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 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. */
67 unsigned char *context;
75 /* Definitions needed for typechecking. */
76 static OSSL_FUNC_kdf_newctx_fn kbkdf_new;
77 static OSSL_FUNC_kdf_freectx_fn kbkdf_free;
78 static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
79 static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
80 static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
81 static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
82 static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
83 static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;
85 /* Not all platforms have htobe32(). */
86 static uint32_t be32(uint32_t host)
91 if (!IS_LITTLE_ENDIAN)
94 big |= (host & 0xff000000) >> 24;
95 big |= (host & 0x00ff0000) >> 8;
96 big |= (host & 0x0000ff00) << 8;
97 big |= (host & 0x000000ff) << 24;
101 static void init(KBKDF *ctx)
104 ctx->use_separator = 1;
107 static void *kbkdf_new(void *provctx)
111 if (!ossl_prov_is_running())
114 ctx = OPENSSL_zalloc(sizeof(*ctx));
116 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
120 ctx->provctx = provctx;
125 static void kbkdf_free(void *vctx)
127 KBKDF *ctx = (KBKDF *)vctx;
135 static void kbkdf_reset(void *vctx)
137 KBKDF *ctx = (KBKDF *)vctx;
138 void *provctx = ctx->provctx;
140 EVP_MAC_CTX_free(ctx->ctx_init);
141 OPENSSL_clear_free(ctx->context, ctx->context_len);
142 OPENSSL_clear_free(ctx->label, ctx->label_len);
143 OPENSSL_clear_free(ctx->ki, ctx->ki_len);
144 OPENSSL_clear_free(ctx->iv, ctx->iv_len);
145 memset(ctx, 0, sizeof(*ctx));
146 ctx->provctx = provctx;
150 /* SP800-108 section 5.1 or section 5.2 depending on mode. */
151 static int derive(EVP_MAC_CTX *ctx_init, kbkdf_mode mode, unsigned char *iv,
152 size_t iv_len, unsigned char *label, size_t label_len,
153 unsigned char *context, size_t context_len,
154 unsigned char *k_i, size_t h, uint32_t l, int has_separator,
155 unsigned char *ko, size_t ko_len)
158 EVP_MAC_CTX *ctx = NULL;
159 size_t written = 0, to_write, k_i_len = iv_len;
160 const unsigned char zero = 0;
164 * The fixed input data is a concatenation of a Label,
165 * a separation indicator 0x00, the Context, and L.
166 * One or more of these fixed input data fields may be omitted.
168 * has_separator == 0 means that the separator is omitted.
169 * Passing a value of l == 0 means that L is omitted.
170 * The Context and L are omitted automatically if a NULL buffer is passed.
172 int has_l = (l != 0);
174 /* Setup K(0) for feedback mode. */
176 memcpy(k_i, iv, iv_len);
178 for (counter = 1; written < ko_len; counter++) {
181 ctx = EVP_MAC_CTX_dup(ctx_init);
185 /* Perform feedback, if appropriate. */
186 if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
189 if (!EVP_MAC_update(ctx, (unsigned char *)&i, 4)
190 || !EVP_MAC_update(ctx, label, label_len)
191 || (has_separator && !EVP_MAC_update(ctx, &zero, 1))
192 || !EVP_MAC_update(ctx, context, context_len)
193 || (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
194 || !EVP_MAC_final(ctx, k_i, NULL, h))
197 to_write = ko_len - written;
198 memcpy(ko + written, k_i, MIN(to_write, h));
202 EVP_MAC_CTX_free(ctx);
208 EVP_MAC_CTX_free(ctx);
212 static int kbkdf_derive(void *vctx, unsigned char *key, size_t keylen,
213 const OSSL_PARAM params[])
215 KBKDF *ctx = (KBKDF *)vctx;
217 unsigned char *k_i = NULL;
221 if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx, params))
224 /* label, context, and iv are permitted to be empty. Check everything
226 if (ctx->ctx_init == NULL) {
227 if (ctx->ki_len == 0 || ctx->ki == NULL) {
228 ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
231 /* Could either be missing MAC or missing message digest or missing
232 * cipher - arbitrarily, I pick this one. */
233 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
237 /* Fail if the output length is zero */
239 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
243 h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
246 if (ctx->iv_len != 0 && ctx->iv_len != h) {
247 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
252 l = be32(keylen * 8);
254 k_i = OPENSSL_zalloc(h);
258 ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
259 ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
260 ctx->use_separator, key, keylen);
263 OPENSSL_cleanse(key, keylen);
264 OPENSSL_clear_free(k_i, h);
268 static int kbkdf_set_buffer(unsigned char **out, size_t *out_len,
271 if (p->data == NULL || p->data_size == 0)
274 OPENSSL_clear_free(*out, *out_len);
276 return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
279 static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
281 KBKDF *ctx = (KBKDF *)vctx;
282 OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
288 if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
291 else if (ctx->ctx_init != NULL
292 && !EVP_MAC_is_a(EVP_MAC_CTX_mac(ctx->ctx_init),
294 && !EVP_MAC_is_a(EVP_MAC_CTX_mac(ctx->ctx_init),
295 OSSL_MAC_NAME_CMAC)) {
296 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
300 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
301 if (p != NULL && strncasecmp("counter", p->data, p->data_size) == 0) {
304 && strncasecmp("feedback", p->data, p->data_size) == 0) {
305 ctx->mode = FEEDBACK;
306 } else if (p != NULL) {
307 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
311 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
312 if (p != NULL && !kbkdf_set_buffer(&ctx->ki, &ctx->ki_len, p))
315 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT);
316 if (p != NULL && !kbkdf_set_buffer(&ctx->label, &ctx->label_len, p))
319 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO);
320 if (p != NULL && !kbkdf_set_buffer(&ctx->context, &ctx->context_len, p))
323 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED);
324 if (p != NULL && !kbkdf_set_buffer(&ctx->iv, &ctx->iv_len, p))
327 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
328 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
331 p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
332 if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
335 /* Set up digest context, if we can. */
336 if (ctx->ctx_init != NULL && ctx->ki_len != 0
337 && !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
342 static const OSSL_PARAM *kbkdf_settable_ctx_params(ossl_unused void *ctx,
343 ossl_unused void *provctx)
345 static const OSSL_PARAM known_settable_ctx_params[] = {
346 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
347 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
348 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
349 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
350 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
351 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
352 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
353 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
354 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
355 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
356 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
359 return known_settable_ctx_params;
362 static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
366 p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
370 /* KBKDF can produce results as large as you like. */
371 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
374 static const OSSL_PARAM *kbkdf_gettable_ctx_params(ossl_unused void *ctx,
375 ossl_unused void *provctx)
377 static const OSSL_PARAM known_gettable_ctx_params[] =
378 { OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), OSSL_PARAM_END };
379 return known_gettable_ctx_params;
382 const OSSL_DISPATCH ossl_kdf_kbkdf_functions[] = {
383 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
384 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
385 { OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
386 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
387 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
388 (void(*)(void))kbkdf_settable_ctx_params },
389 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
390 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
391 (void(*)(void))kbkdf_gettable_ctx_params },
392 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },