2 * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2019 Red Hat, Inc.
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
12 * This implements https://csrc.nist.gov/publications/detail/sp/800-108/final
13 * section 5.1 ("counter mode") and section 5.2 ("feedback mode") in both HMAC
14 * and CMAC. That document does not name the KDFs it defines; the name is
16 * https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/Key-Derivation
18 * Note that section 5.3 ("double-pipeline mode") is not implemented, though
19 * it would be possible to do so in the future.
21 * These versions all assume the counter is used. It would be relatively
22 * straightforward to expose a configuration handle should the need arise.
24 * Variable names attempt to match those of SP800-108.
31 #include <openssl/core_names.h>
32 #include <openssl/evp.h>
33 #include <openssl/hmac.h>
34 #include <openssl/kdf.h>
35 #include <openssl/params.h>
36 #include <openssl/proverr.h>
38 #include "internal/cryptlib.h"
39 #include "crypto/evp.h"
40 #include "internal/numbers.h"
41 #include "internal/endian.h"
42 #include "prov/implementations.h"
43 #include "prov/provider_ctx.h"
44 #include "prov/provider_util.h"
45 #include "prov/providercommon.h"
47 #include "internal/e_os.h"
49 #define ossl_min(a, b) ((a) < (b)) ? (a) : (b)
56 /* Our context structure. */
60 EVP_MAC_CTX *ctx_init;
62 /* Names are lowercased versions of those found in SP800-108. */
68 unsigned char *context;
76 /* Definitions needed for typechecking. */
77 static OSSL_FUNC_kdf_newctx_fn kbkdf_new;
78 static OSSL_FUNC_kdf_newctx_fn kbkdf_dup;
79 static OSSL_FUNC_kdf_freectx_fn kbkdf_free;
80 static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
81 static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
82 static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
83 static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
84 static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
85 static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;
87 /* Not all platforms have htobe32(). */
88 static uint32_t be32(uint32_t host)
93 if (!IS_LITTLE_ENDIAN)
96 big |= (host & 0xff000000) >> 24;
97 big |= (host & 0x00ff0000) >> 8;
98 big |= (host & 0x0000ff00) << 8;
99 big |= (host & 0x000000ff) << 24;
103 static void init(KBKDF *ctx)
107 ctx->use_separator = 1;
110 static void *kbkdf_new(void *provctx)
114 if (!ossl_prov_is_running())
117 ctx = OPENSSL_zalloc(sizeof(*ctx));
119 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
123 ctx->provctx = provctx;
128 static void kbkdf_free(void *vctx)
130 KBKDF *ctx = (KBKDF *)vctx;
138 static void kbkdf_reset(void *vctx)
140 KBKDF *ctx = (KBKDF *)vctx;
141 void *provctx = ctx->provctx;
143 EVP_MAC_CTX_free(ctx->ctx_init);
144 OPENSSL_clear_free(ctx->context, ctx->context_len);
145 OPENSSL_clear_free(ctx->label, ctx->label_len);
146 OPENSSL_clear_free(ctx->ki, ctx->ki_len);
147 OPENSSL_clear_free(ctx->iv, ctx->iv_len);
148 memset(ctx, 0, sizeof(*ctx));
149 ctx->provctx = provctx;
153 static void *kbkdf_dup(void *vctx)
155 const KBKDF *src = (const KBKDF *)vctx;
158 dest = kbkdf_new(src->provctx);
160 dest->ctx_init = EVP_MAC_CTX_dup(src->ctx_init);
161 if (dest->ctx_init == NULL
162 || !ossl_prov_memdup(src->ki, src->ki_len,
163 &dest->ki, &dest->ki_len)
164 || !ossl_prov_memdup(src->label, src->label_len,
165 &dest->label, &dest->label_len)
166 || !ossl_prov_memdup(src->context, src->context_len,
167 &dest->context, &dest->context_len)
168 || !ossl_prov_memdup(src->iv, src->iv_len,
169 &dest->iv, &dest->iv_len))
171 dest->mode = src->mode;
173 dest->use_l = src->use_l;
174 dest->use_separator = src->use_separator;
183 /* SP800-108 section 5.1 or section 5.2 depending on mode. */
184 static int derive(EVP_MAC_CTX *ctx_init, kbkdf_mode mode, unsigned char *iv,
185 size_t iv_len, unsigned char *label, size_t label_len,
186 unsigned char *context, size_t context_len,
187 unsigned char *k_i, size_t h, uint32_t l, int has_separator,
188 unsigned char *ko, size_t ko_len, int r)
191 EVP_MAC_CTX *ctx = NULL;
192 size_t written = 0, to_write, k_i_len = iv_len;
193 const unsigned char zero = 0;
197 * The fixed input data is a concatenation of a Label,
198 * a separation indicator 0x00, the Context, and L.
199 * One or more of these fixed input data fields may be omitted.
201 * has_separator == 0 means that the separator is omitted.
202 * Passing a value of l == 0 means that L is omitted.
