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gnupg/g10/parse-packet.c
Werner Koch 0e5a31d7be can create v4 signatures
1998-05-13 17:53:36 +00:00

1407 lines
38 KiB
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/* parse-packet.c - read packets
* Copyright (C) 1998 Free Software Foundation, Inc.
*
* This file is part of GNUPG.
*
* GNUPG 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 version 2 of the License, or
* (at your option) any later version.
*
* GNUPG 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 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "packet.h"
#include "iobuf.h"
#include "mpi.h"
#include "util.h"
#include "cipher.h"
#include "memory.h"
#include "filter.h"
#include "options.h"
static int mpi_print_mode = 0;
static int list_mode = 0;
static int parse( IOBUF inp, PACKET *pkt, int reqtype,
ulong *retpos, int *skip, IOBUF out, int do_skip );
static int copy_packet( IOBUF inp, IOBUF out, int pkttype,
unsigned long pktlen );
static void skip_packet( IOBUF inp, int pkttype, unsigned long pktlen );
static void skip_rest( IOBUF inp, unsigned long pktlen );
static int parse_symkeyenc( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static int parse_pubkeyenc( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static int parse_signature( IOBUF inp, int pkttype, unsigned long pktlen,
PKT_signature *sig );
static int parse_onepass_sig( IOBUF inp, int pkttype, unsigned long pktlen,
PKT_onepass_sig *ops );
static int parse_certificate( IOBUF inp, int pkttype, unsigned long pktlen,
byte *hdr, int hdrlen, PACKET *packet );
static int parse_user_id( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static int parse_comment( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static void parse_trust( IOBUF inp, int pkttype, unsigned long pktlen );
static int parse_plaintext( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *pkt );
static int parse_compressed( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static int parse_encrypted( IOBUF inp, int pkttype, unsigned long pktlen,
PACKET *packet );
static unsigned short
read_16(IOBUF inp)
{
unsigned short a;
a = iobuf_get_noeof(inp) << 8;
a |= iobuf_get_noeof(inp);
return a;
}
static unsigned long
read_32(IOBUF inp)
{
unsigned long a;
a = iobuf_get_noeof(inp) << 24;
a |= iobuf_get_noeof(inp) << 16;
a |= iobuf_get_noeof(inp) << 8;
a |= iobuf_get_noeof(inp);
return a;
}
static unsigned long
buffer_to_u32( const byte *buffer )
{
unsigned long a;
a = *buffer << 24;
a |= buffer[1] << 16;
a |= buffer[2] << 8;
a |= buffer[3];
return a;
}
int
set_packet_list_mode( int mode )
{
int old = list_mode;
list_mode = mode;
mpi_print_mode = DBG_MPI;
return old;
}
/****************
* Parse a Packet and return it in packet
* Returns: 0 := valid packet in pkt
* -1 := no more packets
* >0 := error
* Note: The function may return an error and a partly valid packet;
* caller must free this packet.
*/
int
parse_packet( IOBUF inp, PACKET *pkt )
{
int skip, rc;
do {
rc = parse( inp, pkt, 0, NULL, &skip, NULL, 0 );
} while( skip );
return rc;
}
/****************
* Like parse packet, but only return packets of the given type.
*/
int
search_packet( IOBUF inp, PACKET *pkt, int pkttype, ulong *retpos )
{
int skip, rc;
do {
rc = parse( inp, pkt, pkttype, retpos, &skip, NULL, 0 );
} while( skip );
return rc;
}
/****************
* Copy all packets from INP to OUT, thereby removing unused spaces.
*/
int
copy_all_packets( IOBUF inp, IOBUF out )
{
PACKET pkt;
int skip, rc=0;
do {
init_packet(&pkt);
} while( !(rc = parse( inp, &pkt, 0, NULL, &skip, out, 0 )));
return rc;
}
/****************
* Copy some packets from INP to OUT, thereby removing unused spaces.
* Stop at offset STOPoff (i.e. don't copy packets at this or later offsets)
*/
int
copy_some_packets( IOBUF inp, IOBUF out, ulong stopoff )
{
PACKET pkt;
int skip, rc=0;
do {
if( iobuf_tell(inp) >= stopoff )
return 0;
init_packet(&pkt);
} while( !(rc = parse( inp, &pkt, 0, NULL, &skip, out, 0 )) );
return rc;
}
/****************
* Skip over N packets
*/
int
skip_some_packets( IOBUF inp, unsigned n )
{
int skip, rc=0;
PACKET pkt;
for( ;n && !rc; n--) {
init_packet(&pkt);
rc = parse( inp, &pkt, 0, NULL, &skip, NULL, 1 );
}
return rc;
}
/****************
* Parse packet. Set the variable skip points to to 1 if the packet
* should be skipped; this is the case if either there is a
* requested packet type and the parsed packet doesn't match or the
* packet-type is 0, indicating deleted stuff.
* if OUT is not NULL, a special copymode is used.
