2 * Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 * See SP800-185 "Appendix A - KMAC, .... in Terms of Keccak[c]"
14 * K = Key (len(K) < 2^2040 bits)
16 * L = Output length (0 <= L < 2^2040 bits)
17 * S = Customization String Default="" (len(S) < 2^2040 bits)
21 * newX = bytepad(encode_string(K), 168) || X || right_encode(L).
22 * T = bytepad(encode_string("KMAC") || encode_string(S), 168).
23 * return KECCAK[256](T || newX || 00, L).
28 * newX = bytepad(encode_string(K), 136) || X || right_encode(L).
29 * T = bytepad(encode_string("KMAC") || encode_string(S), 136).
30 * return KECCAK[512](T || newX || 00, L).
33 * KMAC128XOF(K, X, L, S)
35 * newX = bytepad(encode_string(K), 168) || X || right_encode(0).
36 * T = bytepad(encode_string("KMAC") || encode_string(S), 168).
37 * return KECCAK[256](T || newX || 00, L).
40 * KMAC256XOF(K, X, L, S)
42 * newX = bytepad(encode_string(K), 136) || X || right_encode(0).
43 * T = bytepad(encode_string("KMAC") || encode_string(S), 136).
44 * return KECCAK[512](T || newX || 00, L).
51 #include <openssl/core_dispatch.h>
52 #include <openssl/core_names.h>
53 #include <openssl/params.h>
54 #include <openssl/evp.h>
55 #include <openssl/err.h>
57 #include "prov/providercommonerr.h"
58 #include "prov/implementations.h"
59 #include "prov/provider_ctx.h"
60 #include "prov/provider_util.h"
61 #include "prov/providercommon.h"
64 * Forward declaration of everything implemented here. This is not strictly
65 * necessary for the compiler, but provides an assurance that the signatures
66 * of the functions in the dispatch table are correct.
68 static OSSL_FUNC_mac_newctx_fn kmac128_new
;
69 static OSSL_FUNC_mac_newctx_fn kmac256_new
;
70 static OSSL_FUNC_mac_dupctx_fn kmac_dup
;
71 static OSSL_FUNC_mac_freectx_fn kmac_free
;
72 static OSSL_FUNC_mac_gettable_ctx_params_fn kmac_gettable_ctx_params
;
73 static OSSL_FUNC_mac_get_ctx_params_fn kmac_get_ctx_params
;
74 static OSSL_FUNC_mac_settable_ctx_params_fn kmac_settable_ctx_params
;
75 static OSSL_FUNC_mac_set_ctx_params_fn kmac_set_ctx_params
;
76 static OSSL_FUNC_mac_size_fn kmac_size
;
77 static OSSL_FUNC_mac_init_fn kmac_init
;
78 static OSSL_FUNC_mac_update_fn kmac_update
;
79 static OSSL_FUNC_mac_final_fn kmac_final
;
81 #define KMAC_MAX_BLOCKSIZE ((1600 - 128*2) / 8) /* 168 */
82 #define KMAC_MIN_BLOCKSIZE ((1600 - 256*2) / 8) /* 136 */
84 /* Length encoding will be a 1 byte size + length in bits (2 bytes max) */
85 #define KMAC_MAX_ENCODED_HEADER_LEN 3
88 * Custom string max size is chosen such that:
89 * len(encoded_string(custom) + len(kmac_encoded_string) <= KMAC_MIN_BLOCKSIZE
90 * i.e: (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_LEN) + 6 <= 136
92 #define KMAC_MAX_CUSTOM 127
94 /* Maximum size of encoded custom string */
95 #define KMAC_MAX_CUSTOM_ENCODED (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_HEADER_LEN)
97 /* Maximum key size in bytes = 2040 / 8 */
98 #define KMAC_MAX_KEY 255
101 * Maximum Encoded Key size will be padded to a multiple of the blocksize
102 * i.e KMAC_MAX_KEY + KMAC_MAX_ENCODED_LEN = 258
103 * Padded to a multiple of KMAC_MAX_BLOCKSIZE
105 #define KMAC_MAX_KEY_ENCODED (KMAC_MAX_BLOCKSIZE * 2)
107 /* Fixed value of encode_string("KMAC") */
108 static const unsigned char kmac_string
[] = {
109 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43
113 #define KMAC_FLAG_XOF_MODE 1
115 struct kmac_data_st
{
122 /* If xof_mode = 1 then we use right_encode(0) */
124 /* key and custom are stored in encoded form */
125 unsigned char key
[KMAC_MAX_KEY_ENCODED
];
126 unsigned char custom
[KMAC_MAX_CUSTOM_ENCODED
];
129 static int encode_string(unsigned char *out
, int *out_len
,
130 const unsigned char *in
, int in_len
);
131 static int right_encode(unsigned char *out
, int *out_len
, size_t bits
);
132 static int bytepad(unsigned char *out
, int *out_len
,
133 const unsigned char *in1
, int in1_len
,
134 const unsigned char *in2
, int in2_len
,
136 static int kmac_bytepad_encode_key(unsigned char *out
, int *out_len
,
137 const unsigned char *in
, int in_len
,
140 static void kmac_free(void *vmacctx
)
142 struct kmac_data_st
*kctx
= vmacctx
;
145 EVP_MD_CTX_free(kctx
->ctx
);
146 ossl_prov_digest_reset(&kctx
->digest
);
147 OPENSSL_cleanse(kctx
->key
, kctx
->key_len
);
148 OPENSSL_cleanse(kctx
->custom
, kctx
->custom_len
);
154 * We have KMAC implemented as a hash, which we can use instead of
155 * reimplementing the EVP functionality with direct use of
156 * keccak_mac_init() and friends.