203 * The Context and L are omitted automatically if a NULL buffer is passed.
205 int has_l = (l != 0);
207 /* Setup K(0) for feedback mode. */
209 memcpy(k_i, iv, iv_len);
211 for (counter = 1; written < ko_len; counter++) {
214 ctx = EVP_MAC_CTX_dup(ctx_init);
218 /* Perform feedback, if appropriate. */
219 if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
222 if (!EVP_MAC_update(ctx, 4 - (r / 8) + (unsigned char *)&i, r / 8)
223 || !EVP_MAC_update(ctx, label, label_len)
224 || (has_separator && !EVP_MAC_update(ctx, &zero, 1))
225 || !EVP_MAC_update(ctx, context, context_len)
226 || (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
227 || !EVP_MAC_final(ctx, k_i, NULL, h))
230 to_write = ko_len - written;
231 memcpy(ko + written, k_i, ossl_min(to_write, h));
235 EVP_MAC_CTX_free(ctx);
241 EVP_MAC_CTX_free(ctx);
245 static int kbkdf_derive(void *vctx, unsigned char *key, size_t keylen,
246 const OSSL_PARAM params[])
248 KBKDF *ctx = (KBKDF *)vctx;
250 unsigned char *k_i = NULL;
253 uint64_t counter_max;
255 if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx, params))
258 /* label, context, and iv are permitted to be empty. Check everything
260 if (ctx->ctx_init == NULL) {
261 if (ctx->ki_len == 0 || ctx->ki == NULL) {
262 ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
265 /* Could either be missing MAC or missing message digest or missing
266 * cipher - arbitrarily, I pick this one. */
267 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
271 /* Fail if the output length is zero */
273 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
277 h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
280 if (ctx->iv_len != 0 && ctx->iv_len != h) {
281 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
285 if (ctx->mode == COUNTER) {
286 /* Fail if keylen is too large for r */
287 counter_max = (uint64_t)1 << (uint64_t)ctx->r;
288 if ((uint64_t)(keylen / h) >= counter_max) {
289 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
295 l = be32(keylen * 8);
297 k_i = OPENSSL_zalloc(h);
301 ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
302 ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
303 ctx->use_separator, key, keylen, ctx->r);
306 OPENSSL_cleanse(key, keylen);
307 OPENSSL_clear_free(k_i, h);
311 static int kbkdf_set_buffer(unsigned char **out, size_t *out_len,
314 if (p->data == NULL || p->data_size == 0)
317 OPENSSL_clear_free(*out, *out_len);
319 return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
322 static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
324 KBKDF *ctx = (KBKDF *)vctx;
325 OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
331 if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
334 else if (ctx->ctx_init != NULL
335 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
337 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
338 OSSL_MAC_NAME_CMAC)) {
339 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
343 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
345 && OPENSSL_strncasecmp("counter", p->data, p->data_size) == 0) {
348 && OPENSSL_strncasecmp("feedback", p->data, p->data_size) == 0) {
349 ctx->mode = FEEDBACK;
350 } else if (p != NULL) {
351 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
355 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
356 if (p != NULL && !kbkdf_set_buffer(&ctx->ki, &ctx->ki_len, p))
359 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT);
360 if (p != NULL && !kbkdf_set_buffer(&ctx->label, &ctx->label_len, p))
363 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO);
364 if (p != NULL && !kbkdf_set_buffer(&ctx->context, &ctx->context_len, p))
367 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED);
368 if (p != NULL && !kbkdf_set_buffer(&ctx->iv, &ctx->iv_len, p))
371 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
372 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
375 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_R);
379 if (!OSSL_PARAM_get_int(p, &new_r))
381 if (new_r != 8 && new_r != 16 && new_r != 24 && new_r != 32)
386 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
387 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
390 /* Set up digest context, if we can. */
391 if (ctx->ctx_init != NULL && ctx->ki_len != 0
392 && !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
397 static const OSSL_PARAM *kbkdf_settable_ctx_params(ossl_unused void *ctx,
398 ossl_unused void *provctx)
400 static const OSSL_PARAM known_settable_ctx_params[] = {
401 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
402 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
403 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
404 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
405 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
406 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
407 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
408 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
409 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
410 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
411 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
412 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R, NULL),
415 return known_settable_ctx_params;
418 static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
422 p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
426 /* KBKDF can produce results as large as you like. */
427 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
430 static const OSSL_PARAM *kbkdf_gettable_ctx_params(ossl_unused void *ctx,
431 ossl_unused void *provctx)
433 static const OSSL_PARAM known_gettable_ctx_params[] =
434 { OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), OSSL_PARAM_END };
435 return known_gettable_ctx_params;
438 const OSSL_DISPATCH ossl_kdf_kbkdf_functions[] = {
439 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
440 { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kbkdf_dup },
441 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
442 { OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
443 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
444 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
445 (void(*)(void))kbkdf_settable_ctx_params },
446 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
447 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
448 (void(*)(void))kbkdf_gettable_ctx_params },
449 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },