From 11922961a781bb840c7e06b0ca32054ae0e65645 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Rafa=C3=ABl=20Carr=C3=A9?= Date: Sun, 18 May 2008 01:39:28 +0200 Subject: [PATCH] Update: supports file v4 signatures Note: public key v3 signatures are not supported Fix various bugs and potentials buffer overflows --- doc/release-howto.txt | 8 +- include/vlc_pgpkey.h | 2 +- include/vlc_update.h | 90 +++--- src/misc/update.c | 642 ++++++++++++++++++++++++++++-------------- 4 files changed, 483 insertions(+), 259 deletions(-) diff --git a/doc/release-howto.txt b/doc/release-howto.txt index ede0d2b9cd..10def46e8a 100644 --- a/doc/release-howto.txt +++ b/doc/release-howto.txt @@ -23,7 +23,7 @@ - copy the tar.gz and tar.bz2 file on ftp.videolan.org in /opt/ftp/pub/videolan/testing/vlc-X.X.X/ - generate md5 hashes and gpg signature of these files - (use gpg --sign --detach --armor --force-v3-sigs) + (use gpg --sign --detach --armor) * Contribs - Put a copy of the libraries or git snapshot in vlc-X.X.X/contrib @@ -36,7 +36,7 @@ Build in the "buildbeos" chroot on altair. # add the .zip files to /opt/ftp/pub/videolan/testing/vlc-X.X.X/beos/ generate md5 hashes and gpg signature of these files - (use gpg --sign --detach --armor --force-v3-sigs) + (use gpg --sign --detach --armor) * Win32 Packages make the packages using the nightly builds configure/options/... , don't forget --enable-update-check @@ -44,12 +44,12 @@ kind of suxxs) add the .zip and .exe files to /opt/ftp/pub/videolan/testing/vlc-X.X.X/win32/ generate md5 hashes and gpg signature of these files - (use gpg --sign --detach --armor --force-v3-sigs) + (use gpg --sign --detach --armor) * OS X packages configure with --enable-update-check generate md5 hashes and gpg signature of these files - (use gpg --sign --detach --armor --force-v3-sigs) + (use gpg --sign --detach --armor) * Commit changes ... it never works the first time diff --git a/include/vlc_pgpkey.h b/include/vlc_pgpkey.h index 32331dba88..6aedee3d21 100644 --- a/include/vlc_pgpkey.h +++ b/include/vlc_pgpkey.h @@ -32,6 +32,7 @@ static uint8_t videolan_public_key_longid[8] = { 0x8B, 0x08, 0x52, 0x31, 0xD0, 0x38, 0x35, 0x37 }; +/* gpg --export --armor "VideoLAN Release"|sed -e s/^/\"/ -e s/\$/\\\\n\"/ */ static uint8_t videolan_public_key[] = { "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" "Version: GnuPG v2.0.4 (FreeBSD)\n" @@ -78,4 +79,3 @@ static uint8_t videolan_public_key[] = { "=Ic/K\n" "-----END PGP PUBLIC KEY BLOCK-----\n" }; - diff --git a/include/vlc_update.h b/include/vlc_update.h index 46add4c528..2bf5318b0c 100644 --- a/include/vlc_update.h +++ b/include/vlc_update.h @@ -33,17 +33,25 @@ #include -#include /* key & signature downloading */ -#include /* b64 decoding */ -#include /* utf8_fopen() */ -#include /* cryptography and digest algorithms */ - /** * \defgroup update Update * * @{ */ +/* Go reading the rfc 4880 ! NOW !! */ + +/* + * XXX + * When PGP-signing a file, we only sign a SHA-1 hash of this file + * + * As soon as SHA-1 is broken, this method is not secure anymore, because an + * attacker could generate a file with the same SHA-1 hash. + * + * Whenever this happens, we need to use another algorithm / type of key. + * XXX + */ + enum /* Public key algorithms */ { /* we will only use DSA public keys */ @@ -75,14 +83,11 @@ enum /* Signature types */ POSITIVE_KEY_SIGNATURE = 0x13 /* Substantial verification */ }; - enum /* Signature subpacket types */ { ISSUER_SUBPACKET = 0x10 }; - - struct public_key_packet_t { /* a public key packet (DSA/SHA-1) is 418 bytes */ @@ -96,52 +101,49 @@ struct public_key_packet_t uint8_t y[2+128]; }; -/* used for public key signatures */ -struct signature_packet_v4_t -{ /* hashed_data or unhashed_data can be empty, so the signature packet is - * theorically at least 54 bytes long, but always more than that. */ +/* used for public key and file signatures */ +struct signature_packet_t +{ + uint8_t version; /* 3 or 4 */ - uint8_t version; uint8_t type; - uint8_t public_key_algo; - uint8_t digest_algo; - uint8_t hashed_data_len[2]; - uint8_t *hashed_data; - uint8_t unhashed_data_len[2]; - uint8_t *unhashed_data; - uint8_t hash_verification[2]; - - /* The part below is made of consecutive MPIs, their number and size being - * public-key-algorithm dependant. - * But since we use DSA signatures only, we fix it. */ - uint8_t r[2+20]; - uint8_t s[2+20]; -}; + uint8_t public_key_algo; /* DSA only */ + uint8_t digest_algo; /* SHA-1 only */ -/* Used for binary document signatures (to be compatible with older software) - * DSA/SHA-1 is always 65 bytes */ -struct signature_packet_v3_t -{ - uint8_t header[2]; - uint8_t version; /* 3 */ - uint8_t hashed_data_len; /* MUST be 5 */ - uint8_t type; - uint8_t timestamp[4]; /* 4 bytes scalar number */ - uint8_t issuer_longid[8]; /* The key which signed the document */ - uint8_t public_key_algo; /* we only know about DSA */ - uint8_t digest_algo; /* and his little sister SHA-1 */ - uint8_t hash_verification[2];/* the 2 1st bytes of the SHA-1 hash */ + uint8_t hash_verification[2]; + uint8_t issuer_longid[8]; + + union /* version specific data */ + { + struct + { + uint8_t hashed_data_len[2]; /* scalar number */ + uint8_t *hashed_data; /* hashed_data_len bytes */ + uint8_t unhashed_data_len[2]; /* scalar number */ + uint8_t *unhashed_data; /* unhashed_data_len bytes */ + } v4; + struct + { + uint8_t hashed_data_len; /* MUST be 5 */ + uint8_t timestamp[4]; /* 4 bytes scalar number */ + } v3; + } specific; /* The part below is made of consecutive MPIs, their number and size being * public-key-algorithm dependant. - * But since we use DSA signatures only, we fix it. */ + * + * Since we use DSA signatures only, there is 2 integers, r & s, made of: + * 2 bytes for the integer length (scalar number) + * 160 bits (20 bytes) for the integer itself + * + * Note: the integers may be less than 160 significant bits + */ uint8_t r[2+20]; uint8_t s[2+20]; }; typedef struct public_key_packet_t public_key_packet_t; -typedef struct signature_packet_v4_t signature_packet_v4_t; -typedef struct signature_packet_v3_t signature_packet_v3_t; +typedef struct signature_packet_t signature_packet_t; struct public_key_t { @@ -150,7 +152,7 @@ struct public_key_t public_key_packet_t key; /* Public key packet */ - signature_packet_v4_t sig; /* Signature packet, by the embedded key */ + signature_packet_t sig; /* Signature packet, by the embedded key */ }; typedef struct public_key_t public_key_t; diff --git a/src/misc/update.c b/src/misc/update.c index cd1cd408bf..5b7f366be8 100644 --- a/src/misc/update.c +++ b/src/misc/update.c @@ -22,9 +22,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ -/* - * XXX: should use v4 signatures for binary files (already used for public key) - */ + /** * \file * This file contains functions related to VLC update management @@ -47,7 +45,11 @@ #include #include #include +#include +#include #include + +#include #include @@ -101,14 +103,16 @@ static char * size_str( long int l_size ); static inline int scalar_number( uint8_t *p, int header_len ) { + assert( header_len == 1 || header_len == 2 || header_len == 4 ); + 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(); + + abort(); /* to shut up GCC warning */ } /* number of data bytes in a MPI */ @@ -121,150 +125,294 @@ static inline int scalar_number( uint8_t *p, int header_len ) 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 ) + + if( i_packet_len > 418 || i_packet_len < 6 ) return VLC_EGENERIC; - p_key->version = *p_buf++; + size_t i_read = 0; + + p_key->version = *p_buf++; i_read++; if( p_key->version != 4 ) return VLC_EGENERIC; - /* warn when timestamp is > date ? */ - memcpy( p_key->timestamp, p_buf, 4 ); p_buf += 4; + /* XXX: warn when timestamp is > date ? */ + memcpy( p_key->timestamp, p_buf, 4 ); p_buf += 4; i_read += 4; - p_key->algo = *p_buf++; + p_key->algo = *p_buf++; i_read++; if( p_key->algo != PUBLIC_KEY_ALGO_DSA ) return VLC_EGENERIC; + /* read p */ + if( i_read + 2 > i_packet_len ) + return VLC_EGENERIC; + int i_p_len = mpi_len( p_buf ); - if( i_p_len > 128 ) + + 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 ) return VLC_EGENERIC; - else - { - memcpy( p_key->p, p_buf, 2+i_p_len ); p_buf += 2+i_p_len; - if( i_p_len < 128 ) - memmove( p_key->q, p_key->p + 2+i_p_len, 2+20 + 2+128 + 2+128 ); - } int i_q_len = mpi_len( p_buf ); - if( i_q_len > 20 ) + + 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 ) return VLC_EGENERIC; - else - { - memcpy( p_key->q, p_buf, 2+i_q_len ); p_buf += 2+i_q_len; - if( i_p_len < 20 ) - memmove( p_key->g, p_key->q + 2+i_q_len, 2+128 + 2+128 ); - } int i_g_len = mpi_len( p_buf ); - if( i_g_len > 128 ) + + 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 ) return VLC_EGENERIC; - else - { - memcpy( p_key->g, p_buf, 2+i_g_len ); p_buf += 2+i_g_len; - if( i_g_len < 128 ) - memmove( p_key->y, p_key->g + 2+i_g_len, 2+128 ); - } int i_y_len = mpi_len( p_buf ); - if( i_y_len > 128 ) + + + 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 ? */ return VLC_EGENERIC; - else - memcpy( p_key->y, p_buf, 2+i_y_len ); return VLC_SUCCESS; } +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; +} + /* * 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, +static size_t parse_signature_v4_packet( signature_packet_t *p_sig, uint8_t *p_buf, size_t i_sig_len ) { - if( i_sig_len < 54 ) - return VLC_EGENERIC; + size_t i_read = 1; /* we already read the version byte */ - p_sig->version = *p_buf++; - if( p_sig->version != 4 ) - return VLC_EGENERIC; + if( i_sig_len < 10 ) /* signature is at least 10 bytes + the 2 MPIs */ + return 0; - p_sig->type = *p_buf++; - if( p_sig->type < GENERIC_KEY_SIGNATURE || - p_sig->type > POSITIVE_KEY_SIGNATURE ) - return VLC_EGENERIC; + p_sig->type = *p_buf++; i_read++; - p_sig->public_key_algo = *p_buf++; - if( p_sig->public_key_algo != PUBLIC_KEY_ALGO_DSA ) - return VLC_EGENERIC; + p_sig->public_key_algo = *p_buf++; i_read++; - p_sig->digest_algo = *p_buf++; - if( p_sig->digest_algo != DIGEST_ALGO_SHA1 ) - return VLC_EGENERIC; + p_sig->digest_algo = *p_buf++; i_read++; - memcpy( p_sig->hashed_data_len, p_buf, 2 ); p_buf += 2; + memcpy( p_sig->specific.v4.hashed_data_len, p_buf, 2 ); + p_buf += 2; i_read += 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; + 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; - 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_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 ); p_buf += i_hashed_data_len; - memcpy( p_sig->unhashed_data_len, p_buf, 2 ); p_buf += 2; + memcpy( p_sig->specific.v4.unhashed_data_len, p_buf, 2 ); + p_buf += 2; i_read += 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; - } + 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; - 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_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 ); p_buf += i_unhashed_data_len; - memcpy( p_sig->hash_verification, p_buf, 2 ); p_buf += 2; + 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 ); - int i_r_len = mpi_len( p_buf ); - if( i_r_len > 20 ) + for( ;; ) { - free( p_sig->hashed_data ); - free( p_sig->unhashed_data ); - return VLC_EGENERIC; + 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; } - else +} + +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 ) { - memcpy( p_sig->r, p_buf, 2 + i_r_len ); - p_buf += 2 + i_r_len; + 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; } - int i_s_len = mpi_len( p_buf ); - if( i_s_len > 20 ) + 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 ) { - free( p_sig->hashed_data ); - free( p_sig->unhashed_data ); - return VLC_EGENERIC; + 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; } - else + + 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 ) { - memcpy( p_sig->s, p_buf, 2 + i_s_len ); - p_buf += 2 + i_s_len; + free( p_sig->specific.v4.hashed_data ); + free( p_sig->specific.v4.unhashed_data ); } - return VLC_SUCCESS; + return VLC_EGENERIC; } /* @@ -362,7 +510,7 @@ static int pgp_unarmor( char *p_ibuf, size_t i_ibuf_len, * 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, + signature_packet_t *p_sig, const char *psz_url ) { char *psz_sig = (char*) malloc( strlen( psz_url ) + 4 + 1 ); /* ".asc" + \0 */ @@ -379,22 +527,9 @@ static int download_signature( vlc_object_t *p_this, return VLC_ENOMEM; int64_t i_size = stream_Size( p_stream ); - 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 ); + msg_Dbg( p_this, "Downloading signature (%"PRId64" bytes)", i_size ); + uint8_t *p_buf = (uint8_t*)malloc( i_size ); if( !p_buf ) { stream_Delete( p_stream ); @@ -405,41 +540,83 @@ static int download_signature( vlc_object_t *p_this, stream_Delete( p_stream ); - if( i_read != i_size ) + if( i_read != (int)i_size ) { - msg_Dbg( p_this, "Couldn't read full signature" ); + msg_Dbg( p_this, + "Couldn't download full signature (only %d bytes)", i_read ); free( p_buf ); return VLC_EGENERIC; } - int i_bytes = pgp_unarmor( p_buf, i_size, (uint8_t*)p_sig, 65 ); - free( p_buf ); + 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; + } + } - if( i_bytes == 0 ) + if( packet_type( *p_buf ) != SIGNATURE_PACKET ) { - msg_Dbg( p_this, "Unarmoring failed" ); + free( p_buf ); + msg_Dbg( p_this, "Not a signature: %d", *p_buf ); return VLC_EGENERIC; } - else if( i_bytes > 65 ) + + 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 ) { - msg_Dbg( p_this, "Signature is too big: %d bytes", i_bytes ); + free( p_buf ); + msg_Dbg( p_this, "Invalid signature packet header" ); return VLC_EGENERIC; } - else + + 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 ) { - int i_r_len = mpi_len( p_sig->r ); - if( i_r_len > 20 ) + msg_Dbg( p_this, "Invalid signature type: %d", p_sig->type ); + if( p_sig->version == 4 ) { - msg_Dbg( p_this, "Invalid signature, r number too big: %d bytes", - i_r_len ); - return VLC_EGENERIC; + free( p_sig->specific.v4.hashed_data ); + free( p_sig->specific.v4.unhashed_data ); } - else if( i_r_len < 20 ) - /* move s to the right place if r is less than 20 bytes */ - memmove( p_sig->s, p_sig->r + 2 + i_r_len, 20 + 2 ); - - return VLC_SUCCESS; + return VLC_EGENERIC; } + + return VLC_SUCCESS; } /* @@ -503,38 +680,14 @@ problem: 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 ) +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; @@ -546,10 +699,9 @@ static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len, public 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; + p_key->sig.specific.v4.hashed_data = NULL; + p_key->sig.specific.v4.unhashed_data = NULL; if( !