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Commit | Line | Data |
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d2e9e320 | 1 | /* |
e3405a4a | 2 | * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved. |
aacfb134 | 3 | * |
7bb803e8 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
d2e9e320 RS |
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 | |
aacfb134 AG |
8 | */ |
9 | ||
10 | #include <stdlib.h> | |
5a285add | 11 | #include <stdarg.h> |
aacfb134 AG |
12 | #include <string.h> |
13 | #include <openssl/hmac.h> | |
aacfb134 | 14 | #include <openssl/evp.h> |
5a285add | 15 | #include <openssl/kdf.h> |
e3405a4a | 16 | #include <openssl/core_names.h> |
aacfb134 | 17 | #include "internal/cryptlib.h" |
cee719c2 | 18 | #include "internal/numbers.h" |
aacfb134 | 19 | #include "internal/evp_int.h" |
e3405a4a P |
20 | #include "internal/provider_ctx.h" |
21 | #include "internal/providercommonerr.h" | |
22 | #include "internal/provider_algs.h" | |
23 | #include "e_os.h" | |
aacfb134 AG |
24 | |
25 | #define HKDF_MAXBUF 1024 | |
26 | ||
e3405a4a P |
27 | static OSSL_OP_kdf_newctx_fn kdf_hkdf_new; |
28 | static OSSL_OP_kdf_freectx_fn kdf_hkdf_free; | |
29 | static OSSL_OP_kdf_reset_fn kdf_hkdf_reset; | |
30 | static OSSL_OP_kdf_derive_fn kdf_hkdf_derive; | |
31 | static OSSL_OP_kdf_settable_ctx_params_fn kdf_hkdf_settable_ctx_params; | |
32 | static OSSL_OP_kdf_set_ctx_params_fn kdf_hkdf_set_ctx_params; | |
33 | static OSSL_OP_kdf_gettable_ctx_params_fn kdf_hkdf_gettable_ctx_params; | |
34 | static OSSL_OP_kdf_get_ctx_params_fn kdf_hkdf_get_ctx_params; | |
35 | ||
5a285add DM |
36 | static int HKDF(const EVP_MD *evp_md, |
37 | const unsigned char *salt, size_t salt_len, | |
38 | const unsigned char *key, size_t key_len, | |
39 | const unsigned char *info, size_t info_len, | |
40 | unsigned char *okm, size_t okm_len); | |
41 | static int HKDF_Extract(const EVP_MD *evp_md, | |
42 | const unsigned char *salt, size_t salt_len, | |
e7018588 | 43 | const unsigned char *ikm, size_t ikm_len, |
5a285add DM |
44 | unsigned char *prk, size_t prk_len); |
45 | static int HKDF_Expand(const EVP_MD *evp_md, | |
46 | const unsigned char *prk, size_t prk_len, | |
47 | const unsigned char *info, size_t info_len, | |
48 | unsigned char *okm, size_t okm_len); | |
49 | ||
e3405a4a P |
50 | typedef struct { |
51 | void *provctx; | |
d2139cf8 | 52 | int mode; |
e3405a4a | 53 | EVP_MD *md; |
aacfb134 AG |
54 | unsigned char *salt; |
55 | size_t salt_len; | |
56 | unsigned char *key; | |
57 | size_t key_len; | |
58 | unsigned char info[HKDF_MAXBUF]; | |
59 | size_t info_len; | |
e3405a4a | 60 | } KDF_HKDF; |
aacfb134 | 61 | |
e3405a4a | 62 | static void *kdf_hkdf_new(void *provctx) |
aacfb134 | 63 | { |
e3405a4a | 64 | KDF_HKDF *ctx; |
aacfb134 | 65 | |
e3405a4a P |
66 | if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) |
67 | ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); | |
68 | else | |
69 | ctx->provctx = provctx; | |
70 | return ctx; | |
5a285add | 71 | } |
aacfb134 | 72 | |
e3405a4a | 73 | static void kdf_hkdf_free(void *vctx) |
5a285add | 74 | { |
e3405a4a | 75 | KDF_HKDF *ctx = (KDF_HKDF *)vctx; |
aacfb134 | 76 | |
e3405a4a | 77 | kdf_hkdf_reset(ctx); |
e3405a4a | 78 | OPENSSL_free(ctx); |
aacfb134 AG |
79 | } |
80 | ||
e3405a4a | 81 | static void kdf_hkdf_reset(void *vctx) |
aacfb134 | 82 | { |
e3405a4a | 83 | KDF_HKDF *ctx = (KDF_HKDF *)vctx; |
aacfb134 | 84 | |
df2f8af4 | 85 | EVP_MD_meth_free(ctx->md); |
e3405a4a P |
86 | OPENSSL_free(ctx->salt); |
87 | OPENSSL_clear_free(ctx->key, ctx->key_len); | |
88 | OPENSSL_cleanse(ctx->info, ctx->info_len); | |
89 | memset(ctx, 0, sizeof(*ctx)); | |