*/
static int
parse( IOBUF inp, PACKET *pkt, int reqtype, ulong *retpos,
int *skip, IOBUF out, int do_skip )
{
int rc, c, ctb, pkttype, lenbytes;
unsigned long pktlen;
byte hdr[8];
int hdrlen;
int pgp3 = 0;
*skip = 0;
assert( !pkt->pkt.generic );
if( retpos )
*retpos = iobuf_tell(inp);
if( (ctb = iobuf_get(inp)) == -1 )
return -1;
hdrlen=0;
hdr[hdrlen++] = ctb;
if( !(ctb & 0x80) ) {
log_error("%s: invalid packet (ctb=%02x)\n", iobuf_where(inp), ctb );
return G10ERR_INVALID_PACKET;
}
pktlen = 0;
pgp3 = !!(ctb & 0x40);
if( pgp3 ) {
pkttype = ctb & 0x3f;
if( (c = iobuf_get(inp)) == -1 ) {
log_error("%s: 1st length byte missing\n", iobuf_where(inp) );
return G10ERR_INVALID_PACKET;
}
hdr[hdrlen++] = c;
if( c < 192 )
pktlen = c;
else if( c < 224 ) {
pktlen = (c - 192) * 256;
if( (c = iobuf_get(inp)) == -1 ) {
log_error("%s: 2nd length byte missing\n", iobuf_where(inp) );
return G10ERR_INVALID_PACKET;
}
hdr[hdrlen++] = c;
pktlen += c + 192;
}
else if( c < 255 ) {
pktlen = (hdr[hdrlen++] = iobuf_get_noeof(inp)) << 24;
pktlen |= (hdr[hdrlen++] = iobuf_get_noeof(inp)) << 16;
pktlen |= (hdr[hdrlen++] = iobuf_get_noeof(inp)) << 8;
if( (c = iobuf_get(inp)) == -1 ) {
log_error("%s: 4 byte length invalid\n", iobuf_where(inp) );
return G10ERR_INVALID_PACKET;
}
pktlen |= (hdr[hdrlen++] = c );
}
else { /* partial body length */
log_debug("partial body length of %lu bytes\n", pktlen );
iobuf_set_partial_block_mode(inp, pktlen);
pktlen = 0;/* to indicate partial length */
}
}
else {
pkttype = (ctb>>2)&0xf;
lenbytes = ((ctb&3)==3)? 0 : (1<<(ctb & 3));
if( !lenbytes ) {
pktlen = 0; /* don't know the value */
if( pkttype != PKT_COMPRESSED )
iobuf_set_block_mode(inp, 1);
}
else {
for( ; lenbytes; lenbytes-- ) {
pktlen <<= 8;
pktlen |= hdr[hdrlen++] = iobuf_get_noeof(inp);
}
}
}
if( out && pkttype ) {
if( iobuf_write( out, hdr, hdrlen ) == -1 )
rc = G10ERR_WRITE_FILE;
else
rc = copy_packet(inp, out, pkttype, pktlen );
return rc;
}
if( do_skip || !pkttype || (reqtype && pkttype != reqtype) ) {
skip_packet(inp, pkttype, pktlen);
*skip = 1;
return 0;
}
if( DBG_PACKET )
log_debug("parse_packet(iob=%d): type=%d length=%lu%s\n",
iobuf_id(inp), pkttype, pktlen, pgp3?" (pgp3)":"" );
pkt->pkttype = pkttype;
rc = G10ERR_UNKNOWN_PACKET; /* default error */
switch( pkttype ) {
case PKT_PUBLIC_CERT:
case PKT_PUBKEY_SUBCERT:
pkt->pkt.public_cert = m_alloc_clear(sizeof *pkt->pkt.public_cert );
rc = parse_certificate(inp, pkttype, pktlen, hdr, hdrlen, pkt );
break;
case PKT_SECRET_CERT:
case PKT_SECKEY_SUBCERT:
pkt->pkt.secret_cert = m_alloc_clear(sizeof *pkt->pkt.secret_cert );
rc = parse_certificate(inp, pkttype, pktlen, hdr, hdrlen, pkt );
break;
case PKT_SYMKEY_ENC:
rc = parse_symkeyenc( inp, pkttype, pktlen, pkt );
break;
case PKT_PUBKEY_ENC:
rc = parse_pubkeyenc(inp, pkttype, pktlen, pkt );
break;
case PKT_SIGNATURE:
pkt->pkt.signature = m_alloc_clear(sizeof *pkt->pkt.signature );
rc = parse_signature(inp, pkttype, pktlen, pkt->pkt.signature );
break;
case PKT_ONEPASS_SIG:
pkt->pkt.onepass_sig = m_alloc_clear(sizeof *pkt->pkt.onepass_sig );
rc = parse_onepass_sig(inp, pkttype, pktlen, pkt->pkt.onepass_sig );
break;
case PKT_USER_ID:
rc = parse_user_id(inp, pkttype, pktlen, pkt );
break;
case PKT_OLD_COMMENT:
case PKT_COMMENT:
rc = parse_comment(inp, pkttype, pktlen, pkt);
break;
case PKT_RING_TRUST:
parse_trust(inp, pkttype, pktlen);
break;
case PKT_PLAINTEXT:
rc = parse_plaintext(inp, pkttype, pktlen, pkt );
break;
case PKT_COMPRESSED:
rc = parse_compressed(inp, pkttype, pktlen, pkt );
break;
case PKT_ENCRYPTED:
rc = parse_encrypted(inp, pkttype, pktlen, pkt );
break;
default:
skip_packet(inp, pkttype, pktlen);
break;
}
return rc;
}
static void
dump_hex_line( int c, int *i )
{
if( *i && !(*i%8) ) {
if( *i && !(*i%24) )
printf("\n%4d:", *i );
else
putchar(' ');
}
if( c == -1 )
printf(" EOF" );
else
printf(" %02x", c );
++*i;
}
static int
copy_packet( IOBUF inp, IOBUF out, int pkttype, unsigned long pktlen )
{
int n;
char buf[100];
if( iobuf_in_block_mode(inp) ) {
while( (n = iobuf_read( inp, buf, 100 )) != -1 )
if( iobuf_write(out, buf, n ) )
return G10ERR_WRITE_FILE; /* write error */
}
