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846e33c7 | 1 | /* |
33388b44 | 2 | * Copyright 2012-2020 The OpenSSL Project Authors. All Rights Reserved. |
a693ead6 | 3 | * |
2c18d164 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
846e33c7 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 | |
a693ead6 BL |
8 | */ |
9 | ||
85d843c8 | 10 | /* |
781aa7ab | 11 | * MD5 and SHA-1 low level APIs are deprecated for public use, but still ok for |
85d843c8 P |
12 | * internal use. |
13 | */ | |
14 | #include "internal/deprecated.h" | |
15 | ||
706457b7 DMSP |
16 | #include "internal/constant_time.h" |
17 | #include "ssl_local.h" | |
67dc995e | 18 | #include "internal/cryptlib.h" |
a693ead6 BL |
19 | |
20 | #include <openssl/md5.h> | |
21 | #include <openssl/sha.h> | |
22 | ||
0f113f3e MC |
23 | /* |
24 | * MAX_HASH_BIT_COUNT_BYTES is the maximum number of bytes in the hash's | |
25 | * length field. (SHA-384/512 have 128-bit length.) | |
26 | */ | |
a693ead6 BL |
27 | #define MAX_HASH_BIT_COUNT_BYTES 16 |
28 | ||
0f113f3e MC |
29 | /* |
30 | * MAX_HASH_BLOCK_SIZE is the maximum hash block size that we'll support. | |
a693ead6 | 31 | * Currently SHA-384/512 has a 128-byte block size and that's the largest |
0f113f3e MC |
32 | * supported by TLS.) |
33 | */ | |
a693ead6 BL |
34 | #define MAX_HASH_BLOCK_SIZE 128 |
35 | ||
0f113f3e | 36 | /* |
aa97970c | 37 | * u32toLE serializes an unsigned, 32-bit number (n) as four bytes at (p) in |
0f113f3e MC |
38 | * little-endian order. The value of p is advanced by four. |
39 | */ | |
32620fe9 | 40 | #define u32toLE(n, p) \ |
0f113f3e MC |
41 | (*((p)++)=(unsigned char)(n), \ |
42 | *((p)++)=(unsigned char)(n>>8), \ | |
43 | *((p)++)=(unsigned char)(n>>16), \ | |
44 | *((p)++)=(unsigned char)(n>>24)) | |
45 | ||
46 | /* | |
47 | * These functions serialize the state of a hash and thus perform the | |
48 | * standard "final" operation without adding the padding and length that such | |
49 | * a function typically does. | |
50 | */ | |
51 | static void tls1_md5_final_raw(void *ctx, unsigned char *md_out) | |
52 | { | |
53 | MD5_CTX *md5 = ctx; | |
54 | u32toLE(md5->A, md_out); | |
55 | u32toLE(md5->B, md_out); | |
56 | u32toLE(md5->C, md_out); | |
57 | u32toLE(md5->D, md_out); | |
58 | } | |
59 | ||
60 | static void tls1_sha1_final_raw(void *ctx, unsigned char *md_out) | |
61 | { | |
62 | SHA_CTX *sha1 = ctx; | |
63 | l2n(sha1->h0, md_out); | |
64 | l2n(sha1->h1, md_out); | |
65 | l2n(sha1->h2, md_out); | |
66 | l2n(sha1->h3, md_out); | |
67 | l2n(sha1->h4, md_out); | |
68 | } | |
69 | ||
0f113f3e MC |
70 | static void tls1_sha256_final_raw(void *ctx, unsigned char *md_out) |
71 | { | |
72 | SHA256_CTX *sha256 = ctx; | |
73 | unsigned i; | |
74 | ||
75 | for (i = 0; i < 8; i++) { | |
76 | l2n(sha256->h[i], md_out); | |
77 | } | |
78 | } | |
79 | ||
0f113f3e MC |
80 | static void tls1_sha512_final_raw(void *ctx, unsigned char *md_out) |
81 | { | |
82 | SHA512_CTX *sha512 = ctx; | |
83 | unsigned i; | |
84 | ||
85 | for (i = 0; i < 8; i++) { | |
86 | l2n8(sha512->h[i], md_out); | |
87 | } | |
88 | } | |
89 | ||
474e469b RS |
90 | #undef LARGEST_DIGEST_CTX |
91 | #define LARGEST_DIGEST_CTX SHA512_CTX | |
a693ead6 | 92 | |
0f113f3e MC |
93 | /* |
94 | * ssl3_cbc_record_digest_supported returns 1 iff |ctx| uses a hash function | |
95 | * which ssl3_cbc_digest_record supports. | |
96 | */ | |
a693ead6 | 97 | char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx) |
0f113f3e | 98 | { |
0f113f3e MC |
