2 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
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 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
15 * The Single Step KDF algorithm is given by:
17 * Result(0) = empty bit string (i.e., the null string).
18 * For i = 1 to reps, do the following:
19 * Increment counter by 1.
20 * Result(i) = Result(i - 1) || H(counter || Z || FixedInfo).
21 * DKM = LeftmostBits(Result(reps), L))
24 * Z is a shared secret required to produce the derived key material.
25 * counter is a 4 byte buffer.
26 * FixedInfo is a bit string containing context specific data.
27 * DKM is the output derived key material.
28 * L is the required size of the DKM.
29 * reps = [L / H_outputBits]
30 * H(x) is the auxiliary function that can be either a hash, HMAC or KMAC.
31 * H_outputBits is the length of the output of the auxiliary function H(x).
33 * Currently there is not a comprehensive list of test vectors for this
34 * algorithm, especially for H(x) = HMAC and H(x) = KMAC.
35 * Test vectors for H(x) = Hash are indirectly used by CAVS KAS tests.
40 #include <openssl/hmac.h>
41 #include <openssl/evp.h>
42 #include <openssl/kdf.h>
43 #include <openssl/core_names.h>
44 #include <openssl/params.h>
45 #include "internal/cryptlib.h"
46 #include "internal/numbers.h"
47 #include "internal/evp_int.h"
48 #include "internal/provider_ctx.h"
49 #include "internal/providercommonerr.h"
50 #include "internal/provider_algs.h"
51 #include "internal/provider_util.h"
55 EVP_MAC_CTX
*macctx
; /* H(x) = HMAC_hash OR H(x) = KMAC */
56 PROV_DIGEST digest
; /* H(x) = hash(x) */
57 unsigned char *secret
;
63 size_t out_len
; /* optional KMAC parameter */
66 #define SSKDF_MAX_INLEN (1<<30)
67 #define SSKDF_KMAC128_DEFAULT_SALT_SIZE (168 - 4)
68 #define SSKDF_KMAC256_DEFAULT_SALT_SIZE (136 - 4)
70 /* KMAC uses a Customisation string of 'KDF' */
71 static const unsigned char kmac_custom_str
[] = { 0x4B, 0x44, 0x46 };
73 static OSSL_OP_kdf_newctx_fn sskdf_new
;
74 static OSSL_OP_kdf_freectx_fn sskdf_free
;
75 static OSSL_OP_kdf_reset_fn sskdf_reset
;
76 static OSSL_OP_kdf_derive_fn sskdf_derive
;
77 static OSSL_OP_kdf_derive_fn x963kdf_derive
;
78 static OSSL_OP_kdf_settable_ctx_params_fn sskdf_settable_ctx_params
;
79 static OSSL_OP_kdf_set_ctx_params_fn sskdf_set_ctx_params
;
80 static OSSL_OP_kdf_gettable_ctx_params_fn sskdf_gettable_ctx_params
;
81 static OSSL_OP_kdf_get_ctx_params_fn sskdf_get_ctx_params
;
84 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
85 * Section 4. One-Step Key Derivation using H(x) = hash(x)
86 * Note: X9.63 also uses this code with the only difference being that the
87 * counter is appended to the secret 'z'.
89 * result[i] = Hash(counter || z || info) for One Step OR
90 * result[i] = Hash(z || counter || info) for X9.63.
