--- /dev/null
+/* -*-c-*-
+ *
+ * Generic code for HMAC and NMAC
+ *
+ * (c) 1998 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb 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 Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Notes on the HMAC and NMAC constructions --------------------------*
+ *
+ * Designed by Mihir Bellare, Ran Canetti and Hugo Krawczyk, NMAC is a method
+ * for constructing keyed message authentication algorithms from unkeyed hash
+ * functions. It has been proven to provide useful security given reasonable
+ * assumptions about the underlying hash function. HMAC is an alternative
+ * formulation which doesn't require low-level access to the hash function's
+ * implementation. NMAC was designed to allow MD5 has a suitable underlying
+ * hash function, even though doubts were already being raised about its
+ * collision resistance.
+ */
+
+#ifndef CATACOMB_HMAC_H
+#define CATACOMB_HMAC_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+#ifndef CATACOMB_GMAC_H
+# include "gmac.h"
+#endif
+
+/*----- Macros ------------------------------------------------------------*/
+
+/* --- @HMAC_DECL@ --- *
+ *
+ * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function
+ *
+ * Use: Creates declarations for the HMAC and NMAC functions.
+ */
+
+#define HMAC_DECL(PRE, pre) \
+ \
+/* --- An HMAC or NMAC key --- */ \
+ \
+typedef struct pre##_mackey { \
+ octet ochain[PRE##_STATESZ]; /* Chaining for outer hash */ \
+ unsigned ocount; /* Byte count for outer hash */ \
+ octet ichain[PRE##_STATESZ]; /* Chaining for inner hash */ \
+ unsigned icount; /* Byte count for inner hash */ \
+} pre##_mackey; \
+ \
+/* --- An HMAC or NMAC hashing context --- */ \
+ \
+typedef struct pre##_macctx { \
+ pre##_ctx ctx; /* Context for main hashing */ \
+ octet chain[PRE##_STATESZ]; /* Chaining for outer hash */ \
+ unsigned count; /* Byte count for outer hash */ \
+} pre##_macctx; \
+ \
+/* --- Other useful constants --- */ \
+ \
+extern const octet pre##_hmackeysz[]; \
+extern const octet pre##_nmackeysz[]; \
+extern const octet pre##_sslmackeysz[]; \
+ \
+/* --- @pre_nmacinit@ --- * \
+ * \
+ * Arguments: @pre_macctx *key@ = pointer to a MAC key object \
+ * @const void *ok@ = pointer to outer hash init vector \
+ * @const void *ik@ = pointer to inner hash init vector \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Initializes a MAC key for doing NMAC hashing. \
+ */ \
+ \
+extern void pre##_nmacinit(pre##_mackey */*key*/, \
+ const void */*ok*/, const void */*ik*/); \
+ \
+/* --- @pre_hmacinit@ --- * \
+ * \
+ * Arguments: @pre_mackey *key@ = pointer to MAC key object \
+ * @const void *k@ = pointer to key to use \
+ * @size_t sz@ = size of key data \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Initializes a MAC key for doing HMAC hashing. Keys \
+ * longer than the hash function's output size aren't very \
+ * useful, but are accepted. Keys longer than the hash's \
+ * block size are also accepted; they are hashed before \
+ * use, as specified in RFC2104. \
+ */ \
+ \
+extern void pre##_hmacinit(pre##_mackey */*key*/, \
+ const void */*k*/, size_t /*sz*/); \
+ \
+/* --- @pre_sslmacinit@ --- * \
+ * \
+ * Arguments: @pre_mackey *key@ = pointer to MAC key object \
+ * @const void *k@ = pointer to key to use \
+ * @size_t sz@ = size of key data \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Initializes a MAC key for doing hasing using the SSL3 \
+ * variant of HMAC. \
+ */ \
+ \
+extern void pre##_sslmacinit(pre##_mackey */*key*/, \
+ const void */*k*/, size_t /*sz*/); \
+ \
+/* --- @pre_macinit@ --- * \
+ * \
+ * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \
+ * @const pre_mackey *key@ = pointer to MAC key block \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Instantiates a MAC context from a key block. \
+ */ \
+ \
+extern void pre##_macinit(pre##_macctx */*ctx*/, \
+ const pre##_mackey */*key*/); \
+ \
+/* --- @pre_machash@ --- * \
+ * \
+ * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \
+ * @const void *buf@ = pointer to buffer \
+ * @size_t sz@ = size of the buffer \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Hashes a buffer. \
+ */ \
+ \
+extern void pre##_machash(pre##_macctx */*ctx*/, \
+ const void */*buf*/, size_t /*sz*/); \
+ \
+/* --- @pre_macdone@ --- * \
+ * \
+ * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \
+ * @void *mac@ = pointer to buffer to receive MAC \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Returns the result of a MAC computation. \
+ */ \
+ \
+extern void pre##_macdone(pre##_macctx */*ctx*/, void */*mac*/); \
+ \
+/* --- Generic MAC interface --- */ \
+ \
+extern const gcmac pre##_hmac; \
+extern const gcmac pre##_nmac; \
+extern const gcmac pre##_sslmac;
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
projects / u / mdw / catacomb / blobdiff