update.c 49.8 KB
Newer Older
1
/*****************************************************************************
Rafaël Carré's avatar
Rafaël Carré committed
2
 * update.c: VLC update checking and downloading
3
 *****************************************************************************
4
 * Copyright © 2005-2008 the VideoLAN team
5
 * $Id$
6 7
 *
 * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
Rafaël Carré's avatar
Rafaël Carré committed
8 9
 *          Rémi Duraffort <ivoire at via.ecp.fr>
            Rafaël Carré <funman@videolanorg>
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 *
 * This program 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 release 2 of the License, or
 * (at your option) any later release.
 *
 * This program 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, USA.
 *****************************************************************************/
25

26 27
/**
 *   \file
28
 *   This file contains functions related to VLC update management
29 30 31 32 33
 */

/*****************************************************************************
 * Preamble
 *****************************************************************************/
34

35 36 37 38
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

39
#include <vlc_common.h>
40
#include <vlc_update.h>
41

42 43
#ifdef UPDATE_CHECK

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
44
#include <assert.h>
45

46
#include <vlc_pgpkey.h>
Clément Stenac's avatar
Clément Stenac committed
47
#include <vlc_stream.h>
48 49
#include <vlc_strings.h>
#include <vlc_charset.h>
Clément Stenac's avatar
Clément Stenac committed
50
#include <vlc_interface.h>
51 52

#include <gcrypt.h>
53
#include <vlc_gcrypt.h>
54

55
#include "update.h"
56
#include "../libvlc.h"
57

58 59 60 61
/*****************************************************************************
 * Misc defines
 *****************************************************************************/

Rafaël Carré's avatar
Rafaël Carré committed
62 63 64 65 66 67 68 69
/*
 * Here is the format of these "status files" :
 * First line is the last version: "X.Y.Ze" where:
 *      * X is the major number
 *      * Y is the minor number
 *      * Z is the revision number
 *      * e is an OPTIONAL extra letter
 *      * AKA "0.8.6d" or "0.9.0"
70
 * Second line is an url of the binary for this last version
71
 * Remaining text is a required description of the update
Rafaël Carré's avatar
Rafaël Carré committed
72 73
 */

74
#if defined( UNDER_CE )
75
#   define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status-ce"
76
#elif defined( WIN32 )
77
#   define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status-win-x86"
78 79
#elif defined( __APPLE__ )
#   if defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
80
#       define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status-mac-ppc"
81
#   else
82
#       define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status-mac-x86"
83 84
#   endif
#elif defined( SYS_BEOS )
85
#       define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status-beos-x86"
86
#else
87
#   define UPDATE_VLC_STATUS_URL "http://update.videolan.org/vlc/status"
88 89
#endif

90

91 92 93
/*****************************************************************************
 * Local Prototypes
 *****************************************************************************/
94
static void EmptyRelease( update_t *p_update );
95
static bool GetUpdateFile( update_t *p_update );
96 97
static char * size_str( long int l_size );

98

99 100 101 102 103 104 105 106 107
/*****************************************************************************
 * OpenPGP functions
 *****************************************************************************/

#define packet_type( c ) ( ( c & 0x3c ) >> 2 )      /* 0x3C = 00111100 */
#define packet_header_len( c ) ( ( c & 0x03 ) + 1 ) /* number of bytes in a packet header */

static inline int scalar_number( uint8_t *p, int header_len )
{
108 109
    assert( header_len == 1 || header_len == 2 || header_len == 4 );

110 111 112 113 114 115
    if( header_len == 1 )
        return( p[0] );
    else if( header_len == 2 )
        return( (p[0] << 8) + p[1] );
    else if( header_len == 4 )
        return( (p[0] << 24) + (p[1] << 16) + (p[2] << 8) + p[3] );
116 117

    abort(); /* to shut up GCC warning */
118 119 120 121 122
}

/* number of data bytes in a MPI */
#define mpi_len( mpi ) ( ( scalar_number( mpi, 2 ) + 7 ) / 8 )

123
/*
124 125 126 127 128 129
 * fill a public_key_packet_t structure from public key packet data
 * verify that it is a version 4 public key packet, using DSA
 */
static int parse_public_key_packet( public_key_packet_t *p_key, uint8_t *p_buf,
                                    size_t i_packet_len )
{
130 131

    if( i_packet_len > 418 || i_packet_len < 6 )
132 133
        return VLC_EGENERIC;

134 135 136
    size_t i_read = 0;

    p_key->version   = *p_buf++; i_read++;
137 138 139
    if( p_key->version != 4 )
        return VLC_EGENERIC;

140 141
    /* XXX: warn when timestamp is > date ? */
    memcpy( p_key->timestamp, p_buf, 4 ); p_buf += 4; i_read += 4;
142

143
    p_key->algo      = *p_buf++; i_read++;
144 145 146
    if( p_key->algo != PUBLIC_KEY_ALGO_DSA )
        return VLC_EGENERIC;

147 148 149 150
    /* read p */
    if( i_read + 2 > i_packet_len )
        return VLC_EGENERIC;

151
    int i_p_len = mpi_len( p_buf );
152 153 154 155 156 157 158 159 160

    if( i_p_len > 128 || i_read + 2 + i_p_len > i_packet_len )
        return VLC_EGENERIC;

    memcpy( p_key->p, p_buf, 2+i_p_len );
    p_buf += 2+i_p_len; i_read += 2+i_p_len;

