Ashley Mills / tinydtls

Version 0.5.0 of tinydtls

Dependents:   tinydtls_test_cellular tinydtls_test_ethernet tiny-dtls

hmac.h@1:598a56fe116e, 2014-02-12 (annotated)

Committer:
ashleymills
Date:
Wed Feb 12 09:30:16 2014 +0000
Revision:
1:598a56fe116e
Parent:
0:ff9ebe0cf0e9 
Explicitly removed something instead of relying on MACRO to disable it. Mbed can't use it.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ashleymills 0:ff9ebe0cf0e9 1 /* dtls -- a very basic DTLS implementation
ashleymills 0:ff9ebe0cf0e9 2 *
ashleymills 0:ff9ebe0cf0e9 3 * Copyright (C) 2011--2012 Olaf Bergmann <bergmann@tzi.org>
ashleymills 0:ff9ebe0cf0e9 4 *
ashleymills 0:ff9ebe0cf0e9 5 * Permission is hereby granted, free of charge, to any person
ashleymills 0:ff9ebe0cf0e9 6 * obtaining a copy of this software and associated documentation
ashleymills 0:ff9ebe0cf0e9 7 * files (the "Software"), to deal in the Software without
ashleymills 0:ff9ebe0cf0e9 8 * restriction, including without limitation the rights to use, copy,
ashleymills 0:ff9ebe0cf0e9 9 * modify, merge, publish, distribute, sublicense, and/or sell copies
ashleymills 0:ff9ebe0cf0e9 10 * of the Software, and to permit persons to whom the Software is
ashleymills 0:ff9ebe0cf0e9 11 * furnished to do so, subject to the following conditions:
ashleymills 0:ff9ebe0cf0e9 12 *
ashleymills 0:ff9ebe0cf0e9 13 * The above copyright notice and this permission notice shall be
ashleymills 0:ff9ebe0cf0e9 14 * included in all copies or substantial portions of the Software.
ashleymills 0:ff9ebe0cf0e9 15 *
ashleymills 0:ff9ebe0cf0e9 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
ashleymills 0:ff9ebe0cf0e9 17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
ashleymills 0:ff9ebe0cf0e9 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
ashleymills 0:ff9ebe0cf0e9 19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
ashleymills 0:ff9ebe0cf0e9 20 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ashleymills 0:ff9ebe0cf0e9 21 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
ashleymills 0:ff9ebe0cf0e9 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
ashleymills 0:ff9ebe0cf0e9 23 * SOFTWARE.
ashleymills 0:ff9ebe0cf0e9 24 */
ashleymills 0:ff9ebe0cf0e9 25
ashleymills 0:ff9ebe0cf0e9 26 #ifndef _HMAC_H_
ashleymills 0:ff9ebe0cf0e9 27 #define _HMAC_H_
ashleymills 0:ff9ebe0cf0e9 28
ashleymills 0:ff9ebe0cf0e9 29 #ifndef MBED
ashleymills 0:ff9ebe0cf0e9 30 #include <sys/types.h>
ashleymills 0:ff9ebe0cf0e9 31 #endif
ashleymills 0:ff9ebe0cf0e9 32
ashleymills 0:ff9ebe0cf0e9 33 #include "global.h"
ashleymills 0:ff9ebe0cf0e9 34
ashleymills 0:ff9ebe0cf0e9 35 #ifdef WITH_SHA256
ashleymills 0:ff9ebe0cf0e9 36 /** Aaron D. Gifford's implementation of SHA256
ashleymills 0:ff9ebe0cf0e9 37 * see http://www.aarongifford.com/ */
ashleymills 0:ff9ebe0cf0e9 38 #include "sha2/sha2.h"
ashleymills 0:ff9ebe0cf0e9 39
ashleymills 0:ff9ebe0cf0e9 40 typedef SHA256_CTX dtls_hash_ctx;
ashleymills 0:ff9ebe0cf0e9 41 typedef dtls_hash_ctx *dtls_hash_t;
ashleymills 0:ff9ebe0cf0e9 42 #define DTLS_HASH_CTX_SIZE sizeof(SHA256_CTX)
ashleymills 0:ff9ebe0cf0e9 43
ashleymills 0:ff9ebe0cf0e9 44 static inline void
ashleymills 0:ff9ebe0cf0e9 45 dtls_hash_init(dtls_hash_t ctx) {
ashleymills 0:ff9ebe0cf0e9 46 SHA256_Init((SHA256_CTX *)ctx);
ashleymills 0:ff9ebe0cf0e9 47 }
ashleymills 0:ff9ebe0cf0e9 48
