1 /*****************************************************************************
2 * update_crypto.c: OpenPGP related functions used for updating
3 *****************************************************************************
4 * Copyright © 2008-2009 VLC authors and VideoLAN
7 * Authors: Rafaël Carré <funman@videolanorg>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU Lesser General Public License as published by
11 * the Free Software Foundation; either release 2 of the License, or
12 * (at your option) any later release.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
26 * This file contains functions related to OpenPGP in VLC update management
29 /*****************************************************************************
31 *****************************************************************************/
42 #include "vlc_common.h"
43 #include <vlc_stream.h>
44 #include <vlc_strings.h>
50 /*****************************************************************************
52 *****************************************************************************/
54 #define packet_type( c ) ( ( c & 0x3c ) >> 2 ) /* 0x3C = 00111100 */
55 #define packet_header_len( c ) ( ( c & 0x03 ) + 1 ) /* number of bytes in a packet header */
58 static inline int scalar_number( const uint8_t *p, int header_len )
60 assert( header_len == 1 || header_len == 2 || header_len == 4 );
64 else if( header_len == 2 )
65 return( (p[0] << 8) + p[1] );
66 else if( header_len == 4 )
67 return( (p[0] << 24) + (p[1] << 16) + (p[2] << 8) + p[3] );
73 /* number of data bytes in a MPI */
74 static int mpi_len(const uint8_t *mpi)
76 return (scalar_number(mpi, 2) + 7) / 8;
79 static size_t read_mpi(uint8_t *dst, const uint8_t *buf, size_t buflen, size_t bits)
84 size_t n = mpi_len(buf);
98 #define READ_MPI(d, bits) do { \
99 size_t n = read_mpi(d, p_buf, i_packet_len - i_read, bits); \
100 if (!n) goto error; \
106 * fill a public_key_packet_t structure from public key packet data
107 * verify that it is a version 4 public key packet, using DSA or RSA
109 static int parse_public_key_packet( public_key_packet_t *p_key,
110 const uint8_t *p_buf, size_t i_packet_len )
112 if( i_packet_len < 6 )
117 p_key->version = *p_buf++; i_read++;
118 if( p_key->version != 4 )
121 /* XXX: warn when timestamp is > date ? */
122 memcpy( p_key->timestamp, p_buf, 4 ); p_buf += 4; i_read += 4;
124 p_key->algo = *p_buf++; i_read++;
125 if( p_key->algo == GCRY_PK_DSA ) {
126 READ_MPI(p_key->sig.dsa.p, 3072);
127 READ_MPI(p_key->sig.dsa.q, 256);
128 READ_MPI(p_key->sig.dsa.g, 3072);
129 READ_MPI(p_key->sig.dsa.y, 3072);
130 } else if ( p_key->algo == GCRY_PK_RSA ) {
131 READ_MPI(p_key->sig.rsa.n, 4096);
132 READ_MPI(p_key->sig.rsa.e, 4096);
136 if( i_read == i_packet_len )
139 /* some extra data eh ? */
146 static size_t parse_signature_v3_packet( signature_packet_t *p_sig,
147 const uint8_t *p_buf, size_t i_sig_len )
149 size_t i_read = 1; /* we already read the version byte */
151 if( i_sig_len < 19 ) /* signature is at least 19 bytes + the 2 MPIs */
154 p_sig->specific.v3.hashed_data_len = *p_buf++; i_read++;
155 if( p_sig->specific.v3.hashed_data_len != 5 )
158 p_sig->type = *p_buf++; i_read++;
160 memcpy( p_sig->specific.v3.timestamp, p_buf, 4 );
161 p_buf += 4; i_read += 4;
163 memcpy( p_sig->issuer_longid, p_buf, 8 );
164 p_buf += 8; i_read += 8;
166 p_sig->public_key_algo = *p_buf++; i_read++;
168 p_sig->digest_algo = *p_buf++; i_read++;
170 p_sig->hash_verification[0] = *p_buf++; i_read++;
171 p_sig->hash_verification[1] = *p_buf++; i_read++;
173 assert( i_read == 19 );
180 * fill a signature_packet_v4_t from signature packet data
181 * verify that it was used with a DSA or RSA public key
183 static size_t parse_signature_v4_packet( signature_packet_t *p_sig,
184 const uint8_t *p_buf, size_t i_sig_len )
186 size_t i_read = 1; /* we already read the version byte */
188 if( i_sig_len < 10 ) /* signature is at least 10 bytes + the 2 MPIs */
191 p_sig->type = *p_buf++; i_read++;
193 p_sig->public_key_algo = *p_buf++; i_read++;
194 if (p_sig->public_key_algo != GCRY_PK_DSA && p_sig->public_key_algo != GCRY_PK_RSA )
197 p_sig->digest_algo = *p_buf++; i_read++;
199 memcpy( p_sig->specific.v4.hashed_data_len, p_buf, 2 );
200 p_buf += 2; i_read += 2;
202 size_t i_hashed_data_len =
203 scalar_number( p_sig->specific.v4.hashed_data_len, 2 );
204 i_read += i_hashed_data_len;
205 if( i_read + 4 > i_sig_len )
208 p_sig->specific.v4.hashed_data = (uint8_t*) malloc( i_hashed_data_len );
209 if( !p_sig->specific.v4.hashed_data )
211 memcpy( p_sig->specific.v4.hashed_data, p_buf, i_hashed_data_len );
212 p_buf += i_hashed_data_len;
214 memcpy( p_sig->specific.v4.unhashed_data_len, p_buf, 2 );
215 p_buf += 2; i_read += 2;
217 size_t i_unhashed_data_len =
218 scalar_number( p_sig->specific.v4.unhashed_data_len, 2 );
219 i_read += i_unhashed_data_len;
220 if( i_read + 2 > i_sig_len )
223 p_sig->specific.v4.unhashed_data = (uint8_t*) malloc( i_unhashed_data_len );
224 if( !p_sig->specific.v4.unhashed_data )
227 memcpy( p_sig->specific.v4.unhashed_data, p_buf, i_unhashed_data_len );
228 p_buf += i_unhashed_data_len;
230 memcpy( p_sig->hash_verification, p_buf, 2 );
231 p_buf += 2; i_read += 2;
233 uint8_t *p, *max_pos;
234 p = p_sig->specific.v4.unhashed_data;
235 max_pos = p + scalar_number( p_sig->specific.v4.unhashed_data_len, 2 );
242 size_t i_subpacket_len;
245 if( p + 1 > max_pos )
247 i_subpacket_len = *p++;
251 if( p + 2 > max_pos )
253 i_subpacket_len = (*p++ - 192) << 8;
254 i_subpacket_len += *p++ + 192;
258 if( p + 4 > max_pos )
260 i_subpacket_len = *++p << 24;
261 i_subpacket_len += *++p << 16;
262 i_subpacket_len += *++p << 8;
263 i_subpacket_len += *++p;
266 if( *p == ISSUER_SUBPACKET )
268 if( p + 9 > max_pos )
271 memcpy( &p_sig->issuer_longid, p+1, 8 );
276 p += i_subpacket_len;
281 static int parse_signature_packet( signature_packet_t *p_sig,
282 const uint8_t *p_buf, size_t i_packet_len )
284 if( !i_packet_len ) /* 1st sanity check, we need at least the version */
287 p_sig->version = *p_buf++;
290 switch( p_sig->version )
293 i_read = parse_signature_v3_packet( p_sig, p_buf, i_packet_len );
296 p_sig->specific.v4.hashed_data = NULL;
297 p_sig->specific.v4.unhashed_data = NULL;
298 i_read = parse_signature_v4_packet( p_sig, p_buf, i_packet_len );
304 if( i_read == 0 ) /* signature packet parsing has failed */
307 if( p_sig->public_key_algo != GCRY_PK_DSA && p_sig->public_key_algo != GCRY_PK_RSA )
310 switch( p_sig->type )
312 case BINARY_SIGNATURE:
314 case GENERIC_KEY_SIGNATURE:
315 case PERSONA_KEY_SIGNATURE:
316 case CASUAL_KEY_SIGNATURE:
317 case POSITIVE_KEY_SIGNATURE:
323 p_buf--; /* rewind to the version byte */
326 if( p_sig->public_key_algo == GCRY_PK_DSA ) {
327 READ_MPI(p_sig->algo_specific.dsa.r, 256);
328 READ_MPI(p_sig->algo_specific.dsa.s, 256);
329 } else if ( p_sig->public_key_algo == GCRY_PK_RSA ) {
330 READ_MPI(p_sig->algo_specific.rsa.s, 4096);
334 assert( i_read == i_packet_len );
335 if( i_read < i_packet_len ) /* some extra data, hm ? */
342 if( p_sig->version == 4 )
344 free( p_sig->specific.v4.hashed_data );
345 free( p_sig->specific.v4.unhashed_data );
353 * crc_octets() was lamely copied from rfc 2440
354 * Copyright (C) The Internet Society (1998). All Rights Reserved.
