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"
48 #include "internal/params.h"
50 #define ossl_min(a, b) ((a) < (b)) ? (a) : (b)
57 /* Our context structure. */
61 EVP_MAC_CTX *ctx_init;
63 /* Names are lowercased versions of those found in SP800-108. */
69 unsigned char *context;
78 /* Definitions needed for typechecking. */
79 static OSSL_FUNC_kdf_newctx_fn kbkdf_new;
80 static OSSL_FUNC_kdf_dupctx_fn kbkdf_dup;
81 static OSSL_FUNC_kdf_freectx_fn kbkdf_free;
82 static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
83 static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
84 static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
85 static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
86 static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
87 static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;
89 /* Not all platforms have htobe32(). */
90 static uint32_t be32(uint32_t host)
95 if (!IS_LITTLE_ENDIAN)
98 big |= (host & 0xff000000) >> 24;
99 big |= (host & 0x00ff0000) >> 8;
100 big |= (host & 0x0000ff00) << 8;
101 big |= (host & 0x000000ff) << 24;
105 static void init(KBKDF *ctx)
109 ctx->use_separator = 1;
113 static void *kbkdf_new(void *provctx)
117 if (!ossl_prov_is_running())
120 ctx = OPENSSL_zalloc(sizeof(*ctx));
124 ctx->provctx = provctx;
129 static void kbkdf_free(void *vctx)
131 KBKDF *ctx = (KBKDF *)vctx;
139 static void kbkdf_reset(void *vctx)
141 KBKDF *ctx = (KBKDF *)vctx;
142 void *provctx = ctx->provctx;
144 EVP_MAC_CTX_free(ctx->ctx_init);
145 OPENSSL_clear_free(ctx->context, ctx->context_len);
146 OPENSSL_clear_free(ctx->label, ctx->label_len);
147 OPENSSL_clear_free(ctx->ki, ctx->ki_len);
148 OPENSSL_clear_free(ctx->iv, ctx->iv_len);
149 memset(ctx, 0, sizeof(*ctx));
150 ctx->provctx = provctx;
154 static void *kbkdf_dup(void *vctx)
156 const KBKDF *src = (const KBKDF *)vctx;
159 dest = kbkdf_new(src->provctx);
161 dest->ctx_init = EVP_MAC_CTX_dup(src->ctx_init);
162 if (dest->ctx_init == NULL
163 || !ossl_prov_memdup(src->ki, src->ki_len,
164 &dest->ki, &dest->ki_len)
165 || !ossl_prov_memdup(src->label, src->label_len,
166 &dest->label, &dest->label_len)
167 || !ossl_prov_memdup(src->context, src->context_len,
168 &dest->context, &dest->context_len)
169 || !ossl_prov_memdup(src->iv, src->iv_len,
170 &dest->iv, &dest->iv_len))
172 dest->mode = src->mode;
174 dest->use_l = src->use_l;
175 dest->use_separator = src->use_separator;
176 dest->is_kmac = src->is_kmac;
185 /* SP800-108 section 5.1 or section 5.2 depending on mode. */
186 static int derive(EVP_MAC_CTX *ctx_init, kbkdf_mode mode, unsigned char *iv,
187 size_t iv_len, unsigned char *label, size_t label_len,
188 unsigned char *context, size_t context_len,
189 unsigned char *k_i, size_t h, uint32_t l, int has_separator,
190 unsigned char *ko, size_t ko_len, int r)
193 EVP_MAC_CTX *ctx = NULL;
194 size_t written = 0, to_write, k_i_len = iv_len;
195 const unsigned char zero = 0;
199 * The fixed input data is a concatenation of a Label,
200 * a separation indicator 0x00, the Context, and L.
201 * One or more of these fixed input data fields may be omitted.
203 * has_separator == 0 means that the separator is omitted.
204 * Passing a value of l == 0 means that L is omitted.
205 * The Context and L are omitted automatically if a NULL buffer is passed.
207 int has_l = (l != 0);
209 /* Setup K(0) for feedback mode. */
211 memcpy(k_i, iv, iv_len);
213 for (counter = 1; written < ko_len; counter++) {
216 ctx = EVP_MAC_CTX_dup(ctx_init);
220 /* Perform feedback, if appropriate. */
221 if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
224 if (!EVP_MAC_update(ctx, 4 - (r / 8) + (unsigned char *)&i, r / 8)
225 || !EVP_MAC_update(ctx, label, label_len)
226 || (has_separator && !EVP_MAC_update(ctx, &zero, 1))
227 || !EVP_MAC_update(ctx, context, context_len)
228 || (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
229 || !EVP_MAC_final(ctx, k_i, NULL, h))
232 to_write = ko_len - written;
233 memcpy(ko + written, k_i, ossl_min(to_write, h));
237 EVP_MAC_CTX_free(ctx);
243 EVP_MAC_CTX_free(ctx);
247 /* This must be run before the key is set */
248 static int kmac_init(EVP_MAC_CTX *ctx, const unsigned char *custom, size_t customlen)
250 OSSL_PARAM params[2];
252 if (custom == NULL || customlen == 0)
254 params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
255 (void *)custom, customlen);
256 params[1] = OSSL_PARAM_construct_end();
257 return EVP_MAC_CTX_set_params(ctx, params) > 0;
260 static int kmac_derive(EVP_MAC_CTX *ctx, unsigned char *out, size_t outlen,
261 const unsigned char *context, size_t contextlen)
263 OSSL_PARAM params[2];
265 params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE, &outlen);
266 params[1] = OSSL_PARAM_construct_end();
267 return EVP_MAC_CTX_set_params(ctx, params) > 0
268 && EVP_MAC_update(ctx, context, contextlen)
269 && EVP_MAC_final(ctx, out, NULL, outlen);
272 static int kbkdf_derive(void *vctx, unsigned char *key, size_t keylen,
273 const OSSL_PARAM params[])
275 KBKDF *ctx = (KBKDF *)vctx;
277 unsigned char *k_i = NULL;
280 uint64_t counter_max;
282 if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx, params))
285 /* label, context, and iv are permitted to be empty. Check everything
287 if (ctx->ctx_init == NULL) {
288 if (ctx->ki_len == 0 || ctx->ki == NULL) {
289 ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
292 /* Could either be missing MAC or missing message digest or missing
293 * cipher - arbitrarily, I pick this one. */
294 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
298 /* Fail if the output length is zero */
300 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
305 ret = kmac_derive(ctx->ctx_init, key, keylen,
306 ctx->context, ctx->context_len);
310 h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
314 if (ctx->iv_len != 0 && ctx->iv_len != h) {
315 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
319 if (ctx->mode == COUNTER) {
320 /* Fail if keylen is too large for r */
321 counter_max = (uint64_t)1 << (uint64_t)ctx->r;
322 if ((uint64_t)(keylen / h) >= counter_max) {
323 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
329 l = be32(keylen * 8);
331 k_i = OPENSSL_zalloc(h);
335 ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
336 ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
337 ctx->use_separator, key, keylen, ctx->r);
340 OPENSSL_cleanse(key, keylen);
341 OPENSSL_clear_free(k_i, h);
345 static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
347 KBKDF *ctx = (KBKDF *)vctx;
348 OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
354 if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
357 else if (ctx->ctx_init != NULL) {
358 if (EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
359 OSSL_MAC_NAME_KMAC128)
360 || EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
361 OSSL_MAC_NAME_KMAC256)) {
363 } else if (!EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
365 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
366 OSSL_MAC_NAME_CMAC)) {
367 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
372 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
374 && OPENSSL_strncasecmp("counter", p->data, p->data_size) == 0) {
377 && OPENSSL_strncasecmp("feedback", p->data, p->data_size) == 0) {
378 ctx->mode = FEEDBACK;
379 } else if (p != NULL) {
380 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
384 if (ossl_param_get1_octet_string(params, OSSL_KDF_PARAM_KEY,
385 &ctx->ki, &ctx->ki_len) == 0)
388 if (ossl_param_get1_octet_string(params, OSSL_KDF_PARAM_SALT,
389 &ctx->label, &ctx->label_len) == 0)
392 if (ossl_param_get1_concat_octet_string(params, OSSL_KDF_PARAM_INFO,
393 &ctx->context, &ctx->context_len,
397 if (ossl_param_get1_octet_string(params, OSSL_KDF_PARAM_SEED,
398 &ctx->iv, &ctx->iv_len) == 0)
401 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
402 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
405 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_R);
409 if (!OSSL_PARAM_get_int(p, &new_r))
411 if (new_r != 8 && new_r != 16 && new_r != 24 && new_r != 32)
416 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
417 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
420 /* Set up digest context, if we can. */
421 if (ctx->ctx_init != NULL && ctx->ki_len != 0) {
422 if ((ctx->is_kmac && !kmac_init(ctx->ctx_init, ctx->label, ctx->label_len))
423 || !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
429 static const OSSL_PARAM *kbkdf_settable_ctx_params(ossl_unused void *ctx,
430 ossl_unused void *provctx)
432 static const OSSL_PARAM known_settable_ctx_params[] = {
433 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
434 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
435 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
436 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
437 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
438 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
439 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
440 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
441 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
442 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
443 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
444 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R, NULL),
447 return known_settable_ctx_params;
450 static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
454 p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
458 /* KBKDF can produce results as large as you like. */
459 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
462 static const OSSL_PARAM *kbkdf_gettable_ctx_params(ossl_unused void *ctx,
463 ossl_unused void *provctx)
465 static const OSSL_PARAM known_gettable_ctx_params[] =
466 { OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), OSSL_PARAM_END };
467 return known_gettable_ctx_params;
470 const OSSL_DISPATCH ossl_kdf_kbkdf_functions[] = {
471 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
472 { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kbkdf_dup },
473 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
474 { OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
475 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
476 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
477 (void(*)(void))kbkdf_settable_ctx_params },
478 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
479 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
480 (void(*)(void))kbkdf_gettable_ctx_params },
481 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },