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See ChangeLog: Mon Dec 14 21:18:49 CET 1998 Werner Koch

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Werner Koch 1998-12-14 20:22:42 +00:00
parent c6be02da77
commit 7a7a5630af
21 changed files with 642 additions and 524 deletions
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134
g10/parse-packet.c
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@ -714,21 +714,60 @@ dump_sig_subpkt( int hashed, int type, int critical,
printf("%s)\n", p? p: "");
}
/****************
* Returns: >= 0 offset into buffer
* -1 unknown type
* -2 unsupported type
* -3 subpacket too short
*/
static int
parse_one_sig_subpkt( const byte *buffer, size_t n, int type )
{
switch( type ) {
case SIGSUBPKT_SIG_CREATED:
case SIGSUBPKT_SIG_EXPIRE:
case SIGSUBPKT_KEY_EXPIRE:
if( n < 4 )
break;
return 0;
case SIGSUBPKT_EXPORTABLE:
if( !n )
break;
return 0;
case SIGSUBPKT_ISSUER:/* issuer key ID */
if( n < 8 )
break;
return 0;
case SIGSUBPKT_PREF_SYM:
case SIGSUBPKT_PREF_HASH:
case SIGSUBPKT_PREF_COMPR:
return 0;
case SIGSUBPKT_PRIV_ADD_SIG:
/* because we use private data, we check the GNUPG marker */
if( n < 24 )
break;
if( buffer[0] != 'G' || buffer[1] != 'P' || buffer[2] != 'G' )
return -2;
return 3;
default: return -1;
}
return -3;
}
const byte *
parse_sig_subpkt( const byte *buffer, sigsubpkttype_t reqtype, size_t *ret_n )
{
int buflen;
int type;
int critical;
int offset;
size_t n;
if( !buffer )
return NULL;
buflen = (*buffer << 8) | buffer[1];
buffer += 2;
for(;;) {
if( !buflen )
return NULL; /* end of packets; not found */
while( buflen ) {
n = *buffer++; buflen--;
if( n == 255 ) {
if( buflen < 4 )
@ -754,49 +793,47 @@ parse_sig_subpkt( const byte *buffer, sigsubpkttype_t reqtype, size_t *ret_n )
}
else
critical = 0;
if( reqtype < 0 ) /* list packets */
if( reqtype == SIGSUBPKT_TEST_CRITICAL ) {
if( critical ) {
if( n-1 > buflen+1 )
goto too_short;
if( parse_one_sig_subpkt(buffer+1, n-1, type ) < 0 ) {
log_info(_("subpacket of type %d has critical bit set\n"),
type);
return NULL; /* this is an error */
}
}
}
else if( reqtype < 0 ) /* list packets */
dump_sig_subpkt( reqtype == SIGSUBPKT_LIST_HASHED,
type, critical, buffer, buflen, n );
else if( type == reqtype )
break; /* found */
else if( type == reqtype ) { /* found */
buffer++;
n--;
if( n > buflen )
goto too_short;
if( ret_n )
*ret_n = n;
offset = parse_one_sig_subpkt(buffer, n, type );
switch( offset ) {
case -3:
log_error("subpacket of type %d too short\n", type);
return NULL;
case -2:
return NULL;
case -1:
BUG(); /* not yet needed */
default:
break;
}
return buffer+offset;
}
buffer += n; buflen -=n;
}
buffer++;
n--;
if( n > buflen )
goto too_short;
if( ret_n )
*ret_n = n;
switch( type ) {
case SIGSUBPKT_SIG_CREATED:
case SIGSUBPKT_SIG_EXPIRE:
case SIGSUBPKT_KEY_EXPIRE:
if( n < 4 )
break;
return buffer;
case SIGSUBPKT_EXPORTABLE:
if( !n )
break;
return buffer;
case SIGSUBPKT_ISSUER:/* issuer key ID */
if( n < 8 )
break;
return buffer;
case SIGSUBPKT_PREF_SYM:
case SIGSUBPKT_PREF_HASH:
case SIGSUBPKT_PREF_COMPR:
return buffer;
case SIGSUBPKT_PRIV_ADD_SIG:
/* because we use private data, we check the GNUPG marker */
if( n < 24 )
break;
if( buffer[0] != 'G' || buffer[1] != 'P' || buffer[2] != 'G' )
return NULL;
return buffer+3;
default: BUG(); /* not yet needed */
}
log_error("subpacket of type %d too short\n", type);
return NULL;
if( reqtype == SIGSUBPKT_TEST_CRITICAL )
return buffer; /* as value true to indicate that there is no
/* critical bit we don't understand */
return NULL; /* end of packets; not found */
too_short:
log_error("buffer shorter than subpacket\n");
@ -899,10 +936,15 @@ parse_signature( IOBUF inp, int pkttype, unsigned long pktlen,
if( is_v4 ) { /*extract required information */
const byte *p;
/* FIXME: set sig->flags.unknown_critical is there is a
* critical bit set for packets which are not understood
* It does only make sense for hashed data.
*/
/* set sig->flags.unknown_critical if there is a
* critical bit set for packets which we do not understand */
if( !parse_sig_subpkt( sig->hashed_data, SIGSUBPKT_TEST_CRITICAL, NULL)
|| !parse_sig_subpkt( sig->unhashed_data, SIGSUBPKT_TEST_CRITICAL,
NULL) )
{
sig->flags.unknown_critical = 1;
}
p = parse_sig_subpkt( sig->hashed_data, SIGSUBPKT_SIG_CREATED, NULL );
if( !p )
log_error("signature packet without timestamp\n");