-
-/*****************************************************************************
- * Local Prototypes
- *****************************************************************************/
-static void EmptyRelease( update_t *p_update );
-static vlc_bool_t GetUpdateFile( update_t *p_update );
-static int CompareReleases( const struct update_release_t *p1,
- const struct update_release_t *p2 );
-static char * size_str( long int l_size );
-
-
-/*****************************************************************************
- * 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 )
-{
- 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] );
- else
- abort();
-}
-
-/* number of data bytes in a MPI */
-#define mpi_len( mpi ) ( ( scalar_number( mpi, 2 ) + 7 ) / 8 )
-
-/*
- * 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 )
-{
- if( i_packet_len != 418 )
- return VLC_EGENERIC;
-
- p_key->version = *p_buf++;
- if( p_key->version != 4 )
- return VLC_EGENERIC;
-
- /* warn when timestamp is > date ? */
- memcpy( p_key->timestamp, p_buf, 4 ); p_buf += 4;
-
- p_key->algo = *p_buf++;
- if( p_key->algo != PUBLIC_KEY_ALGO_DSA )
- return VLC_EGENERIC;
-
- memcpy( p_key->p, p_buf, 2+128 ); p_buf += 2+128;
- if( mpi_len( p_key->p ) != 128 )
- return VLC_EGENERIC;
-
- memcpy( p_key->q, p_buf, 2+20 ); p_buf += 2+20;
- if( mpi_len( p_key->q ) != 20 )
- return VLC_EGENERIC;
-
- memcpy( p_key->g, p_buf, 2+128 ); p_buf += 2+128;
- if( mpi_len( p_key->g ) != 128 )
- return VLC_EGENERIC;
-
- memcpy( p_key->y, p_buf, 2+128 ); p_buf += 2+128;
- if( mpi_len( p_key->y ) != 128 )
- return VLC_EGENERIC;
-
- return VLC_SUCCESS;
-}
-
-/*
- * fill a signature_packet_v4_t from signature packet data
- * verify that it was used with a DSA public key, using SHA-1 digest
- */
-static int parse_signature_v4_packet( signature_packet_v4_t *p_sig,
- uint8_t *p_buf, size_t i_sig_len )
-{
- if( i_sig_len < 54 )
- return VLC_EGENERIC;
-
- p_sig->version = *p_buf++;
- if( p_sig->version != 4 )
- return VLC_EGENERIC;
-
- p_sig->type = *p_buf++;
- if( p_sig->type < GENERIC_KEY_SIGNATURE ||
- p_sig->type > POSITIVE_KEY_SIGNATURE )
- return VLC_EGENERIC;
-
- p_sig->public_key_algo = *p_buf++;
- if( p_sig->public_key_algo != PUBLIC_KEY_ALGO_DSA )
- return VLC_EGENERIC;
-
- p_sig->digest_algo = *p_buf++;
- if( p_sig->digest_algo != DIGEST_ALGO_SHA1 )
- return VLC_EGENERIC;
-
- memcpy( p_sig->hashed_data_len, p_buf, 2 ); p_buf += 2;
-
- size_t i_pos = 6;
- size_t i_hashed_data_len = scalar_number( p_sig->hashed_data_len, 2 );
- i_pos += i_hashed_data_len;
- if( i_pos > i_sig_len - 48 ) /* r & s are 44 bytes in total,
- * + the unhashed data length (2 bytes)
- * + the hash verification (2 bytes) */
- return VLC_EGENERIC;
-
- p_sig->hashed_data = (uint8_t*) malloc( i_hashed_data_len );
- if( !p_sig->hashed_data )
- return VLC_ENOMEM;
- memcpy( p_sig->hashed_data, p_buf, i_hashed_data_len );
- p_buf += i_hashed_data_len;
-
- memcpy( p_sig->unhashed_data_len, p_buf, 2 ); p_buf += 2;
-
- size_t i_unhashed_data_len = scalar_number( p_sig->unhashed_data_len, 2 );
- i_pos += 2 + i_unhashed_data_len;
- if( i_pos != i_sig_len - 46 )
- {
- free( p_sig->hashed_data );
- return VLC_EGENERIC;
- }
-
- p_sig->unhashed_data = (uint8_t*) malloc( i_unhashed_data_len );
- if( !p_sig->unhashed_data )
- {
- free( p_sig->hashed_data );
- return VLC_ENOMEM;
- }
- memcpy( p_sig->unhashed_data, p_buf, i_unhashed_data_len );
- p_buf += i_unhashed_data_len;
-
- memcpy( p_sig->hash_verification, p_buf, 2 ); p_buf += 2;
-
- memcpy( p_sig->r, p_buf, 22 ); p_buf += 22;
- if( mpi_len( p_sig->r ) != 20 )
- {
- free( p_sig->hashed_data );
- free( p_sig->unhashed_data );
- return VLC_EGENERIC;
- }
-
- memcpy( p_sig->s, p_buf, 22 );
- if( mpi_len( p_sig->s ) != 20 )
- {
- free( p_sig->hashed_data );
- free( p_sig->unhashed_data );
- return VLC_EGENERIC;
- }
-
- return VLC_SUCCESS;
-}
-
-/*
- * 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;
-
- while( !i_end && p_ipos < p_ibuf + i_ibuf_len && *p_ipos != '=' )
- {
- 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;
- }
-
- 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,
- p_obuf - p_opos + i_obuf_len, p_ipos );
- 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.
