Poly1305-AEAD: updated implementation to match draft-irtf-cfrg-chacha20-poly1305-03
* cipher/cipher-internal.h (gcry_cipher_handle): Use separate byte counters for AAD and data in Poly1305. * cipher/cipher-poly1305.c (poly1305_fill_bytecount): Remove. (poly1305_fill_bytecounts, poly1305_do_padding): New. (poly1305_aad_finish): Fill padding to Poly1305 and do not fill AAD length. (_gcry_cipher_poly1305_authenticate, _gcry_cipher_poly1305_encrypt) (_gcry_cipher_poly1305_decrypt): Update AAD and data length separately. (_gcry_cipher_poly1305_tag): Fill padding and bytecounts to Poly1305. (_gcry_cipher_poly1305_setkey, _gcry_cipher_poly1305_setiv): Reset AAD and data byte counts; only allow 96-bit IV. * cipher/cipher.c (_gcry_cipher_open_internal): Limit Poly1305-AEAD to ChaCha20 cipher. * tests/basic.c (_check_poly1305_cipher): Update test-vectors. (check_ciphers): Limit Poly1305-AEAD checks to ChaCha20. * tests/bench-slope.c (cipher_bench_one): Ditto.
Latest Internet-Draft version for "ChaCha20 and Poly1305 for IETF protocols"
has added additional padding to Poly1305-AEAD and limited support IV size to
96-bits:
https://www.ietf.org/rfcdiff?url1=draft-nir-cfrg-chacha20-poly1305-03&difftype=--html&submit=Go!&url2=draft-irtf-cfrg-chacha20-poly1305-03
Patch makes Poly1305-AEAD implementation to match the changes and limits
Poly1305-AEAD to ChaCha20 only.
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>