158 static struct kmac_data_st
*kmac_new(void *provctx
)
160 struct kmac_data_st
*kctx
;
162 if (!ossl_prov_is_running())
165 if ((kctx
= OPENSSL_zalloc(sizeof(*kctx
))) == NULL
166 || (kctx
->ctx
= EVP_MD_CTX_new()) == NULL
) {
170 kctx
->provctx
= provctx
;
174 static void *kmac_fetch_new(void *provctx
, const OSSL_PARAM
*params
)
176 struct kmac_data_st
*kctx
= kmac_new(provctx
);
180 if (!ossl_prov_digest_load_from_params(&kctx
->digest
, params
,
181 PROV_LIBRARY_CONTEXT_OF(provctx
))) {
186 kctx
->out_len
= EVP_MD_size(ossl_prov_digest_md(&kctx
->digest
));
190 static void *kmac128_new(void *provctx
)
192 static const OSSL_PARAM kmac128_params
[] = {
193 OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC128
,
194 sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC128
)),
197 return kmac_fetch_new(provctx
, kmac128_params
);
200 static void *kmac256_new(void *provctx
)
202 static const OSSL_PARAM kmac256_params
[] = {
203 OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC256
,
204 sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC256
)),
207 return kmac_fetch_new(provctx
, kmac256_params
);
210 static void *kmac_dup(void *vsrc
)
212 struct kmac_data_st
*src
= vsrc
;
213 struct kmac_data_st
*dst
;
215 if (!ossl_prov_is_running())
218 dst
= kmac_new(src
->provctx
);
222 if (!EVP_MD_CTX_copy(dst
->ctx
, src
->ctx
)
223 || !ossl_prov_digest_copy(&dst
->digest
, &src
->digest
)) {
228 dst
->out_len
= src
->out_len
;
229 dst
->key_len
= src
->key_len
;
230 dst
->custom_len
= src
->custom_len
;
231 dst
->xof_mode
= src
->xof_mode
;
232 memcpy(dst
->key
, src
->key
, src
->key_len
);
233 memcpy(dst
->custom
, src
->custom
, dst
->custom_len
);
239 * The init() assumes that any ctrl methods are set beforehand for
240 * md, key and custom. Setting the fields afterwards will have no
241 * effect on the output mac.