    /* read q */
    if( i_read + 2 > i_packet_len )
161 162
        return VLC_EGENERIC;

163
    int i_q_len = mpi_len( p_buf );
164 165 166 167 168 169 170 171 172

    if( i_q_len > 20 || i_read+2+i_q_len > i_packet_len )
        return VLC_EGENERIC;

    memcpy( p_key->q, p_buf, 2+i_q_len );
    p_buf += 2+i_q_len; i_read += 2+i_q_len;

    /* read g */
    if( i_read + 2 > i_packet_len )
173 174
        return VLC_EGENERIC;

175
    int i_g_len = mpi_len( p_buf );
176 177 178 179 180 181 182 183 184

    if( i_g_len > 128 || i_read+2+i_g_len > i_packet_len )
        return VLC_EGENERIC;

    memcpy( p_key->g, p_buf, 2+i_g_len );
    p_buf += 2+i_g_len; i_read += 2+i_g_len;

    /* read y */
    if( i_read + 2 > i_packet_len )
185
        return VLC_EGENERIC;
186

187
    int i_y_len = mpi_len( p_buf );
188 189 190 191 192 193 194 195 196


    if( i_y_len > 128 || i_read+2+i_y_len > i_packet_len )
        return VLC_EGENERIC;

    memcpy( p_key->y, p_buf, 2+i_y_len );
    i_read += 2+i_y_len;

    if( i_read != i_packet_len ) /* some extra data eh ? */
197 198 199 200 201
        return VLC_EGENERIC;

    return VLC_SUCCESS;
}

202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233
static size_t parse_signature_v3_packet( signature_packet_t *p_sig,
                                      uint8_t *p_buf, size_t i_sig_len )
{
    size_t i_read = 1; /* we already read the version byte */

    if( i_sig_len < 19 ) /* signature is at least 19 bytes + the 2 MPIs */
        return 0;

    p_sig->specific.v3.hashed_data_len = *p_buf++; i_read++;
    if( p_sig->specific.v3.hashed_data_len != 5 )
        return 0;

    p_sig->type = *p_buf++; i_read++;

    memcpy( p_sig->specific.v3.timestamp, p_buf, 4 );
    p_buf += 4; i_read += 4;

    memcpy( p_sig->issuer_longid, p_buf, 8 );
    p_buf += 8; i_read += 8;

    p_sig->public_key_algo = *p_buf++; i_read++;

    p_sig->digest_algo = *p_buf++; i_read++;

    p_sig->hash_verification[0] = *p_buf++; i_read++;
    p_sig->hash_verification[1] = *p_buf++; i_read++;

    assert( i_read == 19 );

    return i_read;
}

234 235 236 237
/*
 * fill a signature_packet_v4_t from signature packet data
 * verify that it was used with a DSA public key, using SHA-1 digest
 */
238
static size_t parse_signature_v4_packet( signature_packet_t *p_sig,
239 240
                                      uint8_t *p_buf, size_t i_sig_len )
{
241
    size_t i_read = 1; /* we already read the version byte */
242

243 244
    if( i_sig_len < 10 ) /* signature is at least 10 bytes + the 2 MPIs */
        return 0;
245

246
    p_sig->type = *p_buf++; i_read++;
247

248
    p_sig->public_key_algo = *p_buf++; i_read++;
249

250
    p_sig->digest_algo = *p_buf++; i_read++;
251

252 253
    memcpy( p_sig->specific.v4.hashed_data_len, p_buf, 2 );
    p_buf += 2; i_read += 2;
254

255 256 257 258 259
    size_t i_hashed_data_len =
        scalar_number( p_sig->specific.v4.hashed_data_len, 2 );
    i_read += i_hashed_data_len;
    if( i_read + 4 > i_sig_len )
        return 0;
260

261 262 263 264
    p_sig->specific.v4.hashed_data = (uint8_t*) malloc( i_hashed_data_len );
    if( !p_sig->specific.v4.hashed_data )
        return 0;
    memcpy( p_sig->specific.v4.hashed_data, p_buf, i_hashed_data_len );
265 266
    p_buf += i_hashed_data_len;

267 268
    memcpy( p_sig->specific.v4.unhashed_data_len, p_buf, 2 );
    p_buf += 2; i_read += 2;
269

270 271 272 273 274
    size_t i_unhashed_data_len =
        scalar_number( p_sig->specific.v4.unhashed_data_len, 2 );
    i_read += i_unhashed_data_len;
    if( i_read + 2 > i_sig_len )
        return 0;
275

276 277 278 279 280
    p_sig->specific.v4.unhashed_data = (uint8_t*) malloc( i_unhashed_data_len );
    if( !p_sig->specific.v4.unhashed_data )
        return 0;

    memcpy( p_sig->specific.v4.unhashed_data, p_buf, i_unhashed_data_len );
281 282
    p_buf += i_unhashed_data_len;

283 284 285 286 287 288
    memcpy( p_sig->hash_verification, p_buf, 2 );
    p_buf += 2; i_read += 2;

    uint8_t *p, *max_pos;
    p = p_sig->specific.v4.unhashed_data;
    max_pos = p + scalar_number( p_sig->specific.v4.unhashed_data_len, 2 );
289

