pk: Allow the use of a hash element for DSA sign and verify.
37d0a1ebdc2dUnpublished
Actions

Unpublished Commit · Learn More

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

Description

pk: Allow the use of a hash element for DSA sign and verify.

* cipher/pubkey.c (pubkey_sign): Add arg ctx and pass it to the sign
module.
(gcry_pk_sign): Pass CTX to pubkey_sign.
(sexp_data_to_mpi): Add flag rfc6979 and code to alls hash with *DSA
* cipher/rsa.c (rsa_sign, rsa_verify): Return an error if an opaque
MPI is given for DATA/HASH.
* cipher/elgamal.c (elg_sign, elg_verify): Ditto.
* cipher/dsa.c (dsa_sign, dsa_verify): Convert a given opaque MPI.
* cipher/ecc.c (ecc_sign, ecc_verify): Ditto.
* tests/basic.c (check_pubkey_sign_ecdsa): Add a test for using a hash
element with DSA.

This patch allows the use of

(data (flags raw)
  (hash sha256 #80112233445566778899AABBCCDDEEFF
                000102030405060708090A0B0C0D0E0F#))

in addition to the old but more efficient

(data (flags raw)
  (value #80112233445566778899AABBCCDDEEFF
          000102030405060708090A0B0C0D0E0F#))

for DSA and ECDSA. With the hash element the flag "raw" must be
explicitly given because existing regression test code expects that
conflict error is return if no flags but a hash element is given.

Note that the hash algorithm name is currently not checked. It may
eventually be used to cross-check the length of the provided hash
value. It is suggested that the correct hash name is given - even if
a truncated hash value is used.

Finally this patch adds a way to pass the hash algorithm and flag
values to the signing module. "rfc6979" as been implemented as a new
but not yet used flag.