1 /*
2  * Copyright 2018-2024 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  * CMAC low level APIs are deprecated for public use, but still ok for internal
12  * use.
13  */
14 #include "internal/deprecated.h"
15 
16 #include <openssl/core_dispatch.h>
17 #include <openssl/core_names.h>
18 #include <openssl/params.h>
19 #include <openssl/evp.h>
20 #include <openssl/cmac.h>
21 #include <openssl/err.h>
22 #include <openssl/proverr.h>
23 
24 #include "prov/securitycheck.h"
25 #include "prov/implementations.h"
26 #include "prov/provider_ctx.h"
27 #include "prov/provider_util.h"
28 #include "prov/providercommon.h"
29 #include "crypto/cmac.h"
30 
31 /*
32  * Forward declaration of everything implemented here.  This is not strictly
33  * necessary for the compiler, but provides an assurance that the signatures
34  * of the functions in the dispatch table are correct.
35  */
36 static OSSL_FUNC_mac_newctx_fn cmac_new;
37 static OSSL_FUNC_mac_dupctx_fn cmac_dup;
38 static OSSL_FUNC_mac_freectx_fn cmac_free;
39 static OSSL_FUNC_mac_gettable_ctx_params_fn cmac_gettable_ctx_params;
40 static OSSL_FUNC_mac_get_ctx_params_fn cmac_get_ctx_params;
41 static OSSL_FUNC_mac_settable_ctx_params_fn cmac_settable_ctx_params;
42 static OSSL_FUNC_mac_set_ctx_params_fn cmac_set_ctx_params;
43 static OSSL_FUNC_mac_init_fn cmac_init;
44 static OSSL_FUNC_mac_update_fn cmac_update;
45 static OSSL_FUNC_mac_final_fn cmac_final;
46 
47 /* local CMAC data */
48 
49 struct cmac_data_st {
50     void *provctx;
51     CMAC_CTX *ctx;
52     PROV_CIPHER cipher;
53     OSSL_FIPS_IND_DECLARE
54 };
55 
cmac_new(void * provctx)56 static void *cmac_new(void *provctx)
57 {
58     struct cmac_data_st *macctx;
59 
60     if (!ossl_prov_is_running())
61         return NULL;
62 
63     if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
64         || (macctx->ctx = CMAC_CTX_new()) == NULL) {
65         OPENSSL_free(macctx);
66         macctx = NULL;
67     } else {
68         macctx->provctx = provctx;
69         OSSL_FIPS_IND_INIT(macctx)
70     }
71 
72     return macctx;
73 }
74 
cmac_free(void * vmacctx)75 static void cmac_free(void *vmacctx)
76 {
77     struct cmac_data_st *macctx = vmacctx;
78 
79     if (macctx != NULL) {
80         CMAC_CTX_free(macctx->ctx);
81         ossl_prov_cipher_reset(&macctx->cipher);
82         OPENSSL_free(macctx);
83     }
84 }
85 
cmac_dup(void * vsrc)86 static void *cmac_dup(void *vsrc)
87 {
88     struct cmac_data_st *src = vsrc;
89     struct cmac_data_st *dst;
90 
91     if (!ossl_prov_is_running())
92         return NULL;
93 
94     dst = cmac_new(src->provctx);
95     if (dst == NULL)
96         return NULL;
97     if (!CMAC_CTX_copy(dst->ctx, src->ctx)
98         || !ossl_prov_cipher_copy(&dst->cipher, &src->cipher)) {
99         cmac_free(dst);
100         return NULL;
101     }
102     OSSL_FIPS_IND_COPY(dst, src)
103     return dst;
104 }
105 
cmac_size(void * vmacctx)106 static size_t cmac_size(void *vmacctx)
107 {
108     struct cmac_data_st *macctx = vmacctx;
109     const EVP_CIPHER_CTX *cipherctx = CMAC_CTX_get0_cipher_ctx(macctx->ctx);
110 
111     if (EVP_CIPHER_CTX_get0_cipher(cipherctx) == NULL)
112         return 0;
113 
114     return EVP_CIPHER_CTX_get_block_size(cipherctx);
115 }
116 
117 #ifdef FIPS_MODULE
118 /*
119  * TDES Encryption is not approved in FIPS 140-3.