( *pos & 0x80 ) ) { /* first byte is ASCII, unarmoring */ @@ -574,7 +726,8 @@ static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len, public int i_type = packet_type( *pos ); int i_header_len = packet_header_len( *pos++ ); - if( pos + i_header_len > max_pos ) + if( pos + i_header_len > max_pos || + ( i_header_len != 1 && i_header_len != 2 && i_header_len != 4 ) ) goto error; int i_packet_len = scalar_number( pos, i_header_len ); @@ -585,29 +738,31 @@ static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len, public 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 ) + case SIGNATURE_PACKET: /* we accept only v4 signatures here */ + if( i_status & SIGNATURE_FOUND || !p_sig_issuer ) break; - p_issuer = get_issuer_from_signature_v4( &sig ); - if( memcmp( p_issuer, p_sig_issuer, 8 ) == 0 ) + int i_ret = parse_signature_packet( &p_key->sig, pos, + i_packet_len ); + if( i_ret == VLC_SUCCESS ) { - memcpy( &p_key->sig, &sig, sizeof( signature_packet_v4_t ) ); + 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; + } i_status |= SIGNATURE_FOUND; } - else - { - free( sig.hashed_data ); - free( sig.unhashed_data ); - } break; case USER_ID_PACKET: @@ -629,7 +784,7 @@ static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len, public } free( p_key_unarmored ); - if( !( i_status & ( PUBLIC_KEY_FOUND + USER_ID_FOUND ) ) ) + if( !( i_status & ( PUBLIC_KEY_FOUND | USER_ID_FOUND ) ) ) return VLC_EGENERIC; if( p_sig_issuer && !( i_status & SIGNATURE_FOUND ) ) @@ -638,8 +793,11 @@ static int parse_public_key( const uint8_t *p_key_data, size_t i_key_len, public return VLC_SUCCESS; error: - free( p_key->sig.hashed_data ); - free( p_key->sig.unhashed_data ); + if( p_key->sig.version == 4 ) + { + free( p_key->sig.specific.v4.hashed_data ); + free( p_key->sig.specific.v4.unhashed_data ); + } free( p_key->psz_username ); free( p_key_unarmored ); return VLC_EGENERIC; @@ -649,8 +807,11 @@ error: * return a sha1 hash of a file */ static uint8_t *hash_sha1_from_file( const char *psz_file, - signature_packet_v3_t *p_sig ) + signature_packet_t *p_sig ) { + if( p_sig->type != BINARY_SIGNATURE && p_sig->type != TEXT_SIGNATURE ) + return NULL; + FILE *f = utf8_fopen( psz_file, "r" ); if( !f ) return NULL; @@ -668,8 +829,26 @@ static uint8_t *hash_sha1_from_file( const char *psz_file, 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 ); + 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; + } fclose( f ); gcry_md_final( hd ); @@ -685,7 +864,8 @@ static uint8_t *hash_sha1_from_file( const char *psz_file, /* * 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 ) +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", @@ -729,6 +909,8 @@ static public_key_t *download_key( vlc_object_t *p_this, const uint8_t *p_longid return NULL; } + memcpy( p_pkey->longid, p_longid, 8 ); + int i_error = parse_public_key( p_buf, i_read, p_pkey, p_signature_issuer ); free( p_buf ); @@ -743,11 +925,18 @@ static public_key_t *download_key( vlc_object_t *p_this, const uint8_t *p_longid } /* - * 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 + * 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 */ static uint8_t *key_sign_hash( public_key_t *p_pkey ) { + 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; + gcry_error_t error = 0; gcry_md_hd_t hd; @@ -757,30 +946,35 @@ static uint8_t *key_sign_hash( public_key_t *p_pkey ) gcry_md_putc( hd, 0x99 ); - gcry_md_putc( hd, (418 >> 8) & 0xff ); - gcry_md_putc( hd, 418 & 0xff ); + 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 ); - gcry_md_write( hd, (uint8_t*)&p_pkey->key, 6 ); /* version,timestamp,algo */ + 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 ); - int i_p_len = mpi_len( p_pkey->key.p ); 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 ); - int i_g_len = mpi_len( p_pkey->key.g ); - 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 ); - - int i_q_len = mpi_len( p_pkey->key.q ); 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 ); - int i_y_len = mpi_len( p_pkey->key.y ); + 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 ); + 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 ); gcry_md_putc( hd, 0xb4 ); - int i_len = strlen((char*)p_pkey->psz_username); + size_t i_len = strlen((char*)p_pkey->psz_username); gcry_md_putc( hd, (i_len << 24) & 0xff ); gcry_md_putc( hd, (i_len << 16) & 0xff ); @@ -789,14 +983,15 @@ static uint8_t *key_sign_hash( public_key_t *p_pkey ) 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 ); + size_t i_hashed_data_len = + scalar_number( p_pkey->sig.specific.v4.