99 | switch (EVP_MD_CTX_type(ctx)) { |
100 | case NID_md5: | |
101 | case NID_sha1: | |
0f113f3e MC |
102 | case NID_sha224: |
103 | case NID_sha256: | |
0f113f3e MC |
104 | case NID_sha384: |
105 | case NID_sha512: | |
0f113f3e MC |
106 | return 1; |
107 | default: | |
108 | return 0; | |
109 | } | |
110 | } | |
a693ead6 | 111 | |
1d97c843 TH |
112 | /*- |
113 | * ssl3_cbc_digest_record computes the MAC of a decrypted, padded SSLv3/TLS | |
a693ead6 BL |
114 | * record. |
115 | * | |
116 | * ctx: the EVP_MD_CTX from which we take the hash function. | |
117 | * ssl3_cbc_record_digest_supported must return true for this EVP_MD_CTX. | |
118 | * md_out: the digest output. At most EVP_MAX_MD_SIZE bytes will be written. | |
119 | * md_out_size: if non-NULL, the number of output bytes is written here. | |
120 | * header: the 13-byte, TLS record header. | |
478b50cf | 121 | * data: the record data itself, less any preceding explicit IV. |
a693ead6 BL |
122 | * data_plus_mac_size: the secret, reported length of the data and MAC |
123 | * once the padding has been removed. | |
124 | * data_plus_mac_plus_padding_size: the public length of the whole | |
125 | * record, including padding. | |
126 | * is_sslv3: non-zero if we are to use SSLv3. Otherwise, TLS. | |
127 | * | |
128 | * On entry: by virtue of having been through one of the remove_padding | |
129 | * functions, above, we know that data_plus_mac_size is large enough to contain | |
130 | * a padding byte and MAC. (If the padding was invalid, it might contain the | |
0f113f3e | 131 | * padding too. ) |
5f3d93e4 | 132 | * Returns 1 on success or 0 on error |
1d97c843 | 133 | */ |
73d391ad MC |
134 | int ssl3_cbc_digest_record(SSL *s, |
135 | const EVP_MD_CTX *ctx, | |
a230b26e EK |
136 | unsigned char *md_out, |
137 | size_t *md_out_size, | |
138 | const unsigned char header[13], | |
139 | const unsigned char *data, | |
140 | size_t data_plus_mac_size, | |
141 | size_t data_plus_mac_plus_padding_size, | |
142 | const unsigned char *mac_secret, | |
d0e7c31d | 143 | size_t mac_secret_length, char is_sslv3) |
0f113f3e MC |
144 | { |
145 | union { | |
39147079 | 146 | OSSL_UNION_ALIGN; |
0f113f3e MC |
147 | unsigned char c[sizeof(LARGEST_DIGEST_CTX)]; |
148 | } md_state; | |
149 | void (*md_final_raw) (void *ctx, unsigned char *md_out); | |
150 | void (*md_transform) (void *ctx, const unsigned char *block); | |
d0e7c31d MC |
151 | size_t md_size, md_block_size = 64; |
152 | size_t sslv3_pad_length = 40, header_length, variance_blocks, | |
0f113f3e MC |
153 | len, max_mac_bytes, num_blocks, |
154 | num_starting_blocks, k, mac_end_offset, c, index_a, index_b; | |
d0e7c31d | 155 | size_t bits; /* at most 18 bits */ |
0f113f3e MC |
156 | unsigned char length_bytes[MAX_HASH_BIT_COUNT_BYTES]; |
157 | /* hmac_pad is the masked HMAC key. */ | |
158 | unsigned char hmac_pad[MAX_HASH_BLOCK_SIZE]; | |
159 | unsigned char first_block[MAX_HASH_BLOCK_SIZE]; | |
160 | unsigned char mac_out[EVP_MAX_MD_SIZE]; | |
d0e7c31d MC |
161 | size_t i, j; |
162 | unsigned md_out_size_u; | |
6e59a892 | 163 | EVP_MD_CTX *md_ctx = NULL; |
0f113f3e MC |
164 | /* |
165 | * mdLengthSize is the number of bytes in the length field that | |
166 | * terminates * the hash. | |
167 | */ | |
d0e7c31d | 168 | size_t md_length_size = 8; |
0f113f3e | 169 | char length_is_big_endian = 1; |
73d391ad MC |
170 | int ret = 0; |
171 | const EVP_MD *md = NULL; | |
0f113f3e MC |
172 | |
173 | /* | |
174 | * This is a, hopefully redundant, check that allows us to forget about | |