243 static int kmac_init(void *vmacctx
)
245 struct kmac_data_st
*kctx
= vmacctx
;
246 EVP_MD_CTX
*ctx
= kctx
->ctx
;
247 unsigned char out
[KMAC_MAX_BLOCKSIZE
];
248 int out_len
, block_len
;
250 if (!ossl_prov_is_running())
253 /* Check key has been set */
254 if (kctx
->key_len
== 0) {
255 EVPerr(EVP_F_KMAC_INIT
, EVP_R_NO_KEY_SET
);
258 if (!EVP_DigestInit_ex(kctx
->ctx
, ossl_prov_digest_md(&kctx
->digest
),
262 block_len
= EVP_MD_block_size(ossl_prov_digest_md(&kctx
->digest
));
266 /* Set default custom string if it is not already set */
267 if (kctx
->custom_len
== 0) {
268 const OSSL_PARAM params
[] = {
269 OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM
, "", 0),
272 (void)kmac_set_ctx_params(kctx
, params
);
275 return bytepad(out
, &out_len
, kmac_string
, sizeof(kmac_string
),
276 kctx
->custom
, kctx
->custom_len
, block_len
)
277 && EVP_DigestUpdate(ctx
, out
, out_len
)
278 && EVP_DigestUpdate(ctx
, kctx
->key
, kctx
->key_len
);
281 static size_t kmac_size(void *vmacctx
)
283 struct kmac_data_st
*kctx
= vmacctx
;
285 return kctx
->out_len
;
288 static int kmac_update(void *vmacctx
, const unsigned char *data
,
291 struct kmac_data_st
*kctx
= vmacctx
;
293 return EVP_DigestUpdate(kctx
->ctx
, data
, datalen
);
296 static int kmac_final(void *vmacctx
, unsigned char *out
, size_t *outl
,
299 struct kmac_data_st
*kctx
= vmacctx
;
300 EVP_MD_CTX
*ctx
= kctx
->ctx
;
302 unsigned char encoded_outlen
[KMAC_MAX_ENCODED_HEADER_LEN
];
305 if (!ossl_prov_is_running())
308 /* KMAC XOF mode sets the encoded length to 0 */
309 lbits
= (kctx
->xof_mode
? 0 : (kctx
->out_len
* 8));
311 ok
= right_encode(encoded_outlen
, &len
, lbits
)
312 && EVP_DigestUpdate(ctx
, encoded_outlen
, len
)
313 && EVP_DigestFinalXOF(ctx
, out
, kctx
->out_len
);
314 *outl
= kctx
->out_len
;
318 static const OSSL_PARAM known_gettable_ctx_params
[] = {
319 OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE
, NULL
),
322 static const OSSL_PARAM
*kmac_gettable_ctx_params(ossl_unused
void *provctx
)
324 return known_gettable_ctx_params
;
327 static int kmac_get_ctx_params(void *vmacctx
, OSSL_PARAM params
[])
331 if ((p
= OSSL_PARAM_locate(params
, OSSL_MAC_PARAM_SIZE
)) != NULL
)
332 return OSSL_PARAM_set_size_t(p
, kmac_size(vmacctx
));
337 static const OSSL_PARAM known_settable_ctx_params
[] = {
338 OSSL_PARAM_int(OSSL_MAC_PARAM_XOF
, NULL
),
339 OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE
, NULL
),
340 OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY
, NULL
, 0),
341 OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM
, NULL
, 0),
344 static const OSSL_PARAM
*kmac_settable_ctx_params(ossl_unused
void *provctx
)
346 return known_settable_ctx_params
;
350 * The following params can be set any time before final():
351 * - "outlen" or "size": The requested output length.
352 * - "xof": If set, this indicates that right_encoded(0)
353 * is part of the digested data, otherwise it
354 * uses right_encoded(requested output length).
356 * All other params should be set before init().
358 static int kmac_set_ctx_params(void *vmacctx
, const OSSL_PARAM
*params
)
360 struct kmac_data_st
*kctx
= vmacctx
;
362 const EVP_MD
*digest
= ossl_prov_digest_md(&kctx
->digest
);
364 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_MAC_PARAM_XOF
)) != NULL
365 && !OSSL_PARAM_get_int(p
, &kctx
->xof_mode
))
367 if (((p
= OSSL_PARAM_locate_const(params
, OSSL_MAC_PARAM_SIZE
)) != NULL
)
368 && !OSSL_PARAM_get_size_t(p
, &kctx
->out_len
))
370 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_MAC_PARAM_KEY
)) != NULL
) {
371 if (p
->data_size
< 4 || p
->data_size
> KMAC_MAX_KEY
) {
372 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_KEY_LENGTH
);
375 if (!kmac_bytepad_encode_key(kctx
->key
, &kctx
->key_len
,
376 p
->data
, p
->data_size
,
377 EVP_MD_block_size(digest
)))
380 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_MAC_PARAM_CUSTOM
))
382 if (p
->data_size
> KMAC_MAX_CUSTOM
) {
383 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_CUSTOM_LENGTH
);
386 if (!encode_string(kctx
->custom
, &kctx
->custom_len
,
387 p
->data
, p
->data_size
))
394 * Encoding/Padding Methods.
397 /* Returns the number of bytes required to store 'bits' into a byte array */
398 static unsigned int get_encode_size(size_t bits
)
400 unsigned int cnt
= 0, sz
= sizeof(size_t);
402 while (bits
&& (cnt
< sz
)) {
406 /* If bits is zero 1 byte is required */
413 * Convert an integer into bytes . The number of bytes is appended
414 * to the end of the buffer. Returns an array of bytes 'out' of size
417 * e.g if bits = 32, out[2] = { 0x20, 0x01 }
420 static int right_encode(unsigned char *out
, int *out_len
, size_t bits
)
422 unsigned int len
= get_encode_size(bits
);
425 /* The length is constrained to a single byte: 2040/8 = 255 */
429 /* MSB's are at the start of the bytes array */
430 for (i
= len
- 1; i
>= 0; --i
) {
431 out
[i
] = (unsigned char)(bits
& 0xFF);
434 /* Tack the length onto the end */
435 out
[len
] = (unsigned char)len
;
437 /* The Returned length includes the tacked on byte */
443 * Encodes a string with a left encoded length added. Note that the
444 * in_len is converted to bits (*8).
446 * e.g- in="KMAC" gives out[6] = { 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43 }
449 static int encode_string(unsigned char *out
, int *out_len
,
450 const unsigned char *in
, int in_len
)
458 len
= get_encode_size(bits
);
463 for (i
= len
; i
> 0; --i
) {
464 out
[i
] = (bits
& 0xFF);
467 memcpy(out
+ len
+ 1, in
, in_len
);
468 *out_len
= (1 + len
+ in_len
);
474 * Returns a zero padded encoding of the inputs in1 and an optional
475 * in2 (can be NULL). The padded output must be a multiple of the blocksize 'w'.
476 * The value of w is in bytes (< 256).
478 * The returned output is:
479 * zero_padded(multiple of w, (left_encode(w) || in1 [|| in2])
481 static int bytepad(unsigned char *out
, int *out_len
,
482 const unsigned char *in1
, int in1_len
,
483 const unsigned char *in2
, int in2_len
, int w
)
486 unsigned char *p
= out
;
493 memcpy(p
, in1
, in1_len
);
496 if (in2
!= NULL
&& in2_len
> 0) {
497 memcpy(p
, in2
, in2_len
);
500 /* Figure out the pad size (divisible by w) */
505 /* zero pad the end of the buffer */
506 memset(p
, 0, sz
- len
);
512 * Returns out = bytepad(encode_string(in), w)
514 static int kmac_bytepad_encode_key(unsigned char *out
, int *out_len
,
515 const unsigned char *in
, int in_len
,
518 unsigned char tmp
[KMAC_MAX_KEY
+ KMAC_MAX_ENCODED_HEADER_LEN
];
521 if (!encode_string(tmp
, &tmp_len
, in
, in_len
))
524 return bytepad(out
, out_len
, tmp
, tmp_len
, NULL
, 0, w
);
527 const OSSL_DISPATCH ossl_kmac128_functions
[] = {
528 { OSSL_FUNC_MAC_NEWCTX
, (void (*)(void))kmac128_new
},
529 { OSSL_FUNC_MAC_DUPCTX
, (void (*)(void))kmac_dup
},
530 { OSSL_FUNC_MAC_FREECTX
, (void (*)(void))kmac_free
},
531 { OSSL_FUNC_MAC_INIT
, (void (*)(void))kmac_init
},
532 { OSSL_FUNC_MAC_UPDATE
, (void (*)(void))kmac_update
},
533 { OSSL_FUNC_MAC_FINAL
, (void (*)(void))kmac_final
},
534 { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS
,
535 (void (*)(void))kmac_gettable_ctx_params
},
536 { OSSL_FUNC_MAC_GET_CTX_PARAMS
, (void (*)(void))kmac_get_ctx_params
},
537 { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS
,
538 (void (*)(void))kmac_settable_ctx_params
},
539 { OSSL_FUNC_MAC_SET_CTX_PARAMS
, (void (*)(void))kmac_set_ctx_params
},
543 const OSSL_DISPATCH ossl_kmac256_functions
[] = {
544 { OSSL_FUNC_MAC_NEWCTX
, (void (*)(void))kmac256_new
},
545 { OSSL_FUNC_MAC_DUPCTX
, (void (*)(void))kmac_dup
},
546 { OSSL_FUNC_MAC_FREECTX
, (void (*)(void))kmac_free
},
547 { OSSL_FUNC_MAC_INIT
, (void (*)(void))kmac_init
},
548 { OSSL_FUNC_MAC_UPDATE
, (void (*)(void))kmac_update
},
549 { OSSL_FUNC_MAC_FINAL
, (void (*)(void))kmac_final
},
550 { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS
,
551 (void (*)(void))kmac_gettable_ctx_params
},
552 { OSSL_FUNC_MAC_GET_CTX_PARAMS
, (void (*)(void))kmac_get_ctx_params
},
553 { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS
,
554 (void (*)(void))kmac_settable_ctx_params
},
555 { OSSL_FUNC_MAC_SET_CTX_PARAMS
, (void (*)(void))kmac_set_ctx_params
},