1 /*
2 * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10 /*
11 * HMAC low level APIs are deprecated for public use, but still ok for internal
12 * use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <string.h>
17
18 #include <openssl/core_dispatch.h>
19 #include <openssl/core_names.h>
20 #include <openssl/params.h>
21 #include <openssl/evp.h>
22 #include <openssl/hmac.h>
23
24 #include "prov/implementations.h"
25 #include "prov/provider_ctx.h"
26 #include "prov/provider_util.h"
27 #include "prov/providercommon.h"
28
29 /*
30 * Forward declaration of everything implemented here. This is not strictly
31 * necessary for the compiler, but provides an assurance that the signatures
32 * of the functions in the dispatch table are correct.
33 */
34 static OSSL_FUNC_mac_newctx_fn hmac_new;
35 static OSSL_FUNC_mac_dupctx_fn hmac_dup;
36 static OSSL_FUNC_mac_freectx_fn hmac_free;
37 static OSSL_FUNC_mac_gettable_ctx_params_fn hmac_gettable_ctx_params;
38 static OSSL_FUNC_mac_get_ctx_params_fn hmac_get_ctx_params;
39 static OSSL_FUNC_mac_settable_ctx_params_fn hmac_settable_ctx_params;
40 static OSSL_FUNC_mac_set_ctx_params_fn hmac_set_ctx_params;
41 static OSSL_FUNC_mac_init_fn hmac_init;
42 static OSSL_FUNC_mac_update_fn hmac_update;
43 static OSSL_FUNC_mac_final_fn hmac_final;
44
45 /* local HMAC context structure */
46
47 /* typedef EVP_MAC_IMPL */
48 struct hmac_data_st {
49 void *provctx;
50 HMAC_CTX *ctx; /* HMAC context */
51 PROV_DIGEST digest;
52 unsigned char *key;
53 size_t keylen;
54 /* Length of full TLS record including the MAC and any padding */
55 size_t tls_data_size;
56 unsigned char tls_header[13];
57 int tls_header_set;
58 unsigned char tls_mac_out[EVP_MAX_MD_SIZE];
59 size_t tls_mac_out_size;
60 };
61
62 /* Defined in ssl/s3_cbc.c */
63 int ssl3_cbc_digest_record(const EVP_MD *md,
64 unsigned char *md_out,
65 size_t *md_out_size,
66 const unsigned char header[13],
67 const unsigned char *data,
68 size_t data_size,
69 size_t data_plus_mac_plus_padding_size,
70 const unsigned char *mac_secret,
71 size_t mac_secret_length, char is_sslv3);
72
hmac_new(void * provctx)73 static void *hmac_new(void *provctx)
74 {
75 struct hmac_data_st *macctx;
76
77 if (!ossl_prov_is_running())
78 return NULL;
79
80 if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
81 || (macctx->ctx = HMAC_CTX_new()) == NULL) {
82 OPENSSL_free(macctx);
83 return NULL;
84 }
85 macctx->provctx = provctx;
86
87 return macctx;
88 }
89
hmac_free(void * vmacctx)90 static void hmac_free(void *vmacctx)
91 {
92 struct hmac_data_st *macctx = vmacctx;
93
94 if (macctx != NULL) {
95 HMAC_CTX_free(macctx->ctx);
96 ossl_prov_digest_reset(&macctx->digest);
97 OPENSSL_secure_clear_free(macctx->key, macctx->keylen);
98 OPENSSL_free(macctx);
99 }
100 }
101
hmac_dup(void * vsrc)102 static void *hmac_dup(void *vsrc)
103 {
104 struct hmac_data_st *src = vsrc;
105 struct hmac_data_st *dst;
106 HMAC_CTX *ctx;
107
108 if (!ossl_prov_is_running())
109 return NULL;
110 dst = hmac_new(src->provctx);
111 if (dst == NULL)
112 return NULL;
113
114 ctx = dst->ctx;
115 *dst = *src;
116 dst->ctx = ctx;
117 dst->key = NULL;
118 memset(&dst->digest, 0, sizeof(dst->digest));
119
120 if (!HMAC_CTX_copy(dst->ctx, src->ctx)
121 || !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
122 hmac_free(dst);
123 return NULL;
124 }
125 if (src->key != NULL) {
126 /* There is no "secure" OPENSSL_memdup */
127 dst->key = OPENSSL_secure_malloc(src->keylen > 0 ? src->keylen : 1);
128 if (dst->key == NULL) {
129 hmac_free(dst);
130 return 0;
131 }
132 memcpy(dst->key, src->key, src->keylen);
133 }
134 return dst;
135 }
136
hmac_size(struct hmac_data_st * macctx)137 static size_t hmac_size(struct hmac_data_st *macctx)