290
    for( ;; )
291
    {
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
        if( p > max_pos )
            return 0;

        size_t i_subpacket_len;
        if( *p < 192 )
        {
            if( p + 1 > max_pos )
                return 0;
            i_subpacket_len = *p++;
        }
        else if( *p < 255 )
        {
            if( p + 2 > max_pos )
                return 0;
            i_subpacket_len = (*p++ - 192) << 8;
            i_subpacket_len += *p++ + 192;
        }
        else
        {
            if( p + 4 > max_pos )
                return 0;
            i_subpacket_len = *++p << 24;
            i_subpacket_len += *++p << 16;
            i_subpacket_len += *++p << 8;
            i_subpacket_len += *++p;
        }

        if( *p == ISSUER_SUBPACKET )
        {
            if( p + 9 > max_pos )
                return 0;

            memcpy( &p_sig->issuer_longid, p+1, 8 );

            return i_read;
        }

        p += i_subpacket_len;
330
    }
331 332 333 334 335 336 337 338 339 340 341 342
}

static int parse_signature_packet( signature_packet_t *p_sig,
                                   uint8_t *p_buf, size_t i_sig_len )
{
    if( !i_sig_len ) /* 1st sanity check, we need at least the version */
        return VLC_EGENERIC;

    p_sig->version = *p_buf++;

    size_t i_read;
    switch( p_sig->version )
343
    {
344 345 346 347 348 349 350 351 352 353
        case 3:
            i_read = parse_signature_v3_packet( p_sig, p_buf, i_sig_len );
            break;
        case 4:
            p_sig->specific.v4.hashed_data = NULL;
            p_sig->specific.v4.unhashed_data = NULL;
            i_read = parse_signature_v4_packet( p_sig, p_buf, i_sig_len );
            break;
        default:
            return VLC_EGENERIC;
354
    }
355

356 357 358 359 360 361 362 363 364 365
    if( i_read == 0 ) /* signature packet parsing has failed */
        goto error;

    if( p_sig->public_key_algo != PUBLIC_KEY_ALGO_DSA )
        goto error;

    if( p_sig->digest_algo != DIGEST_ALGO_SHA1 )
        goto error;

    switch( p_sig->type )
366
    {
367 368 369 370 371 372 373 374 375
        case BINARY_SIGNATURE:
        case TEXT_SIGNATURE:
        case GENERIC_KEY_SIGNATURE:
        case PERSONA_KEY_SIGNATURE:
        case CASUAL_KEY_SIGNATURE:
        case POSITIVE_KEY_SIGNATURE:
            break;
        default:
            goto error;
376
    }
377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411

    p_buf--; /* rewind to the version byte */
    p_buf += i_read;

    if( i_read + 2 > i_sig_len )
        goto error;

    size_t i_r_len = mpi_len( p_buf ); i_read += 2;
    if( i_read + i_r_len > i_sig_len || i_r_len > 20 )
        goto error;

    memcpy( p_sig->r, p_buf, 2 + i_r_len );
    p_buf += 2 + i_r_len;
    i_read += i_r_len;

    if( i_read + 2 > i_sig_len )
        goto error;

    size_t i_s_len = mpi_len( p_buf ); i_read += 2;
    if( i_read + i_s_len > i_sig_len || i_s_len > 20 )
        goto error;

    memcpy( p_sig->s, p_buf, 2 + i_s_len );
    p_buf += 2 + i_s_len;
    i_read += i_s_len;

    assert( i_read == i_sig_len );
    if( i_read < i_sig_len ) /* some extra data, hm ? */
        goto error;

    return VLC_SUCCESS;

error:

    if( p_sig->version == 4 )
412
    {
413 414
        free( p_sig->specific.v4.hashed_data );
        free( p_sig->specific.v4.unhashed_data );
415
    }
416

417
    return VLC_EGENERIC;
418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455
}

/*
 * crc_octets() was lamely copied from rfc 2440
 * Copyright (C) The Internet Society (1998).  All Rights Reserved.
 */
#define CRC24_INIT 0xB704CEL
#define CRC24_POLY 0x1864CFBL

static long crc_octets( uint8_t *octets, size_t len )
{
    long crc = CRC24_INIT;
    int i;
    while (len--)
    {
        crc ^= (*octets++) << 16;
        for (i = 0; i < 8; i++)
        {
            crc <<= 1;
            if (crc & 0x1000000)
                crc ^= CRC24_POLY;
        }
    }
    return crc & 0xFFFFFFL;
}

/*
 * Transform an armored document in binary format
 * Used on public keys and signatures
 */
static int pgp_unarmor( char *p_ibuf, size_t i_ibuf_len,
                        uint8_t *p_obuf, size_t i_obuf_len )
{
    char *p_ipos = p_ibuf;
    uint8_t *p_opos = p_obuf;
    int i_end = 0;
    int i_header_skipped = 0;

456
    while( !i_end && p_ipos < p_ibuf + i_ibuf_len && *p_ipos != '=' )
457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475
    {
        if( *p_ipos == '\r' || *p_ipos == '\n' )
        {
            p_ipos++;
            continue;
        }

        size_t i_line_len = strcspn( p_ipos, "\r\n" );
        if( i_line_len == 0 )
            continue;

        if( !i_header_skipped )
        {
            if( !strncmp( p_ipos, "-----BEGIN PGP", 14 ) )
                i_header_skipped = 1;

            p_ipos += i_line_len + 1;
            continue;
        }
476

477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
        if( !strncmp( p_ipos, "Version:", 8 ) )
        {
            p_ipos += i_line_len + 1;
            continue;
        }

        if( p_ipos[i_line_len - 1] == '=' )
        {
            i_end = 1;
            p_ipos[i_line_len - 1] = '\0';
        }
        else
            p_ipos[i_line_len] = '\0';

        p_opos += vlc_b64_decode_binary_to_buffer(  p_opos,
492
                        p_obuf - p_opos + i_obuf_len, p_ipos );
493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511
        p_ipos += i_line_len + 1;
    }