92 static int SSKDF_hash_kdm(const EVP_MD
*kdf_md
,
93 const unsigned char *z
, size_t z_len
,
94 const unsigned char *info
, size_t info_len
,
95 unsigned int append_ctr
,
96 unsigned char *derived_key
, size_t derived_key_len
)
99 size_t counter
, out_len
, len
= derived_key_len
;
101 unsigned char mac
[EVP_MAX_MD_SIZE
];
102 unsigned char *out
= derived_key
;
103 EVP_MD_CTX
*ctx
= NULL
, *ctx_init
= NULL
;
105 if (z_len
> SSKDF_MAX_INLEN
|| info_len
> SSKDF_MAX_INLEN
106 || derived_key_len
> SSKDF_MAX_INLEN
107 || derived_key_len
== 0)
110 hlen
= EVP_MD_size(kdf_md
);
113 out_len
= (size_t)hlen
;
115 ctx
= EVP_MD_CTX_create();
116 ctx_init
= EVP_MD_CTX_create();
117 if (ctx
== NULL
|| ctx_init
== NULL
)
120 if (!EVP_DigestInit(ctx_init
, kdf_md
))
123 for (counter
= 1;; counter
++) {
124 c
[0] = (unsigned char)((counter
>> 24) & 0xff);
125 c
[1] = (unsigned char)((counter
>> 16) & 0xff);
126 c
[2] = (unsigned char)((counter
>> 8) & 0xff);
127 c
[3] = (unsigned char)(counter
& 0xff);
129 if (!(EVP_MD_CTX_copy_ex(ctx
, ctx_init
)
130 && (append_ctr
|| EVP_DigestUpdate(ctx
, c
, sizeof(c
)))
131 && EVP_DigestUpdate(ctx
, z
, z_len
)
132 && (!append_ctr
|| EVP_DigestUpdate(ctx
, c
, sizeof(c
)))
133 && EVP_DigestUpdate(ctx
, info
, info_len
)))
135 if (len
>= out_len
) {
136 if (!EVP_DigestFinal_ex(ctx
, out
, NULL
))
143 if (!EVP_DigestFinal_ex(ctx
, mac
, NULL
))
145 memcpy(out
, mac
, len
);
151 EVP_MD_CTX_destroy(ctx
);
152 EVP_MD_CTX_destroy(ctx_init
);
153 OPENSSL_cleanse(mac
, sizeof(mac
));
157 static int kmac_init(EVP_MAC_CTX
*ctx
, const unsigned char *custom
,
158 size_t custom_len
, size_t kmac_out_len
,
159 size_t derived_key_len
, unsigned char **out
)
161 OSSL_PARAM params
[2];
163 /* Only KMAC has custom data - so return if not KMAC */
167 params
[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM
,
168 (void *)custom
, custom_len
);
169 params
[1] = OSSL_PARAM_construct_end();
171 if (!EVP_MAC_CTX_set_params(ctx
, params
))
174 /* By default only do one iteration if kmac_out_len is not specified */
175 if (kmac_out_len
== 0)
176 kmac_out_len
= derived_key_len
;
177 /* otherwise check the size is valid */
178 else if (!(kmac_out_len
== derived_key_len
179 || kmac_out_len
== 20
180 || kmac_out_len
== 28
181 || kmac_out_len
== 32
182 || kmac_out_len
== 48
183 || kmac_out_len
== 64))
186 params
[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE
,
189 if (EVP_MAC_CTX_set_params(ctx
, params
) <= 0)
193 * For kmac the output buffer can be larger than EVP_MAX_MD_SIZE: so
194 * alloc a buffer for this case.
