( md, buf, 6 ); + md_final( md ); + + /* pack the hash into data[0] */ + memcpy( sig->digest_start, md_read( md, DIGEST_ALGO_SHA1), 2 ); + sig->data[0] = mpi_alloc( (20+BYTES_PER_MPI_LIMB-1) + /BYTES_PER_MPI_LIMB ); + mpi_set_buffer( sig->data[0], md_read(md, DIGEST_ALGO_SHA1), + md_digest_length(DIGEST_ALGO_SHA1), 0 ); + + md_close( md ); + + if( !rc ) { /* and write it */ + init_packet(&pkt); + pkt.pkttype = PKT_SIGNATURE; + pkt.pkt.signature = sig; + rc = build_packet( out, &pkt ); + free_packet( &pkt ); + if( rc ) + log_error("build MDC packet failed: %s\n", g10_errstr(rc) ); + } + if( rc ) + goto leave; + } + + + leave: + if( rc ) + iobuf_cancel(out); + else + iobuf_close(out); + iobuf_close(inp); + md_close( mfx.md ); + release_pk_list( pk_list ); + return rc; +} + + + + + + + + + /**************** * Filter to do a complete public key encryption. */ |