1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay@cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay@cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] */ 56 57 #ifndef OPENSSL_HEADER_HMAC_H 58 #define OPENSSL_HEADER_HMAC_H 59 60 #include <openssl/base.h> 61 62 #include <openssl/digest.h> 63 64 #if defined(__cplusplus) 65 extern "C" { 66 #endif 67 68 69 /* HMAC contains functions for constructing PRFs from Merkle–Damgård hash 70 * functions using HMAC. */ 71 72 73 /* One-shot operation. */ 74 75 /* HMAC calculates the HMAC of |data_len| bytes of |data|, using the given key 76 * and hash function, and writes the result to |out|. On entry, |out| must 77 * contain at least |EVP_MD_size| bytes of space. The actual length of the 78 * result is written to |*out_len|. An output size of |EVP_MAX_MD_SIZE| will 79 * always be large enough. It returns |out| or NULL on error. */ 80 OPENSSL_EXPORT uint8_t *HMAC(const EVP_MD *evp_md, const void *key, 81 size_t key_len, const uint8_t *data, 82 size_t data_len, uint8_t *out, 83 unsigned int *out_len); 84 85 86 /* Incremental operation. */ 87 88 /* HMAC_CTX_init initialises |ctx| for use in an HMAC operation. It's assumed 89 * that HMAC_CTX objects will be allocated on the stack thus no allocation 90 * function is provided. If needed, allocate |sizeof(HMAC_CTX)| and call 91 * |HMAC_CTX_init| on it. */ 92 OPENSSL_EXPORT void HMAC_CTX_init(HMAC_CTX *ctx); 93 94 /* HMAC_CTX_cleanup frees data owned by |ctx|. */ 95 OPENSSL_EXPORT void HMAC_CTX_cleanup(HMAC_CTX *ctx); 96 97 /* HMAC_Init_ex sets up an initialised |HMAC_CTX| to use |md| as the hash 98 * function and |key| as the key. For a non-initial call, |md| may be NULL, in 99 * which case the previous hash function will be used. If the hash function has 100 * not changed and |key| is NULL, |ctx| reuses the previous key. It returns one 101 * on success or zero otherwise. 102 * 103 * WARNING: NULL and empty keys are ambiguous on non-initial calls. Passing NULL 104 * |key| but repeating the previous |md| reuses the previous key rather than the 105 * empty key. */ 106 OPENSSL_EXPORT int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, size_t key_len, 107 const EVP_MD *md, ENGINE *impl); 108 109 /* HMAC_Update hashes |data_len| bytes from |data| into the current HMAC 110 * operation in |ctx|. It returns one. */ 111 OPENSSL_EXPORT int HMAC_Update(HMAC_CTX *ctx, const uint8_t *data, 112 size_t data_len); 113 114 /* HMAC_Final completes the HMAC operation in |ctx| and writes the result to 115 * |out| and the sets |*out_len| to the length of the result. On entry, |out| 116 * must contain at least |HMAC_size| bytes of space. An output size of 117 * |EVP_MAX_MD_SIZE| will always be large enough. It returns one on success or 118 * zero on error. */ 119 OPENSSL_EXPORT int HMAC_Final(HMAC_CTX *ctx, uint8_t *out, 120 unsigned int *out_len); 121 122 123 /* Utility functions. */ 124 125 /* HMAC_size returns the size, in bytes, of the HMAC that will be produced by 126 * |ctx|. On entry, |ctx| must have been setup with |HMAC_Init_ex|. */ 127 OPENSSL_EXPORT size_t HMAC_size(const HMAC_CTX *ctx); 128 129 /* HMAC_CTX_copy_ex sets |dest| equal to |src|. On entry, |dest| must have been 130 * initialised by calling |HMAC_CTX_init|. It returns one on success and zero 131 * on error. */ 132 OPENSSL_EXPORT int HMAC_CTX_copy_ex(HMAC_CTX *dest, const HMAC_CTX *src); 133 134 135 /* Deprecated functions. */ 136 137 OPENSSL_EXPORT int HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len, 138 const EVP_MD *md); 139 140 /* HMAC_CTX_copy calls |HMAC_CTX_init| on |dest| and then sets it equal to 141 * |src|. On entry, |dest| must /not/ be initialised for an operation with 142 * |HMAC_Init_ex|. It returns one on success and zero on error. */ 143 OPENSSL_EXPORT int HMAC_CTX_copy(HMAC_CTX *dest, const HMAC_CTX *src); 144 145 146 /* Private functions */ 147 148 struct hmac_ctx_st { 149 const EVP_MD *md; 150 EVP_MD_CTX md_ctx; 151 EVP_MD_CTX i_ctx; 152 EVP_MD_CTX o_ctx; 153 } /* HMAC_CTX */; 154 155 156 #if defined(__cplusplus) 157 } /* extern C */ 158 159 #if !defined(BORINGSSL_NO_CXX) 160 extern "C++" { 161 162 namespace bssl { 163 164 using ScopedHMAC_CTX = 165 internal::StackAllocated<HMAC_CTX, void, HMAC_CTX_init, HMAC_CTX_cleanup>; 166 167 } // namespace bssl 168 169 } // extern C++ 170 #endif 171 172 #endif 173 174 #endif /* OPENSSL_HEADER_HMAC_H */ 175