196 if (kmac_out_len
> EVP_MAX_MD_SIZE
) {
197 *out
= OPENSSL_zalloc(kmac_out_len
);
205 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
206 * Section 4. One-Step Key Derivation using MAC: i.e either
207 * H(x) = HMAC-hash(salt, x) OR
208 * H(x) = KMAC#(salt, x, outbits, CustomString='KDF')
210 static int SSKDF_mac_kdm(EVP_MAC_CTX
*ctx_init
,
211 const unsigned char *kmac_custom
,
212 size_t kmac_custom_len
, size_t kmac_out_len
,
213 const unsigned char *salt
, size_t salt_len
,
214 const unsigned char *z
, size_t z_len
,
215 const unsigned char *info
, size_t info_len
,
216 unsigned char *derived_key
, size_t derived_key_len
)
219 size_t counter
, out_len
, len
;
221 unsigned char mac_buf
[EVP_MAX_MD_SIZE
];
222 unsigned char *out
= derived_key
;
223 EVP_MAC_CTX
*ctx
= NULL
;
224 unsigned char *mac
= mac_buf
, *kmac_buffer
= NULL
;
225 OSSL_PARAM params
[2], *p
= params
;
227 if (z_len
> SSKDF_MAX_INLEN
|| info_len
> SSKDF_MAX_INLEN
228 || derived_key_len
> SSKDF_MAX_INLEN
229 || derived_key_len
== 0)
232 *p
++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY
,
233 (void *)salt
, salt_len
);
234 *p
= OSSL_PARAM_construct_end();
236 if (!EVP_MAC_CTX_set_params(ctx_init
, params
))
239 if (!kmac_init(ctx_init
, kmac_custom
, kmac_custom_len
, kmac_out_len
,
240 derived_key_len
, &kmac_buffer
))
242 if (kmac_buffer
!= NULL
)
245 if (!EVP_MAC_init(ctx_init
))
248 out_len
= EVP_MAC_size(ctx_init
); /* output size */
251 len
= derived_key_len
;
253 for (counter
= 1;; counter
++) {
254 c
[0] = (unsigned char)((counter
>> 24) & 0xff);
255 c
[1] = (unsigned char)((counter
>> 16) & 0xff);
256 c
[2] = (unsigned char)((counter
>> 8) & 0xff);
257 c
[3] = (unsigned char)(counter
& 0xff);
259 ctx
= EVP_MAC_CTX_dup(ctx_init
);
261 && EVP_MAC_update(ctx
, c
, sizeof(c
))
262 && EVP_MAC_update(ctx
, z
, z_len
)
263 && EVP_MAC_update(ctx
, info
, info_len
)))
265 if (len
>= out_len
) {
266 if (!EVP_MAC_final(ctx
, out
, NULL
, len
))
273 if (!EVP_MAC_final(ctx
, mac
, NULL
, len
))
275 memcpy(out
, mac
, len
);
278 EVP_MAC_CTX_free(ctx
);
283 if (kmac_buffer
!= NULL
)
284 OPENSSL_clear_free(kmac_buffer
, kmac_out_len
);
286 OPENSSL_cleanse(mac_buf
, sizeof(mac_buf
));
288 EVP_MAC_CTX_free(ctx
);
292 static void *sskdf_new(void *provctx
)
296 if ((ctx
= OPENSSL_zalloc(sizeof(*ctx
))) == NULL
)
297 ERR_raise(ERR_LIB_PROV
, ERR_R_MALLOC_FAILURE
);
298 ctx
->provctx
= provctx
;
302 static void sskdf_reset(void *vctx
)
304 KDF_SSKDF
*ctx
= (KDF_SSKDF
*)vctx
;
306 EVP_MAC_CTX_free(ctx
->macctx
);
307 ossl_prov_digest_reset(&ctx
->digest
);
308 OPENSSL_clear_free(ctx
->secret
, ctx
->secret_len
);
309 OPENSSL_clear_free(ctx
->info
, ctx
->info_len
);
310 OPENSSL_clear_free(ctx
->salt
, ctx
->salt_len
);
311 memset(ctx
, 0, sizeof(*ctx
));
314 static void sskdf_free(void *vctx
)
316 KDF_SSKDF
*ctx
= (KDF_SSKDF
*)vctx
;
322 static int sskdf_set_buffer(unsigned char **out
, size_t *out_len
,
325 if (p
->data
== NULL
|| p
->data_size
== 0)
329 return OSSL_PARAM_get_octet_string(p
, (void **)out
, 0, out_len
);
332 static size_t sskdf_size(KDF_SSKDF
*ctx
)
335 const EVP_MD
*md
= ossl_prov_digest_md(&ctx
->digest
);
338 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_MESSAGE_DIGEST
);
341 len
= EVP_MD_size(md
);
342 return (len
<= 0) ? 0 : (size_t)len
;
345 static int sskdf_derive(void *vctx
, unsigned char *key
, size_t keylen
)
347 KDF_SSKDF
*ctx
= (KDF_SSKDF
*)vctx
;
348 const EVP_MD
*md
= ossl_prov_digest_md(&ctx
->digest
);
350 if (ctx
->secret
== NULL
) {
351 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_SECRET
);
355 if (ctx
->macctx
!= NULL
) {
356 /* H(x) = KMAC or H(x) = HMAC */
358 const unsigned char *custom
= NULL
;
359 size_t custom_len
= 0;
360 int default_salt_len
;
361 EVP_MAC
*mac
= EVP_MAC_CTX_mac(ctx
->macctx
);
364 * TODO(3.0) investigate the necessity to have all these controls.