    /* XXX: the CRC is OPTIONAL, really require it ? */
    if( p_ipos + 5 > p_ibuf + i_ibuf_len || *p_ipos++ != '=' )
        return 0;

    uint8_t p_crc[3];
    if( vlc_b64_decode_binary_to_buffer( p_crc, 3, p_ipos ) != 3 )
        return 0;

    long l_crc = crc_octets( p_obuf, p_opos - p_obuf );
    long l_crc2 = ( 0 << 24 ) + ( p_crc[0] << 16 ) + ( p_crc[1] << 8 ) + p_crc[2];

    return l_crc2 == l_crc ? p_opos - p_obuf : 0;
}

/*
 * Download the signature associated to a document or a binary file.
512
 * We're given the file's url, we just append ".asc" to it and download
513 514
 */
static int download_signature(  vlc_object_t *p_this,
515
                                signature_packet_t *p_sig,
516
                                const char *psz_url )
517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532
{
    char *psz_sig = (char*) malloc( strlen( psz_url ) + 4 + 1 ); /* ".asc" + \0 */
    if( !psz_sig )
        return VLC_ENOMEM;

    strcpy( psz_sig, psz_url );
    strcat( psz_sig, ".asc" );

    stream_t *p_stream = stream_UrlNew( p_this, psz_sig );
    free( psz_sig );

    if( !p_stream )
        return VLC_ENOMEM;

    int64_t i_size = stream_Size( p_stream );

533 534
    msg_Dbg( p_this, "Downloading signature (%"PRId64" bytes)", i_size );
    uint8_t *p_buf = (uint8_t*)malloc( i_size );
535 536 537 538 539
    if( !p_buf )
    {
        stream_Delete( p_stream );
        return VLC_ENOMEM;
    }
540

541 542 543 544
    int i_read = stream_Read( p_stream, p_buf, (int)i_size );

    stream_Delete( p_stream );

545
    if( i_read != (int)i_size )
546
    {
547 548
        msg_Dbg( p_this,
            "Couldn't download full signature (only %d bytes)", i_read );
549 550 551
        free( p_buf );
        return VLC_EGENERIC;
    }
552

553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
    if( (uint8_t)*p_buf < 0x80 ) /* ASCII */
    {
        msg_Dbg( p_this, "Unarmoring signature" );

        uint8_t* p_unarmored = (uint8_t*) malloc( ( i_size * 3 ) / 4 + 1 );
        if( !p_unarmored )
        {
            free( p_buf );
            return VLC_EGENERIC;
        }

        int i_bytes = pgp_unarmor( (char*)p_buf, i_size, p_unarmored, i_size );
        free( p_buf );

        p_buf = p_unarmored;
        i_size = i_bytes;

        if( i_bytes < 2 )
        {
            free( p_buf );
            msg_Dbg( p_this, "Unarmoring failed : corrupted signature ?" );
            return VLC_EGENERIC;
        }
    }
577

578
    if( packet_type( *p_buf ) != SIGNATURE_PACKET )
579
    {
580 581
        free( p_buf );
        msg_Dbg( p_this, "Not a signature: %d", *p_buf );
582 583
        return VLC_EGENERIC;
    }
584 585 586 587

    size_t i_header_len = packet_header_len( *p_buf );
    if( ( i_header_len != 1 && i_header_len != 2 && i_header_len != 4 ) ||
        i_header_len + 1 > (size_t)i_size )
588
    {
589 590
        free( p_buf );
        msg_Dbg( p_this, "Invalid signature packet header" );
591
        return VLC_EGENERIC;
592
    }
593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610

    size_t i_len = scalar_number( p_buf+1, i_header_len );
    if( i_len + i_header_len + 1 != (size_t)i_size )
    {
        free( p_buf );
        msg_Dbg( p_this, "Invalid signature packet" );
        return VLC_EGENERIC;
    }

    int i_ret = parse_signature_packet( p_sig, p_buf+1+i_header_len, i_len );
    free( p_buf );
    if( i_ret != VLC_SUCCESS )
    {
        msg_Dbg( p_this, "Couldn't parse signature" );
        return i_ret;
    }

    if( p_sig->type != BINARY_SIGNATURE && p_sig->type != TEXT_SIGNATURE )
611
    {
612 613
        msg_Dbg( p_this, "Invalid signature type: %d", p_sig->type );
        if( p_sig->version == 4 )
614
        {
615 616
            free( p_sig->specific.v4.hashed_data );
            free( p_sig->specific.v4.unhashed_data );
617
        }
618
        return VLC_EGENERIC;
619
    }
620 621

    return VLC_SUCCESS;
622 623 624 625 626
}

/*
 * Verify an OpenPGP signature made on some SHA-1 hash, with some DSA public key
 */
627
static int verify_signature( uint8_t *p_r, uint8_t *p_s,
628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
        public_key_packet_t *p_key, uint8_t *p_hash )
{
    /* the data to be verified (a SHA-1 hash) */
    const char *hash_sexp_s = "(data(flags raw)(value %m))";
    /* the public key */
    const char *key_sexp_s = "(public-key(dsa(p %m)(q %m)(g %m)(y %m)))";
    /* the signature */
    const char *sig_sexp_s = "(sig-val(dsa(r %m )(s %m )))";

    size_t erroff;
    gcry_mpi_t p, q, g, y, r, s, hash;
    p = q = g = y = r = s = hash = NULL;
    gcry_sexp_t key_sexp, hash_sexp, sig_sexp;
    key_sexp = hash_sexp = sig_sexp = NULL;

