* This file contains functions related to VLC and plugins update management
*/
+/*
+ * TODO: * pgp verification of the update file
+ * binary download, and pgp verification
+ */
+
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <vlc/vlc.h>
+#ifdef UPDATE_CHECK
+
#include <ctype.h> /* tolower() */
#include <assert.h>
static int CompareReleases( const struct update_release_t *p1,
const struct update_release_t *p2 );
+/*****************************************************************************
+ * 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 )
+ {
+ 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, 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 );
+ if( i_size < 65 )
+ {
+ stream_Delete( p_stream );
+ return VLC_EGENERIC;
+ }
+ else if( i_size == 65 ) /* binary format signature */
+ {
+ int i_read = stream_Read( p_stream, p_sig, (int)i_size );
+ stream_Delete( p_stream );
+ if( i_read != i_size )
+ return VLC_EGENERIC;
+ else
+ return VLC_SUCCESS;
+ }
+
+ 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 )
+ {
+ 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 )
+ 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]; //FIXME
+
+ 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 )
+ {
+ 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 )
+ {
+ 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;
+}
+
/*****************************************************************************
* Update_t functions
}
return i_result;
}
+
+#endif
projects / vlc / blobdiff