365 * Why does KMAC require a salt length that's shorter than the MD
368 if (EVP_MAC_is_a(mac
, OSSL_MAC_NAME_HMAC
)) {
369 /* H(x) = HMAC(x, salt, hash) */
371 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_MESSAGE_DIGEST
);
374 default_salt_len
= EVP_MD_size(md
);
375 if (default_salt_len
<= 0)
377 } else if (EVP_MAC_is_a(mac
, OSSL_MAC_NAME_KMAC128
)
378 || EVP_MAC_is_a(mac
, OSSL_MAC_NAME_KMAC256
)) {
379 /* H(x) = KMACzzz(x, salt, custom) */
380 custom
= kmac_custom_str
;
381 custom_len
= sizeof(kmac_custom_str
);
382 if (EVP_MAC_is_a(mac
, OSSL_MAC_NAME_KMAC128
))
383 default_salt_len
= SSKDF_KMAC128_DEFAULT_SALT_SIZE
;
385 default_salt_len
= SSKDF_KMAC256_DEFAULT_SALT_SIZE
;
387 ERR_raise(ERR_LIB_PROV
, PROV_R_UNSUPPORTED_MAC_TYPE
);
390 /* If no salt is set then use a default_salt of zeros */
391 if (ctx
->salt
== NULL
|| ctx
->salt_len
<= 0) {
392 ctx
->salt
= OPENSSL_zalloc(default_salt_len
);
393 if (ctx
->salt
== NULL
) {
394 ERR_raise(ERR_LIB_PROV
, ERR_R_MALLOC_FAILURE
);
397 ctx
->salt_len
= default_salt_len
;
399 ret
= SSKDF_mac_kdm(ctx
->macctx
,
400 custom
, custom_len
, ctx
->out_len
,
401 ctx
->salt
, ctx
->salt_len
,
402 ctx
->secret
, ctx
->secret_len
,
403 ctx
->info
, ctx
->info_len
, key
, keylen
);
408 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_MESSAGE_DIGEST
);
411 return SSKDF_hash_kdm(md
, ctx
->secret
, ctx
->secret_len
,
412 ctx
->info
, ctx
->info_len
, 0, key
, keylen
);
416 static int x963kdf_derive(void *vctx
, unsigned char *key
, size_t keylen
)
418 KDF_SSKDF
*ctx
= (KDF_SSKDF
*)vctx
;
419 const EVP_MD
*md
= ossl_prov_digest_md(&ctx
->digest
);
421 if (ctx
->secret
== NULL
) {
422 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_SECRET
);
426 if (ctx
->macctx
!= NULL
) {
427 ERR_raise(ERR_LIB_PROV
, PROV_R_NOT_SUPPORTED
);
433 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_MESSAGE_DIGEST
);
437 return SSKDF_hash_kdm(md
, ctx
->secret
, ctx
->secret_len
,
438 ctx
->info
, ctx
->info_len
, 1, key
, keylen
);
441 static int sskdf_set_ctx_params(void *vctx
, const OSSL_PARAM params
[])
444 KDF_SSKDF
*ctx
= vctx
;
445 OPENSSL_CTX
*libctx
= PROV_LIBRARY_CONTEXT_OF(ctx
->provctx
);
448 if (!ossl_prov_digest_load_from_params(&ctx
->digest
, params
, libctx
))
451 if (!ossl_prov_macctx_load_from_params(&ctx
->macctx
, params
,
452 NULL
, NULL
, NULL
, libctx
))
455 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_SECRET
)) != NULL
456 || (p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KEY
)) != NULL
)
457 if (!sskdf_set_buffer(&ctx
->secret
, &ctx
->secret_len
, p
))
460 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_INFO
)) != NULL
)
461 if (!sskdf_set_buffer(&ctx
->info
, &ctx
->info_len
, p
))