356 #define CRC24_INIT 0xB704CEL
357 #define CRC24_POLY 0x1864CFBL
359 static long crc_octets( uint8_t *octets, size_t len )
361 long crc = CRC24_INIT;
365 crc ^= (*octets++) << 16;
366 for (i = 0; i < 8; i++)
373 return crc & 0xFFFFFFL;
378 * Transform an armored document in binary format
379 * Used on public keys and signatures
381 static int pgp_unarmor( const char *p_ibuf, size_t i_ibuf_len,
382 uint8_t *p_obuf, size_t i_obuf_len )
384 const char *p_ipos = p_ibuf;
385 uint8_t *p_opos = p_obuf;
387 int i_header_skipped = 0;
389 while( !i_end && p_ipos < p_ibuf + i_ibuf_len && *p_ipos != '=' )
391 if( *p_ipos == '\r' || *p_ipos == '\n' )
397 size_t i_line_len = strcspn( p_ipos, "\r\n" );
398 if( i_line_len == 0 )
401 if( !i_header_skipped )
403 if( !strncmp( p_ipos, "-----BEGIN PGP", 14 ) )
404 i_header_skipped = 1;
406 p_ipos += i_line_len + 1;
410 if( !strncmp( p_ipos, "Version:", 8 ) )
412 p_ipos += i_line_len + 1;
416 if( p_ipos[i_line_len - 1] == '=' )
421 p_opos += vlc_b64_decode_binary_to_buffer( p_opos,
422 p_obuf - p_opos + i_obuf_len, p_ipos );
423 p_ipos += i_line_len + 1;
426 /* XXX: the CRC is OPTIONAL, really require it ? */
427 if( p_ipos + 5 > p_ibuf + i_ibuf_len || *p_ipos++ != '=' )
431 if( vlc_b64_decode_binary_to_buffer( p_crc, 3, p_ipos ) != 3 )
434 long l_crc = crc_octets( p_obuf, p_opos - p_obuf );
435 long l_crc2 = ( 0 << 24 ) + ( p_crc[0] << 16 ) + ( p_crc[1] << 8 ) + p_crc[2];
437 return l_crc2 == l_crc ? p_opos - p_obuf : 0;
440 static int rsa_pkcs1_encode_sig(gcry_mpi_t *r_result, size_t size,
441 const uint8_t *hash, int algo)
444 uint8_t frame[4096/8];
446 size_t asnlen = sizeof(asn);
447 size_t hashlen = gcry_md_get_algo_dlen(algo);
449 if (gcry_md_algo_info(algo, GCRYCTL_GET_ASNOID, asn, &asnlen))
452 if (!hashlen || hashlen + asnlen + 4 > size)
456 frame[1] = 1; /* block type */
457 int pad = size - hashlen - asnlen - 3 ;
458 memset (&frame[2], 0xff, pad );
460 memcpy(&frame[3+pad], asn, asnlen);
461 memcpy(&frame[3+pad+asnlen], hash, hashlen);
463 if (gcry_mpi_scan(r_result, GCRYMPI_FMT_USG, frame, size, &size))
469 * Verify an OpenPGP signature made with some RSA public key
471 static int verify_signature_rsa( signature_packet_t *sign, public_key_packet_t *p_key,
474 int ret = VLC_EGENERIC;
475 /* the data to be verified (a hash) */
476 const char *hash_sexp_s = "(data(flags raw)(value %m))";
478 const char *key_sexp_s = "(public-key(rsa(n %m)(e %m)))";
480 const char *sig_sexp_s = "(sig-val(rsa(s%m)))";
483 gcry_mpi_t n, e, s, hash;
484 n = e = s = hash = NULL;
485 gcry_sexp_t key_sexp, hash_sexp, sig_sexp;
486 key_sexp = hash_sexp = sig_sexp = NULL;
488 int i_n_len = mpi_len( p_key->sig.rsa.n );
489 int i_e_len = mpi_len( p_key->sig.rsa.e );
490 if( gcry_mpi_scan( &n, GCRYMPI_FMT_USG, p_key->sig.rsa.n + 2, i_n_len, NULL ) ||
491 gcry_mpi_scan( &e, GCRYMPI_FMT_USG, p_key->sig.rsa.e + 2, i_e_len, NULL ) ||