- * We're given the file's url, we just append ".asc" to it and download
- */
-static int download_signature( vlc_object_t *p_this,
- signature_packet_v3_t *p_sig,
- const char *psz_url )
-{
- 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 );
- /* FIXME: a signature can be less than 65 bytes, if r & s numbers
- * do not have 160 significant bits.
- */
- if( i_size < 65 )
- {
- stream_Delete( p_stream );
- msg_Dbg( p_this, "Signature too small" );
- return VLC_EGENERIC;
- }
- else if( i_size == 65 ) /* binary format signature */
- {
- msg_Dbg( p_this, "Downloading unarmored signature" );
- int i_read = stream_Read( p_stream, p_sig, (int)i_size );
- stream_Delete( p_stream );
- if( i_read != i_size )
- {
- msg_Dbg( p_this, "Couldn't read full signature" );
- return VLC_EGENERIC;
- }
- else
- return VLC_SUCCESS;
- }
-
- msg_Dbg( p_this, "Downloading armored signature" );
- char *p_buf = (char*)malloc( i_size );
- if( !p_buf )
- {
- stream_Delete( p_stream );
- return VLC_ENOMEM;
- }
-
- int i_read = stream_Read( p_stream, p_buf, (int)i_size );
-
- stream_Delete( p_stream );
-
- if( i_read != i_size )
- {
- msg_Dbg( p_this, "Couldn't read full signature" );
- free( p_buf );
- return VLC_EGENERIC;
- }
-
- int i_bytes = pgp_unarmor( p_buf, i_size, (uint8_t*)p_sig, 65 );
- free( p_buf );
-
- if( i_bytes != 65 )
- {
- msg_Dbg( p_this, "Unarmoring failed: signature is %d bytes", i_bytes );
- return VLC_EGENERIC;
- }
- else
- return VLC_SUCCESS;
-}
-
-/*
- * Verify an OpenPGP signature made on some SHA-1 hash, with some DSA public key
- */
-static int verify_signature( vlc_object_t *p_this, uint8_t *p_r, uint8_t *p_s,
- 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;
-
- if( gcry_mpi_scan( &p, GCRYMPI_FMT_USG, p_key->p + 2, 128, NULL ) ||
- gcry_mpi_scan( &q, GCRYMPI_FMT_USG, p_key->q + 2, 20, NULL ) ||
- gcry_mpi_scan( &g, GCRYMPI_FMT_USG, p_key->g + 2, 128, NULL ) ||
- gcry_mpi_scan( &y, GCRYMPI_FMT_USG, p_key->y + 2, 128, NULL ) ||
- gcry_sexp_build( &key_sexp, &erroff, key_sexp_s, p, q, g, y ) )
- goto problem;
-
- if( gcry_mpi_scan( &r, GCRYMPI_FMT_USG, p_r + 2, 20, NULL ) ||
- gcry_mpi_scan( &s, GCRYMPI_FMT_USG, p_s + 2, 20, NULL ) ||
- gcry_sexp_build( &sig_sexp, &erroff, sig_sexp_s, r, s ) )
- goto problem;
-
- if( gcry_mpi_scan( &hash, GCRYMPI_FMT_USG, p_hash, 20, NULL ) ||
- 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;
-}
-
-/*
- * Return the long id (8 bytes) of the public key used to generate a signature
- */
-static uint8_t *get_issuer_from_signature_v4( signature_packet_v4_t *p_sig )
-{
- uint8_t *p = p_sig->unhashed_data;
- uint8_t *max_pos = p + scalar_number( p_sig->unhashed_data_len, 2 );
-
- while( p < max_pos )
- {
- int i_subpacket_len = *p < 192 ? *p++ :
- *p < 255 ? ((*p++ - 192) << 8) + *p++ + 192 :
- ((*++p) << 24) + (*++p << 16) + (*++p << 8) + *++p;
-
- if( p >= max_pos - 1 )
- return NULL;
-
- if( *p == ISSUER_SUBPACKET )
- return p+1;
- else
- p += i_subpacket_len;
- }
- return NULL;
-}
-
-/*
- * 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
- */
-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 )
-{
- 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;
-
- signature_packet_v4_t sig;
-
- p_key->psz_username = NULL;
- p_key->sig.hashed_data = p_key->sig.unhashed_data = NULL;
-
- 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++ );
- if( pos + i_header_len > max_pos )