643 644 645 646 647 648 649 650
    int i_p_len = mpi_len( p_key->p );
    int i_q_len = mpi_len( p_key->q );
    int i_g_len = mpi_len( p_key->g );
    int i_y_len = mpi_len( p_key->y );
    if( gcry_mpi_scan( &p, GCRYMPI_FMT_USG, p_key->p + 2, i_p_len, NULL ) ||
        gcry_mpi_scan( &q, GCRYMPI_FMT_USG, p_key->q + 2, i_q_len, NULL ) ||
        gcry_mpi_scan( &g, GCRYMPI_FMT_USG, p_key->g + 2, i_g_len, NULL ) ||
        gcry_mpi_scan( &y, GCRYMPI_FMT_USG, p_key->y + 2, i_y_len, NULL ) ||
651 652 653
        gcry_sexp_build( &key_sexp, &erroff, key_sexp_s, p, q, g, y ) )
        goto problem;

654 655 656 657
    int i_r_len = mpi_len( p_r );
    int i_s_len = mpi_len( p_s );
    if( gcry_mpi_scan( &r, GCRYMPI_FMT_USG, p_r + 2, i_r_len, NULL ) ||
        gcry_mpi_scan( &s, GCRYMPI_FMT_USG, p_s + 2, i_s_len, NULL ) ||
658 659 660
        gcry_sexp_build( &sig_sexp, &erroff, sig_sexp_s, r, s ) )
        goto problem;

661 662
    int i_hash_len = 20;
    if( gcry_mpi_scan( &hash, GCRYMPI_FMT_USG, p_hash, i_hash_len, NULL ) ||
663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
        gcry_sexp_build( &hash_sexp, &erroff, hash_sexp_s, hash ) )
        goto problem;

    if( gcry_pk_verify( sig_sexp, hash_sexp, key_sexp ) )
        goto problem;

    return VLC_SUCCESS;

problem:
    if( p ) gcry_mpi_release( p );
    if( q ) gcry_mpi_release( q );
    if( g ) gcry_mpi_release( g );
    if( y ) gcry_mpi_release( y );
    if( r ) gcry_mpi_release( r );
    if( s ) gcry_mpi_release( s );
    if( hash ) gcry_mpi_release( hash );
    if( key_sexp ) gcry_sexp_release( key_sexp );
    if( sig_sexp ) gcry_sexp_release( sig_sexp );
    if( hash_sexp ) gcry_sexp_release( hash_sexp );
    return VLC_EGENERIC;
}

/*
 * fill a public_key_t with public key data, including:
 *   * public key packet
 *   * signature packet issued by key which long id is p_sig_issuer
 *   * user id packet
 */
691 692
static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len,
                             public_key_t *p_key, const uint8_t *p_sig_issuer )
693 694 695 696 697 698 699 700 701 702 703 704
{
    uint8_t *pos = (uint8_t*) p_key_data;
    uint8_t *max_pos = pos + i_key_len;

    int i_status = 0;
#define PUBLIC_KEY_FOUND    0x01
#define USER_ID_FOUND       0x02
#define SIGNATURE_FOUND     0X04

    uint8_t *p_key_unarmored = NULL;

    p_key->psz_username = NULL;
705 706
    p_key->sig.specific.v4.hashed_data = NULL;
    p_key->sig.specific.v4.unhashed_data = NULL;
707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730

    if( !( *pos & 0x80 ) )
    {   /* first byte is ASCII, unarmoring */
        p_key_unarmored = (uint8_t*)malloc( i_key_len );
        if( !p_key_unarmored )
            return VLC_ENOMEM;
        int i_len = pgp_unarmor( (char*)p_key_data, i_key_len,
                                 p_key_unarmored, i_key_len );

        if( i_len == 0 )
            goto error;

        pos = p_key_unarmored;
        max_pos = pos + i_len;
    }

    while( pos < max_pos )
    {
        if( !(*pos & 0x80) || *pos & 0x40 )
            goto error;

        int i_type = packet_type( *pos );

        int i_header_len = packet_header_len( *pos++ );
731 732
        if( pos + i_header_len > max_pos ||
            ( i_header_len != 1 && i_header_len != 2 && i_header_len != 4 ) )
733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748
            goto error;

        int i_packet_len = scalar_number( pos, i_header_len );
        pos += i_header_len;

        if( pos + i_packet_len > max_pos )
            goto error;

        switch( i_type )
        {
            case PUBLIC_KEY_PACKET:
                i_status |= PUBLIC_KEY_FOUND;
                if( parse_public_key_packet( &p_key->key, pos, i_packet_len ) != VLC_SUCCESS )
                    goto error;
                break;

749 750
            case SIGNATURE_PACKET: /* we accept only v4 signatures here */
                if( i_status & SIGNATURE_FOUND || !p_sig_issuer )
751
                    break;
752 753 754
                int i_ret = parse_signature_packet( &p_key->sig, pos,
                                                    i_packet_len );
                if( i_ret == VLC_SUCCESS )
755
                {
756 757 758 759 760 761 762 763 764 765
                    if( p_key->sig.version != 4 )
                        break;
                    if( memcmp( p_key->sig.issuer_longid, p_sig_issuer, 8 ) )
                    {
                        free( p_key->sig.specific.v4.hashed_data );
                        free( p_key->sig.specific.v4.unhashed_data );
                        p_key->sig.specific.v4.hashed_data = NULL;
                        p_key->sig.specific.v4.unhashed_data = NULL;
                        break;
                    }
766 767 768 769 770 771 772 773 774 775 776 777 778 779 780
                    i_status |= SIGNATURE_FOUND;
                }
                break;

            case USER_ID_PACKET:
                if( p_key->psz_username ) /* save only the first User ID */
                    break;
                i_status |= USER_ID_FOUND;
                p_key->psz_username = (uint8_t*)malloc( i_packet_len + 1);
                if( !p_key->psz_username )
                    goto error;

                memcpy( p_key->psz_username, pos, i_packet_len );
                p_key->psz_username[i_packet_len] = '\0';
                break;
781

782 783 784 785 786 787 788
            default:
                break;
        }
        pos += i_packet_len;
    }
    free( p_key_unarmored );

789
    if( !( i_status & ( PUBLIC_KEY_FOUND | USER_ID_FOUND ) ) )
790 791 792 793 794 795 796 797
        return VLC_EGENERIC;

    if( p_sig_issuer && !( i_status & SIGNATURE_FOUND ) )
        return VLC_EGENERIC;

    return VLC_SUCCESS;

error:
798 799 800 801 802
    if( p_key->sig.version == 4 )
    {
        free( p_key->sig.specific.v4.hashed_data );
        free( p_key->sig.specific.v4.unhashed_data );
    }
803 804 805 806 807 808 809 810 811
    free( p_key->psz_username );
    free( p_key_unarmored );
    return VLC_EGENERIC;
}

/*
 * return a sha1 hash of a file
 */
static uint8_t *hash_sha1_from_file( const char *psz_file,
812
                            signature_packet_t *p_sig )
813
{
814 815 816
    if( p_sig->type != BINARY_SIGNATURE && p_sig->type != TEXT_SIGNATURE )
        return NULL;

817 818 819 820
    FILE *f = utf8_fopen( psz_file, "r" );
    if( !f )
        return NULL;

821
    uint8_t buffer[4096];
822 823 824 825 826 827

    gcry_md_hd_t hd;
    if( gcry_md_open( &hd, GCRY_MD_SHA1, 0 ) )
    {
        fclose( f );
        return NULL;
828
    }
829 830 831 832 833

    size_t i_read;
    while( ( i_read = fread( buffer, 1, sizeof(buffer), f ) ) > 0 )
        gcry_md_write( hd, buffer, i_read );

834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853
    if( p_sig->version == 3 )
    {
        gcry_md_putc( hd, p_sig->type );
        gcry_md_write( hd, &p_sig->specific.v3.timestamp, 4 );
    }
    else if( p_sig->version == 4 )
    {
        gcry_md_putc( hd, p_sig->version );
        gcry_md_putc( hd, p_sig->type );
        gcry_md_putc( hd, p_sig->public_key_algo );
        gcry_md_putc( hd, p_sig->digest_algo );
        gcry_md_write( hd, p_sig->specific.v4.hashed_data_len, 2 );
        size_t i_len = scalar_number( p_sig->specific.v4.hashed_data_len, 2 );
        gcry_md_write( hd, p_sig->specific.v4.hashed_data, i_len );
    }
    else
    {   /* RFC 4880 only tells about versions 3 and 4 */
        gcry_md_close( hd );
        return NULL;
    }
854 855 856 857

    fclose( f );
    gcry_md_final( hd );

858 859 860 861
    uint8_t *p_tmp = (uint8_t*) gcry_md_read( hd, GCRY_MD_SHA1);
    uint8_t *p_hash = malloc( 20 );
    if( p_hash )
        memcpy( p_hash, p_tmp, 20 );
Antoine Cellerier's avatar
Antoine Cellerier committed
862 863
    gcry_md_close( hd );
    return p_hash;
864 865 866 867 868
}

/*
 * download a public key (the last one) from videolan server, and parse it
 */
869 870
static public_key_t *download_key( vlc_object_t *p_this,
                    const uint8_t *p_longid, const uint8_t *p_signature_issuer )
871 872
{
    char *psz_url;
873 874 875
    if( asprintf( &psz_url, "http://download.videolan.org/pub/keys/%.2X%.2X%.2X%.2X%.2X%.2X%.2X%.2X.asc",
                    p_longid[0], p_longid[1], p_longid[2], p_longid[3],
                    p_longid[4], p_longid[5], p_longid[6], p_longid[7] ) == -1 )
876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
        return NULL;

    stream_t *p_stream = stream_UrlNew( p_this, psz_url );
    free( psz_url );
    if( !p_stream )
        return NULL;

    int64_t i_size = stream_Size( p_stream );
    if( i_size < 0 )
    {
        stream_Delete( p_stream );
        return NULL;
    }

    uint8_t *p_buf = (uint8_t*)malloc( i_size );
    if( !p_buf )
    {
        stream_Delete( p_stream );
        return NULL;
    }

    int i_read = stream_Read( p_stream, p_buf, (int)i_size );
    stream_Delete( p_stream );

    if( i_read != (int)i_size )
    {
902
        msg_Dbg( p_this, "Couldn't read full GPG key" );
903 904 905 906 907 908 909 910 911 912 913
        free( p_buf );
        return NULL;
    }

    public_key_t *p_pkey = (public_key_t*) malloc( sizeof( public_key_t ) );
    if( !p_pkey )
    {
        free( p_buf );
        return NULL;
    }