492 gcry_sexp_build( &key_sexp, &erroff, key_sexp_s, n, e ) )
495 uint8_t *p_s = sign->algo_specific.rsa.s;
496 int i_s_len = mpi_len( p_s );
497 if( gcry_mpi_scan( &s, GCRYMPI_FMT_USG, p_s + 2, i_s_len, NULL ) ||
498 gcry_sexp_build( &sig_sexp, &erroff, sig_sexp_s, s ) )
501 if( rsa_pkcs1_encode_sig (&hash, i_n_len, p_hash, sign->digest_algo) ||
502 gcry_sexp_build( &hash_sexp, &erroff, hash_sexp_s, hash ) )
505 if( gcry_pk_verify( sig_sexp, hash_sexp, key_sexp ) )
511 if( n ) gcry_mpi_release( n );
512 if( e ) gcry_mpi_release( e );
513 if( s ) gcry_mpi_release( s );
514 if( hash ) gcry_mpi_release( hash );
515 if( key_sexp ) gcry_sexp_release( key_sexp );
516 if( sig_sexp ) gcry_sexp_release( sig_sexp );
517 if( hash_sexp ) gcry_sexp_release( hash_sexp );
522 * Verify an OpenPGP signature made with some DSA public key
524 static int verify_signature_dsa( signature_packet_t *sign, public_key_packet_t *p_key,
527 int ret = VLC_EGENERIC;
529 /* the data to be verified (a hash) */
530 const char *hash_sexp_s = "(data(flags raw)(value %m))";
532 const char *key_sexp_s = "(public-key(dsa(p %m)(q %m)(g %m)(y %m)))";
534 const char *sig_sexp_s = "(sig-val(dsa(r %m )(s %m )))";
537 gcry_mpi_t p, q, g, y, r, s, hash;
538 p = q = g = y = r = s = hash = NULL;
539 gcry_sexp_t key_sexp, hash_sexp, sig_sexp;
540 key_sexp = hash_sexp = sig_sexp = NULL;
542 int i_p_len = mpi_len( p_key->sig.dsa.p );
543 int i_q_len = mpi_len( p_key->sig.dsa.q );
544 int i_g_len = mpi_len( p_key->sig.dsa.g );
545 int i_y_len = mpi_len( p_key->sig.dsa.y );
546 if( gcry_mpi_scan( &p, GCRYMPI_FMT_USG, p_key->sig.dsa.p + 2, i_p_len, NULL ) ||
547 gcry_mpi_scan( &q, GCRYMPI_FMT_USG, p_key->sig.dsa.q + 2, i_q_len, NULL ) ||
548 gcry_mpi_scan( &g, GCRYMPI_FMT_USG, p_key->sig.dsa.g + 2, i_g_len, NULL ) ||
549 gcry_mpi_scan( &y, GCRYMPI_FMT_USG, p_key->sig.dsa.y + 2, i_y_len, NULL ) ||
550 gcry_sexp_build( &key_sexp, &erroff, key_sexp_s, p, q, g, y ) )
553 uint8_t *p_r = sign->algo_specific.dsa.r;
554 uint8_t *p_s = sign->algo_specific.dsa.s;
555 int i_r_len = mpi_len( p_r );
556 int i_s_len = mpi_len( p_s );
557 if( gcry_mpi_scan( &r, GCRYMPI_FMT_USG, p_r + 2, i_r_len, NULL ) ||
558 gcry_mpi_scan( &s, GCRYMPI_FMT_USG, p_s + 2, i_s_len, NULL ) ||
559 gcry_sexp_build( &sig_sexp, &erroff, sig_sexp_s, r, s ) )
562 int i_hash_len = gcry_md_get_algo_dlen (sign->digest_algo);
563 if (i_hash_len > i_q_len)
564 i_hash_len = i_q_len;
565 if( gcry_mpi_scan( &hash, GCRYMPI_FMT_USG, p_hash, i_hash_len, NULL ) ||
566 gcry_sexp_build( &hash_sexp, &erroff, hash_sexp_s, hash ) )
569 if( gcry_pk_verify( sig_sexp, hash_sexp, key_sexp ) )
575 if( p ) gcry_mpi_release( p );
576 if( q ) gcry_mpi_release( q );
577 if( g ) gcry_mpi_release( g );
578 if( y ) gcry_mpi_release( y );
579 if( r ) gcry_mpi_release( r );
580 if( s ) gcry_mpi_release( s );
581 if( hash ) gcry_mpi_release( hash );
582 if( key_sexp ) gcry_sexp_release( key_sexp );