else if( !pktlen && pkttype == PKT_COMPRESSED ) {
/* compressed packet, copy till EOF */
while( (n = iobuf_read( inp, buf, 100 )) != -1 )
if( iobuf_write(out, buf, n ) )
return G10ERR_WRITE_FILE; /* write error */
}
else {
for( ; pktlen; pktlen -= n ) {
n = pktlen > 100 ? 100 : pktlen;
n = iobuf_read( inp, buf, n );
if( n == -1 )
return G10ERR_READ_FILE;
if( iobuf_write(out, buf, n ) )
return G10ERR_WRITE_FILE; /* write error */
}
}
return 0;
}
static void
skip_packet( IOBUF inp, int pkttype, unsigned long pktlen )
{
if( list_mode ) {
printf(":unknown packet: type %2d, length %lu\n", pkttype, pktlen );
if( pkttype ) {
int c, i=0 ;
printf("dump:");
if( iobuf_in_block_mode(inp) ) {
while( (c=iobuf_get(inp)) != -1 )
dump_hex_line(c, &i);
}
else {
for( ; pktlen; pktlen-- )
dump_hex_line(iobuf_get(inp), &i);
}
putchar('\n');
return;
}
}
skip_rest(inp,pktlen);
}
static void
skip_rest( IOBUF inp, unsigned long pktlen )
{
if( iobuf_in_block_mode(inp) ) {
while( iobuf_get(inp) != -1 )
;
}
else {
for( ; pktlen; pktlen-- )
iobuf_get(inp);
}
}
static int
parse_symkeyenc( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *packet )
{
PKT_symkey_enc *k;
int i, version, s2kmode, cipher_algo, hash_algo, seskeylen, minlen;
if( pktlen < 4 ) {
log_error("packet(%d) too short\n", pkttype);
goto leave;
}
version = iobuf_get_noeof(inp); pktlen--;
if( version != 4 ) {
log_error("packet(%d) with unknown version %d\n", pkttype, version);
goto leave;
}
if( pktlen > 200 ) { /* (we encode the seskeylen in a byte) */
log_error("packet(%d) too large\n", pkttype);
goto leave;
}
cipher_algo = iobuf_get_noeof(inp); pktlen--;
s2kmode = iobuf_get_noeof(inp); pktlen--;
hash_algo = iobuf_get_noeof(inp); pktlen--;
switch( s2kmode ) {
case 0: /* simple s2k */
minlen = 0;
break;
case 1: /* salted s2k */
minlen = 8;
break;
case 4: /* iterated+salted s2k */
minlen = 12;
break;
default:
log_error("unknown S2K %d\n", s2kmode );
goto leave;
}
if( minlen > pktlen ) {
log_error("packet with S2K %d too short\n", s2kmode );
goto leave;
}
seskeylen = pktlen - minlen;
k = packet->pkt.symkey_enc = m_alloc_clear( sizeof *packet->pkt.symkey_enc
+ seskeylen - 1 );
k->version = version;
k->cipher_algo = cipher_algo;
k->s2k.mode = s2kmode;
k->s2k.hash_algo = hash_algo;
if( s2kmode == 1 || s2kmode == 4 ) {
for(i=0; i < 8 && pktlen; i++, pktlen-- )
k->s2k.salt[i] = iobuf_get_noeof(inp);
}
if( s2kmode == 4 ) {
k->s2k.count = read_32(inp); pktlen -= 4;
}
k->seskeylen = seskeylen;
for(i=0; i < seskeylen && pktlen; i++, pktlen-- )
k->seskey[i] = iobuf_get_noeof(inp);
assert( !pktlen );
if( list_mode ) {
printf(":symkey enc packet: version %d, cipher %d, s2k %d, hash %d\n",
version, cipher_algo, s2kmode, hash_algo);
if( s2kmode == 1 || s2kmode == 4 ) {
printf("\tsalt ");
for(i=0; i < 8; i++ )
printf("%02x", k->s2k.salt[i]);
if( s2kmode == 4 )
printf(", count %lu\n", (ulong)k->s2k.count );
printf("\n");
}
}
leave:
skip_rest(inp, pktlen);
return 0;
}
static int
parse_pubkeyenc( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *packet )
{
unsigned n;
PKT_pubkey_enc *k;
k = packet->pkt.pubkey_enc = m_alloc(sizeof *packet->pkt.pubkey_enc );
if( pktlen < 12 ) {
log_error("packet(%d) too short\n", pkttype);
goto leave;
}
k->version = iobuf_get_noeof(inp); pktlen--;
if( k->version != 2 && k->version != 3 ) {
log_error("packet(%d) with unknown version %d\n", pkttype, k->version);
goto leave;
}
k->keyid[0] = read_32(inp); pktlen -= 4;
k->keyid[1] = read_32(inp); pktlen -= 4;
k->pubkey_algo = iobuf_get_noeof(inp); pktlen--;
if( list_mode )
printf(":pubkey enc packet: version %d, algo %d, keyid %08lX%08lX\n",
k->version, k->pubkey_algo, (ulong)k->keyid[0], (ulong)k->keyid[1]);
if( is_ELGAMAL(k->pubkey_algo) ) {
n = pktlen;
k->d.elg.a = mpi_read(inp, &n, 0); pktlen -=n;
n = pktlen;
k->d.elg.b = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf("\telg a: ");
mpi_print(stdout, k->d.elg.a, mpi_print_mode );
printf("\n\telg b: ");
mpi_print(stdout, k->d.elg.b, mpi_print_mode );
putchar('\n');
}
}
else if( is_RSA(k->pubkey_algo) ) {
n = pktlen;
k->d.rsa.rsa_integer = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf("\trsa integer: ");
