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
));
121 ctx
->provctx
= provctx
;
126 static void kbkdf_free(void *vctx
)
128 KBKDF
*ctx
= (KBKDF
*)vctx
;
136 static void kbkdf_reset(void *vctx
)
138 KBKDF
*ctx
= (KBKDF
*)vctx
;
139 void *provctx
= ctx
->provctx
;
141 EVP_MAC_CTX_free(ctx
->ctx_init
);
142 OPENSSL_clear_free(ctx
->context
, ctx
->context_len
);
143 OPENSSL_clear_free(ctx
->label
, ctx
->label_len
);
144 OPENSSL_clear_free(ctx
->ki
, ctx
->ki_len
);
145 OPENSSL_clear_free(ctx
->iv
, ctx
->iv_len
);
146 memset(ctx
, 0, sizeof(*ctx
));
147 ctx
->provctx
= provctx
;
151 static void *kbkdf_dup(void *vctx
)
153 const KBKDF
*src
= (const KBKDF
*)vctx
;
156 dest
= kbkdf_new(src
->provctx
);
158 dest
->ctx_init
= EVP_MAC_CTX_dup(src
->ctx_init
);
159 if (dest
->ctx_init
== NULL
160 || !ossl_prov_memdup(src
->ki
, src
->ki_len
,
161 &dest
->ki
, &dest
->ki_len
)
162 || !ossl_prov_memdup(src
->label
, src
->label_len
,
163 &dest
->label
, &dest
->label_len
)
164 || !ossl_prov_memdup(src
->context
, src
->context_len
,
165 &dest
->context
, &dest
->context_len
)
166 || !ossl_prov_memdup(src
->iv
, src
->iv_len
,
167 &dest
->iv
, &dest
->iv_len
))
169 dest
->mode
= src
->mode
;
171 dest
->use_l
= src
->use_l
;
172 dest
->use_separator
= src
->use_separator
;
181 /* SP800-108 section 5.1 or section 5.2 depending on mode. */
182 static int derive(EVP_MAC_CTX
*ctx_init
, kbkdf_mode mode
, unsigned char *iv
,
183 size_t iv_len
, unsigned char *label
, size_t label_len
,
184 unsigned char *context
, size_t context_len
,
185 unsigned char *k_i
, size_t h
, uint32_t l
, int has_separator
,
186 unsigned char *ko
, size_t ko_len
, int r
)
189 EVP_MAC_CTX
*ctx
= NULL
;
190 size_t written
= 0, to_write
, k_i_len
= iv_len
;
191 const unsigned char zero
= 0;
195 * The fixed input data is a concatenation of a Label,
196 * a separation indicator 0x00, the Context, and L.
197 * One or more of these fixed input data fields may be omitted.
199 * has_separator == 0 means that the separator is omitted.
200 * Passing a value of l == 0 means that L is omitted.
201 * The Context and L are omitted automatically if a NULL buffer is passed.
203 int has_l
= (l
!= 0);
205 /* Setup K(0) for feedback mode. */
207 memcpy(k_i
, iv
, iv_len
);
209 for (counter
= 1; written
< ko_len
; counter
++) {
212 ctx
= EVP_MAC_CTX_dup(ctx_init
);
216 /* Perform feedback, if appropriate. */
217 if (mode
== FEEDBACK
&& !EVP_MAC_update(ctx
, k_i
, k_i_len
))
220 if (!EVP_MAC_update(ctx
, 4 - (r
/ 8) + (unsigned char *)&i
, r
/ 8)
221 || !EVP_MAC_update(ctx
, label
, label_len
)
222 || (has_separator
&& !EVP_MAC_update(ctx
, &zero
, 1))
223 || !EVP_MAC_update(ctx
, context
, context_len
)
224 || (has_l
&& !EVP_MAC_update(ctx
, (unsigned char *)&l
, 4))
225 || !EVP_MAC_final(ctx
, k_i
, NULL
, h
))
228 to_write
= ko_len
- written
;
229 memcpy(ko
+ written
, k_i
, ossl_min(to_write
, h
));
233 EVP_MAC_CTX_free(ctx
);
239 EVP_MAC_CTX_free(ctx
);
243 static int kbkdf_derive(void *vctx
, unsigned char *key
, size_t keylen
,
244 const OSSL_PARAM params
[])
246 KBKDF
*ctx
= (KBKDF
*)vctx
;
248 unsigned char *k_i
= NULL
;
251 uint64_t counter_max
;
253 if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx
, params
))
256 /* label, context, and iv are permitted to be empty. Check everything
258 if (ctx
->ctx_init
== NULL
) {
259 if (ctx
->ki_len
== 0 || ctx
->ki
== NULL
) {
260 ERR_raise(ERR_LIB_PROV
, PROV_R_NO_KEY_SET
);
263 /* Could either be missing MAC or missing message digest or missing
264 * cipher - arbitrarily, I pick this one. */
265 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_MAC
);
269 /* Fail if the output length is zero */
271 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_KEY_LENGTH
);
275 h
= EVP_MAC_CTX_get_mac_size(ctx
->ctx_init
);
278 if (ctx
->iv_len
!= 0 && ctx
->iv_len
!= h
) {
279 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_SEED_LENGTH
);
283 if (ctx
->mode
== COUNTER
) {
284 /* Fail if keylen is too large for r */
285 counter_max
= (uint64_t)1 << (uint64_t)ctx
->r
;
286 if ((uint64_t)(keylen
/ h
) >= counter_max
) {
287 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_KEY_LENGTH
);
293 l
= be32(keylen
* 8);
295 k_i
= OPENSSL_zalloc(h
);
299 ret
= derive(ctx
->ctx_init
, ctx
->mode
, ctx
->iv
, ctx
->iv_len
, ctx
->label
,
300 ctx
->label_len
, ctx
->context
, ctx
->context_len
, k_i
, h
, l
,
301 ctx
->use_separator
, key
, keylen
, ctx
->r
);
304 OPENSSL_cleanse(key
, keylen
);
305 OPENSSL_clear_free(k_i
, h
);
309 static int kbkdf_set_buffer(unsigned char **out
