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See ChangeLog: Fri Jul 2 11:45:54 CEST 1999 Werner Koch

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This commit is contained in:
Werner Koch 1999-07-02 09:50:57 +00:00
parent 28eb86c006
commit 86abac78a2
15 changed files with 366 additions and 64 deletions
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45
cipher/dsa.c
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@ -66,30 +66,49 @@ static MPI
gen_k( MPI q )
{
MPI k = mpi_alloc_secure( mpi_get_nlimbs(q) );
unsigned nbits = mpi_get_nbits(q);
unsigned int nbits = mpi_get_nbits(q);
unsigned int nbytes = (nbits+7)/8;
char *rndbuf = NULL;
if( DBG_CIPHER )
log_debug("choosing a random k ");
for(;;) {
if( DBG_CIPHER )
progress('.');
{ char *p = get_random_bits( nbits, 1, 1 );
mpi_set_buffer( k, p, (nbits+7)/8, 0 );
m_free(p);
/* make sure that the number is of the exact lenght */
if( mpi_test_bit( k, nbits-1 ) )
mpi_set_highbit( k, nbits-1 );
else {
mpi_set_highbit( k, nbits-1 );
mpi_clear_bit( k, nbits-1 );
}
if( !rndbuf || nbits < 32 ) {
m_free(rndbuf);
rndbuf = get_random_bits( nbits, 1, 1 );
}
if( !(mpi_cmp( k, q ) < 0) ) /* check: k < q */
else { /* change only some of the higher bits */
/* we could imporove this by directly requesting more memory
* at the first call to get_random_bits() and use this the here
* maybe it is easier to do this directly in random.c */
char *pp = get_random_bits( 32, 1, 1 );
memcpy( rndbuf,pp, 4 );
m_free(pp);
}
mpi_set_buffer( k, rndbuf, nbytes, 0 );
if( mpi_test_bit( k, nbits-1 ) )
mpi_set_highbit( k, nbits-1 );
else {
mpi_set_highbit( k, nbits-1 );
mpi_clear_bit( k, nbits-1 );
}
if( !(mpi_cmp( k, q ) < 0) ) { /* check: k < q */
if( DBG_CIPHER )
progress('+');
continue; /* no */
if( !(mpi_cmp_ui( k, 0 ) > 0) ) /* check: k > 0 */
}
if( !(mpi_cmp_ui( k, 0 ) > 0) ) { /* check: k > 0 */
if( DBG_CIPHER )
progress('-');
continue; /* no */
}
break; /* okay */
}
m_free(rndbuf);
if( DBG_CIPHER )
progress('\n');