120  *
121  * In strict approved mode we just fail here (by returning 0).
122  * If we are going to bypass it using a FIPS indicator then we need to pass that
123  * information down to the cipher also.
124  * This function returns the param to pass down in 'p'.
125  * state will return OSSL_FIPS_IND_STATE_UNKNOWN if the param has not been set.
126  *
127  * The name 'OSSL_CIPHER_PARAM_FIPS_ENCRYPT_CHECK' used below matches the
128  * key name used by the Triple-DES.
129  */
tdes_check_param(struct cmac_data_st * macctx,OSSL_PARAM * p,int * state)130 static int tdes_check_param(struct cmac_data_st *macctx, OSSL_PARAM *p,
131                             int *state)
132 {
133     OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(macctx->provctx);
134     const EVP_CIPHER *cipher = ossl_prov_cipher_cipher(&macctx->cipher);
135 
136     *state = OSSL_FIPS_IND_STATE_UNKNOWN;
137     if (EVP_CIPHER_is_a(cipher, "DES-EDE3-CBC")) {
138         if (!OSSL_FIPS_IND_ON_UNAPPROVED(macctx, OSSL_FIPS_IND_SETTABLE0,
139                                          libctx, "CMAC", "Triple-DES",
140                                          ossl_fips_config_tdes_encrypt_disallowed))
141             return 0;
142         OSSL_FIPS_IND_GET_PARAM(macctx, p, state, OSSL_FIPS_IND_SETTABLE0,
143                                 OSSL_CIPHER_PARAM_FIPS_ENCRYPT_CHECK)
144     }
145     return 1;
146 }
147 #endif
148 
cmac_setkey(struct cmac_data_st * macctx,const unsigned char * key,size_t keylen)149 static int cmac_setkey(struct cmac_data_st *macctx,
150                        const unsigned char *key, size_t keylen)
151 {
152     int rv;
153     OSSL_PARAM *p = NULL;
154 #ifdef FIPS_MODULE
155     int state = OSSL_FIPS_IND_STATE_UNKNOWN;
156     OSSL_PARAM prms[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
157 
158     if (!tdes_check_param(macctx, &prms[0], &state))
159         return 0;
160     if (state != OSSL_FIPS_IND_STATE_UNKNOWN)
161         p = prms;
162 #endif
163     rv = ossl_cmac_init(macctx->ctx, key, keylen,
164                         ossl_prov_cipher_cipher(&macctx->cipher),
165                         ossl_prov_cipher_engine(&macctx->cipher), p);
166     ossl_prov_cipher_reset(&macctx->cipher);
167     return rv;
168 }
169 
cmac_init(void * vmacctx,const unsigned char * key,size_t keylen,const OSSL_PARAM params[])170 static int cmac_init(void *vmacctx, const unsigned char *key,
171                      size_t keylen, const OSSL_PARAM params[])
172 {
173     struct cmac_data_st *macctx = vmacctx;
174 
175     if (!ossl_prov_is_running() || !cmac_set_ctx_params(macctx, params))
176         return 0;
177     if (key != NULL)
178         return cmac_setkey(macctx, key, keylen);
179     /* Reinitialize the CMAC context */
180     return CMAC_Init(macctx->ctx, NULL, 0, NULL, NULL);
181 }
182 
cmac_update(void * vmacctx,const unsigned char * data,size_t datalen)183 static int cmac_update(void *vmacctx, const unsigned char *data,
184                        size_t datalen)
185 {
186     struct cmac_data_st *macctx = vmacctx;
187 
188     return CMAC_Update(macctx->ctx, data, datalen);
189 }
190 
cmac_final(void * vmacctx,unsigned char * out,size_t * outl,size_t outsize)191 static int cmac_final(void *vmacctx, unsigned char *out, size_t *outl,
192                       size_t outsize)
193 {
194     struct cmac_data_st *macctx = vmacctx;
195 
196     if (!ossl_prov_is_running())
197         return 0;
198 
199     return CMAC_Final(macctx->ctx, out, outl);
200 }
201 
202 static const OSSL_PARAM known_gettable_ctx_params[] = {
203     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
204     OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
205     OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
206     OSSL_PARAM_END
207 };
cmac_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)208 static const OSSL_PARAM *cmac_gettable_ctx_params(ossl_unused void *ctx,
209                                                   ossl_unused void *provctx)
210 {
211     return known_gettable_ctx_params;
