Add OCB cipher mode
authorWerner Koch <wk@gnupg.org>
Fri, 16 Jan 2015 13:55:03 +0000 (14:55 +0100)
committerWerner Koch <wk@gnupg.org>
Fri, 16 Jan 2015 13:55:03 +0000 (14:55 +0100)
commit067d7d8752d4d8a98f8e0e5e9b1a5b13e1b7ff9c
tree1eab7affe5d24e919a22a5d4a29c8303342cf8db
parent9d2a22c94ae99f9301321082c4fb8d73f4085fda
Add OCB cipher mode

* cipher/cipher-ocb.c: New.
* cipher/Makefile.am (libcipher_la_SOURCES): Add cipher-ocb.c
* cipher/cipher-internal.h (OCB_BLOCK_LEN, OCB_L_TABLE_SIZE): New.
(gcry_cipher_handle): Add fields marks.finalize and u_mode.ocb.
* cipher/cipher.c (_gcry_cipher_open_internal): Add OCB mode.
(_gcry_cipher_open_internal): Setup default taglen of OCB.
(cipher_reset): Clear OCB specific data.
(cipher_encrypt, cipher_decrypt, _gcry_cipher_authenticate)
(_gcry_cipher_gettag, _gcry_cipher_checktag): Call OCB functions.
(_gcry_cipher_setiv): Add OCB specific nonce setting.
(_gcry_cipher_ctl): Add GCRYCTL_FINALIZE and GCRYCTL_SET_TAGLEN

* src/gcrypt.h.in (GCRYCTL_SET_TAGLEN): New.
(gcry_cipher_final): New.

* cipher/bufhelp.h (buf_xor_1): New.

* tests/basic.c (hex2buffer): New.
(check_ocb_cipher): New.
(main): Call it here.  Add option --cipher-modes.
* tests/bench-slope.c (bench_aead_encrypt_do_bench): Call
gcry_cipher_final.
(bench_aead_decrypt_do_bench): Ditto.
(bench_aead_authenticate_do_bench): Ditto.  Check error code.
(bench_ocb_encrypt_do_bench): New.
(bench_ocb_decrypt_do_bench): New.
(bench_ocb_authenticate_do_bench): New.
(ocb_encrypt_ops): New.
(ocb_decrypt_ops): New.
(ocb_authenticate_ops): New.
(cipher_modes): Add them.
(cipher_bench_one): Skip wrong block length for OCB.
* tests/benchmark.c (cipher_bench): Add field noncelen to MODES.  Add
OCB support.

--

See the comments on top of cipher/cipher-ocb.c for the patent status
of the OCB mode.

The implementation has not yet been optimized and as such is not faster
that the other AEAD modes.  A first candidate for optimization is the
double_block function.  Large improvements can be expected by writing
an AES ECB function to work on multiple blocks.

Signed-off-by: Werner Koch <wk@gnupg.org>
NEWS
cipher/Makefile.am
cipher/bufhelp.h
cipher/cipher-internal.h
cipher/cipher-ocb.c [new file with mode: 0644]
cipher/cipher.c
doc/gcrypt.texi
src/gcrypt.h.in
tests/basic.c
tests/bench-slope.c
tests/benchmark.c