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 
cmac_new(void * provctx)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 
cmac_free(void * vmacctx)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 
cmac_dup(void * vsrc)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 
cmac_size(void * vmacctx)99 static size_t cmac_size(void *vmacctx)
100 {
101     struct cmac_data_st *macctx = vmacctx;
102 
103     return EVP_CIPHER_CTX_get_block_size(CMAC_CTX_get0_cipher_ctx(macctx->ctx));
104 }
105 
cmac_setkey(struct cmac_data_st * macctx,const unsigned char * key,size_t keylen)106 static int cmac_setkey(struct cmac_data_st *macctx,
107                        const unsigned char *key, size_t keylen)
108 {
109     int rv = CMAC_Init(macctx->ctx, key, keylen,
110                        ossl_prov_cipher_cipher(&macctx->cipher),
111                        ossl_prov_cipher_engine(&macctx->cipher));
112     ossl_prov_cipher_reset(&macctx->cipher);
113     return rv;
114 }
115 
cmac_init(void * vmacctx,const unsigned char * key,size_t keylen,const OSSL_PARAM params[])116 static int cmac_init(void *vmacctx, const unsigned char *key,
117                      size_t keylen, const OSSL_PARAM params[])
118 {
119     struct cmac_data_st *macctx = vmacctx;
120 
121     if (!ossl_prov_is_running() || !cmac_set_ctx_params(macctx, params))
122         return 0;
123     if (key != NULL)
124         return cmac_setkey(macctx, key, keylen);
125     /* Reinitialize the CMAC context */
126     return CMAC_Init(macctx->ctx, NULL, 0, NULL, NULL);
127 }
128 
cmac_update(void * vmacctx,const unsigned char * data,size_t datalen)129 static int cmac_update(void *vmacctx, const unsigned char *data,
130                        size_t datalen)
131 {
132     struct cmac_data_st *macctx = vmacctx;
133 
134     return CMAC_Update(macctx->ctx, data, datalen);
135 }
136 
cmac_final(void * vmacctx,unsigned char * out,size_t * outl,size_t outsize)137 static int cmac_final(void *vmacctx, unsigned char *out, size_t *outl,
138                       size_t outsize)
139 {
140     struct cmac_data_st *macctx = vmacctx;
141 
142     if (!ossl_prov_is_running())
143         return 0;
144 
145     return CMAC_Final(macctx->ctx, out, outl);
146 }
147 
148 static const OSSL_PARAM known_gettable_ctx_params[] = {
149     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
150     OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
151     OSSL_PARAM_END
152 };
cmac_gettable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)153 static const OSSL_PARAM *cmac_gettable_ctx_params(ossl_unused void *ctx,
154                                                   ossl_unused void *provctx)
155 {
156     return known_gettable_ctx_params;
157 }
158 
cmac_get_ctx_params(void * vmacctx,OSSL_PARAM params[])159 static int cmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
160 {
161     OSSL_PARAM *p;
162 
163     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
164             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
165         return 0;
166 
167     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
168             && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
169         return 0;
170 
171     return 1;
172 }
173 
174 static const OSSL_PARAM known_settable_ctx_params[] = {
175     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_CIPHER, NULL, 0),
176     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
177     OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
178     OSSL_PARAM_END
179 };
cmac_settable_ctx_params(ossl_unused void * ctx,ossl_unused void * provctx)180 static const OSSL_PARAM *cmac_settable_ctx_params(ossl_unused void *ctx,
181                                                   ossl_unused void *provctx)
182 {
183     return known_settable_ctx_params;
184 }
185 
186 /*
187  * ALL parameters should be set before init().
188  */
cmac_set_ctx_params(void * vmacctx,const OSSL_PARAM params[])189 static int cmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
190 {
191     struct cmac_data_st *macctx = vmacctx;
192     OSSL_LIB_CTX *ctx = PROV_LIBCTX_OF(macctx->provctx);
193     const OSSL_PARAM *p;
194 
195     if (params == NULL)
196         return 1;
197 
198     if (!ossl_prov_cipher_load_from_params(&macctx->cipher, params, ctx))
199         return 0;
200 
201     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
202         if (p->data_type != OSSL_PARAM_OCTET_STRING)
203             return 0;
204         return cmac_setkey(macctx, p->data, p->data_size);
205     }
206     return 1;
207 }
208 
209 const OSSL_DISPATCH ossl_cmac_functions[] = {
210     { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))cmac_new },
211     { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))cmac_dup },
212     { OSSL_FUNC_MAC_FREECTX, (void (*)(void))cmac_free },
213     { OSSL_FUNC_MAC_INIT, (void (*)(void))cmac_init },
214     { OSSL_FUNC_MAC_UPDATE, (void (*)(void))cmac_update },
215     { OSSL_FUNC_MAC_FINAL, (void (*)(void))cmac_final },
216     { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
217       (void (*)(void))cmac_gettable_ctx_params },
218     { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))cmac_get_ctx_params },
219     { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
220       (void (*)(void))cmac_settable_ctx_params },
221     { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))cmac_set_ctx_params },
222     { 0, NULL }
223 };
224