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  * 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 
22 #include "prov/implementations.h"
23 #include "prov/provider_ctx.h"
24 #include "prov/provider_util.h"
25 #include "prov/providercommon.h"
26 
27 /*
28  * Forward declaration of everything implemented here.  This is not strictly
29  * necessary for the compiler, but provides an assurance that the signatures
30  * of the functions in the dispatch table are correct.
31  */
32 static OSSL_FUNC_mac_newctx_fn cmac_new;
33 static OSSL_FUNC_mac_dupctx_fn cmac_dup;
34 static OSSL_FUNC_mac_freectx_fn cmac_free;
35 static OSSL_FUNC_mac_gettable_ctx_params_fn cmac_gettable_ctx_params;
36 static OSSL_FUNC_mac_get_ctx_params_fn cmac_get_ctx_params;
37 static OSSL_FUNC_mac_settable_ctx_params_fn cmac_settable_ctx_params;
38 static OSSL_FUNC_mac_set_ctx_params_fn cmac_set_ctx_params;
39 static OSSL_FUNC_mac_init_fn cmac_init;
40 static OSSL_FUNC_mac_update_fn cmac_update;
41 static OSSL_FUNC_mac_final_fn cmac_final;
42 
43 /* local CMAC data */
44 
45 struct cmac_data_st {
46     void *provctx;
47     CMAC_CTX *ctx;
48     PROV_CIPHER cipher;
49 };
50 
51 static void *cmac_new(void *provctx)
52 {
53     struct cmac_data_st *macctx;
54 
55     if (!ossl_prov_is_running())
56         return NULL;
57 
58     if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
59         || (macctx->ctx = CMAC_CTX_new()) == NULL) {
60         OPENSSL_free(macctx);
61         macctx = NULL;
62     } else {
63         macctx->provctx = provctx;
64     }
65 
66     return macctx;
67 }
68 
69 static void cmac_free(void *vmacctx)
70 {
71     struct cmac_data_st *macctx = vmacctx;
72 
73     if (macctx != NULL) {
74         CMAC_CTX_free(macctx->ctx);
75         ossl_prov_cipher_reset(&macctx->cipher);
76         OPENSSL_free(macctx);
77     }
78 }
79 
80 static void *cmac_dup(void *vsrc)
81 {
82     struct cmac_data_st *src = vsrc;
83     struct cmac_data_st *dst;
84 
85     if (!ossl_prov_is_running())
86         return NULL;
87 
88     dst = cmac_new(src->provctx);
89     if (dst == NULL)
90         return NULL;
91     if (!CMAC_CTX_copy(dst->ctx, src->ctx)
92         || !ossl_prov_cipher_copy(&dst->cipher, &src->cipher)) {
93         cmac_free(dst);
94         return NULL;
95     }
96     return dst;
97 }
98 
99 static size_t cmac_size(void *vmacctx)
100 {
101     struct cmac_data_st *macctx = vmacctx;
102     const EVP_CIPHER_CTX *cipherctx = CMAC_CTX_get0_cipher_ctx(macctx->ctx);
103 
104     if (EVP_CIPHER_CTX_get0_cipher(cipherctx) == NULL)
105         return 0;
106 
107     return EVP_CIPHER_CTX_get_block_size(cipherctx);
108 }
109 
110 static int cmac_setkey(struct cmac_data_st *macctx,
111                        const unsigned char *key, size_t keylen)
112 {
113     int rv = CMAC_Init(macctx->ctx, key, keylen,
114                        ossl_prov_cipher_cipher(&macctx->cipher),
115                        ossl_prov_cipher_engine(&macctx->cipher));
116     ossl_prov_cipher_reset(&macctx->cipher);
117     return rv;
118 }
119 
120 static int cmac_init(void *vmacctx, const unsigned char *key,
121                      size_t keylen, const OSSL_PARAM params[])
122 {
123     struct cmac_data_st *macctx = vmacctx;
124 
125     if (!ossl_prov_is_running() || !cmac_set_ctx_params(macctx, params))
126         return 0;
127     if (key != NULL)
128         return cmac_setkey(macctx, key, keylen);
129     /* Reinitialize the CMAC context */
130     return CMAC_Init(macctx->ctx, NULL, 0, NULL, NULL);
131 }
132 
133 static int cmac_update(void *vmacctx, const unsigned char *data,
134                        size_t datalen)
135 {
136     struct cmac_data_st *macctx = vmacctx;
137 
138     return CMAC_Update(macctx->ctx, data, datalen);
139 }
140 
141 static int cmac_final(void *vmacctx, unsigned char *out, size_t *outl,
142                       size_t outsize)
143 {
144     struct cmac_data_st *macctx = vmacctx;
145 
146     if (!ossl_prov_is_running())
147         return 0;
148 
149     return CMAC_Final(macctx->ctx, out, outl);
150 }
151 
152 static const OSSL_PARAM known_gettable_ctx_params[] = {
153     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
154     OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
155     OSSL_PARAM_END
156 };
157 static const OSSL_PARAM *cmac_gettable_ctx_params(ossl_unused void *ctx,
158                                                   ossl_unused void *provctx)
159 {
160     return known_gettable_ctx_params;
161 }
162 
163 static int cmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
164 {
165     OSSL_PARAM *p;
166 
167     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
168             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
169         return 0;
170 
171     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
172             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
173         return 0;
174 
175     return 1;
176 }
177 
178 static const OSSL_PARAM known_settable_ctx_params[] = {
179     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_CIPHER, NULL, 0),
180     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
181     OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
182     OSSL_PARAM_END
183 };
184 static const OSSL_PARAM *cmac_settable_ctx_params(ossl_unused void *ctx,
185                                                   ossl_unused void *provctx)
186 {
187     return known_settable_ctx_params;
188 }
189 
190 /*
191  * ALL parameters should be set before init().
192  */
193 static int cmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
194 {
195     struct cmac_data_st *macctx = vmacctx;
196     OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx);
197     const OSSL_PARAM *p;
198 
199     if (params == NULL)
200         return 1;
201 
202     if (!ossl_prov_cipher_load_from_params(&macctx->cipher, params, ctx))
203         return 0;
204 
205     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
206         if (p->data_type != OSSL_PARAM_OCTET_STRING)
207             return 0;
208         return cmac_setkey(macctx, p->data, p->data_size);
209     }
210     return 1;
211 }
212 
213 const OSSL_DISPATCH ossl_cmac_functions[] = {
214     { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))cmac_new },
215     { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))cmac_dup },
216     { OSSL_FUNC_MAC_FREECTX, (void (*)(void))cmac_free },
217     { OSSL_FUNC_MAC_INIT, (void (*)(void))cmac_init },
218     { OSSL_FUNC_MAC_UPDATE, (void (*)(void))cmac_update },
219     { OSSL_FUNC_MAC_FINAL, (void (*)(void))cmac_final },
220     { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
221       (void (*)(void))cmac_gettable_ctx_params },
222     { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))cmac_get_ctx_params },
223     { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
224       (void (*)(void))cmac_settable_ctx_params },
225     { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))cmac_set_ctx_params },
226     { 0, NULL }
227 };
228