mpi_print(stdout, k->d.rsa.rsa_integer, mpi_print_mode );
putchar('\n');
}
}
else if( list_mode )
printf("\tunknown algorithm %d\n", k->pubkey_algo );
leave:
skip_rest(inp, pktlen);
return 0;
}
const byte *
parse_sig_subpkt( const byte *buffer, sigsubpkttype_t reqtype, size_t *ret_n )
{
int buflen;
int type;
int critical;
size_t n;
if( !buffer )
return NULL;
buflen = (*buffer << 8) | buffer[1];
buffer += 2;
for(;;) {
if( !buflen )
return NULL; /* end of packets; not found */
n = *buffer++; buflen--;
if( n == 255 ) {
if( buflen < 4 )
goto too_short;
n = (buffer[0] << 24) | (buffer[1] << 16)
| (buffer[2] << 8) | buffer[3];
buffer += 4;
buflen -= 4;
}
else if( n >= 192 ) {
if( buflen < 2 )
goto too_short;
n = (( n - 192 ) << 8) + *buffer + 192;
buflen--;
}
if( buflen < n )
goto too_short;
type = *buffer;
if( type & 0x80 ) {
type &= 0x7f;
critical = 1;
}
else
critical = 0;
if( reqtype < 0 ) { /* list packets */
printf("\t%ssubpacket %d of length %u (%s)\n",
reqtype == SIGSUBPKT_LIST_HASHED ? "hashed ":"", type, (unsigned)n,
type == SIGSUBPKT_SIG_CREATED ? "signature creation time"
: type == SIGSUBPKT_SIG_EXPIRE ? "signature expiration time"
: type == SIGSUBPKT_EXPORTABLE ? "exportable"
: type == SIGSUBPKT_TRUST ? "trust signature"
: type == SIGSUBPKT_REGEXP ? "regular expression"
: type == SIGSUBPKT_REVOCABLE ? "revocable"
: type == SIGSUBPKT_KEY_EXPIRE ? "key expiration time"
: type == SIGSUBPKT_ARR ? "additional recipient request"
: type == SIGSUBPKT_PREF_SYM ? "preferred symmetric algorithms"
: type == SIGSUBPKT_REV_KEY ? "revocation key"
: type == SIGSUBPKT_ISSUER ? "issuer key ID"
: type == SIGSUBPKT_NOTATION ? "notation data"
: type == SIGSUBPKT_PREF_HASH ? "preferred hash algorithms"
: type == SIGSUBPKT_PREF_COMPR ? "preferred compression algorithms"
: type == SIGSUBPKT_KS_FLAGS ? "key server preferences"
: type == SIGSUBPKT_PREF_KS ? "preferred key server"
: type == SIGSUBPKT_PRIMARY_UID ? "primary user id"
: type == SIGSUBPKT_POLICY ? "policy URL"
: type == SIGSUBPKT_KEY_FLAGS ? "key flags"
: type == SIGSUBPKT_SIGNERS_UID ? "signer's user id"
: "?");
}
else if( type == reqtype )
break; /* found */
buffer += n; buflen -=n;
}
buffer++;
n--;
if( n > buflen )
goto too_short;
if( ret_n )
*ret_n = n;
switch( type ) {
case SIGSUBPKT_SIG_CREATED:
if( n < 4 )
break;
return buffer;
case SIGSUBPKT_ISSUER:/* issuer key ID */
if( n < 8 )
break;
return buffer;
default: BUG(); /* not yet needed */
}
log_error("subpacket of type %d too short\n", type);
return NULL;
too_short:
log_error("buffer shorter than subpacket\n");
return NULL;
}
static int
parse_signature( IOBUF inp, int pkttype, unsigned long pktlen,
PKT_signature *sig )
{
int md5_len=0;
unsigned n;
int is_v4=0;
int rc=0;
if( pktlen < 16 ) {
log_error("packet(%d) too short\n", pkttype);
goto leave;
}
sig->version = iobuf_get_noeof(inp); pktlen--;
if( sig->version == 4 )
is_v4=1;
else if( sig->version != 2 && sig->version != 3 ) {
log_error("packet(%d) with unknown version %d\n", pkttype, sig->version);
goto leave;
}
if( !is_v4 ) {
md5_len = iobuf_get_noeof(inp); pktlen--;
}
sig->sig_class = iobuf_get_noeof(inp); pktlen--;
if( !is_v4 ) {
sig->timestamp = read_32(inp); pktlen -= 4;
sig->keyid[0] = read_32(inp); pktlen -= 4;
sig->keyid[1] = read_32(inp); pktlen -= 4;
}
sig->pubkey_algo = iobuf_get_noeof(inp); pktlen--;
sig->digest_algo = iobuf_get_noeof(inp); pktlen--;
if( is_v4 ) { /* read subpackets */
n = read_16(inp); pktlen -= 2; /* length of hashed data */
if( n > 10000 ) {
log_error("signature packet: hashed data too long\n");
rc = G10ERR_INVALID_PACKET;
goto leave;
}
if( n ) {
sig->hashed_data = m_alloc( n + 2 );
sig->hashed_data[0] = n << 8;
sig->hashed_data[1] = n;
if( iobuf_read(inp, sig->hashed_data+2, n ) != n ) {
log_error("premature eof while reading hashed signature data\n");
rc = -1;
goto leave;
}
pktlen -= n;
}
n = read_16(inp); pktlen -= 2; /* length of unhashed data */
if( n > 10000 ) {
log_error("signature packet: unhashed data too long\n");
rc = G10ERR_INVALID_PACKET;
goto leave;
}
if( n ) {
sig->unhashed_data = m_alloc( n + 2 );
sig->unhashed_data[0] = n << 8;
sig->unhashed_data[1] = n;