ashleymills 0:ff9ebe0cf0e9 49 static inline void
ashleymills 0:ff9ebe0cf0e9 50 dtls_hash_update(dtls_hash_t ctx, const unsigned char *input, size_t len) {
ashleymills 0:ff9ebe0cf0e9 51 SHA256_Update((SHA256_CTX *)ctx, input, len);
ashleymills 0:ff9ebe0cf0e9 52 }
ashleymills 0:ff9ebe0cf0e9 53
ashleymills 0:ff9ebe0cf0e9 54 static inline size_t
ashleymills 0:ff9ebe0cf0e9 55 dtls_hash_finalize(unsigned char *buf, dtls_hash_t ctx) {
ashleymills 0:ff9ebe0cf0e9 56 SHA256_Final(buf, (SHA256_CTX *)ctx);
ashleymills 0:ff9ebe0cf0e9 57 return SHA256_DIGEST_LENGTH;
ashleymills 0:ff9ebe0cf0e9 58 }
ashleymills 0:ff9ebe0cf0e9 59 #endif /* WITH_SHA256 */
ashleymills 0:ff9ebe0cf0e9 60
ashleymills 0:ff9ebe0cf0e9 61 #ifndef WITH_CONTIKI
ashleymills 0:ff9ebe0cf0e9 62 static inline void dtls_hmac_storage_init()
ashleymills 0:ff9ebe0cf0e9 63 { }
ashleymills 0:ff9ebe0cf0e9 64 #else
ashleymills 0:ff9ebe0cf0e9 65 void dtls_hmac_storage_init();
ashleymills 0:ff9ebe0cf0e9 66 #endif
ashleymills 0:ff9ebe0cf0e9 67
ashleymills 0:ff9ebe0cf0e9 68 /**
ashleymills 0:ff9ebe0cf0e9 69 * \defgroup HMAC Keyed-Hash Message Authentication Code (HMAC)
ashleymills 0:ff9ebe0cf0e9 70 * NIST Standard FIPS 198 describes the Keyed-Hash Message Authentication
ashleymills 0:ff9ebe0cf0e9 71 * Code (HMAC) which is used as hash function for the DTLS PRF.
ashleymills 0:ff9ebe0cf0e9 72 * @{
ashleymills 0:ff9ebe0cf0e9 73 */
ashleymills 0:ff9ebe0cf0e9 74
ashleymills 0:ff9ebe0cf0e9 75 #define DTLS_HMAC_BLOCKSIZE 64 /**< size of hmac blocks */
ashleymills 0:ff9ebe0cf0e9 76 #define DTLS_HMAC_DIGEST_SIZE 32 /**< digest size (for SHA-256) */
ashleymills 0:ff9ebe0cf0e9 77 #define DTLS_HMAC_MAX 64 /**< max number of bytes in digest */
ashleymills 0:ff9ebe0cf0e9 78
ashleymills 0:ff9ebe0cf0e9 79 /**
ashleymills 0:ff9ebe0cf0e9 80 * List of known hash functions for use in dtls_hmac_init(). The
ashleymills 0:ff9ebe0cf0e9 81 * identifiers are the same as the HashAlgorithm defined in
ashleymills 0:ff9ebe0cf0e9 82 * <a href="http://tools.ietf.org/html/rfc5246#section-7.4.1.4.1"
ashleymills 0:ff9ebe0cf0e9 83 * >Section 7.4.1.4.1 of RFC 5246</a>.
ashleymills 0:ff9ebe0cf0e9 84 */
ashleymills 0:ff9ebe0cf0e9 85 typedef enum {
ashleymills 0:ff9ebe0cf0e9 86 HASH_NONE=0, HASH_MD5=1, HASH_SHA1=2, HASH_SHA224=3,
ashleymills 0:ff9ebe0cf0e9 87 HASH_SHA256=4, HASH_SHA384=5, HASH_SHA512=6
ashleymills 0:ff9ebe0cf0e9 88 } dtls_hashfunc_t;
ashleymills 0:ff9ebe0cf0e9 89
ashleymills 0:ff9ebe0cf0e9 90 /**
ashleymills 0:ff9ebe0cf0e9 91 * Context for HMAC generation. This object is initialized with
ashleymills 0:ff9ebe0cf0e9 92 * dtls_hmac_init() and must be passed to dtls_hmac_update() and
ashleymills 0:ff9ebe0cf0e9 93 * dtls_hmac_finalize(). Once, finalized, the component \c H is
ashleymills 0:ff9ebe0cf0e9 94 * invalid and must be initialized again with dtls_hmac_init() before
ashleymills 0:ff9ebe0cf0e9 95 * the structure can be used again.
ashleymills 0:ff9ebe0cf0e9 96 */
ashleymills 0:ff9ebe0cf0e9 97 typedef struct {
ashleymills 0:ff9ebe0cf0e9 98 unsigned char pad[DTLS_HMAC_BLOCKSIZE]; /**< ipad and opad storage */
ashleymills 0:ff9ebe0cf0e9 99 dtls_hash_ctx data; /**< context for hash function */
ashleymills 0:ff9ebe0cf0e9 100 } dtls_hmac_context_t;
ashleymills 0:ff9ebe0cf0e9 101
ashleymills 0:ff9ebe0cf0e9 102 /**
ashleymills 0:ff9ebe0cf0e9 103 * Initializes an existing HMAC context.
ashleymills 0:ff9ebe0cf0e9 104 *
ashleymills 0:ff9ebe0cf0e9 105 * @param ctx The HMAC context to initialize.
ashleymills 0:ff9ebe0cf0e9 106 * @param key The secret key.
ashleymills 0:ff9ebe0cf0e9 107 * @param klen The length of @p key.
ashleymills 0:ff9ebe0cf0e9 108 */
ashleymills 0:ff9ebe0cf0e9 109 void dtls_hmac_init(dtls_hmac_context_t *ctx, const unsigned char *key, size_t klen);
ashleymills 0:ff9ebe0cf0e9 110
ashleymills 0:ff9ebe0cf0e9 111 /**
ashleymills 0:ff9ebe0cf0e9 112 * Allocates a new HMAC context \p ctx with the given secret key.
ashleymills 0:ff9ebe0cf0e9 113 * This function returns \c 1 if \c ctx has been set correctly, or \c
ashleymills 0:ff9ebe0cf0e9 114 * 0 or \c -1 otherwise. Note that this function allocates new storage
ashleymills 0:ff9ebe0cf0e9 115 * that must be released by dtls_hmac_free().
ashleymills 0:ff9ebe0cf0e9 116 *
ashleymills 0:ff9ebe0cf0e9 117 * \param key The secret key.
ashleymills 0:ff9ebe0cf0e9 118 * \param klen The length of \p key.
ashleymills 0:ff9ebe0cf0e9 119 * \return A new dtls_hmac_context_t object or @c NULL on error
ashleymills 0:ff9ebe0cf0e9 120 */
ashleymills 0:ff9ebe0cf0e9 121 dtls_hmac_context_t *dtls_hmac_new(const unsigned char *key, size_t klen);
ashleymills 0:ff9ebe0cf0e9 122
ashleymills 0:ff9ebe0cf0e9 123 /**
ashleymills 0:ff9ebe0cf0e9 124 * Releases the storage for @p ctx that has been allocated by
ashleymills 0:ff9ebe0cf0e9 125 * dtls_hmac_new().
ashleymills 0:ff9ebe0cf0e9 126 *
ashleymills 0:ff9ebe0cf0e9 127 * @param ctx The dtls_hmac_context_t to free.
ashleymills 0:ff9ebe0cf0e9 128 */
ashleymills 0:ff9ebe0cf0e9 129 void dtls_hmac_free(dtls_hmac_context_t *ctx);
ashleymills 0:ff9ebe0cf0e9 130
ashleymills 0:ff9ebe0cf0e9 131 /**
ashleymills 0:ff9ebe0cf0e9 132 * Updates the HMAC context with data from \p input.
ashleymills 0:ff9ebe0cf0e9 133 *
ashleymills 0:ff9ebe0cf0e9 134 * \param ctx The HMAC context.
ashleymills 0:ff9ebe0cf0e9 135 * \param input The input data.
ashleymills 0:ff9ebe0cf0e9 136 * \param ilen Size of \p input.
ashleymills 0:ff9ebe0cf0e9 137 */
ashleymills 0:ff9ebe0cf0e9 138 void dtls_hmac_update(dtls_hmac_context_t *ctx,
ashleymills 0:ff9ebe0cf0e9 139 const unsigned char *input, size_t ilen);
ashleymills 0:ff9ebe0cf0e9 140
ashleymills 0:ff9ebe0cf0e9 141 /**
ashleymills 0:ff9ebe0cf0e9 142 * Completes the HMAC generation and writes the result to the given
ashleymills 0:ff9ebe0cf0e9 143 * output parameter \c result. The buffer must be large enough to hold
ashleymills 0:ff9ebe0cf0e9 144 * the message digest created by the actual hash function. If in
ashleymills 0:ff9ebe0cf0e9 145 * doubt, use \c DTLS_HMAC_MAX. The function returns the number of
ashleymills 0:ff9ebe0cf0e9 146 * bytes written to \c result.
ashleymills 0:ff9ebe0cf0e9 147 *
ashleymills 0:ff9ebe0cf0e9 148 * \param ctx The HMAC context.
ashleymills 0:ff9ebe0cf0e9 149 * \param result Output parameter where the MAC is written to.
ashleymills 0:ff9ebe0cf0e9 150 * \return Length of the MAC written to \p result.
ashleymills 0:ff9ebe0cf0e9 151 */
ashleymills 0:ff9ebe0cf0e9 152 int dtls_hmac_finalize(dtls_hmac_context_t *ctx, unsigned char *result);
ashleymills 0:ff9ebe0cf0e9 153
ashleymills 0:ff9ebe0cf0e9 154 /**@}*/
ashleymills 0:ff9ebe0cf0e9 155
ashleymills 0:ff9ebe0cf0e9 156 #endif /* _HMAC_H_ */