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intermediate check in

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This commit is contained in:
Werner Koch 1998-08-05 16:51:59 +00:00
parent 6fbee8ab86
commit 9b609091ab
38 changed files with 812 additions and 180 deletions
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99
g10/pkclist.c
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@ -512,3 +512,102 @@ build_pk_list( STRLIST remusr, PK_LIST *ret_pk_list, unsigned usage )
}
/****************
* Return -1 if we could not find an algorithm.
*/
int
select_algo_from_prefs( PK_LIST pk_list, int preftype )
{
PK_LIST pkr;
u32 bits[8];
byte *pref = NULL;
size_t npref;
int i, j;
int compr_hack=0;
int any;
if( !pk_list )
return -1;
memset( bits, ~0, 8 * sizeof *bits );
for( pkr = pk_list; pkr; pkr = pkr->next ) {
u32 mask[8];
memset( mask, 0, 8 * sizeof *mask );
if( !pkr->pk->local_id )
BUG(); /* if this occurs, we can use get_ownertrust to set it */
if( preftype == PREFTYPE_SYM )
bits[0] = (1<<2); /* 3DES is implicitly there */
m_free(pref);
pref = get_pref_data( pkr->pk->local_id, pkr->pk->namehash, &npref);
any = 0;
if( pref ) {
/*log_hexdump("raw: ", pref, npref );*/
for(i=0; i+1 < npref; i+=2 ) {
if( pref[i] == preftype ) {
mask[pref[i+1]/32] |= 1 << (pref[i+1]%32);
any = 1;
}
}
}
if( (!pref || !any) && preftype == PREFTYPE_COMPR ) {
mask[0] |= 3; /* asume no_compression and old pgp */
compr_hack = 1;
}
/*log_debug("mask=%08lX%08lX%08lX%08lX%08lX%08lX%08lX%08lX\n",
(ulong)mask[7], (ulong)mask[6], (ulong)mask[5], (ulong)mask[4],
(ulong)mask[3], (ulong)mask[2], (ulong)mask[1], (ulong)mask[0]);*/
for(i=0; i < 8; i++ )
bits[i] &= mask[i];
/*log_debug("bits=%08lX%08lX%08lX%08lX%08lX%08lX%08lX%08lX\n",
(ulong)bits[7], (ulong)bits[6], (ulong)bits[5], (ulong)bits[4],
(ulong)bits[3], (ulong)bits[2], (ulong)bits[1], (ulong)bits[0]);*/
}
/* usable algorithms are now in bits
* We now use the last key from pk_list to select
* the algorithm we want to use. there are no
* preferences for the last key, we select the one
* corresponding to first set bit.
*/
i = -1;
any = 0;
if( pref ) {
for(j=0; j+1 < npref; j+=2 ) {
if( pref[j] == preftype ) {
any = 1;
if( (bits[pref[j+1]/32] & (1<<(pref[j+1]%32))) ) {
i = pref[j+1];
break;
}
}
}
}
if( !pref || !any ) {
for(j=0; j < 256; j++ )
if( (bits[j/32] & (1<<(j%32))) ) {
i = j;
break;
}
}
/*log_debug("prefs of type %d: selected %d\n", preftype, i );*/
if( compr_hack && !i ) {
/* selected no compression, but we should check whether
* algorithm 1 is also available (the ordering is not relevant
* in this case). */
if( bits[0] & (1<<1) )
i = 1; /* yep; we can use compression algo 1 */
}
if( preftype == PREFTYPE_SYM && i == CIPHER_ALGO_3DES ) {
i = CIPHER_ALGO_BLOWFISH;
if( opt.verbose )
log_info("replacing 3DES by Blowfish\n");
}
m_free(pref);
return i;
}