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_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 ); gcry_md_putc( hd, 0x04 ); gcry_md_putc( hd, 0xff ); @@ -968,7 +1163,7 @@ static bool GetUpdateFile( update_t *p_update ) /* Now that we know the status is valid, we must download its signature * to authenticate it */ - signature_packet_v3_t sign; + signature_packet_t sign; if( download_signature( VLC_OBJECT( p_update->p_libvlc ), &sign, UPDATE_VLC_STATUS_URL ) != VLC_SUCCESS ) { @@ -994,7 +1189,9 @@ static bool GetUpdateFile( update_t *p_update ) goto error; } - if( memcmp( sign.issuer_longid, videolan_public_key_longid , 8 ) != 0 ) + memcpy( p_update->p_pkey->longid, videolan_public_key_longid, 8 ); + + if( memcmp( sign.issuer_longid, p_update->p_pkey->longid , 8 ) != 0 ) { msg_Dbg( p_update->p_libvlc, "Need to download the GPG key" ); public_key_t *p_new_pkey = download_key( @@ -1052,8 +1249,37 @@ static bool GetUpdateFile( update_t *p_update ) gcry_md_putc( hd, '\r' ); gcry_md_putc( hd, '\n' ); - gcry_md_putc( hd, sign.type ); - gcry_md_write( hd, &sign.timestamp, 4 ); + + if( sign.version == 3 ) + { + gcry_md_putc( hd, sign.type ); + gcry_md_write( hd, &sign.specific.v3.timestamp, 4 ); + } + else if( sign.version == 4 ) + { + gcry_md_putc( hd, sign.version ); + gcry_md_putc( hd, sign.type ); + gcry_md_putc( hd, sign.public_key_algo ); + gcry_md_putc( hd, sign.digest_algo ); + gcry_md_write( hd, sign.specific.v4.hashed_data_len, 2 ); + size_t i_len = scalar_number( sign.specific.v4.hashed_data_len, 2 ); + gcry_md_write( hd, sign.specific.v4.hashed_data, i_len ); + gcry_md_putc( hd, 0x04 ); + gcry_md_putc( hd, 0xFF ); + + i_len += 6; /* hashed data + 6 bytes header */ + + 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 ); + } + else + { /* RFC 4880 only tells about versions 3 and 4 */ + msg_Warn( p_update->p_libvlc, "Invalid signature version %d", + sign.version); + goto error_hd; + } gcry_md_final( hd ); @@ -1116,11 +1342,7 @@ void update_Check( update_t *p_update, void (*pf_callback)( void*, bool ), void update_check_thread_t *p_uct = vlc_object_create( p_update->p_libvlc, sizeof( update_check_thread_t ) ); - if( !p_uct ) - { - msg_Err( p_update->p_libvlc, "out of memory" ); - return; - } + if( !p_uct ) return; p_uct->p_update = p_update; p_uct->pf_callback = pf_callback; @@ -1155,10 +1377,10 @@ bool update_NeedUpgrade( update_t *p_update ) { assert( p_update ); - return p_update->release.i_major < *PACKAGE_VERSION_MAJOR - '0' || - p_update->release.i_minor < *PACKAGE_VERSION_MINOR - '0' || - p_update->release.i_revision < *PACKAGE_VERSION_REVISION || - p_update->release.extra < *PACKAGE_VERSION_EXTRA; + return p_update->release.i_major < *PACKAGE_VERSION_MAJOR - '0' || + p_update->release.i_minor < *PACKAGE_VERSION_MINOR - '0' || + p_update->release.i_revision < *PACKAGE_VERSION_REVISION - '0' || + p_update->release.extra < *PACKAGE_VERSION_EXTRA; } /** @@ -1326,7 +1548,7 @@ void update_DownloadReal( update_download_thread_t *p_udt ) goto end; } - signature_packet_v3_t sign; + signature_packet_t sign; if( download_signature( VLC_OBJECT( p_udt ), &sign, p_update->release.psz_url ) != VLC_SUCCESS ) { -- 2.39.2