583 if( sig_sexp ) gcry_sexp_release( sig_sexp );
584 if( hash_sexp ) gcry_sexp_release( hash_sexp );
590 * Verify an OpenPGP signature made with some public key
592 int verify_signature( signature_packet_t *sign, public_key_packet_t *p_key,
595 if (sign->public_key_algo == GCRY_PK_DSA)
596 return verify_signature_dsa(sign, p_key, p_hash);
597 else if (sign->public_key_algo == GCRY_PK_RSA)
598 return verify_signature_rsa(sign, p_key, p_hash);
605 * fill a public_key_t with public key data, including:
606 * * public key packet
607 * * signature packet issued by key which long id is p_sig_issuer
610 int parse_public_key( const uint8_t *p_key_data, size_t i_key_len,
611 public_key_t *p_key, const uint8_t *p_sig_issuer )
613 const uint8_t *pos = p_key_data;
614 const uint8_t *max_pos = pos + i_key_len;
617 #define PUBLIC_KEY_FOUND 0x01
618 #define USER_ID_FOUND 0x02
619 #define SIGNATURE_FOUND 0X04
621 uint8_t *p_key_unarmored = NULL;
623 p_key->psz_username = NULL;
624 p_key->sig.specific.v4.hashed_data = NULL;
625 p_key->sig.specific.v4.unhashed_data = NULL;
627 if( !( *pos & 0x80 ) )
628 { /* first byte is ASCII, unarmoring */
629 p_key_unarmored = (uint8_t*)malloc( i_key_len );
630 if( !p_key_unarmored )
632 int i_len = pgp_unarmor( (char*)p_key_data, i_key_len,
633 p_key_unarmored, i_key_len );
638 pos = p_key_unarmored;
639 max_pos = pos + i_len;
642 while( pos < max_pos )
644 if( !(*pos & 0x80) || *pos & 0x40 )
647 int i_type = packet_type( *pos );
649 int i_header_len = packet_header_len( *pos++ );
650 if( pos + i_header_len > max_pos ||
651 ( i_header_len != 1 && i_header_len != 2 && i_header_len != 4 ) )
654 int i_packet_len = scalar_number( pos, i_header_len );
657 if( pos + i_packet_len > max_pos )
662 case PUBLIC_KEY_PACKET:
663 i_status |= PUBLIC_KEY_FOUND;
664 if( parse_public_key_packet( &p_key->key, pos, i_packet_len ) != VLC_SUCCESS )
668 case SIGNATURE_PACKET: /* we accept only v4 signatures here */
669 if( i_status & SIGNATURE_FOUND || !p_sig_issuer )
671 int i_ret = parse_signature_packet( &p_key->sig, pos,
673 if( i_ret == VLC_SUCCESS )
675 if( p_key->sig.version != 4 )
677 if( memcmp( p_key->sig.issuer_longid, p_sig_issuer, 8 ) )
679 free( p_key->sig.specific.v4.hashed_data );
680 free( p_key->sig.specific.v4.unhashed_data );
681 p_key->sig.specific.v4.hashed_data = NULL;
682 p_key->sig.specific.v4.unhashed_data = NULL;
685 i_status |= SIGNATURE_FOUND;
690 if( p_key->psz_username ) /* save only the first User ID */
692 i_status |= USER_ID_FOUND;
693 p_key->psz_username = (uint8_t*)malloc( i_packet_len + 1);
694 if( !p_key->psz_username )
697 memcpy( p_key->psz_username, pos, i_packet_len );
698 p_key->psz_username[i_packet_len] = '\0';
706 free( p_key_unarmored );
708 if( !( i_status & ( PUBLIC_KEY_FOUND | USER_ID_FOUND ) ) )
711 if( p_sig_issuer && !( i_status & SIGNATURE_FOUND ) )
717 if( p_key->sig.version == 4 )
719 free( p_key->sig.specific.v4.hashed_data );
720 free( p_key->sig.specific.v4.unhashed_data );
722 free( p_key->psz_username );
723 free( p_key_unarmored );
728 /* hash a binary file */
729 static int hash_from_binary_file( const char *psz_file, gcry_md_hd_t hd )
731 uint8_t buffer[4096];
734 FILE *f = vlc_fopen( psz_file, "r" );
738 while( ( i_read = fread( buffer, 1, sizeof(buffer), f ) ) > 0 )
739 gcry_md_write( hd, buffer, i_read );
747 /* final part of the hash */
748 static uint8_t *hash_finish( gcry_md_hd_t hd, signature_packet_t *p_sig )
750 if( p_sig->version == 3 )
752 gcry_md_putc( hd, p_sig->type );
753 gcry_md_write( hd, &p_sig->specific.v3.timestamp, 4 );
755 else if( p_sig->version == 4 )
757 gcry_md_putc( hd, p_sig->version );
758 gcry_md_putc( hd, p_sig->type );
759 gcry_md_putc( hd, p_sig->public_key_algo );
760 gcry_md_putc( hd, p_sig->digest_algo );
761 gcry_md_write( hd, p_sig->specific.v4.hashed_data_len, 2 );
762 size_t i_len = scalar_number( p_sig->specific.v4.hashed_data_len, 2 );
763 gcry_md_write( hd, p_sig->specific.v4.hashed_data, i_len );
765 gcry_md_putc( hd, 0x04 );
766 gcry_md_putc( hd, 0xFF );
768 i_len += 6; /* hashed data + 6 bytes header */
770 gcry_md_putc( hd, (i_len >> 24) & 0xff );
771 gcry_md_putc( hd, (i_len >> 16) & 0xff );
772 gcry_md_putc( hd, (i_len >> 8) & 0xff );
773 gcry_md_putc( hd, (i_len) & 0xff );
776 { /* RFC 4880 only tells about versions 3 and 4 */
782 uint8_t *p_tmp = (uint8_t*) gcry_md_read( hd, p_sig->digest_algo) ;
783 unsigned int hash_len = gcry_md_get_algo_dlen (p_sig->digest_algo);
784 uint8_t *p_hash = malloc(hash_len);
786 memcpy(p_hash, p_tmp, hash_len);
793 * return a hash of a text
795 uint8_t *hash_from_text( const char *psz_string,
796 signature_packet_t *p_sig )
799 if( gcry_md_open( &hd, p_sig->digest_algo, 0 ) )
802 if( p_sig->type == TEXT_SIGNATURE )
805 size_t i_len = strcspn( psz_string, "\r\n" );
809 gcry_md_write( hd, psz_string, i_len );
812 gcry_md_putc( hd, '\r' );
813 gcry_md_putc( hd, '\n' );
815 if( *psz_string == '\r' )
817 if( *psz_string == '\n' )
821 gcry_md_write( hd, psz_string, strlen( psz_string ) );
823 return hash_finish( hd, p_sig );
828 * return a hash of a file
830 uint8_t *hash_from_file( const char *psz_file, signature_packet_t *p_sig )
833 if( gcry_md_open( &hd, p_sig->digest_algo, 0 ) )
836 if( hash_from_binary_file( psz_file, hd ) < 0 )
842 return hash_finish( hd, p_sig );
847 * Generate a hash on a public key, to verify a signature made on that hash
848 * Note that we need the signature (v4) to compute the hash
850 uint8_t *hash_from_public_key( public_key_t *p_pkey )
852 const uint8_t pk_algo = p_pkey->key.algo;
854 size_t i_p_len, i_g_len, i_q_len, i_y_len;
855 size_t i_n_len, i_e_len;
857 if( p_pkey->sig.version != 4 )
860 if( p_pkey->sig.type < GENERIC_KEY_SIGNATURE ||
861 p_pkey->sig.type > POSITIVE_KEY_SIGNATURE )
864 gcry_error_t error = 0;
867 if (pk_algo == GCRY_PK_DSA) {
868 i_p_len = mpi_len( p_pkey->key.sig.dsa.p );