464 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_SALT
)) != NULL
)
465 if (!sskdf_set_buffer(&ctx
->salt
, &ctx
->salt_len
, p
))
468 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_MAC_SIZE
))
470 if (!OSSL_PARAM_get_size_t(p
, &sz
) || sz
== 0)
477 static const OSSL_PARAM
*sskdf_settable_ctx_params(void)
479 static const OSSL_PARAM known_settable_ctx_params
[] = {
480 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET
, NULL
, 0),
481 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY
, NULL
, 0),
482 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO
, NULL
, 0),
483 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES
, NULL
, 0),
484 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST
, NULL
, 0),
485 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC
, NULL
, 0),
486 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT
, NULL
, 0),
487 OSSL_PARAM_size_t(OSSL_KDF_PARAM_MAC_SIZE
, NULL
),
490 return known_settable_ctx_params
;
493 static int sskdf_get_ctx_params(void *vctx
, OSSL_PARAM params
[])
495 KDF_SSKDF
*ctx
= (KDF_SSKDF
*)vctx
;
498 if ((p
= OSSL_PARAM_locate(params
, OSSL_KDF_PARAM_SIZE
)) != NULL
)
499 return OSSL_PARAM_set_size_t(p
, sskdf_size(ctx
));
503 static const OSSL_PARAM
*sskdf_gettable_ctx_params(void)
505 static const OSSL_PARAM known_gettable_ctx_params
[] = {
506 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE
, NULL
),
509 return known_gettable_ctx_params
;
512 const OSSL_DISPATCH kdf_sskdf_functions
[] = {
513 { OSSL_FUNC_KDF_NEWCTX
, (void(*)(void))sskdf_new
},
514 { OSSL_FUNC_KDF_FREECTX
, (void(*)(void))sskdf_free
},
515 { OSSL_FUNC_KDF_RESET
, (void(*)(void))sskdf_reset
},
516 { OSSL_FUNC_KDF_DERIVE
, (void(*)(void))sskdf_derive
},
517 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS
,
518 (void(*)(void))sskdf_settable_ctx_params
},
519 { OSSL_FUNC_KDF_SET_CTX_PARAMS
, (void(*)(void))sskdf_set_ctx_params
},
520 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS
,
521 (void(*)(void))sskdf_gettable_ctx_params
},
522 { OSSL_FUNC_KDF_GET_CTX_PARAMS
, (void(*)(void))sskdf_get_ctx_params
},
526 const OSSL_DISPATCH kdf_x963_kdf_functions
[] = {
527 { OSSL_FUNC_KDF_NEWCTX
, (void(*)(void))sskdf_new
},
528 { OSSL_FUNC_KDF_FREECTX
, (void(*)(void))sskdf_free
},
529 { OSSL_FUNC_KDF_RESET
, (void(*)(void))sskdf_reset
},
530 { OSSL_FUNC_KDF_DERIVE
, (void(*)(void))x963kdf_derive
},
531 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS
,
532 (void(*)(void))sskdf_settable_ctx_params
},
533 { OSSL_FUNC_KDF_SET_CTX_PARAMS
, (void(*)(void))sskdf_set_ctx_params
},
534 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS
,
535 (void(*)(void))sskdf_gettable_ctx_params
},
536 { OSSL_FUNC_KDF_GET_CTX_PARAMS
, (void(*)(void))sskdf_get_ctx_params
},