1 /*
2  * Copyright 2022-2024 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 #include <stdlib.h>
11 #include <string.h>
12 #include <openssl/crypto.h>
13 #include <openssl/err.h>
14 #include <openssl/kdf.h>
15 #include <openssl/proverr.h>
16 #include <openssl/core_names.h>
17 #include "prov/providercommon.h"
18 #include "prov/implementations.h"
19 #include "prov/hmac_drbg.h"
20 #include "prov/provider_ctx.h"
21 
22 static OSSL_FUNC_kdf_newctx_fn hmac_drbg_kdf_new;
23 static OSSL_FUNC_kdf_dupctx_fn hmac_drbg_kdf_dup;
24 static OSSL_FUNC_kdf_freectx_fn hmac_drbg_kdf_free;
25 static OSSL_FUNC_kdf_reset_fn hmac_drbg_kdf_reset;
26 static OSSL_FUNC_kdf_derive_fn hmac_drbg_kdf_derive;
27 static OSSL_FUNC_kdf_settable_ctx_params_fn hmac_drbg_kdf_settable_ctx_params;
28 static OSSL_FUNC_kdf_set_ctx_params_fn hmac_drbg_kdf_set_ctx_params;
29 static OSSL_FUNC_kdf_gettable_ctx_params_fn hmac_drbg_kdf_gettable_ctx_params;
30 static OSSL_FUNC_kdf_get_ctx_params_fn hmac_drbg_kdf_get_ctx_params;
31 
32 typedef struct {
33     PROV_DRBG_HMAC base;
34     void *provctx;
35     unsigned char *entropy, *nonce;
36     size_t entropylen, noncelen;
37     int init;
38 } KDF_HMAC_DRBG;
39 
hmac_drbg_kdf_new(void * provctx)40 static void *hmac_drbg_kdf_new(void *provctx)
41 {
42     KDF_HMAC_DRBG *ctx;
43 
44     if (!ossl_prov_is_running())
45         return NULL;
46 
47     ctx = OPENSSL_zalloc(sizeof(*ctx));
48     if (ctx == NULL) {
49         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
50         return NULL;
51     }
52     ctx->provctx = provctx;
53     return ctx;
54 }
55 
hmac_drbg_kdf_reset(void * vctx)56 static void hmac_drbg_kdf_reset(void *vctx)
57 {
58     KDF_HMAC_DRBG *ctx = (KDF_HMAC_DRBG *)vctx;
59     PROV_DRBG_HMAC *drbg = &ctx->base;
60     void *provctx = ctx->provctx;
61 
62     EVP_MAC_CTX_free(drbg->ctx);
63     ossl_prov_digest_reset(&drbg->digest);
64     OPENSSL_clear_free(ctx->entropy, ctx->entropylen);
65     OPENSSL_clear_free(ctx->nonce, ctx->noncelen);
66     OPENSSL_cleanse(ctx, sizeof(*ctx));
67     ctx->provctx = provctx;
68 }
69 
hmac_drbg_kdf_free(void * vctx)70 static void hmac_drbg_kdf_free(void *vctx)
71 {
72     KDF_HMAC_DRBG *ctx = (KDF_HMAC_DRBG *)vctx;
73 
74     if (ctx != NULL) {
75         hmac_drbg_kdf_reset(ctx);
76         OPENSSL_free(ctx);
77     }
78 }
79 
ossl_drbg_hmac_dup(PROV_DRBG_HMAC * dst,const PROV_DRBG_HMAC * src)80 static int ossl_drbg_hmac_dup(PROV_DRBG_HMAC *dst, const PROV_DRBG_HMAC *src) {
81     if (src->ctx != NULL) {
82         dst->ctx = EVP_MAC_CTX_dup(src->ctx);
83         if (dst->ctx == NULL)
84             return 0;
85     }
86     if (!ossl_prov_digest_copy(&dst->digest, &src->digest))
87         return 0;
88     memcpy(dst->K, src->K, sizeof(dst->K));
89     memcpy(dst->V, src->V, sizeof(dst->V));
90     dst->blocklen = src->blocklen;
91     return 1;
92 }
93 
hmac_drbg_kdf_dup(void * vctx)94 static void *hmac_drbg_kdf_dup(void *vctx)
95 {
96     const KDF_HMAC_DRBG *src = (const KDF_HMAC_DRBG *)vctx;
97     KDF_HMAC_DRBG *dst;
98 
99     dst = hmac_drbg_kdf_new(src->provctx);
100     if (dst != NULL) {
101         if (!ossl_drbg_hmac_dup(&dst->base, &src->base)
102                 || !ossl_prov_memdup(src->entropy, src->entropylen,
103                                      &dst->entropy , &dst->entropylen)
104                 || !ossl_prov_memdup(src->nonce, src->noncelen,
105                                      &dst->nonce, &dst->noncelen))
106             goto err;
107         dst->init = src->init;
108     }
109     return dst;
110 
111  err:
112     hmac_drbg_kdf_free(dst);
113     return NULL;
114 }
115 
hmac_drbg_kdf_derive(void * vctx,unsigned char * out,size_t outlen,const OSSL_PARAM params[])116 static int hmac_drbg_kdf_derive(void *vctx, unsigned char *out, size_t outlen,
117                                 const OSSL_PARAM params[])
118 {
119     KDF_HMAC_DRBG *ctx = (KDF_HMAC_DRBG *)vctx;
120     PROV_DRBG_HMAC *drbg = &ctx->base;
121 
122     if (!ossl_prov_is_running()
123             || !hmac_drbg_kdf_set_ctx_params(vctx, params))
124         return 0;
125     if (!ctx->init) {
126         if (ctx->entropy == NULL
127                 || ctx->entropylen == 0
128                 || ctx->nonce == NULL
129                 || ctx->noncelen == 0
130                 || !ossl_drbg_hmac_init(drbg, ctx->entropy, ctx->entropylen,
131                                         ctx->nonce, ctx->noncelen, NULL, 0))
132             return 0;
133         ctx->init = 1;
134     }
135 
136     return ossl_drbg_hmac_generate(drbg, out, outlen, NULL, 0);
137 }
138 
hmac_drbg_kdf_get_ctx_params(void * vctx,OSSL_PARAM params[])139 static int hmac_drbg_kdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
140 {
141     KDF_HMAC_DRBG *hmac = (KDF_HMAC_DRBG *)vctx;
142     PROV_DRBG_HMAC *drbg = &hmac->base;
143     const char *name;
144     const EVP_MD *md;
145     OSSL_PARAM *p;
146 