869 i_g_len = mpi_len( p_pkey->key.sig.dsa.g );
870 i_q_len = mpi_len( p_pkey->key.sig.dsa.q );
871 i_y_len = mpi_len( p_pkey->key.sig.dsa.y );
873 i_size = 6 + 2*4 + i_p_len + i_g_len + i_q_len + i_y_len;
874 } else if (pk_algo == GCRY_PK_RSA) {
875 i_n_len = mpi_len( p_pkey->key.sig.rsa.n );
876 i_e_len = mpi_len( p_pkey->key.sig.rsa.e );
878 i_size = 6 + 2*2 + i_n_len + i_e_len;
882 error = gcry_md_open( &hd, p_pkey->sig.digest_algo, 0 );
886 gcry_md_putc( hd, 0x99 );
888 gcry_md_putc( hd, (i_size >> 8) & 0xff );
889 gcry_md_putc( hd, i_size & 0xff );
891 gcry_md_putc( hd, p_pkey->key.version );
892 gcry_md_write( hd, p_pkey->key.timestamp, 4 );
893 gcry_md_putc( hd, p_pkey->key.algo );
895 if (pk_algo == GCRY_PK_DSA) {
896 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.dsa.p, 2 + i_p_len );
897 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.dsa.q, 2 + i_q_len );
898 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.dsa.g, 2 + i_g_len );
899 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.dsa.y, 2 + i_y_len );
900 } else if (pk_algo == GCRY_PK_RSA) {
901 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.rsa.n, 2 + i_n_len );
902 gcry_md_write( hd, (uint8_t*)&p_pkey->key.sig.rsa.e, 2 + i_e_len );
905 gcry_md_putc( hd, 0xb4 );
907 size_t i_len = strlen((char*)p_pkey->psz_username);
909 gcry_md_putc( hd, (i_len >> 24) & 0xff );
910 gcry_md_putc( hd, (i_len >> 16) & 0xff );
911 gcry_md_putc( hd, (i_len >> 8) & 0xff );
912 gcry_md_putc( hd, (i_len) & 0xff );
914 gcry_md_write( hd, p_pkey->psz_username, i_len );
916 uint8_t *p_hash = hash_finish( hd, &p_pkey->sig );
918 p_hash[0] != p_pkey->sig.hash_verification[0] ||
919 p_hash[1] != p_pkey->sig.hash_verification[1] )
930 * download a public key (the last one) from videolan server, and parse it
932 public_key_t *download_key( vlc_object_t *p_this,
933 const uint8_t *p_longid, const uint8_t *p_signature_issuer )
936 if( asprintf( &psz_url, "http://download.videolan.org/pub/keys/%.2X%.2X%.2X%.2X%.2X%.2X%.2X%.2X.asc",
937 p_longid[0], p_longid[1], p_longid[2], p_longid[3],
938 p_longid[4], p_longid[5], p_longid[6], p_longid[7] ) == -1 )
941 stream_t *p_stream = stream_UrlNew( p_this, psz_url );
946 int64_t i_size = stream_Size( p_stream );
949 stream_Delete( p_stream );
953 uint8_t *p_buf = (uint8_t*)malloc( i_size );
956 stream_Delete( p_stream );
960 int i_read = stream_Read( p_stream, p_buf, (int)i_size );
961 stream_Delete( p_stream );
963 if( i_read != (int)i_size )
965 msg_Dbg( p_this, "Couldn't read full GPG key" );
970 public_key_t *p_pkey = (public_key_t*) malloc( sizeof( public_key_t ) );
977 memcpy( p_pkey->longid, p_longid, 8 );
979 int i_error = parse_public_key( p_buf, i_read, p_pkey, p_signature_issuer );
982 if( i_error != VLC_SUCCESS )
984 msg_Dbg( p_this, "Couldn't parse GPG key" );
994 * Download the signature associated to a document or a binary file.