914 915
    memcpy( p_pkey->longid, p_longid, 8 );

916 917 918 919 920
    int i_error = parse_public_key( p_buf, i_read, p_pkey, p_signature_issuer );
    free( p_buf );

    if( i_error != VLC_SUCCESS )
    {
921
        msg_Dbg( p_this, "Couldn't parse GPG key" );
922 923 924 925 926 927 928 929
        free( p_pkey );
        return NULL;
    }

    return p_pkey;
}

/*
930 931
 * Generate a SHA1 hash on a public key, to verify a signature made on that hash
 * Note that we need the signature (v4) to compute the hash
932 933 934
 */
static uint8_t *key_sign_hash( public_key_t *p_pkey )
{
935 936 937 938 939 940 941
    if( p_pkey->sig.version != 4 )
        return NULL;

    if( p_pkey->sig.type < GENERIC_KEY_SIGNATURE ||
        p_pkey->sig.type > POSITIVE_KEY_SIGNATURE )
        return NULL;

942 943 944 945 946 947 948 949 950
    gcry_error_t error = 0;
    gcry_md_hd_t hd;

    error = gcry_md_open( &hd, GCRY_MD_SHA1, 0 );
    if( error )
        return NULL;

    gcry_md_putc( hd, 0x99 );

951 952 953 954
    size_t i_p_len = mpi_len( p_pkey->key.p );
    size_t i_g_len = mpi_len( p_pkey->key.g );
    size_t i_q_len = mpi_len( p_pkey->key.q );
    size_t i_y_len = mpi_len( p_pkey->key.y );
955

956 957 958 959 960 961 962 963
    size_t i_size = 6 + 2*4 + i_p_len + i_g_len + i_q_len + i_y_len;

    gcry_md_putc( hd, (i_size >> 8) & 0xff );
    gcry_md_putc( hd, i_size & 0xff );

    gcry_md_putc( hd, p_pkey->key.version );
    gcry_md_write( hd, p_pkey->key.timestamp, 4 );
    gcry_md_putc( hd, p_pkey->key.algo );
964 965 966 967 968 969 970

    gcry_md_write( hd, (uint8_t*)&p_pkey->key.p, 2 );
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.p + 2, i_p_len );

    gcry_md_write( hd, (uint8_t*)&p_pkey->key.q, 2 );
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.q + 2, i_q_len );

971 972 973
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.g, 2 );
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.g + 2, i_g_len );

974 975
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.y, 2 );
    gcry_md_write( hd, (uint8_t*)&p_pkey->key.y + 2, i_y_len );
976 977 978

    gcry_md_putc( hd, 0xb4 );

979
    size_t i_len = strlen((char*)p_pkey->psz_username);
980 981 982 983 984 985 986 987

    gcry_md_putc( hd, (i_len << 24) & 0xff );
    gcry_md_putc( hd, (i_len << 16) & 0xff );
    gcry_md_putc( hd, (i_len << 8) & 0xff );
    gcry_md_putc( hd, (i_len) & 0xff );

    gcry_md_write( hd, p_pkey->psz_username, i_len );

988 989
    size_t i_hashed_data_len =
        scalar_number( p_pkey->sig.specific.v4.hashed_data_len, 2 );
990 991 992 993 994

    gcry_md_putc( hd, p_pkey->sig.version );
    gcry_md_putc( hd, p_pkey->sig.type );
    gcry_md_putc( hd, p_pkey->sig.public_key_algo );
    gcry_md_putc( hd, p_pkey->sig.digest_algo );
995 996
    gcry_md_write( hd, p_pkey->sig.specific.v4.hashed_data_len, 2 );
    gcry_md_write( hd, p_pkey->sig.specific.v4.hashed_data, i_hashed_data_len );
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009

    gcry_md_putc( hd, 0x04 );
    gcry_md_putc( hd, 0xff );

    i_hashed_data_len += 6; /* hashed data + 6 bytes header */

    gcry_md_putc( hd, (i_hashed_data_len << 24) & 0xff);
    gcry_md_putc( hd, (i_hashed_data_len << 16) &0xff );
    gcry_md_putc( hd, (i_hashed_data_len << 8) & 0xff );
    gcry_md_putc( hd, (i_hashed_data_len) & 0xff );

    gcry_md_final( hd );

1010
    uint8_t *p_tmp = gcry_md_read( hd, GCRY_MD_SHA1);
1011

1012 1013 1014
    if( !p_tmp ||
        p_tmp[0] != p_pkey->sig.hash_verification[0] ||
        p_tmp[1] != p_pkey->sig.hash_verification[1] )
1015
    {
Antoine Cellerier's avatar
Antoine Cellerier committed
1016
        gcry_md_close( hd );
1017 1018 1019
        return NULL;
    }

1020 1021 1022
    uint8_t *p_hash = malloc( 20 );
    if( p_hash )
        memcpy( p_hash, p_tmp, 20 );
Antoine Cellerier's avatar
Antoine Cellerier committed
1023
    gcry_md_close( hd );
1024 1025 1026
    return p_hash;
}

1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040

/*****************************************************************************
 * Update_t functions
 *****************************************************************************/