, size_t *out_len
,
312 if (p
->data
== NULL
|| p
->data_size
== 0)
315 OPENSSL_clear_free(*out
, *out_len
);
317 return OSSL_PARAM_get_octet_string(p
, (void **)out
, 0, out_len
);
320 static int kbkdf_set_ctx_params(void *vctx
, const OSSL_PARAM params
[])
322 KBKDF
*ctx
= (KBKDF
*)vctx
;
323 OSSL_LIB_CTX
*libctx
= PROV_LIBCTX_OF(ctx
->provctx
);
329 if (!ossl_prov_macctx_load_from_params(&ctx
->ctx_init
, params
, NULL
,
332 else if (ctx
->ctx_init
!= NULL
333 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx
->ctx_init
),
335 && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx
->ctx_init
),
336 OSSL_MAC_NAME_CMAC
)) {
337 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_MAC
);
341 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_MODE
);
343 && OPENSSL_strncasecmp("counter", p
->data
, p
->data_size
) == 0) {
346 && OPENSSL_strncasecmp("feedback", p
->data
, p
->data_size
) == 0) {
347 ctx
->mode
= FEEDBACK
;
348 } else if (p
!= NULL
) {
349 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_MODE
);
353 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KEY
);
354 if (p
!= NULL
&& !kbkdf_set_buffer(&ctx
->ki
, &ctx
->ki_len
, p
))
357 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_SALT
);
358 if (p
!= NULL
&& !kbkdf_set_buffer(&ctx
->label
, &ctx
->label_len
, p
))
361 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_INFO
);
362 if (p
!= NULL
&& !kbkdf_set_buffer(&ctx
->context
, &ctx
->context_len
, p
))
365 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_SEED
);
366 if (p
!= NULL
&& !kbkdf_set_buffer(&ctx
->iv
, &ctx
->iv_len
, p
))
369 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KBKDF_USE_L
);
370 if (p
!= NULL
&& !OSSL_PARAM_get_int(p
, &ctx
->use_l
))
373 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KBKDF_R
);
377 if (!OSSL_PARAM_get_int(p
, &new_r
))
379 if (new_r
!= 8 && new_r
!= 16 && new_r
!= 24 && new_r
!= 32)
384 p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR
);
385 if (p
!= NULL
&& !OSSL_PARAM_get_int(p
, &ctx
->use_separator
))
388 /* Set up digest context, if we can. */
389 if (ctx
->ctx_init
!= NULL
&& ctx
->ki_len
!= 0
390 && !EVP_MAC_init(ctx
->ctx_init
, ctx
->ki
, ctx
->ki_len
, NULL
))
395 static const OSSL_PARAM
*kbkdf_settable_ctx_params(ossl_unused
void *ctx
,
396 ossl_unused
void *provctx
)
398 static const OSSL_PARAM known_settable_ctx_params
[] = {
399 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO
, NULL
, 0),
400 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT
, NULL
, 0),
401 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY
, NULL
, 0),
402 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED
, NULL
, 0),
403 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST
, NULL
, 0),
404 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER
, NULL
, 0),
405 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC
, NULL
, 0),
406 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE
, NULL
, 0),
407 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES
, NULL
, 0),
408 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L
, NULL
),
409 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR
, NULL
),
410 OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R
, NULL
),
413 return known_settable_ctx_params
;
416 static int kbkdf_get_ctx_params(void *vctx
, OSSL_PARAM params
[])
420 p
= OSSL_PARAM_locate(params
, OSSL_KDF_PARAM_SIZE
);
424 /* KBKDF can produce results as large as you like. */
425 return OSSL_PARAM_set_size_t(p
, SIZE_MAX
);
428 static const OSSL_PARAM
*kbkdf_gettable_ctx_params(ossl_unused
void *ctx
,
429 ossl_unused
void *provctx
)
431 static const OSSL_PARAM known_gettable_ctx_params
[] =
432 { OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE
, NULL
), OSSL_PARAM_END
};
433 return known_gettable_ctx_params
;
436 const OSSL_DISPATCH ossl_kdf_kbkdf_functions
[] = {
437 { OSSL_FUNC_KDF_NEWCTX
, (void(*)(void))kbkdf_new
},
438 { OSSL_FUNC_KDF_DUPCTX
, (void(*)(void))kbkdf_dup
},
439 { OSSL_FUNC_KDF_FREECTX
, (void(*)(void))kbkdf_free
},
440 { OSSL_FUNC_KDF_RESET
, (void(*)(void))kbkdf_reset
},
441 { OSSL_FUNC_KDF_DERIVE
, (void(*)(void))kbkdf_derive
},
442 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS
,
443 (void(*)(void))kbkdf_settable_ctx_params
},
444 { OSSL_FUNC_KDF_SET_CTX_PARAMS
, (void(*)(void))kbkdf_set_ctx_params
},
445 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS
,
446 (void(*)(void))kbkdf_gettable_ctx_params
},
447 { OSSL_FUNC_KDF_GET_CTX_PARAMS
, (void(*)(void))kbkdf_get_ctx_params
},