1 /*
2 * Copyright 2020-2022 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 #include <openssl/crypto.h>
11 #include <openssl/kdf.h>
12 #include <openssl/core_dispatch.h>
13 #include <openssl/core_names.h>
14 #include <openssl/err.h>
15 #include <openssl/proverr.h>
16 #include <openssl/params.h>
17 #include "internal/numbers.h"
18 #include "prov/implementations.h"
19 #include "prov/provider_ctx.h"
20 #include "prov/kdfexchange.h"
21 #include "prov/providercommon.h"
22
23 static OSSL_FUNC_keyexch_newctx_fn kdf_tls1_prf_newctx;
24 static OSSL_FUNC_keyexch_newctx_fn kdf_hkdf_newctx;
25 static OSSL_FUNC_keyexch_newctx_fn kdf_scrypt_newctx;
26 static OSSL_FUNC_keyexch_init_fn kdf_init;
27 static OSSL_FUNC_keyexch_derive_fn kdf_derive;
28 static OSSL_FUNC_keyexch_freectx_fn kdf_freectx;
29 static OSSL_FUNC_keyexch_dupctx_fn kdf_dupctx;
30 static OSSL_FUNC_keyexch_set_ctx_params_fn kdf_set_ctx_params;
31 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_tls1_prf_settable_ctx_params;
32 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_hkdf_settable_ctx_params;
33 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
34
35 typedef struct {
36 void *provctx;
37 EVP_KDF_CTX *kdfctx;
38 KDF_DATA *kdfdata;
39 } PROV_KDF_CTX;
40
kdf_newctx(const char * kdfname,void * provctx)41 static void *kdf_newctx(const char *kdfname, void *provctx)
42 {
43 PROV_KDF_CTX *kdfctx;
44 EVP_KDF *kdf = NULL;
45
46 if (!ossl_prov_is_running())
47 return NULL;
48
49 kdfctx = OPENSSL_zalloc(sizeof(PROV_KDF_CTX));
50 if (kdfctx == NULL)
51 return NULL;
52
53 kdfctx->provctx = provctx;
54
55 kdf = EVP_KDF_fetch(PROV_LIBCTX_OF(provctx), kdfname, NULL);
56 if (kdf == NULL)
57 goto err;
58 kdfctx->kdfctx = EVP_KDF_CTX_new(kdf);
59 EVP_KDF_free(kdf);
60
61 if (kdfctx->kdfctx == NULL)
62 goto err;
63
64 return kdfctx;
65 err:
66 OPENSSL_free(kdfctx);
67 return NULL;
68 }
69
70 #define KDF_NEWCTX(funcname, kdfname) \
71 static void *kdf_##funcname##_newctx(void *provctx) \
72 { \
73 return kdf_newctx(kdfname, provctx); \
74 }
75
76 KDF_NEWCTX(tls1_prf, "TLS1-PRF")
77 KDF_NEWCTX(hkdf, "HKDF")
78 KDF_NEWCTX(scrypt, "SCRYPT")
79
kdf_init(void * vpkdfctx,void * vkdf,const OSSL_PARAM params[])80 static int kdf_init(void *vpkdfctx, void *vkdf, const OSSL_PARAM params[])
81 {
82 PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
83
84 if (!ossl_prov_is_running()
85 || pkdfctx == NULL
86 || vkdf == NULL
87 || !ossl_kdf_data_up_ref(vkdf))
88 return 0;
89 pkdfctx->kdfdata = vkdf;
90
91 return kdf_set_ctx_params(pkdfctx, params);
92 }
93
kdf_derive(void * vpkdfctx,unsigned char * secret,size_t * secretlen,size_t outlen)94 static int kdf_derive(void *vpkdfctx, unsigned char *secret, size_t *secretlen,
95 size_t outlen)
96 {
97 PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
98 size_t kdfsize;
99 int ret;
100
101 if (!ossl_prov_is_running())
102 return 0;
103
104 kdfsize = EVP_KDF_CTX_get_kdf_size(pkdfctx->kdfctx);
105
106 if (secret == NULL) {
107 *secretlen = kdfsize;
108 return 1;
109 }
110
111 if (kdfsize != SIZE_MAX) {
112 if (outlen < kdfsize) {
113 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
