1 /* 2 * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 /* 11 * HMAC low level APIs are deprecated for public use, but still ok for internal 12 * use. 13 */ 14 #include "internal/deprecated.h" 15 16 #include <string.h> 17 18 #include <openssl/core_dispatch.h> 19 #include <openssl/core_names.h> 20 #include <openssl/params.h> 21 #include <openssl/evp.h> 22 #include <openssl/hmac.h> 23 24 #include "prov/implementations.h" 25 #include "prov/provider_ctx.h" 26 #include "prov/provider_util.h" 27 #include "prov/providercommon.h" 28 29 /* 30 * Forward declaration of everything implemented here. This is not strictly 31 * necessary for the compiler, but provides an assurance that the signatures 32 * of the functions in the dispatch table are correct. 33 */ 34 static OSSL_FUNC_mac_newctx_fn hmac_new; 35 static OSSL_FUNC_mac_dupctx_fn hmac_dup; 36 static OSSL_FUNC_mac_freectx_fn hmac_free; 37 static OSSL_FUNC_mac_gettable_ctx_params_fn hmac_gettable_ctx_params; 38 static OSSL_FUNC_mac_get_ctx_params_fn hmac_get_ctx_params; 39 static OSSL_FUNC_mac_settable_ctx_params_fn hmac_settable_ctx_params; 40 static OSSL_FUNC_mac_set_ctx_params_fn hmac_set_ctx_params; 41 static OSSL_FUNC_mac_init_fn hmac_init; 42 static OSSL_FUNC_mac_update_fn hmac_update; 43 static OSSL_FUNC_mac_final_fn hmac_final; 44 45 /* local HMAC context structure */ 46 47 /* typedef EVP_MAC_IMPL */ 48 struct hmac_data_st { 49 void *provctx; 50 HMAC_CTX *ctx; /* HMAC context */ 51 PROV_DIGEST digest; 52 unsigned char *key; 53 size_t keylen; 54 /* Length of full TLS record including the MAC and any padding */ 55 size_t tls_data_size; 56 unsigned char tls_header[13]; 57 int tls_header_set; 58 unsigned char tls_mac_out[EVP_MAX_MD_SIZE]; 59 size_t tls_mac_out_size; 60 }; 61 62 /* Defined in ssl/s3_cbc.c */ 63 int ssl3_cbc_digest_record(const EVP_MD *md, 64 unsigned char *md_out, 65 size_t *md_out_size, 66 const unsigned char header[13], 67 const unsigned char *data, 68 size_t data_size, 69 size_t data_plus_mac_plus_padding_size, 70 const unsigned char *mac_secret, 71 size_t mac_secret_length, char is_sslv3); 72 73 static void *hmac_new(void *provctx) 74 { 75 struct hmac_data_st *macctx; 76 77 if (!ossl_prov_is_running()) 78 return NULL; 79 80 if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL 81 || (macctx->ctx = HMAC_CTX_new()) == NULL) { 82 OPENSSL_free(macctx); 83 return NULL; 84 } 85 macctx->provctx = provctx; 86 87 return macctx; 88 } 89 90 static void hmac_free(void *vmacctx) 91 { 92 struct hmac_data_st *macctx = vmacctx; 93 94 if (macctx != NULL) { 95 HMAC_CTX_free(macctx->ctx); 96 ossl_prov_digest_reset(&macctx->digest); 97 OPENSSL_secure_clear_free(macctx->key, macctx->keylen); 98 OPENSSL_free(macctx); 99 } 100 } 101 102 static void *hmac_dup(void *vsrc) 103 { 104 struct hmac_data_st *src = vsrc; 105 struct hmac_data_st *dst; 106 HMAC_CTX *ctx; 107 108 if (!ossl_prov_is_running()) 109 return NULL; 110 dst = hmac_new(src->provctx); 111 if (dst == NULL) 112 return NULL; 113 114 ctx = dst->ctx; 115 *dst = *src; 116 dst->ctx = ctx; 117 dst->key = NULL; 118 memset(&dst->digest, 0, sizeof(dst->digest)); 119 120 if (!HMAC_CTX_copy(dst->ctx, src->ctx) 121 || !ossl_prov_digest_copy(&dst->digest, &src->digest)) { 122 hmac_free(dst); 123 return NULL; 124 } 125 if (src->key != NULL) { 126 /* There is no "secure" OPENSSL_memdup */ 127 dst->key = OPENSSL_secure_malloc(src->keylen > 0 ? src->keylen : 1); 128 if (dst->key == NULL) { 129 hmac_free(dst); 130 return 0; 131 } 132 memcpy(dst->key, src->key, src->keylen); 133 } 134 return dst; 135 } 136 137 static size_t hmac_size(struct hmac_data_st *macctx) 138 { 139 return HMAC_size(macctx->ctx); 140 } 141 142 static int hmac_block_size(struct hmac_data_st *macctx) 143 { 144 const EVP_MD *md = ossl_prov_digest_md(&macctx->digest); 145 146 if (md == NULL) 147 return 0; 148 return EVP_MD_block_size(md); 149 } 150 151 static int hmac_setkey(struct hmac_data_st *macctx, 152 const unsigned char *key, size_t keylen) 153 { 154 const EVP_MD *digest; 155 156 if (macctx->key != NULL) 157 OPENSSL_secure_clear_free(macctx->key, macctx->keylen); 158 /* Keep a copy of the key in case we need it for TLS HMAC */ 159 macctx->key = OPENSSL_secure_malloc(keylen > 0 ? keylen : 1); 160 if (macctx->key == NULL) 161 return 0; 162 memcpy(macctx->key, key, keylen); 163 macctx->keylen = keylen; 164 165 digest = ossl_prov_digest_md(&macctx->digest); 166 /* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */ 167 if (key != NULL || (macctx->tls_data_size == 0 && digest != NULL)) 168 return HMAC_Init_ex(macctx->ctx, key, keylen, digest, 169 ossl_prov_digest_engine(&macctx->digest)); 170 return 1; 171 } 172 173 static int hmac_init(void *vmacctx, const unsigned char *key, 174 size_t keylen, const OSSL_PARAM params[]) 175 { 176 struct hmac_data_st *macctx = vmacctx; 177 178 if (!ossl_prov_is_running() || !hmac_set_ctx_params(macctx, params)) 179 return 0; 180 181 if (key != NULL) 182 return hmac_setkey(macctx, key, keylen); 183 184 /* Just reinit the HMAC context */ 185 return HMAC_Init_ex(macctx->ctx, NULL, 0, NULL, NULL); 186 } 187 188 static int hmac_update(void *vmacctx, const unsigned char *data, 189 size_t datalen) 190 { 191 struct hmac_data_st *macctx = vmacctx; 192 193 if (macctx->tls_data_size > 0) { 194 /* We're doing a TLS HMAC */ 195 if (!macctx->tls_header_set) { 196 /* We expect the first update call to contain the TLS header */ 197 if (datalen != sizeof(macctx->tls_header)) 198 return 0; 199 memcpy(macctx->tls_header, data, datalen); 200 macctx->tls_header_set = 1; 201 return 1; 202 } 203 /* macctx->tls_data_size is datalen plus the padding length */ 204 if (macctx->tls_data_size < datalen) 205 return 0; 206 207 return ssl3_cbc_digest_record(ossl_prov_digest_md(&macctx->digest), 208 macctx->tls_mac_out, 209 &macctx->tls_mac_out_size, 210 macctx->tls_header, 211 data, 212 datalen, 213 macctx->tls_data_size, 214 macctx->key, 215 macctx->keylen, 216 0); 217 } 218 219 return HMAC_Update(macctx->ctx, data, datalen); 220 } 221 222 static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl, 223 size_t outsize) 224 { 225 unsigned int hlen; 226 struct hmac_data_st *macctx = vmacctx; 227 228 if (!ossl_prov_is_running()) 229 return 0; 230 if (macctx->tls_data_size > 0) { 231 if (macctx->tls_mac_out_size == 0) 232 return 0; 233 if (outl != NULL) 234 *outl = macctx->tls_mac_out_size; 235 memcpy(out, macctx->tls_mac_out, macctx->tls_mac_out_size); 236 return 1; 237 } 238 if (!HMAC_Final(macctx->ctx, out, &hlen)) 239 return 0; 240 *outl = hlen; 241 return 1; 242 } 243 244 static const OSSL_PARAM known_gettable_ctx_params[] = { 245 OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL), 246 OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL), 247 OSSL_PARAM_END 248 }; 249 static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *ctx, 250 ossl_unused void *provctx) 251 { 252 return known_gettable_ctx_params; 253 } 254 255 static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[]) 256 { 257 struct hmac_data_st *macctx = vmacctx; 258 OSSL_PARAM *p; 259 260 if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL 261 && !OSSL_PARAM_set_size_t(p, hmac_size(macctx))) 262 return 0; 263 264 if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL 265 && !OSSL_PARAM_set_int(p, hmac_block_size(macctx))) 266 return 0; 267 268 return 1; 269 } 270 271 static const OSSL_PARAM known_settable_ctx_params[] = { 272 OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, NULL, 0), 273 OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0), 274 OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0), 275 OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_NOINIT, NULL), 276 OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_ONESHOT, NULL), 277 OSSL_PARAM_size_t(OSSL_MAC_PARAM_TLS_DATA_SIZE, NULL), 278 OSSL_PARAM_END 279 }; 280 static const OSSL_PARAM *hmac_settable_ctx_params(ossl_unused void *ctx, 281 ossl_unused void *provctx) 282 { 283 return known_settable_ctx_params; 284 } 285 286 static int set_flag(const OSSL_PARAM params[], const char *key, int mask, 287 int *flags) 288 { 289 const OSSL_PARAM *p = OSSL_PARAM_locate_const(params, key); 290 int flag = 0; 291 292 if (p != NULL) { 293 if (!OSSL_PARAM_get_int(p, &flag)) 294 return 0; 295 if (flag == 0) 296 *flags &= ~mask; 297 else 298 *flags |= mask; 299 } 300 return 1; 301 } 302 303 /* 304 * ALL parameters should be set before init(). 305 */ 306 static int hmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[]) 307 { 308 struct hmac_data_st *macctx = vmacctx; 309 OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx); 310 const OSSL_PARAM *p; 311 int flags = 0; 312 313 if (params == NULL) 314 return 1; 315 316 if (!ossl_prov_digest_load_from_params(&macctx->digest, params, ctx)) 317 return 0; 318 319 if (!set_flag(params, OSSL_MAC_PARAM_DIGEST_NOINIT, EVP_MD_CTX_FLAG_NO_INIT, 320 &flags)) 321 return 0; 322 if (!set_flag(params, OSSL_MAC_PARAM_DIGEST_ONESHOT, EVP_MD_CTX_FLAG_ONESHOT, 323 &flags)) 324 return 0; 325 if (flags) 326 HMAC_CTX_set_flags(macctx->ctx, flags); 327 328 if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) { 329 if (p->data_type != OSSL_PARAM_OCTET_STRING) 330 return 0; 331 if (!hmac_setkey(macctx, p->data, p->data_size)) 332 return 0; 333 } 334 335 if ((p = OSSL_PARAM_locate_const(params, 336 OSSL_MAC_PARAM_TLS_DATA_SIZE)) != NULL) { 337 if (!OSSL_PARAM_get_size_t(p, &macctx->tls_data_size)) 338 return 0; 339 } 340 return 1; 341 } 342 343 const OSSL_DISPATCH ossl_hmac_functions[] = { 344 { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_new }, 345 { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup }, 346 { OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free }, 347 { OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init }, 348 { OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update }, 349 { OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final }, 350 { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS, 351 (void (*)(void))hmac_gettable_ctx_params }, 352 { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params }, 353 { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS, 354 (void (*)(void))hmac_settable_ctx_params }, 355 { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params }, 356 { 0, NULL } 357 }; 358