dsa: Adjustments to conform with FIPS 186-4.
* cipher/dsa.c (generate_fips186): FIPS 186-4 adjustments. * cipher/primegen.c (_gcry_generate_fips186_3_prime): Fix incorrect buflen passed to _gcry_mpi_scan.
Generate the DSA keypair by testing candidates. (FIPS 186-4 B.1.2)
Use 2048 bit key for the selftest.
Allow only 2048 and 3072 as pbits size.
- Signed-off-by: Vitezslav Cizek <vcizek@suse.com>