bcrypt: Handle different sized R/S signature components.

Signed-off-by: Hans Leidekker <hans@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
This commit is contained in:
Hans Leidekker 2020-06-05 15:32:48 +02:00 committed by Alexandre Julliard
parent 8a43688b3d
commit ec3ca4ee73
1 changed files with 14 additions and 9 deletions

View File

@ -1431,8 +1431,9 @@ static NTSTATUS format_gnutls_signature( enum alg_id type, gnutls_datum_t signat
case ALG_ID_DSA:
{
int err;
unsigned int pad_size, sig_len = get_signature_length( type );
unsigned int pad_size_r, pad_size_s, sig_len = get_signature_length( type );
gnutls_datum_t r, s; /* format as r||s */
unsigned char *r_data, *s_data;
if ((err = pgnutls_decode_rs_value( &signature, &r, &s )))
{
@ -1442,31 +1443,35 @@ static NTSTATUS format_gnutls_signature( enum alg_id type, gnutls_datum_t signat
if (output_len < sig_len) return STATUS_BUFFER_TOO_SMALL;
/* remove prepended zero byte */
if (r.size % 2)
if (r.size % 2) /* remove prepended zero byte */
{
r.size--;
r.data += 1;
r_data = r.data + 1;
}
else r_data = r.data;
if (s.size % 2)
{
s.size--;
s.data += 1;
s_data = s.data + 1;
}
else s_data = s.data;
if (r.size != s.size || r.size + s.size > sig_len)
if (r.size + s.size > sig_len)
{
ERR( "we didn't get a correct signature\n" );
return STATUS_INTERNAL_ERROR;
}
pad_size = (sig_len / 2) - s.size;
pad_size_r = (sig_len / 2) - r.size;
pad_size_s = (sig_len / 2) - s.size;
memset( output, 0, sig_len );
memcpy( output + pad_size, r.data, r.size );
memcpy( output + (sig_len / 2) + pad_size, s.data, s.size );
memcpy( output + pad_size_r, r_data, r.size );
memcpy( output + (sig_len / 2) + pad_size_s, s_data, s.size );
*ret_len = sig_len;
free( r.data ); free( s.data );
return STATUS_SUCCESS;
}
default: