cmac: add 64-bit mode CMAC

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/cmac.h b/cmac.h
index 3c5b7bea..0cf9462d 100644
--- a/cmac.h
+++ b/cmac.h
@@ -44,6 +44,7 @@ extern "C" {
 #endif
 
 #define CMAC128_DIGEST_SIZE 16
+#define CMAC64_DIGEST_SIZE 8
 
 #define cmac128_set_key nettle_cmac128_set_key
 #define cmac128_init nettle_cmac128_init
@@ -56,6 +57,11 @@ extern "C" {
 #define cmac_aes256_update nettle_cmac_aes256_update
 #define cmac_aes256_digest nettle_cmac_aes256_digest
 
+#define cmac64_set_key nettle_cmac64_set_key
+#define cmac64_init nettle_cmac64_init
+#define cmac64_update nettle_cmac64_update
+#define cmac64_digest nettle_cmac64_digest
+
 struct cmac128_key
 {
   union nettle_block16 K1;
@@ -72,6 +78,22 @@ struct cmac128_ctx
   size_t index;
 };
 
+struct cmac64_key
+{
+  union nettle_block8 K1;
+  union nettle_block8 K2;
+};
+
+struct cmac64_ctx
+{
+  /* MAC state */
+  union nettle_block8 X;
+
+  /* Block buffer */
+  union nettle_block8 block;
+  size_t index;
+};
+
 void
 cmac128_set_key(struct cmac128_key *key, const void *cipher,
 		nettle_cipher_func *encrypt);
@@ -118,6 +140,53 @@ cmac128_digest(struct cmac128_ctx *ctx, const struct cmac128_key *key,
 		      (nettle_cipher_func *) (encrypt),		\
 		      (length), (digest)))
 
+void
+cmac64_set_key(struct cmac64_key *key, const void *cipher,
+		nettle_cipher_func *encrypt);
+
+void
+cmac64_init(struct cmac64_ctx *ctx);
+
+void
+cmac64_update(struct cmac64_ctx *ctx, const void *cipher,
+	       nettle_cipher_func *encrypt,
+	       size_t msg_len, const uint8_t *msg);
+
+void
+cmac64_digest(struct cmac64_ctx *ctx, const struct cmac64_key *key,
+	       const void *cipher, nettle_cipher_func *encrypt,
+	       unsigned length, uint8_t *digest);
+
+
+#define CMAC64_CTX(type) \
+  { struct cmac64_key key; struct cmac64_ctx ctx; type cipher; }
+
+/* NOTE: Avoid using NULL, as we don't include anything defining it. */
+#define CMAC64_SET_KEY(self, set_key, encrypt, cmac_key)	\
+  do {								\
+    (set_key)(&(self)->cipher, (cmac_key));			\
+    if (0) (encrypt)(&(self)->cipher, ~(size_t) 0,		\
+		     (uint8_t *) 0, (const uint8_t *) 0);	\
+    cmac64_set_key(&(self)->key, &(self)->cipher,		\
+		    (nettle_cipher_func *) (encrypt));		\
+    cmac64_init(&(self)->ctx);					\
+  } while (0)
+
+#define CMAC64_UPDATE(self, encrypt, length, src)		\
+  (0 ? (encrypt)(&(self)->cipher, ~(size_t) 0,			\
+		 (uint8_t *) 0, (const uint8_t *) 0)		\
+     : cmac64_update(&(self)->ctx, &(self)->cipher,		\
+		      (nettle_cipher_func *)encrypt,		\
+		      (length), (src)))
+
+#define CMAC64_DIGEST(self, encrypt, length, digest)		\
+  (0 ? (encrypt)(&(self)->cipher, ~(size_t) 0,			\
+		 (uint8_t *) 0, (const uint8_t *) 0)		\
+     : cmac64_digest(&(self)->ctx, &(self)->key,		\
+		      &(self)->cipher,				\
+		      (nettle_cipher_func *) (encrypt),		\
+		      (length), (digest)))
+
 struct cmac_aes128_ctx CMAC128_CTX(struct aes128_ctx);
 
 void