138 {
139 return HMAC_size(macctx->ctx);
140 }
141
hmac_block_size(struct hmac_data_st * macctx)142 static int hmac_block_size(struct hmac_data_st *macctx)
143 {
144 const EVP_MD *md = ossl_prov_digest_md(&macctx->digest);
145
146 if (md == NULL)
147 return 0;
148 return EVP_MD_block_size(md);
149 }
150
hmac_setkey(struct hmac_data_st * macctx,const unsigned char * key,size_t keylen)151 static int hmac_setkey(struct hmac_data_st *macctx,
152 const unsigned char *key, size_t keylen)
153 {
154 const EVP_MD *digest;
155
156 if (macctx->key != NULL)
157 OPENSSL_secure_clear_free(macctx->key, macctx->keylen);
158 /* Keep a copy of the key in case we need it for TLS HMAC */
159 macctx->key = OPENSSL_secure_malloc(keylen > 0 ? keylen : 1);
160 if (macctx->key == NULL)
161 return 0;
162 memcpy(macctx->key, key, keylen);
163 macctx->keylen = keylen;
164
165 digest = ossl_prov_digest_md(&macctx->digest);
166 /* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */
167 if (key != NULL || (macctx->tls_data_size == 0 && digest != NULL))
168 return HMAC_Init_ex(macctx->ctx, key, keylen, digest,
169 ossl_prov_digest_engine(&macctx->digest));
170 return 1;
171 }
172
hmac_init(void * vmacctx,const unsigned char * key,size_t keylen,const OSSL_PARAM params[])173 static int hmac_init(void *vmacctx, const unsigned char *key,
174 size_t keylen, const OSSL_PARAM params[])
175 {
176 struct hmac_data_st *macctx = vmacctx;
177
178 if (!ossl_prov_is_running() || !hmac_set_ctx_params(macctx, params))
179 return 0;
180
181 if (key != NULL)
182 return hmac_setkey(macctx, key, keylen);
183
184 /* Just reinit the HMAC context */
185 return HMAC_Init_ex(macctx->ctx, NULL, 0, NULL, NULL);
186 }
187
hmac_update(void * vmacctx,const unsigned char * data,size_t datalen)188 static int hmac_update(void *vmacctx, const unsigned char *data,
189 size_t datalen)
190 {
191 struct hmac_data_st *macctx = vmacctx;
192
193 if (macctx->tls_data_size > 0) {
194 /* We're doing a TLS HMAC */
195 if (!macctx->tls_header_set) {
196 /* We expect the first update call to contain the TLS header */
197 if (datalen != sizeof(macctx->tls_header))
198 return 0;
199 memcpy(macctx->tls_header, data, datalen);
200 macctx->tls_header_set = 1;
201 return 1;
202 }
203 /* macctx->tls_data_size is datalen plus the padding length */
204 if (macctx->tls_data_size < datalen)
205 return 0;
206
207 return ssl3_cbc_digest_record(ossl_prov_digest_md(&macctx->digest),
208 macctx->tls_mac_out,
209 &macctx->tls_mac_out_size,
210 macctx->tls_header,
211 data,
212 datalen,
213 macctx->tls_data_size,
214 macctx->key,
215 macctx->keylen,
216 0);
217 }
218
219 return HMAC_Update(macctx->ctx, data, datalen);
220 }
221
hmac_final(void * vmacctx,unsigned char * out,size_t * outl,size_t outsize)222 static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl,
223 size_t outsize)
224 {
225 unsigned int hlen;
226 struct hmac_data_st *macctx = vmacctx;
227
228 if (!ossl_prov_is_running())
229 return 0;
230 if (macctx->tls_data_size > 0) {
231 if (macctx->tls_mac_out_size == 0)
232 return 0;
233 if (outl != NULL)
234 *outl = macctx->tls_mac_out_size;
235 memcpy(out, macctx->tls_mac_out, macctx->tls_mac_out_size);
236 return 1;
237 }
238 if (!HMAC_Final(macctx->ctx, out, &hlen))
239 return 0;
240 *outl = hlen;
241 return 1;
242 }
243
244 static const OSSL_PARAM known_gettable_ctx_params[] = {
245 OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
246 OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
247 OSSL_PARAM_END
248 };
hmac_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)249 static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *ctx,