aacfb134 AG |
90 | } |
91 | ||
e3405a4a | 92 | static size_t kdf_hkdf_size(KDF_HKDF *ctx) |
ca55d70b | 93 | { |
97cc9c9b SL |
94 | int sz; |
95 | ||
e3405a4a | 96 | if (ctx->mode != EVP_KDF_HKDF_MODE_EXTRACT_ONLY) |
5a285add | 97 | return SIZE_MAX; |
ca55d70b | 98 | |
e3405a4a P |
99 | if (ctx->md == NULL) { |
100 | ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST); | |
5a285add DM |
101 | return 0; |
102 | } | |
e3405a4a | 103 | sz = EVP_MD_size(ctx->md); |
97cc9c9b SL |
104 | if (sz < 0) |
105 | return 0; | |
106 | ||
107 | return sz; | |
ca55d70b MC |
108 | } |
109 | ||
e3405a4a | 110 | static int kdf_hkdf_derive(void *vctx, unsigned char *key, size_t keylen) |
aacfb134 | 111 | { |
e3405a4a P |
112 | KDF_HKDF *ctx = (KDF_HKDF *)vctx; |
113 | ||
114 | if (ctx->md == NULL) { | |
115 | ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST); | |
f55129c7 JB |
116 | return 0; |
117 | } | |
e3405a4a P |
118 | if (ctx->key == NULL) { |
119 | ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY); | |
aacfb134 | 120 | return 0; |
e65f6509 | 121 | } |
aacfb134 | 122 | |
e3405a4a | 123 | switch (ctx->mode) { |
5a285add | 124 | case EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND: |
e3405a4a P |
125 | return HKDF(ctx->md, ctx->salt, ctx->salt_len, ctx->key, |
126 | ctx->key_len, ctx->info, ctx->info_len, key, | |
5a285add | 127 | keylen); |
d2139cf8 | 128 | |
5a285add | 129 | case EVP_KDF_HKDF_MODE_EXTRACT_ONLY: |
e3405a4a P |
130 | return HKDF_Extract(ctx->md, ctx->salt, ctx->salt_len, ctx->key, |
131 | ctx->key_len, key, keylen); | |
d2139cf8 | 132 | |
5a285add | 133 | case EVP_KDF_HKDF_MODE_EXPAND_ONLY: |
e3405a4a P |
134 | return HKDF_Expand(ctx->md, ctx->key, ctx->key_len, ctx->info, |
135 | ctx->info_len, key, keylen); | |
d2139cf8 MC |
136 | |
137 | default: | |
aacfb134 AG |
138 | return 0; |
139 | } | |
aacfb134 AG |
140 | } |
141 | ||
e3405a4a P |
142 | static int kdf_hkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[]) |
143 | { | |
144 | const OSSL_PARAM *p; | |
145 | KDF_HKDF *ctx = vctx; | |
146 | EVP_MD *md; | |
147 | int n; | |
148 | const char *properties = NULL; | |
149 | ||
150 | /* Grab search properties, this should be before the digest lookup */ | |
151 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES)) | |
152 | != NULL) { | |
153 | if (p->data_type != OSSL_PARAM_UTF8_STRING) | |
154 | return 0; | |
155 | properties = p->data; | |
156 | } | |
157 | /* Handle aliasing of digest parameter names */ | |
158 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) { | |
159 | if (p->data_type != OSSL_PARAM_UTF8_STRING) | |
160 | return 0; | |
161 | md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data, | |
162 | properties); | |
163 | if (md == NULL) { | |
164 | ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST); | |
165 | return 0; | |
166 | } | |
167 | EVP_MD_meth_free(ctx->md); | |
168 | ctx->md = md; | |
169 | } | |
170 | ||
171 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE)) != NULL) { | |
172 | if (p->data_type == OSSL_PARAM_UTF8_STRING) { | |
173 | if (strcasecmp(p->data, "EXTRACT_AND_EXPAND") == 0) { | |
174 | ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND; | |
175 | } else if (strcasecmp(p->data, "EXTRACT_ONLY") == 0) { | |
176 | ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_ONLY; | |
177 | } else if (strcasecmp(p->data, "EXPAND_ONLY") == 0) { | |
178 | ctx->mode = EVP_KDF_HKDF_MODE_EXPAND_ONLY; | |
179 | } else { | |
180 | ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE); | |
181 | return 0; | |
182 | } | |
183 | } else if (OSSL_PARAM_get_int(p, &n)) { | |
184 | if (n != EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND | |
185 | && n != EVP_KDF_HKDF_MODE_EXTRACT_ONLY | |
186 | && n != EVP_KDF_HKDF_MODE_EXPAND_ONLY) { | |
187 | ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE); | |
188 | return 0; | |
189 | } | |
190 | ctx->mode = n; | |
191 | } else { | |
192 | ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE); | |
193 | return 0; | |
194 | } | |
195 | } | |
196 | ||
197 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) { | |
198 | OPENSSL_clear_free(ctx->key, ctx->key_len); | |
199 | ctx->key = NULL; | |
200 | if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->key, 0, | |
201 | &ctx->key_len)) | |
202 | return 0; | |
203 | } | |
204 | ||
205 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) { | |
206 | if (p->data_size != 0 && p->data != NULL) { | |
207 | OPENSSL_free(ctx->salt); | |
208 | ctx->salt = NULL; | |
209 | if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->salt, 0, | |
210 | &ctx->salt_len)) | |
211 | return 0; | |
212 | } | |
213 | } | |
214 | /* The info fields concatenate, so process them all */ | |
215 | if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO)) != NULL) { | |
216 | ctx->info_len = 0; | |
217 | for (; p != NULL; p = OSSL_PARAM_locate_const(p + 1, | |
218 | OSSL_KDF_PARAM_INFO)) { | |
219 | const void *q = ctx->info + ctx->info_len; | |
220 | size_t sz = 0; | |
221 | ||
222 | if (p->data_size != 0 | |
223 | && p->data != NULL | |
224 | && !OSSL_PARAM_get_octet_string(p, (void **)&q, | |
225 | HKDF_MAXBUF - ctx->info_len, | |
226 | &sz)) | |
227 | return 0; | |
228 | ctx->info_len += sz; | |
229 | } | |
230 | } | |
231 | return 1; | |
232 | } | |
233 | ||
234 | static const OSSL_PARAM *kdf_hkdf_settable_ctx_params(void) | |
235 | { | |
236 | static const OSSL_PARAM known_settable_ctx_params[] = { | |
237 | OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0), | |
238 | OSSL_PARAM_int(OSSL_KDF_PARAM_MODE, NULL), | |
239 | OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0), | |
240 | OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0), | |
241 | OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0), | |
242 | OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0), | |
243 | OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0), | |
244 | OSSL_PARAM_END | |
245 | }; | |
246 | return known_settable_ctx_params; | |
247 | } | |
248 | ||
249 | static int kdf_hkdf_get_ctx_params(void *vctx, OSSL_PARAM params[]) | |
250 | { | |
251 | KDF_HKDF *ctx = (KDF_HKDF *)vctx; | |
252 | OSSL_PARAM *p; | |
253 | ||
254 | if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) | |
255 | return OSSL_PARAM_set_size_t(p, kdf_hkdf_size(ctx)); | |
256 | return -2; | |
257 | } | |
258 | ||
259 | static const OSSL_PARAM *kdf_hkdf_gettable_ctx_params(void) | |
260 | { | |
261 | static const OSSL_PARAM known_gettable_ctx_params[] = { | |
262 | OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), | |
263 | OSSL_PARAM_END | |
264 | }; | |
265 | return known_gettable_ctx_params; | |
266 | } | |
267 | ||
268 | const OSSL_DISPATCH kdf_hkdf_functions[] = { | |
269 | { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new }, | |
270 | { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free }, | |
271 | { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset }, | |
272 | { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_hkdf_derive }, | |
273 | { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS, | |
274 | (void(*)(void))kdf_hkdf_settable_ctx_params }, | |
275 | { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_hkdf_set_ctx_params }, | |
276 | { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS, | |
277 | (void(*)(void))kdf_hkdf_gettable_ctx_params }, | |
278 | { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_hkdf_get_ctx_params }, | |
279 | { 0, NULL } | |
aacfb134 AG |
280 | }; |
281 | ||
e7018588 DM |
282 | /* |
283 | * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)" | |
284 | * Section 2 (https://tools.ietf.org/html/rfc5869#section-2) and | |
285 | * "Cryptographic Extraction and Key Derivation: The HKDF Scheme" | |
286 | * Section 4.2 (https://eprint.iacr.org/2010/264.pdf). | |
287 | * | |
288 | * From the paper: | |
289 | * The scheme HKDF is specified as: | |
290 | * HKDF(XTS, SKM, CTXinfo, L) = K(1) | K(2) | ... | K(t) | |
291 | * | |
292 | * where: | |
293 | * SKM is source key material | |
294 | * XTS is extractor salt (which may be null or constant) | |
295 | * CTXinfo is context information (may be null) | |
296 | * L is the number of key bits to be produced by KDF | |
297 | * k is the output length in bits of the hash function used with HMAC | |
298 | * t = ceil(L/k) | |
299 | * the value K(t) is truncated to its first d = L mod k bits. | |
300 | * | |
301 | * From RFC 5869: | |
302 | * 2.2. Step 1: Extract | |
303 | * HKDF-Extract(salt, IKM) -> PRK | |
304 | * 2.3. Step 2: Expand | |
305 | * HKDF-Expand(PRK, info, L) -> OKM | |
306 | */ | |
5a285add DM |
307 | static int HKDF(const EVP_MD *evp_md, |
308 | const unsigned char *salt, size_t salt_len, | |
e7018588 | 309 | const unsigned char *ikm, size_t ikm_len, |
5a285add DM |
310 | const unsigned char *info, size_t info_len, |
311 | unsigned char *okm, size_t okm_len) | |
aacfb134 AG |
312 | { |
313 | unsigned char prk[EVP_MAX_MD_SIZE]; | |
97cc9c9b SL |
314 | int ret, sz; |
315 | size_t prk_len; | |
316 | ||
317 | sz = EVP_MD_size(evp_md); | |
318 | if (sz < 0) | |
319 | return 0; | |
320 | prk_len = (size_t)sz; | |
aacfb134 | 321 | |
e7018588 DM |
322 | /* Step 1: HKDF-Extract(salt, IKM) -> PRK */ |
323 | if (!HKDF_Extract(evp_md, salt, salt_len, ikm, ikm_len, prk, prk_len)) | |
5a285add | 324 | return 0; |
aacfb134 | 325 | |
e7018588 | 326 | /* Step 2: HKDF-Expand(PRK, info, L) -> OKM */ |
d2139cf8 MC |
327 | ret = HKDF_Expand(evp_md, prk, prk_len, info, info_len, okm, okm_len); |
328 | OPENSSL_cleanse(prk, sizeof(prk)); | |
329 | ||
330 | return ret; | |
aacfb134 AG |
331 | } |
332 | ||
e7018588 DM |
333 | /* |
334 | * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)" | |
335 | * Section 2.2 (https://tools.ietf.org/html/rfc5869#section-2.2). | |
336 | * | |
337 | * 2.2. Step 1: Extract | |
338 | * | |
339 | * HKDF-Extract(salt, IKM) -> PRK | |
340 | * | |
341 | * Options: | |
342 | * Hash a hash function; HashLen denotes the length of the | |
343 | * hash function output in octets | |
344 | * | |
345 | * Inputs: | |
346 | * salt optional salt value (a non-secret random value); | |
347 | * if not provided, it is set to a string of HashLen zeros. | |
348 | * IKM input keying material | |
349 | * | |
350 | * Output: | |
351 | * PRK a pseudorandom key (of HashLen octets) | |
352 | * | |
353 | * The output PRK is calculated as follows: | |
354 | * | |
355 | * PRK = HMAC-Hash(salt, IKM) | |
356 | */ | |
5a285add DM |
357 | static int HKDF_Extract(const EVP_MD *evp_md, |
358 | const unsigned char *salt, size_t salt_len, | |
e7018588 | 359 | const unsigned char *ikm, size_t ikm_len, |
5a285add | 360 | unsigned char *prk, size_t prk_len) |
aacfb134 | 361 | { |
97cc9c9b SL |
362 | int sz = EVP_MD_size(evp_md); |
363 | ||
364 | if (sz < 0) | |
365 | return 0; | |
366 | if (prk_len != (size_t)sz) { | |
e3405a4a | 367 | ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_OUTPUT_BUFFER_SIZE); |
5a285add DM |
368 | return 0; |
369 | } | |
e7018588 DM |
370 | /* calc: PRK = HMAC-Hash(salt, IKM) */ |
371 | return HMAC(evp_md, salt, salt_len, ikm, ikm_len, prk, NULL) != NULL; | |
aacfb134 AG |
372 | } |
373 | ||
e7018588 DM |
374 | /* |
375 | * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)" | |
376 | * Section 2.3 (https://tools.ietf.org/html/rfc5869#section-2.3). | |
377 | * | |
378 | * 2.3. Step 2: Expand | |
379 | * | |
380 | * HKDF-Expand(PRK, info, L) -> OKM | |
381 | * | |
382 | * Options: | |
383 | * Hash a hash function; HashLen denotes the length of the | |
384 | * hash function output in octets | |
385 | * | |
386 | * Inputs: | |
387 | * PRK a pseudorandom key of at least HashLen octets | |
388 | * (usually, the output from the extract step) | |
389 | * info optional context and application specific information | |
390 | * (can be a zero-length string) | |
391 | * L length of output keying material in octets | |
392 | * (<= 255*HashLen) | |
393 | * | |
394 | * Output: | |
395 | * OKM output keying material (of L octets) | |
396 | * | |
397 | * The output OKM is calculated as follows: | |
398 | * | |
399 | * N = ceil(L/HashLen) | |
400 | * T = T(1) | T(2) | T(3) | ... | T(N) | |
401 | * OKM = first L octets of T | |
402 | * | |
403 | * where: | |
404 | * T(0) = empty string (zero length) | |
405 | * T(1) = HMAC-Hash(PRK, T(0) | info | 0x01) | |
406 | * T(2) = HMAC-Hash(PRK, T(1) | info | 0x02) | |
407 | * T(3) = HMAC-Hash(PRK, T(2) | info | 0x03) | |
408 | * ... | |
409 | * | |
410 | * (where the constant concatenated to the end of each T(n) is a | |
411 | * single octet.) | |
412 | */ | |
5a285add DM |
413 | static int HKDF_Expand(const EVP_MD *evp_md, |
414 | const unsigned char *prk, size_t prk_len, | |
415 | const unsigned char *info, size_t info_len, | |
416 | unsigned char *okm, size_t okm_len) | |
aacfb134 AG |
417 | { |
418 | HMAC_CTX *hmac; | |
97cc9c9b | 419 | int ret = 0, sz; |
aacfb134 | 420 | unsigned int i; |
aacfb134 | 421 | unsigned char prev[EVP_MAX_MD_SIZE]; |
97cc9c9b SL |
422 | size_t done_len = 0, dig_len, n; |
423 | ||
424 | sz = EVP_MD_size(evp_md); | |
425 | if (sz <= 0) | |
426 | return 0; | |
427 | dig_len = (size_t)sz; | |
5a285add | 428 | |
e7018588 DM |
429 | /* calc: N = ceil(L/HashLen) */ |
430 | n = okm_len / dig_len; | |
aacfb134 AG |
431 | if (okm_len % dig_len) |
432 | n++; | |
433 | ||
d2139cf8 | 434 | if (n > 255 || okm == NULL) |
5a285add | 435 | return 0; |
aacfb134 AG |
436 | |
437 | if ((hmac = HMAC_CTX_new()) == NULL) | |
5a285add | 438 | return 0; |
aacfb134 AG |
439 | |
440 | if (!HMAC_Init_ex(hmac, prk, prk_len, evp_md, NULL)) | |
441 | goto err; | |
442 | ||
443 | for (i = 1; i <= n; i++) { | |
444 | size_t copy_len; | |
445 | const unsigned char ctr = i; | |
446 | ||
e7018588 | 447 | /* calc: T(i) = HMAC-Hash(PRK, T(i - 1) | info | i) */ |
aacfb134 AG |
448 | if (i > 1) { |
449 | if (!HMAC_Init_ex(hmac, NULL, 0, NULL, NULL)) | |
450 | goto err; | |
451 | ||
452 | if (!HMAC_Update(hmac, prev, dig_len)) | |
453 | goto err; | |
454 | } | |
455 | ||
456 | if (!HMAC_Update(hmac, info, info_len)) | |
457 | goto err; | |
458 | ||
459 | if (!HMAC_Update(hmac, &ctr, 1)) | |
460 | goto err; | |
461 | ||
462 | if (!HMAC_Final(hmac, prev, NULL)) | |
463 | goto err; | |
464 | ||
465 | copy_len = (done_len + dig_len > okm_len) ? | |
466 | okm_len - done_len : | |
467 | dig_len; | |
468 | ||
469 | memcpy(okm + done_len, prev, copy_len); | |
470 | ||
471 | done_len += copy_len; | |
472 | } | |
5a285add | 473 | ret = 1; |
aacfb134 AG |
474 | |
475 | err: | |
64ed55ab | 476 | OPENSSL_cleanse(prev, sizeof(prev)); |
aacfb134 | 477 | HMAC_CTX_free(hmac); |
64ed55ab | 478 | return ret; |
aacfb134 | 479 | } |