/**
 * Create a new update VLC struct
 *
 * \param p_this the calling vlc_object
 * \return pointer to new update_t or NULL
 */
update_t *__update_New( vlc_object_t *p_this )
{
    update_t *p_update;
1041
    assert( p_this );
1042 1043

    p_update = (update_t *)malloc( sizeof( update_t ) );
Jean-Paul Saman's avatar
Jean-Paul Saman committed
1044
    if( !p_update ) return NULL;
1045

1046
    vlc_mutex_init( &p_update->lock );
1047

1048
    p_update->p_libvlc = p_this->p_libvlc;
1049

1050 1051
    p_update->release.psz_url = NULL;
    p_update->release.psz_desc = NULL;
1052

1053 1054 1055
    p_update->p_download = NULL;
    p_update->p_check = NULL;

1056
    p_update->p_pkey = NULL;
1057
    vlc_gcrypt_init();
1058

1059
    return p_update;
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
}

/**
 * Delete an update_t struct
 *
 * \param p_update update_t* pointer
 * \return nothing
 */
void update_Delete( update_t *p_update )
{
Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
1070 1071
    assert( p_update );

1072 1073 1074 1075 1076 1077 1078 1079 1080 1081
    if( p_update->p_check )
    {
        assert( !p_update->p_download );
        vlc_object_kill( p_update->p_check );
        vlc_thread_join( p_update->p_check );
    }
    else if( p_update->p_download )
    {
        vlc_object_kill( p_update->p_download );
        vlc_thread_join( p_update->p_download );
1082
        vlc_object_release( p_update->p_download );
1083 1084
    }

1085 1086
    vlc_mutex_destroy( &p_update->lock );

1087 1088 1089
    free( p_update->release.psz_url );
    free( p_update->release.psz_desc );
    free( p_update->p_pkey );
1090 1091

    free( p_update );
1092 1093 1094
}

/**
1095
 * Empty the release struct
1096
 *
1097
 * \param p_update update_t* pointer
1098 1099
 * \return nothing
 */
1100
static void EmptyRelease( update_t *p_update )
1101
{
1102 1103 1104
    p_update->release.i_major = 0;
    p_update->release.i_minor = 0;
    p_update->release.i_revision = 0;
1105

1106 1107
    FREENULL( p_update->release.psz_url );
    FREENULL( p_update->release.psz_desc );
1108 1109 1110
}

/**
1111
 * Get the update file and parse it
Rémi Duraffort's avatar
Rémi Duraffort committed
1112
 * p_update has to be locked when calling this function
1113 1114
 *
 * \param p_update pointer to update struct
1115
 * \return true if the update is valid and authenticated
1116
 */
1117
static bool GetUpdateFile( update_t *p_update )
1118 1119
{
    stream_t *p_stream = NULL;
1120 1121 1122
    int i_major = 0;
    int i_minor = 0;
    int i_revision = 0;
Rafaël Carré's avatar
Rafaël Carré committed
1123
    unsigned char extra;
1124
    char *psz_version_line = NULL;
1125

1126
    p_stream = stream_UrlNew( p_update->p_libvlc, UPDATE_VLC_STATUS_URL );
1127 1128
    if( !p_stream )
    {
1129
        msg_Err( p_update->p_libvlc, "Failed to open %s for reading",
1130 1131 1132 1133
                 UPDATE_VLC_STATUS_URL );
        goto error;
    }

1134 1135
    /* Start reading the status file */
    if( !( psz_version_line = stream_ReadLine( p_stream ) ) )
1136
    {
1137
        msg_Err( p_update->p_libvlc, "Update file %s is corrupted : missing version",
1138 1139 1140 1141
                 UPDATE_VLC_STATUS_URL );
        goto error;
    }

1142
    /* first line : version number */
Rafaël Carré's avatar
Rafaël Carré committed
1143
    p_update->release.extra = 0;
1144 1145
    switch( sscanf( psz_version_line, "%i.%i.%i%c",
                    &i_major, &i_minor, &i_revision, &extra ) )
1146
    {
Rafaël Carré's avatar
Rafaël Carré committed
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
        case 4:
            p_update->release.extra = extra;
        case 3:
            p_update->release.i_major = i_major;
            p_update->release.i_minor = i_minor;
            p_update->release.i_revision = i_revision;
            break;
        default:
            msg_Err( p_update->p_libvlc, "Update version false formated" );
            goto error;
1157
    }
1158

1159 1160
    /* second line : URL */
    if( !( p_update->release.psz_url = stream_ReadLine( p_stream ) ) )
1161 1162 1163 1164 1165
    {
        msg_Err( p_update->p_libvlc, "Update file %s is corrupted : URL missing",
                 UPDATE_VLC_STATUS_URL );
        goto error;
    }
1166

1167 1168 1169 1170 1171 1172 1173 1174 1175
    /* Remaining data : description */
    int i_read = stream_Size( p_stream ) - stream_Tell( p_stream );
    if( i_read <= 0 )
    {
        msg_Err( p_update->p_libvlc,
                "Update file %s is corrupted: description missing",
                UPDATE_VLC_STATUS_URL );
        goto error;
    }
1176

1177 1178 1179 1180 1181
    p_update->release.psz_desc = (char*) malloc( i_read + 1 );
    if( !p_update->release.psz_desc )
        goto error;

    if( stream_Read( p_stream, p_update->release.psz_desc, i_read ) != i_read )
1182
    {