if( iobuf_read(inp, sig->unhashed_data+2, n ) != n ) {
log_error("premature eof while reading unhashed signature data\n");
rc = -1;
goto leave;
}
pktlen -= n;
}
}
if( pktlen < 5 ) { /* sanity check */
log_error("packet(%d) too short\n", pkttype);
rc = G10ERR_INVALID_PACKET;
goto leave;
}
sig->digest_start[0] = iobuf_get_noeof(inp); pktlen--;
sig->digest_start[1] = iobuf_get_noeof(inp); pktlen--;
if( is_v4 ) { /*extract required information */
const byte *p;
p = parse_sig_subpkt( sig->hashed_data, SIGSUBPKT_SIG_CREATED, NULL );
if( !p )
log_error("signature packet without timestamp\n");
else
sig->timestamp = buffer_to_u32(p);
p = parse_sig_subpkt( sig->unhashed_data, SIGSUBPKT_ISSUER, NULL );
if( !p )
log_error("signature packet without keyid\n");
else {
sig->keyid[0] = buffer_to_u32(p);
sig->keyid[1] = buffer_to_u32(p+4);
}
}
if( list_mode ) {
printf(":signature packet: algo %d, keyid %08lX%08lX\n"
"\tversion %d, created %lu, md5len %d, sigclass %02x\n"
"\tdigest algo %d, begin of digest %02x %02x\n",
sig->pubkey_algo,
(ulong)sig->keyid[0], (ulong)sig->keyid[1],
sig->version, (ulong)sig->timestamp, md5_len, sig->sig_class,
sig->digest_algo,
sig->digest_start[0], sig->digest_start[1] );
if( is_v4 ) {
parse_sig_subpkt( sig->hashed_data, SIGSUBPKT_LIST_HASHED, NULL );
parse_sig_subpkt( sig->unhashed_data,SIGSUBPKT_LIST_UNHASHED, NULL);
}
}
if( is_ELGAMAL(sig->pubkey_algo) ) {
n = pktlen;
sig->d.elg.a = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen;
sig->d.elg.b = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf("\telg a: ");
mpi_print(stdout, sig->d.elg.a, mpi_print_mode );
printf("\n\telg b: ");
mpi_print(stdout, sig->d.elg.b, mpi_print_mode );
putchar('\n');
}
}
else if( sig->pubkey_algo == PUBKEY_ALGO_DSA ) {
n = pktlen;
sig->d.dsa.r = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen;
sig->d.dsa.s = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf("\tdsa r: ");
mpi_print(stdout, sig->d.elg.a, mpi_print_mode );
printf("\n\tdsa s: ");
mpi_print(stdout, sig->d.elg.b, mpi_print_mode );
putchar('\n');
}
}
else if( is_RSA(sig->pubkey_algo) ) {
n = pktlen;
sig->d.rsa.rsa_integer = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf("\trsa integer: ");
mpi_print(stdout, sig->d.rsa.rsa_integer, mpi_print_mode );
putchar('\n');
}
}
else if( list_mode )
printf("\tunknown algorithm %d\n", sig->pubkey_algo );
leave:
skip_rest(inp, pktlen);
return rc;
}
static int
parse_onepass_sig( IOBUF inp, int pkttype, unsigned long pktlen,
PKT_onepass_sig *ops )
{
int version;
if( pktlen < 13 ) {
log_error("packet(%d) too short\n", pkttype);
goto leave;
}
version = iobuf_get_noeof(inp); pktlen--;
if( version != 3 ) {
log_error("onepass_sig with unknown version %d\n", version);
goto leave;
}
ops->sig_class = iobuf_get_noeof(inp); pktlen--;
ops->digest_algo = iobuf_get_noeof(inp); pktlen--;
ops->pubkey_algo = iobuf_get_noeof(inp); pktlen--;
ops->keyid[0] = read_32(inp); pktlen -= 4;
ops->keyid[1] = read_32(inp); pktlen -= 4;
ops->last = iobuf_get_noeof(inp); pktlen--;
if( list_mode )
printf(":onepass_sig packet: keyid %08lX%08lX\n"
"\tversion %d, sigclass %02x, digest %d, pubkey %d, last=%d\n",
(ulong)ops->keyid[0], (ulong)ops->keyid[1],
version, ops->sig_class,
ops->digest_algo, ops->pubkey_algo, ops->last );
leave:
skip_rest(inp, pktlen);
return 0;
}
static int
parse_certificate( IOBUF inp, int pkttype, unsigned long pktlen,
byte *hdr, int hdrlen, PACKET *pkt )
{
int i, version, algorithm;
unsigned n;
unsigned long timestamp;
unsigned short valid_period;
int is_v4=0;
int rc=0;
version = iobuf_get_noeof(inp); pktlen--;
if( pkttype == PKT_PUBKEY_SUBCERT && version == '#' ) {
/* early versions of G10 use old PGP comments packets;
* luckily all those comments are started by a hash */
if( list_mode ) {
printf(":rfc1991 comment packet: \"" );
for( ; pktlen; pktlen-- ) {
int c;
c = iobuf_get_noeof(inp);
if( c >= ' ' && c <= 'z' )
putchar(c);
else
printf("\\x%02x", c );
}
printf("\"\n");
}
skip_rest(inp, pktlen);
return 0;
}
else if( version == 4 )
is_v4=1;
else if( version != 2 && version != 3 ) {
log_error("packet(%d) with unknown version %d\n", pkttype, version);