995 * We're given the file's url, we just append ".asc" to it and download
997 int download_signature( vlc_object_t *p_this, signature_packet_t *p_sig,
998 const char *psz_url )
1000 char *psz_sig = (char*) malloc( strlen( psz_url ) + 4 + 1 ); /* ".asc" + \0 */
1004 strcpy( psz_sig, psz_url );
1005 strcat( psz_sig, ".asc" );
1007 stream_t *p_stream = stream_UrlNew( p_this, psz_sig );
1013 int64_t i_size = stream_Size( p_stream );
1015 msg_Dbg( p_this, "Downloading signature (%"PRId64" bytes)", i_size );
1016 uint8_t *p_buf = (uint8_t*)malloc( i_size );
1019 stream_Delete( p_stream );
1023 int i_read = stream_Read( p_stream, p_buf, (int)i_size );
1025 stream_Delete( p_stream );
1027 if( i_read != (int)i_size )
1030 "Couldn't download full signature (only %d bytes)", i_read );
1032 return VLC_EGENERIC;
1035 if( (uint8_t)*p_buf < 0x80 ) /* ASCII */
1037 msg_Dbg( p_this, "Unarmoring signature" );
1039 uint8_t* p_unarmored = (uint8_t*) malloc( ( i_size * 3 ) / 4 + 1 );
1043 return VLC_EGENERIC;
1046 int i_bytes = pgp_unarmor( (char*)p_buf, i_size, p_unarmored, i_size );
1049 p_buf = p_unarmored;
1055 msg_Dbg( p_this, "Unarmoring failed : corrupted signature ?" );
1056 return VLC_EGENERIC;
1060 if( packet_type( *p_buf ) != SIGNATURE_PACKET )
1062 msg_Dbg( p_this, "Not a signature: %d", *p_buf );
1064 return VLC_EGENERIC;
1067 size_t i_header_len = packet_header_len( *p_buf );
1068 if( ( i_header_len != 1 && i_header_len != 2 && i_header_len != 4 ) ||
1069 i_header_len + 1 > (size_t)i_size )
1072 msg_Dbg( p_this, "Invalid signature packet header" );
1073 return VLC_EGENERIC;
1076 size_t i_len = scalar_number( p_buf+1, i_header_len );
1077 if( i_len + i_header_len + 1 != (size_t)i_size )
1080 msg_Dbg( p_this, "Invalid signature packet" );
1081 return VLC_EGENERIC;
1084 int i_ret = parse_signature_packet( p_sig, p_buf+1+i_header_len, i_len );
1086 if( i_ret != VLC_SUCCESS )
1088 msg_Dbg( p_this, "Couldn't parse signature" );
1092 if( p_sig->type != BINARY_SIGNATURE && p_sig->type != TEXT_SIGNATURE )
1094 msg_Dbg( p_this, "Invalid signature type: %d", p_sig->type );
1095 if( p_sig->version == 4 )
1097 free( p_sig->specific.v4.hashed_data );
1098 free( p_sig->specific.v4.unhashed_data );
1100 return VLC_EGENERIC;
1106 #endif /* UPDATE_CHECK */