eax.h 4.57 KB
Newer Older
Niels Möller's avatar
Niels Möller committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
/* eax.h
 *
 * EAX mode, see http://www.cs.ucdavis.edu/~rogaway/papers/eax.pdf
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2013 Niels Möller
 *
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 *
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02111-1301, USA.
 */

#ifndef NETTLE_EAX_H_INCLUDED
#define NETTLE_EAX_H_INCLUDED

#include "aes.h"

#ifdef __cplusplus
extern "C" {
#endif

/* Name mangling */
#define eax_set_key nettle_eax_set_key
#define eax_set_nonce nettle_eax_set_nonce
#define eax_update nettle_eax_update
#define eax_encrypt nettle_eax_encrypt
#define eax_decrypt nettle_eax_decrypt
#define eax_digest nettle_eax_digest

#define eax_aes_set_key nettle_eax_aes_set_key
#define eax_aes_set_nonce nettle_eax_aes_set_nonce
#define eax_aes_update nettle_eax_aes_update
#define eax_aes_encrypt nettle_eax_aes_encrypt
#define eax_aes_decrypt nettle_eax_aes_decrypt
#define eax_aes_digest nettle_eax_aes_digest

/* Restricted to block ciphers with 128 bit block size. FIXME: Reflect
   this in naming? */

#define EAX_BLOCK_SIZE 16
54
#define EAX_DIGEST_SIZE 16
Niels Möller's avatar
Niels Möller committed
55 56 57 58

/* Values independent of message and nonce */
struct eax_key
{
59 60
  union nettle_block16 pad_block;
  union nettle_block16 pad_partial;
Niels Möller's avatar
Niels Möller committed
61 62 63 64
};

struct eax_ctx
{
65 66 67 68
  union nettle_block16 omac_nonce;
  union nettle_block16 omac_data;
  union nettle_block16 omac_message;
  union nettle_block16 ctr;
Niels Möller's avatar
Niels Möller committed
69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
};

void
eax_set_key (struct eax_key *key, void *cipher, nettle_crypt_func *f);

void
eax_set_nonce (struct eax_ctx *eax, const struct eax_key *key,
	       void *cipher, nettle_crypt_func *f,
	       size_t nonce_length, const uint8_t *nonce);

void
eax_update (struct eax_ctx *eax, const struct eax_key *key,
	    void *cipher, nettle_crypt_func *f,
	    size_t data_length, const uint8_t *data);

void
eax_encrypt (struct eax_ctx *eax, const struct eax_key *key,
	     void *cipher, nettle_crypt_func *f,
	     size_t length, uint8_t *dst, const uint8_t *src);

void
eax_decrypt (struct eax_ctx *eax, const struct eax_key *key,
	     void *cipher, nettle_crypt_func *f,
	     size_t length, uint8_t *dst, const uint8_t *src);

void
eax_digest (struct eax_ctx *eax, const struct eax_key *key,
	    void *cipher, nettle_crypt_func *f,
	    size_t length, uint8_t *digest);

/* Put the cipher last, to get cipher-independent offsets for the EAX
 * state. */
#define EAX_CTX(type) \
  { struct eax_key key; struct eax_ctx eax; type cipher; }

104
#define EAX_SET_KEY(ctx, set_key, encrypt, data)			\
Niels Möller's avatar
Niels Möller committed
105
  do {									\
106
    (set_key)(&(ctx)->cipher, (data));					\
Niels Möller's avatar
Niels Möller committed
107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
    if (0) (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0);	\
    eax_set_key (&(ctx)->key, &(ctx)->cipher, (nettle_crypt_func *) encrypt); \
  } while (0)

#define EAX_SET_NONCE(ctx, encrypt, length, nonce) \
  (0 ? (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0)	\
   : eax_set_nonce (&(ctx)->eax, &(ctx)->key,			\
		    &(ctx)->cipher, (nettle_crypt_func *) (encrypt),	\
		    (length), (nonce)))

#define EAX_UPDATE(ctx, encrypt, length, data)				\
  (0 ? (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0)		\
   : eax_update (&(ctx)->eax, &(ctx)->key,				\
		 &(ctx)->cipher, (nettle_crypt_func *) (encrypt),	\
		 (length), (data)))

#define EAX_ENCRYPT(ctx, encrypt, length, dst, src)			\
  (0 ? (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0)		\
   : eax_encrypt (&(ctx)->eax, &(ctx)->key,				\
		 &(ctx)->cipher, (nettle_crypt_func *) (encrypt),	\
		  (length), (dst), (src)))

#define EAX_DECRYPT(ctx, encrypt, length, dst, src)			\
  (0 ? (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0)		\
   : eax_decrypt (&(ctx)->eax, &(ctx)->key,				\
		 &(ctx)->cipher, (nettle_crypt_func *) (encrypt),	\
		  (length), (dst), (src)))

#define EAX_DIGEST(ctx, encrypt, length, digest)			\
  (0 ? (encrypt) (&(ctx)->cipher, 0, (void *) 0, (void *) 0)		\
   : eax_digest (&(ctx)->eax, &(ctx)->key,				\
		 &(ctx)->cipher, (nettle_crypt_func *) (encrypt),	\
		 (length), (digest)))

#ifdef __cplusplus
}
#endif

#endif /* NETTLE_EAX_H_INCLUDED */