2 * Copyright 2018-2019 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
13 #include <openssl/evp.h>
14 #include <openssl/kdf.h>
15 #include <openssl/core_names.h>
16 #include "internal/cryptlib.h"
17 #include "internal/numbers.h"
18 #include "internal/evp_int.h"
19 #include "internal/provider_ctx.h"
20 #include "internal/providercommonerr.h"
21 #include "internal/provider_algs.h"
22 # include "internal/provider_util.h"
24 /* See RFC 4253, Section 7.2 */
25 static OSSL_OP_kdf_newctx_fn kdf_sshkdf_new;
26 static OSSL_OP_kdf_freectx_fn kdf_sshkdf_free;
27 static OSSL_OP_kdf_reset_fn kdf_sshkdf_reset;
28 static OSSL_OP_kdf_derive_fn kdf_sshkdf_derive;
29 static OSSL_OP_kdf_settable_ctx_params_fn kdf_sshkdf_settable_ctx_params;
30 static OSSL_OP_kdf_set_ctx_params_fn kdf_sshkdf_set_ctx_params;
31 static OSSL_OP_kdf_gettable_ctx_params_fn kdf_sshkdf_gettable_ctx_params;
32 static OSSL_OP_kdf_get_ctx_params_fn kdf_sshkdf_get_ctx_params;
34 static int SSHKDF(const EVP_MD *evp_md,
35 const unsigned char *key, size_t key_len,
36 const unsigned char *xcghash, size_t xcghash_len,
37 const unsigned char *session_id, size_t session_id_len,
38 char type, unsigned char *okey, size_t okey_len);
43 unsigned char *key; /* K */
45 unsigned char *xcghash; /* H */
48 unsigned char *session_id;
49 size_t session_id_len;
52 static void *kdf_sshkdf_new(void *provctx)
56 if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
57 ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
58 ctx->provctx = provctx;
62 static void kdf_sshkdf_free(void *vctx)
64 KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
66 kdf_sshkdf_reset(ctx);
70 static void kdf_sshkdf_reset(void *vctx)
72 KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
74 ossl_prov_digest_reset(&ctx->digest);
75 OPENSSL_clear_free(ctx->key, ctx->key_len);
76 OPENSSL_clear_free(ctx->xcghash, ctx->xcghash_len);
77 OPENSSL_clear_free(ctx->session_id, ctx->session_id_len);
78 memset(ctx, 0, sizeof(*ctx));
81 static int sshkdf_set_membuf(unsigned char **dst, size_t *dst_len,
84 OPENSSL_clear_free(*dst, *dst_len);
86 return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
89 static int kdf_sshkdf_derive(void *vctx, unsigned char *key,
92 KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
93 const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
96 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
99 if (ctx->key == NULL) {
100 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
103 if (ctx->xcghash == NULL) {
104 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_XCGHASH);
107 if (ctx->session_id == NULL) {
108 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SESSION_ID);
111 if (ctx->type == 0) {
112 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_TYPE);
115 return SSHKDF(md, ctx->key, ctx->key_len,
116 ctx->xcghash, ctx->xcghash_len,
117 ctx->session_id, ctx->session_id_len,
118 ctx->type, key, keylen);
121 static int kdf_sshkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
124 KDF_SSHKDF *ctx = vctx;
125 OPENSSL_CTX *provctx = PROV_LIBRARY_CONTEXT_OF(ctx->provctx);
128 if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
131 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
132 if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p))
135 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_XCGHASH))
137 if (!sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p))
140 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_SESSION_ID))
142 if (!sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p))
145 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_TYPE))
147 if (p->data == NULL || p->data_size == 0)
149 t = *(unsigned char *)p->data;
150 if (t < 65 || t > 70) {
151 ERR_raise(ERR_LIB_PROV, PROV_R_VALUE_ERROR);
159 static const OSSL_PARAM *kdf_sshkdf_settable_ctx_params(void)
161 static const OSSL_PARAM known_settable_ctx_params[] = {
162 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
163 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
164 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
165 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_XCGHASH, NULL, 0),
166 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_SESSION_ID, NULL, 0),
167 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_SSHKDF_TYPE, NULL, 0),
170 return known_settable_ctx_params;
173 static int kdf_sshkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
177 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
178 return OSSL_PARAM_set_size_t(p, SIZE_MAX);
182 static const OSSL_PARAM *kdf_sshkdf_gettable_ctx_params(void)
184 static const OSSL_PARAM known_gettable_ctx_params[] = {
185 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
188 return known_gettable_ctx_params;
191 const OSSL_DISPATCH kdf_sshkdf_functions[] = {
192 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_sshkdf_new },
193 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_sshkdf_free },
194 { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_sshkdf_reset },
195 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_sshkdf_derive },
196 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
197 (void(*)(void))kdf_sshkdf_settable_ctx_params },
198 { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_set_ctx_params },
199 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
200 (void(*)(void))kdf_sshkdf_gettable_ctx_params },
201 { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_get_ctx_params },
205 static int SSHKDF(const EVP_MD *evp_md,
206 const unsigned char *key, size_t key_len,
207 const unsigned char *xcghash, size_t xcghash_len,
208 const unsigned char *session_id, size_t session_id_len,
209 char type, unsigned char *okey, size_t okey_len)
211 EVP_MD_CTX *md = NULL;
212 unsigned char digest[EVP_MAX_MD_SIZE];
213 unsigned int dsize = 0;
217 md = EVP_MD_CTX_new();
221 if (!EVP_DigestInit_ex(md, evp_md, NULL))
224 if (!EVP_DigestUpdate(md, key, key_len))
227 if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
230 if (!EVP_DigestUpdate(md, &type, 1))
233 if (!EVP_DigestUpdate(md, session_id, session_id_len))
236 if (!EVP_DigestFinal_ex(md, digest, &dsize))
239 if (okey_len < dsize) {
240 memcpy(okey, digest, okey_len);
245 memcpy(okey, digest, dsize);
247 for (cursize = dsize; cursize < okey_len; cursize += dsize) {
249 if (!EVP_DigestInit_ex(md, evp_md, NULL))
252 if (!EVP_DigestUpdate(md, key, key_len))
255 if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
258 if (!EVP_DigestUpdate(md, okey, cursize))
261 if (!EVP_DigestFinal_ex(md, digest, &dsize))
264 if (okey_len < cursize + dsize) {
265 memcpy(okey + cursize, digest, okey_len - cursize);
270 memcpy(okey + cursize, digest, dsize);
277 OPENSSL_cleanse(digest, EVP_MAX_MD_SIZE);