250 ossl_unused void *provctx)
251 {
252 return known_gettable_ctx_params;
253 }
254
hmac_get_ctx_params(void * vmacctx,OSSL_PARAM params[])255 static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
256 {
257 struct hmac_data_st *macctx = vmacctx;
258 OSSL_PARAM *p;
259
260 if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
261 && !OSSL_PARAM_set_size_t(p, hmac_size(macctx)))
262 return 0;
263
264 if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
265 && !OSSL_PARAM_set_int(p, hmac_block_size(macctx)))
266 return 0;
267
268 return 1;
269 }
270
271 static const OSSL_PARAM known_settable_ctx_params[] = {
272 OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, NULL, 0),
273 OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
274 OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
275 OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_NOINIT, NULL),
276 OSSL_PARAM_int(OSSL_MAC_PARAM_DIGEST_ONESHOT, NULL),
277 OSSL_PARAM_size_t(OSSL_MAC_PARAM_TLS_DATA_SIZE, NULL),
278 OSSL_PARAM_END
279 };
hmac_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)280 static const OSSL_PARAM *hmac_settable_ctx_params(ossl_unused void *ctx,
281 ossl_unused void *provctx)
282 {
283 return known_settable_ctx_params;
284 }
285
set_flag(const OSSL_PARAM params[],const char * key,int mask,int * flags)286 static int set_flag(const OSSL_PARAM params[], const char *key, int mask,
287 int *flags)
288 {
289 const OSSL_PARAM *p = OSSL_PARAM_locate_const(params, key);
290 int flag = 0;
291
292 if (p != NULL) {
293 if (!OSSL_PARAM_get_int(p, &flag))
294 return 0;
295 if (flag == 0)
296 *flags &= ~mask;
297 else
298 *flags |= mask;
299 }
300 return 1;
301 }
302
303 /*
304 * ALL parameters should be set before init().
305 */
hmac_set_ctx_params(void * vmacctx,const OSSL_PARAM params[])306 static int hmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
307 {
308 struct hmac_data_st *macctx = vmacctx;
309 OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx);
310 const OSSL_PARAM *p;
311 int flags = 0;
312
313 if (params == NULL)
314 return 1;
315
316 if (!ossl_prov_digest_load_from_params(&macctx->digest, params, ctx))
317 return 0;
318
319 if (!set_flag(params, OSSL_MAC_PARAM_DIGEST_NOINIT, EVP_MD_CTX_FLAG_NO_INIT,
320 &flags))
321 return 0;
322 if (!set_flag(params, OSSL_MAC_PARAM_DIGEST_ONESHOT, EVP_MD_CTX_FLAG_ONESHOT,
323 &flags))
324 return 0;
325 if (flags)
326 HMAC_CTX_set_flags(macctx->ctx, flags);
327
328 if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
329 if (p->data_type != OSSL_PARAM_OCTET_STRING)
330 return 0;
331 if (!hmac_setkey(macctx, p->data, p->data_size))
332 return 0;
333 }
334
335 if ((p = OSSL_PARAM_locate_const(params,
336 OSSL_MAC_PARAM_TLS_DATA_SIZE)) != NULL) {
337 if (!OSSL_PARAM_get_size_t(p, &macctx->tls_data_size))
338 return 0;
339 }
340 return 1;
341 }
342
343 const OSSL_DISPATCH ossl_hmac_functions[] = {
344 { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_new },
345 { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup },
346 { OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free },
347 { OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init },
348 { OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update },
349 { OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final },
350 { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
351 (void (*)(void))hmac_gettable_ctx_params },
352 { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params },
353 { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
354 (void (*)(void))hmac_settable_ctx_params },
355 { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params },
356 { 0, NULL }
357 };
358