goto leave;
}
if( pktlen < 11 ) {
log_error("packet(%d) too short\n", pkttype);
goto leave;
}
timestamp = read_32(inp); pktlen -= 4;
if( is_v4 )
valid_period = 0;
else {
valid_period = read_16(inp); pktlen -= 2;
}
algorithm = iobuf_get_noeof(inp); pktlen--;
if( list_mode )
printf(":%s key packet:\n"
"\tversion %d, algo %d, created %lu, valid for %hu days\n",
pkttype == PKT_PUBLIC_CERT? "public" :
pkttype == PKT_SECRET_CERT? "secret" :
pkttype == PKT_PUBKEY_SUBCERT? "public sub" :
pkttype == PKT_SECKEY_SUBCERT? "secret sub" : "??",
version, algorithm, timestamp, valid_period );
if( pkttype == PKT_SECRET_CERT || pkttype == PKT_SECKEY_SUBCERT ) {
pkt->pkt.secret_cert->timestamp = timestamp;
pkt->pkt.secret_cert->valid_days = valid_period;
pkt->pkt.secret_cert->hdrbytes = hdrlen;
pkt->pkt.secret_cert->version = version;
pkt->pkt.secret_cert->pubkey_algo = algorithm;
}
else {
pkt->pkt.public_cert->timestamp = timestamp;
pkt->pkt.public_cert->valid_days = valid_period;
pkt->pkt.public_cert->hdrbytes = hdrlen;
pkt->pkt.public_cert->version = version;
pkt->pkt.public_cert->pubkey_algo = algorithm;
}
if( is_ELGAMAL(algorithm) ) {
MPI elg_p, elg_g, elg_y;
n = pktlen; elg_p = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; elg_g = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; elg_y = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf( "\telg p: ");
mpi_print(stdout, elg_p, mpi_print_mode );
printf("\n\telg g: ");
mpi_print(stdout, elg_g, mpi_print_mode );
printf("\n\telg y: ");
mpi_print(stdout, elg_y, mpi_print_mode );
putchar('\n');
}
if( pkttype == PKT_PUBLIC_CERT || pkttype == PKT_PUBKEY_SUBCERT ) {
pkt->pkt.public_cert->d.elg.p = elg_p;
pkt->pkt.public_cert->d.elg.g = elg_g;
pkt->pkt.public_cert->d.elg.y = elg_y;
}
else {
PKT_secret_cert *cert = pkt->pkt.secret_cert;
byte temp[8];
pkt->pkt.secret_cert->d.elg.p = elg_p;
pkt->pkt.secret_cert->d.elg.g = elg_g;
pkt->pkt.secret_cert->d.elg.y = elg_y;
cert->protect.algo = iobuf_get_noeof(inp); pktlen--;
if( cert->protect.algo ) {
cert->is_protected = 1;
cert->protect.s2k.count = 0;
if( cert->protect.algo == 255 ) {
if( pktlen < 3 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
cert->protect.algo = iobuf_get_noeof(inp); pktlen--;
cert->protect.s2k.mode = iobuf_get_noeof(inp); pktlen--;
cert->protect.s2k.hash_algo = iobuf_get_noeof(inp); pktlen--;
switch( cert->protect.s2k.mode ) {
case 1:
case 4:
for(i=0; i < 8 && pktlen; i++, pktlen-- )
temp[i] = iobuf_get_noeof(inp);
memcpy(cert->protect.s2k.salt, temp, 8 );
break;
}
switch( cert->protect.s2k.mode ) {
case 0: if( list_mode ) printf( "\tsimple S2K" );
break;
case 1: if( list_mode ) printf( "\tsalted S2K" );
break;
case 4: if( list_mode ) printf( "\titer+salt S2K" );
break;
default:
if( list_mode )
printf( "\tunknown S2K %d\n",
cert->protect.s2k.mode );
rc = G10ERR_INVALID_PACKET;
goto leave;
}
if( list_mode ) {
printf(", algo: %d, hash: %d",
cert->protect.algo,
cert->protect.s2k.hash_algo );
if( cert->protect.s2k.mode == 1
|| cert->protect.s2k.mode == 4 ) {
printf(", salt: ");
for(i=0; i < 8; i++ )
printf("%02x", cert->protect.s2k.salt[i]);
}
putchar('\n');
}
if( cert->protect.s2k.mode == 4 ) {
if( pktlen < 4 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
cert->protect.s2k.count = read_32(inp);
pktlen -= 4;
}
}
else {
if( list_mode )
printf( "\tprotect algo: %d\n",
cert->protect.algo);
/* old version, we don't have a S2K, so we fake one */
cert->protect.s2k.mode = 0;
/* We need this kludge to cope with old GNUPG versions */
cert->protect.s2k.hash_algo =
cert->protect.algo == CIPHER_ALGO_BLOWFISH160?
DIGEST_ALGO_RMD160 : DIGEST_ALGO_MD5;
}
if( pktlen < 8 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
for(i=0; i < 8 && pktlen; i++, pktlen-- )
temp[i] = iobuf_get_noeof(inp);
if( list_mode ) {
printf( "\tprotect IV: ");
for(i=0; i < 8; i++ )
printf(" %02x", temp[i] );
putchar('\n');
}
memcpy(cert->protect.iv, temp, 8 );
}
else
cert->is_protected = 0;
/* It does not make sense to read it into secure memory.
* If the user is so careless, not to protect his secret key,
* we can assume, that he operates an open system :=(.