147     p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_MAC);
148     if (p != NULL) {
149         if (drbg->ctx == NULL)
150             return 0;
151         name = EVP_MAC_get0_name(EVP_MAC_CTX_get0_mac(drbg->ctx));
152         if (!OSSL_PARAM_set_utf8_string(p, name))
153             return 0;
154     }
155 
156     p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_DIGEST);
157     if (p != NULL) {
158         md = ossl_prov_digest_md(&drbg->digest);
159         if (md == NULL || !OSSL_PARAM_set_utf8_string(p, EVP_MD_get0_name(md)))
160             return 0;
161     }
162     return 1;
163 }
164 
hmac_drbg_kdf_gettable_ctx_params(ossl_unused void * vctx,ossl_unused void * p_ctx)165 static const OSSL_PARAM *hmac_drbg_kdf_gettable_ctx_params(
166     ossl_unused void *vctx, ossl_unused void *p_ctx)
167 {
168     static const OSSL_PARAM known_gettable_ctx_params[] = {
169         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
170         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
171         OSSL_PARAM_END
172     };
173     return known_gettable_ctx_params;
174 }
175 
hmac_drbg_kdf_set_ctx_params(void * vctx,const OSSL_PARAM params[])176 static int hmac_drbg_kdf_set_ctx_params(void *vctx,
177                                         const OSSL_PARAM params[])
178 {
179     KDF_HMAC_DRBG *hmac = (KDF_HMAC_DRBG *)vctx;
180     PROV_DRBG_HMAC *drbg = &hmac->base;
181     OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(hmac->provctx);
182     const EVP_MD *md;
183     const OSSL_PARAM *p;
184     void *ptr = NULL;
185     size_t size = 0;
186     int md_size;
187 
188     if (ossl_param_is_empty(params))
189         return 1;
190 
191     p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_HMACDRBG_ENTROPY);
192     if (p != NULL) {
193         if (!OSSL_PARAM_get_octet_string(p, &ptr, 0, &size))
194             return 0;
195         OPENSSL_free(hmac->entropy);
196         hmac->entropy = ptr;
197         hmac->entropylen = size;
198         hmac->init = 0;
199         ptr = NULL;
200     }
201 
202     p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_HMACDRBG_NONCE);
203     if (p != NULL) {
204         if (!OSSL_PARAM_get_octet_string(p, &ptr, 0, &size))
205             return 0;
206         OPENSSL_free(hmac->nonce);
207         hmac->nonce = ptr;
208         hmac->noncelen = size;
209         hmac->init = 0;
210     }
211 
212     p = OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_DIGEST);
213     if (p != NULL) {
214         if (!ossl_prov_digest_load_from_params(&drbg->digest, params, libctx))
215             return 0;
216 
217         /* Confirm digest is allowed. Allow all digests that are not XOF */
218         md = ossl_prov_digest_md(&drbg->digest);
219         if (md != NULL) {
220             if (EVP_MD_xof(md)) {
221                 ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
222                 return 0;
223             }
224             md_size = EVP_MD_get_size(md);
225             if (md_size <= 0)
226                 return 0;
227             drbg->blocklen = (size_t)md_size;
228         }
229         return ossl_prov_macctx_load_from_params(&drbg->ctx, params,
230                                                  "HMAC", NULL, NULL, libctx);
231     }
232     return 1;
233 }
234 
hmac_drbg_kdf_settable_ctx_params(ossl_unused void * vctx,ossl_unused void * p_ctx)235 static const OSSL_PARAM *hmac_drbg_kdf_settable_ctx_params(
236     ossl_unused void *vctx, ossl_unused void *p_ctx)
237 {
238     static const OSSL_PARAM known_settable_ctx_params[] = {
239         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_HMACDRBG_ENTROPY, NULL, 0),
240         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_HMACDRBG_NONCE, NULL, 0),
241         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
242         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
243         OSSL_PARAM_END
244     };
245     return known_settable_ctx_params;
246 }
247 
248 const OSSL_DISPATCH ossl_kdf_hmac_drbg_functions[] = {
249     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))hmac_drbg_kdf_new },
250     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))hmac_drbg_kdf_free },
251     { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))hmac_drbg_kdf_dup },
252     { OSSL_FUNC_KDF_RESET, (void(*)(void))hmac_drbg_kdf_reset },
253     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))hmac_drbg_kdf_derive },
254     { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
255       (void(*)(void))hmac_drbg_kdf_settable_ctx_params },
256     { OSSL_FUNC_KDF_SET_CTX_PARAMS,
257       (void(*)(void))hmac_drbg_kdf_set_ctx_params },
258     { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
259       (void(*)(void))hmac_drbg_kdf_gettable_ctx_params },
260     { OSSL_FUNC_KDF_GET_CTX_PARAMS,
261       (void(*)(void))hmac_drbg_kdf_get_ctx_params },
262     OSSL_DISPATCH_END
263 };
264