1 /*
2  * Copyright 2020-2021 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/params.h>
15 #include "prov/implementations.h"
16 #include "prov/provider_ctx.h"
17 #include "prov/kdfexchange.h"
18 #include "prov/providercommon.h"
19 
20 static OSSL_FUNC_keyexch_newctx_fn kdf_tls1_prf_newctx;
21 static OSSL_FUNC_keyexch_newctx_fn kdf_hkdf_newctx;
22 static OSSL_FUNC_keyexch_newctx_fn kdf_scrypt_newctx;
23 static OSSL_FUNC_keyexch_init_fn kdf_init;
24 static OSSL_FUNC_keyexch_derive_fn kdf_derive;
25 static OSSL_FUNC_keyexch_freectx_fn kdf_freectx;
26 static OSSL_FUNC_keyexch_dupctx_fn kdf_dupctx;
27 static OSSL_FUNC_keyexch_set_ctx_params_fn kdf_set_ctx_params;
28 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_tls1_prf_settable_ctx_params;
29 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_hkdf_settable_ctx_params;
30 static OSSL_FUNC_keyexch_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
31 
32 typedef struct {
33     void *provctx;
34     EVP_KDF_CTX *kdfctx;
35     KDF_DATA *kdfdata;
36 } PROV_KDF_CTX;
37 
kdf_newctx(const char * kdfname,void * provctx)38 static void *kdf_newctx(const char *kdfname, void *provctx)
39 {
40     PROV_KDF_CTX *kdfctx;
41     EVP_KDF *kdf = NULL;
42 
43     if (!ossl_prov_is_running())
44         return NULL;
45 
46     kdfctx = OPENSSL_zalloc(sizeof(PROV_KDF_CTX));
47     if (kdfctx == NULL)
48         return NULL;
49 
50     kdfctx->provctx = provctx;
51 
52     kdf = EVP_KDF_fetch(PROV_LIBCTX_OF(provctx), kdfname, NULL);
53     if (kdf == NULL)
54         goto err;
55     kdfctx->kdfctx = EVP_KDF_CTX_new(kdf);
56     EVP_KDF_free(kdf);
57 
58     if (kdfctx->kdfctx == NULL)
59         goto err;
60 
61     return kdfctx;
62 err:
63     OPENSSL_free(kdfctx);
64     return NULL;
65 }
66 
67 #define KDF_NEWCTX(funcname, kdfname) \
68     static void *kdf_##funcname##_newctx(void *provctx) \
69     { \
70         return kdf_newctx(kdfname, provctx); \
71     }
72 
73 KDF_NEWCTX(tls1_prf, "TLS1-PRF")
74 KDF_NEWCTX(hkdf, "HKDF")
75 KDF_NEWCTX(scrypt, "SCRYPT")
76 
kdf_init(void * vpkdfctx,void * vkdf,const OSSL_PARAM params[])77 static int kdf_init(void *vpkdfctx, void *vkdf, const OSSL_PARAM params[])
78 {
79     PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
80 
81     if (!ossl_prov_is_running()
82             || pkdfctx == NULL
83             || vkdf == NULL
84             || !ossl_kdf_data_up_ref(vkdf))
85         return 0;
86     pkdfctx->kdfdata = vkdf;
87 
88     return kdf_set_ctx_params(pkdfctx, params);
89 }
90 
kdf_derive(void * vpkdfctx,unsigned char * secret,size_t * secretlen,size_t outlen)91 static int kdf_derive(void *vpkdfctx, unsigned char *secret, size_t *secretlen,
92                       size_t outlen)
93 {
94     PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
95 
96     if (!ossl_prov_is_running())
97         return 0;
98 
99     if (secret == NULL) {
100         *secretlen = EVP_KDF_CTX_get_kdf_size(pkdfctx->kdfctx);
101         return 1;
102     }
103 
104     return EVP_KDF_derive(pkdfctx->kdfctx, secret, outlen, NULL);
105 }
106 
kdf_freectx(void * vpkdfctx)107 static void kdf_freectx(void *vpkdfctx)
108 {
109     PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
110 