- 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 )
- {
- uint8_t *p_issuer;
-
- 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;
-
- case SIGNATURE_PACKET:
- if( !p_sig_issuer || i_status & SIGNATURE_FOUND ||
- parse_signature_v4_packet( &sig, pos, i_packet_len ) != VLC_SUCCESS )
- break;
- p_issuer = get_issuer_from_signature_v4( &sig );
- if( memcmp( p_issuer, p_sig_issuer, 8 ) == 0 )
- {
- memcpy( &p_key->sig, &sig, sizeof( signature_packet_v4_t ) );
- i_status |= SIGNATURE_FOUND;
- }
- else
- {
- free( sig.hashed_data );
- free( sig.unhashed_data );
- }
- 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;
-
- default:
- break;
- }
- pos += i_packet_len;
- }
- free( p_key_unarmored );
-
- if( !( i_status & ( PUBLIC_KEY_FOUND + USER_ID_FOUND ) ) )
- return VLC_EGENERIC;
-
- if( p_sig_issuer && !( i_status & SIGNATURE_FOUND ) )
- return VLC_EGENERIC;
-
- return VLC_SUCCESS;
-
-error:
- free( p_key->sig.hashed_data );
- free( p_key->sig.unhashed_data );
- 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,
- signature_packet_v3_t *p_sig )
-{
- FILE *f = utf8_fopen( psz_file, "r" );
- if( !f )
- return NULL;
-
- uint8_t buffer[4096];
-
- gcry_md_hd_t hd;
- if( gcry_md_open( &hd, GCRY_MD_SHA1, 0 ) )
- {
- fclose( f );
- return NULL;
- }
-
- size_t i_read;
- while( ( i_read = fread( buffer, 1, sizeof(buffer), f ) ) > 0 )
- gcry_md_write( hd, buffer, i_read );
-
- gcry_md_putc( hd, p_sig->type );
- gcry_md_write( hd, &p_sig->timestamp, 4 );
-
- fclose( f );
- gcry_md_final( hd );
-
- return( (uint8_t*) gcry_md_read( hd, GCRY_MD_SHA1) );
-}
-
-/*
- * download a public key (the last one) from videolan server, and parse it
- */
-static public_key_t *download_key( vlc_object_t *p_this, const uint8_t *p_longid, const uint8_t *p_signature_issuer )
-{
- char *psz_url;
- 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 )
- 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 )
- {
- msg_Dbg( p_this, "Couldn't read full GPG key" );
- 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;
- }
-
- int i_error = parse_public_key( p_buf, i_read, p_pkey, p_signature_issuer );
- free( p_buf );
-
- if( i_error != VLC_SUCCESS )
- {
- msg_Dbg( p_this, "Couldn't parse GPG key" );
- free( p_pkey );
- return NULL;
- }
-
- return p_pkey;
-}
-
-/*
- * Generate a SHA-1 hash on a public key, to verify a signature made on that hash
- * Note that we need the signature to compute the hash
- */
-static uint8_t *key_sign_hash( public_key_t *p_pkey )
-{
- 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 );
-
- gcry_md_putc( hd, (418 >> 8) & 0xff );
- gcry_md_putc( hd, 418 & 0xff );
-
- gcry_md_write( hd, (uint8_t*)&p_pkey->key, 418 );
-
- gcry_md_putc( hd, 0xb4 );
-
- int i_len = strlen((char*)p_pkey->psz_username);
-
- 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 );
-
- size_t i_hashed_data_len = scalar_number( p_pkey->sig.hashed_data_len, 2 );
-
- 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 );
- gcry_md_write( hd, p_pkey->sig.hashed_data_len, 2 );
- gcry_md_write( hd, p_pkey->sig.hashed_data, i_hashed_data_len );
-
- 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 );
-
- uint8_t *p_hash = gcry_md_read( hd, GCRY_MD_SHA1);
-
- if( p_hash[0] != p_pkey->sig.hash_verification[0] ||
- p_hash[1] != p_pkey->sig.hash_verification[1] )
- {
- free( p_hash );
- return NULL;
- }
-
- return p_hash;
-}
-