175 | * many possible overflows later in this function. | |
176 | */ | |
380a522f MC |
177 | if (!ossl_assert(data_plus_mac_plus_padding_size < 1024 * 1024)) |
178 | return 0; | |
0f113f3e MC |
179 | |
180 | switch (EVP_MD_CTX_type(ctx)) { | |
181 | case NID_md5: | |
5f3d93e4 MC |
182 | if (MD5_Init((MD5_CTX *)md_state.c) <= 0) |
183 | return 0; | |
0f113f3e MC |
184 | md_final_raw = tls1_md5_final_raw; |
185 | md_transform = | |
186 | (void (*)(void *ctx, const unsigned char *block))MD5_Transform; | |
187 | md_size = 16; | |
188 | sslv3_pad_length = 48; | |
189 | length_is_big_endian = 0; | |
190 | break; | |
191 | case NID_sha1: | |
5f3d93e4 MC |
192 | if (SHA1_Init((SHA_CTX *)md_state.c) <= 0) |
193 | return 0; | |
0f113f3e MC |
194 | md_final_raw = tls1_sha1_final_raw; |
195 | md_transform = | |
196 | (void (*)(void *ctx, const unsigned char *block))SHA1_Transform; | |
197 | md_size = 20; | |
198 | break; | |
0f113f3e | 199 | case NID_sha224: |
5f3d93e4 MC |
200 | if (SHA224_Init((SHA256_CTX *)md_state.c) <= 0) |
201 | return 0; | |
0f113f3e MC |
202 | md_final_raw = tls1_sha256_final_raw; |
203 | md_transform = | |
204 | (void (*)(void *ctx, const unsigned char *block))SHA256_Transform; | |
205 | md_size = 224 / 8; | |
206 | break; | |
207 | case NID_sha256: | |
5f3d93e4 MC |
208 | if (SHA256_Init((SHA256_CTX *)md_state.c) <= 0) |
209 | return 0; | |
0f113f3e MC |
210 | md_final_raw = tls1_sha256_final_raw; |
211 | md_transform = | |
212 | (void (*)(void *ctx, const unsigned char *block))SHA256_Transform; | |
213 | md_size = 32; | |
214 | break; | |
0f113f3e | 215 | case NID_sha384: |
5f3d93e4 MC |
216 | if (SHA384_Init((SHA512_CTX *)md_state.c) <= 0) |
217 | return 0; | |
0f113f3e MC |
218 | md_final_raw = tls1_sha512_final_raw; |
219 | md_transform = | |
220 | (void (*)(void *ctx, const unsigned char *block))SHA512_Transform; | |
221 | md_size = 384 / 8; | |
222 | md_block_size = 128; | |
223 | md_length_size = 16; | |
224 | break; | |
225 | case NID_sha512: | |
5f3d93e4 MC |
226 | if (SHA512_Init((SHA512_CTX *)md_state.c) <= 0) |
227 | return 0; | |
0f113f3e MC |
228 | md_final_raw = tls1_sha512_final_raw; |
229 | md_transform = | |
230 | (void (*)(void *ctx, const unsigned char *block))SHA512_Transform; | |
231 | md_size = 64; | |
232 | md_block_size = 128; | |
233 | md_length_size = 16; | |
234 | break; | |
0f113f3e MC |
235 | default: |
236 | /* | |
237 | * ssl3_cbc_record_digest_supported should have been called first to | |
238 | * check that the hash function is supported. | |
239 | */ | |
b77f3ed1 | 240 | if (md_out_size != NULL) |
5c649375 | 241 | *md_out_size = 0; |
b77f3ed1 | 242 | return ossl_assert(0); |
0f113f3e MC |
243 | } |
244 | ||
b77f3ed1 MC |
245 | if (!ossl_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES) |
246 | || !ossl_assert(md_block_size <= MAX_HASH_BLOCK_SIZE) | |
247 | || !ossl_assert(md_size <= EVP_MAX_MD_SIZE)) | |
380a522f | 248 | return 0; |
0f113f3e MC |
249 | |
250 | header_length = 13; | |
251 | if (is_sslv3) { | |
252 | header_length = mac_secret_length + sslv3_pad_length + 8 /* sequence | |
253 | * number */ + | |
254 | 1 /* record type */ + | |
255 | 2 /* record length */ ; | |
256 | } | |
257 | ||
258 | /* | |
259 | * variance_blocks is the number of blocks of the hash that we have to | |
260 | * calculate in constant time because they could be altered by the | |
261 | * padding value. In SSLv3, the padding must be minimal so the end of | |
262 | * the plaintext varies by, at most, 15+20 = 35 bytes. (We conservatively | |