111     EVP_KDF_CTX_free(pkdfctx->kdfctx);
112     ossl_kdf_data_free(pkdfctx->kdfdata);
113 
114     OPENSSL_free(pkdfctx);
115 }
116 
kdf_dupctx(void * vpkdfctx)117 static void *kdf_dupctx(void *vpkdfctx)
118 {
119     PROV_KDF_CTX *srcctx = (PROV_KDF_CTX *)vpkdfctx;
120     PROV_KDF_CTX *dstctx;
121 
122     if (!ossl_prov_is_running())
123         return NULL;
124 
125     dstctx = OPENSSL_zalloc(sizeof(*srcctx));
126     if (dstctx == NULL)
127         return NULL;
128 
129     *dstctx = *srcctx;
130 
131     dstctx->kdfctx = EVP_KDF_CTX_dup(srcctx->kdfctx);
132     if (dstctx->kdfctx == NULL) {
133         OPENSSL_free(dstctx);
134         return NULL;
135     }
136     if (!ossl_kdf_data_up_ref(dstctx->kdfdata)) {
137         EVP_KDF_CTX_free(dstctx->kdfctx);
138         OPENSSL_free(dstctx);
139         return NULL;
140     }
141 
142     return dstctx;
143 }
144 
kdf_set_ctx_params(void * vpkdfctx,const OSSL_PARAM params[])145 static int kdf_set_ctx_params(void *vpkdfctx, const OSSL_PARAM params[])
146 {
147     PROV_KDF_CTX *pkdfctx = (PROV_KDF_CTX *)vpkdfctx;
148 
149     return EVP_KDF_CTX_set_params(pkdfctx->kdfctx, params);
150 }
151 
kdf_settable_ctx_params(ossl_unused void * vpkdfctx,void * provctx,const char * kdfname)152 static const OSSL_PARAM *kdf_settable_ctx_params(ossl_unused void *vpkdfctx,
153                                                  void *provctx,
154                                                  const char *kdfname)
155 {
156     EVP_KDF *kdf = EVP_KDF_fetch(PROV_LIBCTX_OF(provctx), kdfname,
157                                  NULL);
158     const OSSL_PARAM *params;
159 
160     if (kdf == NULL)
161         return NULL;
162 
163     params = EVP_KDF_settable_ctx_params(kdf);
164     EVP_KDF_free(kdf);
165 
166     return params;
167 }
168 
169 #define KDF_SETTABLE_CTX_PARAMS(funcname, kdfname) \
170     static const OSSL_PARAM *kdf_##funcname##_settable_ctx_params(void *vpkdfctx, \
171                                                                   void *provctx) \
172     { \
173         return kdf_settable_ctx_params(vpkdfctx, provctx, kdfname); \
174     }
175 
176 KDF_SETTABLE_CTX_PARAMS(tls1_prf, "TLS1-PRF")
177 KDF_SETTABLE_CTX_PARAMS(hkdf, "HKDF")
178 KDF_SETTABLE_CTX_PARAMS(scrypt, "SCRYPT")
179 
180 #define KDF_KEYEXCH_FUNCTIONS(funcname) \
181     const OSSL_DISPATCH ossl_kdf_##funcname##_keyexch_functions[] = { \
182         { OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))kdf_##funcname##_newctx }, \
183         { OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))kdf_init }, \
184         { OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))kdf_derive }, \
185         { OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))kdf_freectx }, \
186         { OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))kdf_dupctx }, \
187         { OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))kdf_set_ctx_params }, \
188         { OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS, \
189         (void (*)(void))kdf_##funcname##_settable_ctx_params }, \
190         { 0, NULL } \
191     };
192 
193 KDF_KEYEXCH_FUNCTIONS(tls1_prf)
194 KDF_KEYEXCH_FUNCTIONS(hkdf)
195 KDF_KEYEXCH_FUNCTIONS(scrypt)
196