* So we put the key into secure memory when we unprotect it. */
n = pktlen; cert->d.elg.x = mpi_read(inp, &n, 0 ); pktlen -=n;
cert->csum = read_16(inp); pktlen -= 2;
if( list_mode ) {
printf("\telg x: ");
mpi_print(stdout, cert->d.elg.x, mpi_print_mode );
putchar('\n');
printf("\t[secret value x is not shown]\n"
"\tchecksum: %04hx\n", cert->csum);
}
/*log_mpidump("elg p=", cert->d.elg.p );
log_mpidump("elg g=", cert->d.elg.g );
log_mpidump("elg y=", cert->d.elg.y );
log_mpidump("elg x=", cert->d.elg.x ); */
}
}
else if( algorithm == PUBKEY_ALGO_DSA ) {
MPI dsa_p, dsa_q, dsa_g, dsa_y;
n = pktlen; dsa_p = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; dsa_q = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; dsa_g = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; dsa_y = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf( "\tdsa p: ");
mpi_print(stdout, dsa_p, mpi_print_mode );
printf("\n\tdsa q: ");
mpi_print(stdout, dsa_q, mpi_print_mode );
printf("\n\tdsa g: ");
mpi_print(stdout, dsa_g, mpi_print_mode );
printf("\n\tdsa y: ");
mpi_print(stdout, dsa_y, mpi_print_mode );
putchar('\n');
}
if( pkttype == PKT_PUBLIC_CERT || pkttype == PKT_PUBKEY_SUBCERT ) {
pkt->pkt.public_cert->d.dsa.p = dsa_p;
pkt->pkt.public_cert->d.dsa.q = dsa_q;
pkt->pkt.public_cert->d.dsa.g = dsa_g;
pkt->pkt.public_cert->d.dsa.y = dsa_y;
}
else {
PKT_secret_cert *cert = pkt->pkt.secret_cert;
byte temp[8];
pkt->pkt.secret_cert->d.dsa.p = dsa_p;
pkt->pkt.secret_cert->d.dsa.q = dsa_q;
pkt->pkt.secret_cert->d.dsa.g = dsa_g;
pkt->pkt.secret_cert->d.dsa.y = dsa_y;
cert->protect.algo = iobuf_get_noeof(inp); pktlen--;
if( cert->protect.algo ) {
cert->is_protected = 1;
cert->protect.s2k.count = 0;
if( cert->protect.algo == 255 ) {
if( pktlen < 3 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
cert->protect.algo = iobuf_get_noeof(inp); pktlen--;
cert->protect.s2k.mode = iobuf_get_noeof(inp); pktlen--;
cert->protect.s2k.hash_algo = iobuf_get_noeof(inp); pktlen--;
switch( cert->protect.s2k.mode ) {
case 1:
case 4:
for(i=0; i < 8 && pktlen; i++, pktlen-- )
temp[i] = iobuf_get_noeof(inp);
memcpy(cert->protect.s2k.salt, temp, 8 );
break;
}
switch( cert->protect.s2k.mode ) {
case 0: if( list_mode ) printf( "\tsimple S2K" );
break;
case 1: if( list_mode ) printf( "\tsalted S2K" );
break;
case 4: if( list_mode ) printf( "\titer+salt S2K" );
break;
default:
if( list_mode )
printf( "\tunknown S2K %d\n",
cert->protect.s2k.mode );
rc = G10ERR_INVALID_PACKET;
goto leave;
}
if( list_mode ) {
printf(", algo: %d, hash: %d",
cert->protect.algo,
cert->protect.s2k.hash_algo );
if( cert->protect.s2k.mode == 1
|| cert->protect.s2k.mode == 4 ){
printf(", salt: ");
for(i=0; i < 8; i++ )
printf("%02x", cert->protect.s2k.salt[i]);
}
putchar('\n');
}
if( cert->protect.s2k.mode == 4 ) {
if( pktlen < 4 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
cert->protect.s2k.count = read_32(inp);
pktlen -= 4;
}
}
else {
if( list_mode )
printf( "\tprotect algo: %d\n", cert->protect.algo);
/* old version, we don't have a S2K, so we fake one */
cert->protect.s2k.mode = 0;
cert->protect.s2k.hash_algo = DIGEST_ALGO_MD5;
}
if( pktlen < 8 ) {
rc = G10ERR_INVALID_PACKET;
goto leave;
}
for(i=0; i < 8 && pktlen; i++, pktlen-- )
temp[i] = iobuf_get_noeof(inp);
if( list_mode ) {
printf( "\tprotect IV: ");
for(i=0; i < 8; i++ )
printf(" %02x", temp[i] );
putchar('\n');
}
memcpy(cert->protect.iv, temp, 8 );
}
else
cert->is_protected = 0;
/* It does not make sense to read it into secure memory.
* If the user is so careless, not to protect his secret key,
* we can assume, that he operates an open system :=(.
* So we put the key into secure memory when we unprotect it. */
n = pktlen; cert->d.dsa.x = mpi_read(inp, &n, 0 ); pktlen -=n;
cert->csum = read_16(inp); pktlen -= 2;
if( list_mode ) {
printf("\t[secret value x is not shown]\n"
"\tchecksum: %04hx\n", cert->csum);
}
/*log_mpidump("dsa p=", cert->d.dsa.p );
log_mpidump("dsa q=", cert->d.dsa.q );
log_mpidump("dsa g=", cert->d.dsa.g );
log_mpidump("dsa y=", cert->d.dsa.y );
log_mpidump("dsa x=", cert->d.dsa.x ); */
}
}
else if( is_RSA(algorithm) ) {
MPI rsa_pub_mod, rsa_pub_exp;
n = pktlen; rsa_pub_mod = mpi_read(inp, &n, 0); pktlen -=n;
n = pktlen; rsa_pub_exp = mpi_read(inp, &n, 0 ); pktlen -=n;
if( list_mode ) {
printf( "\tpublic modulus n: ");
mpi_print(stdout, rsa_pub_mod, mpi_print_mode );
printf("\n\tpublic exponent e: ");
mpi_print(stdout, rsa_pub_exp, mpi_print_mode );
putchar('\n');
}
if( pkttype == PKT_PUBLIC_CERT || pkttype == PKT_PUBKEY_SUBCERT ) {
pkt->pkt.public_cert->d.rsa.n = rsa_pub_mod;
pkt->pkt.public_cert->d.rsa.e = rsa_pub_exp;
}
else {
PKT_secret_cert *cert = pkt->pkt.secret_cert;
byte temp[8];
pkt->pkt.secret_cert->d.rsa.n = rsa_pub_mod;
pkt->pkt.secret_cert->d.rsa.e = rsa_pub_exp;
cert->protect.algo = iobuf_get_noeof(inp); pktlen--;
if( list_mode )
printf( "\tprotect algo: %d\n", cert->protect.algo);
if( cert->protect.algo ) {
cert->is_protected = 1;
for(i=0; i < 8 && pktlen; i++, pktlen-- )
temp[i] = iobuf_get_noeof(inp);
if( list_mode ) {
printf( "\tprotect IV: ");
for(i=0; i < 8; i++ )
printf(" %02x", temp[i] );
putchar('\n');
}
if( cert->protect.algo == CIPHER_ALGO_BLOWFISH160 )
memcpy(cert->protect.iv, temp, 8 );
}
else
cert->is_protected = 0;
/* (See comments at the code for elg keys) */
n = pktlen; cert->d.rsa.d = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; cert->d.rsa.p = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; cert->d.rsa.q = mpi_read(inp, &n, 0 ); pktlen -=n;
n = pktlen; cert->d.rsa.u = mpi_read(inp, &n, 0 ); pktlen -=n;
cert->csum = read_16(inp); pktlen -= 2;
if( list_mode ) {
printf("\t[secret values d,p,q,u are not shown]\n"
"\tchecksum: %04hx\n", cert->csum);
}
/* log_mpidump("rsa n=", cert->d.rsa.n );
log_mpidump("rsa e=", cert->d.rsa.e );
log_mpidump("rsa d=", cert->d.rsa.d );
log_mpidump("rsa p=", cert->d.rsa.p );
log_mpidump("rsa q=", cert->d.rsa.q );
log_mpidump("rsa u=", cert->d.rsa.u ); */
}
}
else if( list_mode )
printf("\tunknown algorithm %d\n", algorithm );
leave:
skip_rest(inp, pktlen);
return rc;
}
static int
parse_user_id( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *packet )
{
byte *p;
packet->pkt.user_id = m_alloc(sizeof *packet->pkt.user_id + pktlen - 1);
packet->pkt.user_id->len = pktlen;
p = packet->pkt.user_id->name;
for( ; pktlen; pktlen--, p++ )
*p = iobuf_get_noeof(inp);
if( list_mode ) {
int n = packet->pkt.user_id->len;
printf(":user id packet: \"");
for(p=packet->pkt.user_id->name; n; p++, n-- ) {
if( *p >= ' ' && *p <= 'z' )
putchar(*p);
else
printf("\\x%02x", *p );
}
printf("\"\n");
}
return 0;
}
static int
parse_comment( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *packet )
{
byte *p;
packet->pkt.comment = m_alloc(sizeof *packet->pkt.comment + pktlen - 1);
packet->pkt.comment->len = pktlen;
p = packet->pkt.comment->data;
for( ; pktlen; pktlen--, p++ )
*p = iobuf_get_noeof(inp);
if( list_mode ) {
int n = packet->pkt.comment->len;
printf(":%scomment packet: \"", pkttype == PKT_OLD_COMMENT?
"OpenPGP draft " : "" );
for(p=packet->pkt.comment->data; n; p++, n-- ) {
if( *p >= ' ' && *p <= 'z' )
putchar(*p);
else
printf("\\x%02x", *p );
}
printf("\"\n");
}
return 0;
}
static void
parse_trust( IOBUF inp, int pkttype, unsigned long pktlen )
{
int c;
c = iobuf_get_noeof(inp);
if( list_mode )
printf(":trust packet: flag=%02x\n", c );
}
static int
parse_plaintext( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *pkt )
{
int mode, namelen;
PKT_plaintext *pt;
byte *p;
int c, i;
if( pktlen && pktlen < 6 ) {
log_error("packet(%d) too short (%lu)\n", pkttype, (ulong)pktlen);
goto leave;
}
mode = iobuf_get_noeof(inp); if( pktlen ) pktlen--;
namelen = iobuf_get_noeof(inp); if( pktlen ) pktlen--;
pt = pkt->pkt.plaintext = m_alloc(sizeof *pkt->pkt.plaintext + namelen -1);
pt->mode = mode;
pt->namelen = namelen;
if( pktlen ) {
for( i=0; pktlen > 4 && i < namelen; pktlen--, i++ )
pt->name[i] = iobuf_get_noeof(inp);
}
else {
for( i=0; i < namelen; i++ )
if( (c=iobuf_get(inp)) == -1 )
break;
else
pt->name[i] = c;
}
pt->timestamp = read_32(inp); if( pktlen) pktlen -= 4;
pt->len = pktlen;
pt->buf = inp;
pktlen = 0;
if( list_mode ) {
printf(":literal data packet:\n"
"\tmode %c, created %lu, name=\"",
mode >= ' ' && mode <'z'? mode : '?',
(ulong)pt->timestamp );
for(p=pt->name,i=0; i < namelen; p++, i++ ) {
if( *p >= ' ' && *p <= 'z' )
putchar(*p);
else
printf("\\x%02x", *p );
}
printf("\",\n\traw data: %lu bytes\n", (ulong)pt->len );
}
leave:
return 0;
}
static int
parse_compressed( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *pkt )
{
PKT_compressed *zd;
/* pktlen is here 0, but data follows
* (this should be the last object in a file or
* the compress algorithm should know the length)
*/
zd = pkt->pkt.compressed = m_alloc(sizeof *pkt->pkt.compressed );
zd->len = 0; /* not yet used */
zd->algorithm = iobuf_get_noeof(inp);
zd->buf = inp;
if( list_mode )
printf(":compressed packet: algo=%d\n", zd->algorithm);
return 0;
}
static int
parse_encrypted( IOBUF inp, int pkttype, unsigned long pktlen, PACKET *pkt )
{
PKT_encrypted *ed;
ed = pkt->pkt.encrypted = m_alloc(sizeof *pkt->pkt.encrypted );
ed->len = pktlen;
ed->buf = NULL;
if( pktlen && pktlen < 10 ) {
log_error("packet(%d) too short\n", pkttype);
skip_rest(inp, pktlen);
goto leave;
}
if( list_mode ) {
if( pktlen )
printf(":encrypted data packet:\n\tlength: %lu\n", pktlen-10);
else
printf(":encrypted data packet:\n\tlength: unknown\n");
}
ed->buf = inp;
pktlen = 0;
leave:
return 0;
}
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