263 | * assume that the MAC size varies from 0..20 bytes.) In case the 9 bytes | |
264 | * of hash termination (0x80 + 64-bit length) don't fit in the final | |
265 | * block, we say that the final two blocks can vary based on the padding. | |
266 | * TLSv1 has MACs up to 48 bytes long (SHA-384) and the padding is not | |
cb8164b0 | 267 | * required to be minimal. Therefore we say that the final |variance_blocks| |
268 | * blocks can | |
0f113f3e MC |
269 | * vary based on the padding. Later in the function, if the message is |
270 | * short and there obviously cannot be this many blocks then | |
271 | * variance_blocks can be reduced. | |
272 | */ | |
cb8164b0 | 273 | variance_blocks = is_sslv3 ? 2 : ( ((255 + 1 + md_size + md_block_size - 1) / md_block_size) + 1); |
0f113f3e MC |
274 | /* |
275 | * From now on we're dealing with the MAC, which conceptually has 13 | |
276 | * bytes of `header' before the start of the data (TLS) or 71/75 bytes | |
277 | * (SSLv3) | |
278 | */ | |
279 | len = data_plus_mac_plus_padding_size + header_length; | |
280 | /* | |
281 | * max_mac_bytes contains the maximum bytes of bytes in the MAC, | |
282 | * including * |header|, assuming that there's no padding. | |
283 | */ | |
284 | max_mac_bytes = len - md_size - 1; | |
285 | /* num_blocks is the maximum number of hash blocks. */ | |
286 | num_blocks = | |
287 | (max_mac_bytes + 1 + md_length_size + md_block_size - | |
288 | 1) / md_block_size; | |
289 | /* | |
290 | * In order to calculate the MAC in constant time we have to handle the | |
291 | * final blocks specially because the padding value could cause the end | |
292 | * to appear somewhere in the final |variance_blocks| blocks and we can't | |
293 | * leak where. However, |num_starting_blocks| worth of data can be hashed | |
294 | * right away because no padding value can affect whether they are | |
295 | * plaintext. | |
296 | */ | |
297 | num_starting_blocks = 0; | |
298 | /* | |
299 | * k is the starting byte offset into the conceptual header||data where | |
300 | * we start processing. | |
301 | */ | |
302 | k = 0; | |
303 | /* | |
304 | * mac_end_offset is the index just past the end of the data to be MACed. | |
305 | */ | |
306 | mac_end_offset = data_plus_mac_size + header_length - md_size; | |
307 | /* | |
308 | * c is the index of the 0x80 byte in the final hash block that contains | |
309 | * application data. | |
310 | */ | |
311 | c = mac_end_offset % md_block_size; | |
312 | /* | |
313 | * index_a is the hash block number that contains the 0x80 terminating | |
314 | * value. | |
315 | */ | |
316 | index_a = mac_end_offset / md_block_size; | |
317 | /* | |
318 | * index_b is the hash block number that contains the 64-bit hash length, | |
319 | * in bits. | |
320 | */ | |
321 | index_b = (mac_end_offset + md_length_size) / md_block_size; | |
322 | /* | |
323 | * bits is the hash-length in bits. It includes the additional hash block | |
324 | * for the masked HMAC key, or whole of |header| in the case of SSLv3. | |
325 | */ | |
326 | ||
327 | /* | |
328 | * For SSLv3, if we're going to have any starting blocks then we need at | |
329 | * least two because the header is larger than a single block. | |
330 | */ | |
331 | if (num_blocks > variance_blocks + (is_sslv3 ? 1 : 0)) { | |
332 | num_starting_blocks = num_blocks - variance_blocks; | |
333 | k = md_block_size * num_starting_blocks; | |
334 | } | |
335 | ||
336 | bits = 8 * mac_end_offset; | |
337 | if (!is_sslv3) { | |
338 | /* | |
