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Fixed serious bug related to multiple cleartext signatures.

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This commit is contained in:
Werner Koch 2000-10-13 15:03:48 +00:00
parent cfdb80a759
commit 2092d0f6ed
8 changed files with 192 additions and 47 deletions
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60
g10/armor.c
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@ -502,7 +502,7 @@ fake_packet( armor_filter_context_t *afx, IOBUF a,
/* the buffer is always allocated with enough space to append
* the removed [CR], LF and a Nul
* The reason for this complicated procedure is to keep at least
* the original tupe of lineending - handling of the removed
* the original type of lineending - handling of the removed
* trailing spaces seems to be impossible in our method
* of faking a packet; either we have to use a temporary file
* or calculate the hash here in this module and somehow find
@ -815,7 +815,9 @@ armor_filter( void *opaque, int control,
*ret_len = n;
}
else if( control == IOBUFCTRL_UNDERFLOW ) {
if( size < 15+(4*15) ) /* need space for up to 4 onepass_sigs */
/* We need some space for the faked packet. The minmum required
* size is ~18 + length of the session marker */
if( size < 50 )
BUG(); /* supplied buffer too short */
if( afx->faked )
@ -831,7 +833,14 @@ armor_filter( void *opaque, int control,
rc = -1;
}
else if( afx->faked ) {
unsigned hashes = afx->hashes;
unsigned int hashes = afx->hashes;
const byte *sesmark;
size_t sesmarklen;
sesmark = get_session_marker( &sesmarklen );
if ( sesmarklen > 20 )
BUG();
/* the buffer is at least 15+n*15 bytes long, so it
* is easy to construct the packets */
@ -842,36 +851,21 @@ armor_filter( void *opaque, int control,
afx->pgp2mode = 1;
}
n=0;
do {
/* first some onepass signature packets */
buf[n++] = 0x90; /* old format, type 4, 1 length byte */
buf[n++] = 13; /* length */
buf[n++] = 3; /* version */
buf[n++] = afx->not_dash_escaped? 0:1; /* sigclass */
if( hashes & 1 ) {
hashes &= ~1;
buf[n++] = DIGEST_ALGO_RMD160;
}
else if( hashes & 2 ) {
hashes &= ~2;
buf[n++] = DIGEST_ALGO_SHA1;
}
else if( hashes & 4 ) {
hashes &= ~4;
buf[n++] = DIGEST_ALGO_MD5;
}
else if( hashes & 8 ) {
hashes &= ~8;
buf[n++] = DIGEST_ALGO_TIGER;
}
else
buf[n++] = 0; /* (don't know) */
buf[n++] = 0; /* public key algo (don't know) */
memset(buf+n, 0, 8); /* don't know the keyid */
n += 8;
buf[n++] = !hashes; /* last one */
} while( hashes );
/* first a gpg control packet */
buf[n++] = 0xff; /* new format, type 63, 1 length byte */
n++; /* see below */
memcpy(buf+n, sesmark, sesmarklen ); n+= sesmarklen;
buf[n++] = 1; /* control type */
buf[n++] = afx->not_dash_escaped? 0:1; /* sigclass */
if( hashes & 1 )
buf[n++] = DIGEST_ALGO_RMD160;
if( hashes & 2 )
buf[n++] = DIGEST_ALGO_SHA1;
if( hashes & 4 )
buf[n++] = DIGEST_ALGO_MD5;
if( hashes & 8 )
buf[n++] = DIGEST_ALGO_TIGER;
buf[1] = n - 2;
/* followed by a plaintext packet */
buf[n++] = 0xaf; /* old packet format, type 11, var length */