2 * Copyright 2019-2021 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"
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_freectx_fn kbkdf_free;
79 static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
80 static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
81 static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
82 static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
83 static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
84 static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;
86 /* Not all platforms have htobe32(). */
87 static uint32_t be32(uint32_t host)
92 if (!IS_LITTLE_ENDIAN)
95 big |= (host & 0xff000000) >> 24;
96 big |= (host & 0x00ff0000) >> 8;
97 big |= (host & 0x0000ff00) << 8;
98 big |= (host & 0x000000ff) << 24;
102 static void init(KBKDF *ctx)
106 ctx->use_separator = 1;
109 static void *kbkdf_new(void *provctx)
113 if (!ossl_prov_is_running())
116 ctx = OPENSSL_zalloc(sizeof(*ctx));
118 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
122 ctx->provctx = provctx;
127 static void kbkdf_free(void *vctx)
129 KBKDF *ctx = (KBKDF *)vctx;
137 static void kbkdf_reset(void *vctx)
139 KBKDF *ctx = (KBKDF *)vctx;
140 void *provctx = ctx->provctx;
142 EVP_MAC_CTX_free(ctx->ctx_init);
143 OPENSSL_clear_free(ctx->context, ctx->context_len);
144 OPENSSL_clear_free(ctx->label, ctx->label_len);
145 OPENSSL_clear_free(ctx->ki, ctx->ki_len);
146 OPENSSL_clear_free(ctx->iv, ctx->iv_len);
147 memset(ctx, 0, sizeof(*ctx));
148 ctx->provctx = provctx;
152 /* SP800-108 section 5.1 or section 5.2 depending on mode. */
153 static int derive(EVP_MAC_CTX *ctx_init, kbkdf_mode mode, unsigned char *iv,
154 size_t iv_len, unsigned char *label, size_t label_len,
155 unsigned char *context, size_t context_len,
156 unsigned char *k_i, size_t h, uint32_t l, int has_separator,
157 unsigned char *ko, size_t ko_len, int r)
160 EVP_MAC_CTX *ctx = NULL;
161 size_t written = 0, to_write, k_i_len = iv_len;
162 const unsigned char zero = 0;
166 * The fixed input data is a concatenation of a Label,
167 * a separation indicator 0x00, the Context, and L.
168 * One or more of these fixed input data fields may be omitted.
170 * has_separator == 0 means that the separator is omitted.
171 * Passing a value of l == 0 means that L is omitted.
172 * The Context and L are omitted automatically if a NULL buffer is passed.
174 int has_l = (l != 0);
176 /* Setup K(0) for feedback mode. */
178 memcpy(k_i, iv, iv_len);
180 for (counter = 1; written < ko_len; counter++) {
183 ctx = EVP_MAC_CTX_dup(ctx_init);
187 /* Perform feedback, if appropriate. */
188 if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
191 if (!EVP_MAC_update(ctx, 4 - (r / 8) + (unsigned char *)&i, r / 8)
192 || !EVP_MAC_update(ctx, label, label_len)
193 || (has_separator && !EVP_MAC_update(ctx, &zero, 1))
194 || !EVP_MAC_update(ctx, context, context_len)
195 || (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
196 || !EVP_MAC_final(ctx, k_i, NULL, h))
199 to_write = ko_len - written;
200 memcpy(ko + written, k_i, ossl_min(to_write, h));
204 EVP_MAC_CTX_free(ctx);
210 EVP_MAC_CTX_free(ctx);
214 static int kbkdf_derive(void *vctx, unsigned char *key, size_t keylen,
215 const OSSL_PARAM params[])
217 KBKDF *ctx = (KBKDF *)vctx;
219 unsigned char *k_i = NULL;
222 uint64_t counter_max;
224 if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx, params))
227 /* label, context, and iv are permitted to be empty. Check everything
229 if (ctx->ctx_init == NULL) {
230 if (ctx->ki_len == 0 || ctx->ki == NULL) {
231 ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
234 /* Could either be missing MAC or missing message digest or missing
235 * cipher - arbitrarily, I pick this one. */
236 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
240 /* Fail if the output length is zero */
242 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
246 h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
249 if (ctx->iv_len != 0 && ctx->iv_len != h) {
250 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
254 if (ctx->mode == COUNTER) {
255 /* Fail if keylen is too large for r */
256 counter_max = (uint64_t)1 << (uint64_t)ctx->r;
257 if ((uint64_t)(keylen / h) >= counter_max) {
258 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
264 l = be32(keylen * 8);
266 k_i = OPENSSL_zalloc(h);
270 ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
271 ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
272 ctx->use_separator, key, keylen, ctx->r);
275 OPENSSL_cleanse(key, keylen);
276 OPENSSL_clear_free(k_i, h);
280 static int kbkdf_set_buffer(unsigned char **out, size_t *out_len,
283 if (p->data == NULL || p->data_size == 0)
286 OPENSSL_clear_free(*out, *out_len);
288 return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
291 static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
293 KBKDF *ctx = (KBKDF *)vctx;
294 OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
300 if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
303 else if (ctx->ctx_init != NULL
304 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
306 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
307 OSSL_MAC_NAME_CMAC)) {
308 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
312 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
313 if (p != NULL && strncasecmp("counter", p->data, p->data_size) == 0) {
316 && strncasecmp("feedback", p->data, p->data_size) == 0) {
317 ctx->mode = FEEDBACK;
318 } else if (p != NULL) {
319 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
323 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
324 if (p != NULL && !kbkdf_set_buffer(&ctx->ki, &ctx->ki_len, p))
327 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT);
328 if (p != NULL && !kbkdf_set_buffer(&ctx->label, &ctx->label_len, p))
331 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO);
332 if (p != NULL && !kbkdf_set_buffer(&ctx->context, &ctx->context_len, p))
335 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED);
336 if (p != NULL && !kbkdf_set_buffer(&ctx->iv, &ctx->iv_len, p))
339 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
340 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
343 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_R);
347 if (!OSSL_PARAM_get_int(p, &new_r))
349 if (new_r != 8 && new_r != 16 && new_r != 24 && new_r != 32)
354 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
355 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
358 /* Set up digest context, if we can. */
359 if (ctx->ctx_init != NULL && ctx->ki_len != 0
360 && !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
365 static const OSSL_PARAM *kbkdf_settable_ctx_params(ossl_unused void *ctx,
366 ossl_unused void *provctx)
368 static const OSSL_PARAM known_settable_ctx_params[] = {
369 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
370 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
371 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
372 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
373 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
374 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
375 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
376 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
377 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
378 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
379 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
380 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R, NULL),
383 return known_settable_ctx_params;
386 static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
390 p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
394 /* KBKDF can produce results as large as you like. */
395 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
398 static const OSSL_PARAM *kbkdf_gettable_ctx_params(ossl_unused void *ctx,
399 ossl_unused void *provctx)
401 static const OSSL_PARAM known_gettable_ctx_params[] =
402 { OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), OSSL_PARAM_END };
403 return known_gettable_ctx_params;
406 const OSSL_DISPATCH ossl_kdf_kbkdf_functions[] = {
407 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
408 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
409 { OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
410 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
411 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
412 (void(*)(void))kbkdf_settable_ctx_params },
413 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
414 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
415 (void(*)(void))kbkdf_gettable_ctx_params },
416 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },