Implement deterministic DSA as specified by rfc-6979.
1cfa79aabc5dUnpublished
Actions

Unpublished Commit · Learn More

Not On Permanent Ref: This commit is not an ancestor of any permanent ref.

Description

Implement deterministic DSA as specified by rfc-6979.

* cipher/dsa.c (dsa_sign): Move opaque mpi extraction to sign.
(sign): Add args FLAGS and HASHALGO.  Implement deterministic DSA.
Add code path for R==0 to comply with the standard.
(dsa_verify): Left fill opaque mpi based hash values.
* cipher/dsa-common.c (int2octets, bits2octets): New.
(_gcry_dsa_gen_rfc6979_k): New.
* tests/dsa-rfc6979.c: New.
* tests/Makefile.am (TESTS): Add dsa-rfc6979.

This patch also fixes a recent patch (37d0a1e) which allows to pass
the hash in a (hash) element.

Support for deterministic ECDSA will come soon.