339 | * Compute the initial HMAC block. For SSLv3, the padding and secret | |
340 | * bytes are included in |header| because they take more than a | |
341 | * single block. | |
342 | */ | |
343 | bits += 8 * md_block_size; | |
344 | memset(hmac_pad, 0, md_block_size); | |
380a522f MC |
345 | if (!ossl_assert(mac_secret_length <= sizeof(hmac_pad))) |
346 | return 0; | |
0f113f3e MC |
347 | memcpy(hmac_pad, mac_secret, mac_secret_length); |
348 | for (i = 0; i < md_block_size; i++) | |
349 | hmac_pad[i] ^= 0x36; | |
350 | ||
351 | md_transform(md_state.c, hmac_pad); | |
352 | } | |
353 | ||
354 | if (length_is_big_endian) { | |
355 | memset(length_bytes, 0, md_length_size - 4); | |
356 | length_bytes[md_length_size - 4] = (unsigned char)(bits >> 24); | |
357 | length_bytes[md_length_size - 3] = (unsigned char)(bits >> 16); | |
358 | length_bytes[md_length_size - 2] = (unsigned char)(bits >> 8); | |
359 | length_bytes[md_length_size - 1] = (unsigned char)bits; | |
360 | } else { | |
361 | memset(length_bytes, 0, md_length_size); | |
362 | length_bytes[md_length_size - 5] = (unsigned char)(bits >> 24); | |
363 | length_bytes[md_length_size - 6] = (unsigned char)(bits >> 16); | |
364 | length_bytes[md_length_size - 7] = (unsigned char)(bits >> 8); | |
365 | length_bytes[md_length_size - 8] = (unsigned char)bits; | |
366 | } | |
367 | ||
368 | if (k > 0) { | |
369 | if (is_sslv3) { | |
348240c6 | 370 | size_t overhang; |
29b0a15a | 371 | |
0f113f3e MC |
372 | /* |
373 | * The SSLv3 header is larger than a single block. overhang is | |
374 | * the number of bytes beyond a single block that the header | |
29b0a15a MC |
375 | * consumes: either 7 bytes (SHA1) or 11 bytes (MD5). There are no |
376 | * ciphersuites in SSLv3 that are not SHA1 or MD5 based and | |
377 | * therefore we can be confident that the header_length will be | |
378 | * greater than |md_block_size|. However we add a sanity check just | |
379 | * in case | |
0f113f3e | 380 | */ |
29b0a15a MC |
381 | if (header_length <= md_block_size) { |
382 | /* Should never happen */ | |
5f3d93e4 | 383 | return 0; |
29b0a15a MC |
384 | } |
385 | overhang = header_length - md_block_size; | |
0f113f3e MC |
386 | md_transform(md_state.c, header); |
387 | memcpy(first_block, header + md_block_size, overhang); | |
388 | memcpy(first_block + overhang, data, md_block_size - overhang); | |
389 | md_transform(md_state.c, first_block); | |
390 | for (i = 1; i < k / md_block_size - 1; i++) | |
391 | md_transform(md_state.c, data + md_block_size * i - overhang); | |
392 | } else { | |
393 | /* k is a multiple of md_block_size. */ | |
394 | memcpy(first_block, header, 13); | |
395 | memcpy(first_block + 13, data, md_block_size - 13); | |
396 | md_transform(md_state.c, first_block); | |
397 | for (i = 1; i < k / md_block_size; i++) | |
398 | md_transform(md_state.c, data + md_block_size * i - 13); | |
399 | } | |
400 | } | |
401 | ||
402 | memset(mac_out, 0, sizeof(mac_out)); | |
403 | ||
404 | /* | |
405 | * We now process the final hash blocks. For each block, we construct it | |
406 | * in constant time. If the |i==index_a| then we'll include the 0x80 | |
407 | * bytes and zero pad etc. For each block we selectively copy it, in | |
408 | * constant time, to |mac_out|. | |
409 | */ | |
410 | for (i = num_starting_blocks; i <= num_starting_blocks + variance_blocks; | |
411 | i++) { | |
412 | unsigned char block[MAX_HASH_BLOCK_SIZE]; | |
2688e7a0 MC |
413 | unsigned char is_block_a = constant_time_eq_8_s(i, index_a); |