212 }
213 
cmac_get_ctx_params(void * vmacctx,OSSL_PARAM params[])214 static int cmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
215 {
216     OSSL_PARAM *p;
217 
218     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
219             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
220         return 0;
221 
222     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
223             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
224         return 0;
225 
226     if (!OSSL_FIPS_IND_GET_CTX_PARAM((struct cmac_data_st *)vmacctx, params))
227         return 0;
228     return 1;
229 }
230 
231 static const OSSL_PARAM known_settable_ctx_params[] = {
232     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_CIPHER, NULL, 0),
233     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
234     OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
235     OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_CIPHER_PARAM_FIPS_ENCRYPT_CHECK)
236     OSSL_PARAM_END
237 };
cmac_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)238 static const OSSL_PARAM *cmac_settable_ctx_params(ossl_unused void *ctx,
239                                                   ossl_unused void *provctx)
240 {
241     return known_settable_ctx_params;
242 }
243 
244 /*
245  * ALL parameters should be set before init().
246  */
cmac_set_ctx_params(void * vmacctx,const OSSL_PARAM params[])247 static int cmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
248 {
249     struct cmac_data_st *macctx = vmacctx;
250     OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx);
251     const OSSL_PARAM *p;
252 
253     if (params == NULL)
254         return 1;
255 
256     if (!OSSL_FIPS_IND_SET_CTX_PARAM(macctx,
257                                      OSSL_FIPS_IND_SETTABLE0, params,
258                                      OSSL_CIPHER_PARAM_FIPS_ENCRYPT_CHECK))
259         return 0;
260 
261     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CIPHER)) != NULL) {
262         if (!ossl_prov_cipher_load_from_params(&macctx->cipher, params, ctx))
263             return 0;
264 
265         if (EVP_CIPHER_get_mode(ossl_prov_cipher_cipher(&macctx->cipher))
266             != EVP_CIPH_CBC_MODE) {
267             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
268             return 0;
269         }
270 #ifdef FIPS_MODULE
271         {
272             const EVP_CIPHER *cipher = ossl_prov_cipher_cipher(&macctx->cipher);
273 
274             if (!EVP_CIPHER_is_a(cipher, "AES-256-CBC")
275                     && !EVP_CIPHER_is_a(cipher, "AES-192-CBC")
276                     && !EVP_CIPHER_is_a(cipher, "AES-128-CBC")
277                     && !EVP_CIPHER_is_a(cipher, "DES-EDE3-CBC")) {
278                 ERR_raise(ERR_LIB_PROV, EVP_R_UNSUPPORTED_CIPHER);
279                 return 0;
280             }
281         }
282 #endif
283     }
284 
285     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
286         if (p->data_type != OSSL_PARAM_OCTET_STRING)
287             return 0;
288         return cmac_setkey(macctx, p->data, p->data_size);
289     }
290     return 1;
291 }
292 
293 const OSSL_DISPATCH ossl_cmac_functions[] = {
294     { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))cmac_new },
295     { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))cmac_dup },
296     { OSSL_FUNC_MAC_FREECTX, (void (*)(void))cmac_free },
297     { OSSL_FUNC_MAC_INIT, (void (*)(void))cmac_init },
298     { OSSL_FUNC_MAC_UPDATE, (void (*)(void))cmac_update },
299     { OSSL_FUNC_MAC_FINAL, (void (*)(void))cmac_final },
300     { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
301       (void (*)(void))cmac_gettable_ctx_params },
302     { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))cmac_get_ctx_params },
303     { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
304       (void (*)(void))cmac_settable_ctx_params },
305     { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))cmac_set_ctx_params },
306     OSSL_DISPATCH_END
307 };
308