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>

1 files changed, 5 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 0150fdd6..4c74533a 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,8 @@ Noteworthy changes in version 1.7.0 (unreleased)
 
  * Fixed some asm build problems and feature detection bugs.
 
+ * Added OCB mode.
+
  * Interface changes relative to the 1.6.0 release:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  gcry_mac_get_algo               NEW.
@@ -30,6 +32,9 @@ Noteworthy changes in version 1.7.0 (unreleased)
  gcry_cipher_set_sbox            NEW macro.
  GCRY_MD_GOSTR3411_CP            NEW.
  gcry_mpi_ec_sub                 NEW.
+ GCRY_CIPHER_MODE_OCB            NEW.
+ GCRYCTL_SET_TAGLEN              NEW.
+ gcry_cipher_final               NEW macro.
 
 
 Noteworthy changes in version 1.6.0 (2013-12-16)