414 | unsigned char is_block_b = constant_time_eq_8_s(i, index_b); | |
0f113f3e MC |
415 | for (j = 0; j < md_block_size; j++) { |
416 | unsigned char b = 0, is_past_c, is_past_cp1; | |
417 | if (k < header_length) | |
418 | b = header[k]; | |
419 | else if (k < data_plus_mac_plus_padding_size + header_length) | |
420 | b = data[k - header_length]; | |
421 | k++; | |
422 | ||
2688e7a0 MC |
423 | is_past_c = is_block_a & constant_time_ge_8_s(j, c); |
424 | is_past_cp1 = is_block_a & constant_time_ge_8_s(j, c + 1); | |
0f113f3e MC |
425 | /* |
426 | * If this is the block containing the end of the application | |
427 | * data, and we are at the offset for the 0x80 value, then | |
428 | * overwrite b with 0x80. | |
429 | */ | |
430 | b = constant_time_select_8(is_past_c, 0x80, b); | |
431 | /* | |
3519bae5 XL |
432 | * If this block contains the end of the application data |
433 | * and we're past the 0x80 value then just write zero. | |
0f113f3e MC |
434 | */ |
435 | b = b & ~is_past_cp1; | |
436 | /* | |
437 | * If this is index_b (the final block), but not index_a (the end | |
438 | * of the data), then the 64-bit length didn't fit into index_a | |
439 | * and we're having to add an extra block of zeros. | |
440 | */ | |
441 | b &= ~is_block_b | is_block_a; | |
442 | ||
443 | /* | |
444 | * The final bytes of one of the blocks contains the length. | |
445 | */ | |
446 | if (j >= md_block_size - md_length_size) { | |
447 | /* If this is index_b, write a length byte. */ | |
448 | b = constant_time_select_8(is_block_b, | |
449 | length_bytes[j - | |
450 | (md_block_size - | |
451 | md_length_size)], b); | |
452 | } | |
453 | block[j] = b; | |
454 | } | |
455 | ||
456 | md_transform(md_state.c, block); | |
457 | md_final_raw(md_state.c, block); | |
458 | /* If this is index_b, copy the hash value to |mac_out|. */ | |
459 | for (j = 0; j < md_size; j++) | |
460 | mac_out[j] |= block[j] & is_block_b; | |
461 | } | |
462 | ||
bfb0641f | 463 | md_ctx = EVP_MD_CTX_new(); |
6e59a892 RL |
464 | if (md_ctx == NULL) |
465 | goto err; | |
73d391ad MC |
466 | md = ssl_evp_md_fetch(s->ctx->libctx, EVP_MD_type(EVP_MD_CTX_md(ctx)), |
467 | s->ctx->propq); | |
468 | if (md == NULL) | |
469 | goto err; | |
470 | if (EVP_DigestInit_ex(md_ctx, md, NULL /* engine */ ) <= 0) | |
5f3d93e4 | 471 | goto err; |
0f113f3e MC |
472 | if (is_sslv3) { |
473 | /* We repurpose |hmac_pad| to contain the SSLv3 pad2 block. */ | |
474 | memset(hmac_pad, 0x5c, sslv3_pad_length); | |
475 | ||
6e59a892 | 476 | if (EVP_DigestUpdate(md_ctx, mac_secret, mac_secret_length) <= 0 |
a230b26e EK |
477 | || EVP_DigestUpdate(md_ctx, hmac_pad, sslv3_pad_length) <= 0 |
478 | || EVP_DigestUpdate(md_ctx, mac_out, md_size) <= 0) | |
5f3d93e4 | 479 | goto err; |
0f113f3e MC |
480 | } else { |
481 | /* Complete the HMAC in the standard manner. */ | |
482 | for (i = 0; i < md_block_size; i++) | |
483 | hmac_pad[i] ^= 0x6a; | |
484 | ||
6e59a892 | 485 | if (EVP_DigestUpdate(md_ctx, hmac_pad, md_block_size) <= 0 |
a230b26e | 486 | || EVP_DigestUpdate(md_ctx, mac_out, md_size) <= 0) |
5f3d93e4 | 487 | goto err; |
0f113f3e | 488 | } |
d0e7c31d | 489 | /* TODO(size_t): Convert me */ |
6e59a892 | 490 | ret = EVP_DigestFinal(md_ctx, md_out, &md_out_size_u); |
0f113f3e MC |
491 | if (ret && md_out_size) |
492 | *md_out_size = md_out_size_u; | |
5f3d93e4 | 493 | |
73d391ad | 494 | ret = 1; |
a230b26e | 495 | err: |
bfb0641f | 496 | EVP_MD_CTX_free(md_ctx); |
73d391ad MC |
497 | ssl_evp_md_free(md); |
498 | return ret; | |
0f113f3e | 499 | } |