114 return 0;
115 }
116 outlen = kdfsize;
117 }
118
119 ret = EVP_KDF_derive(pkdfctx->kdfctx, secret, outlen, NULL);
120 if (ret <= 0)
121 return 0;
122
123 *secretlen = outlen;
124 return 1;
125 }
126
kdf_freectx(void * vpkdfctx)127 static void kdf_freectx(void *vpkdfctx)
128 {
129 PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
130
131 EVP_KDF_CTX_free(pkdfctx->kdfctx);
132 ossl_kdf_data_free(pkdfctx->kdfdata);
133
134 OPENSSL_free(pkdfctx);
135 }
136
kdf_dupctx(void * vpkdfctx)137 static void *kdf_dupctx(void *vpkdfctx)
138 {
139 PROV_KDF_CTX *srcctx = (PROV_KDF_CTX *)vpkdfctx;
140 PROV_KDF_CTX *dstctx;
141
142 if (!ossl_prov_is_running())
143 return NULL;
144
145 dstctx = OPENSSL_zalloc(sizeof(*srcctx));
146 if (dstctx == NULL)
147 return NULL;
148
149 *dstctx = *srcctx;
150
151 dstctx->kdfctx = EVP_KDF_CTX_dup(srcctx->kdfctx);
152 if (dstctx->kdfctx == NULL) {
153 OPENSSL_free(dstctx);
154 return NULL;
155 }
156 if (!ossl_kdf_data_up_ref(dstctx->kdfdata)) {
157 EVP_KDF_CTX_free(dstctx->kdfctx);
158 OPENSSL_free(dstctx);
159 return NULL;
160 }
161
162 return dstctx;
163 }
164
kdf_set_ctx_params(void * vpkdfctx,const OSSL_PARAM params[])165 static int kdf_set_ctx_params(void *vpkdfctx, const OSSL_PARAM params[])
166 {
167 PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
168
169 return EVP_KDF_CTX_set_params(pkdfctx->kdfctx, params);
170 }
171
kdf_settable_ctx_params(ossl_unused void * vpkdfctx,void * provctx,const char * kdfname)172 static const OSSL_PARAM *kdf_settable_ctx_params(ossl_unused void *vpkdfctx,
173 void *provctx,
174 const char *kdfname)
175 {
176 EVP_KDF *kdf = EVP_KDF_fetch(PROV_LIBCTX_OF(provctx), kdfname,
177 NULL);
178 const OSSL_PARAM *params;
179
180 if (kdf == NULL)
181 return NULL;
182
183 params = EVP_KDF_settable_ctx_params(kdf);
184 EVP_KDF_free(kdf);
185
186 return params;
187 }
188
189 #define KDF_SETTABLE_CTX_PARAMS(funcname, kdfname) \
190 static const OSSL_PARAM *kdf_##funcname##_settable_ctx_params(void *vpkdfctx, \
191 void *provctx) \
192 { \
193 return kdf_settable_ctx_params(vpkdfctx, provctx, kdfname); \
194 }
195
196 KDF_SETTABLE_CTX_PARAMS(tls1_prf, "TLS1-PRF")
197 KDF_SETTABLE_CTX_PARAMS(hkdf, "HKDF")
198 KDF_SETTABLE_CTX_PARAMS(scrypt, "SCRYPT")
199
200 #define KDF_KEYEXCH_FUNCTIONS(funcname) \
201 const OSSL_DISPATCH ossl_kdf_##funcname##_keyexch_functions[] = { \
202 { OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))kdf_##funcname##_newctx }, \
203 { OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))kdf_init }, \
204 { OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))kdf_derive }, \
205 { OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))kdf_freectx }, \
206 { OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))kdf_dupctx }, \
207 { OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))kdf_set_ctx_params }, \
208 { OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS, \
209 (void (*)(void))kdf_##funcname##_settable_ctx_params }, \
210 { 0, NULL } \
211 };
212
213 KDF_KEYEXCH_FUNCTIONS(tls1_prf)
214 KDF_KEYEXCH_FUNCTIONS(hkdf)
215 KDF_KEYEXCH_FUNCTIONS(scrypt)
216