/*
- * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
- * 2016.
+ * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
-/* ====================================================================
- * Copyright (c) 2015 The OpenSSL Project. All rights reserved.
+
+/*
+ * Refer to "The TLS Protocol Version 1.0" Section 5
+ * (https://tools.ietf.org/html/rfc2246#section-5) and
+ * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
+ * (https://tools.ietf.org/html/rfc5246#section-5).
*
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
+ * For TLS v1.0 and TLS v1.1 the TLS PRF algorithm is given by:
*
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
+ * P_SHA-1(S2, label + seed)
*
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
+ * where P_MD5 and P_SHA-1 are defined by P_<hash>, below, and S1 and S2 are
+ * two halves of the secret (with the possibility of one shared byte, in the
+ * case where the length of the original secret is odd). S1 is taken from the
+ * first half of the secret, S2 from the second half.
*
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ * For TLS v1.2 the TLS PRF algorithm is given by:
*
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * licensing@OpenSSL.org.
+ * PRF(secret, label, seed) = P_<hash>(secret, label + seed)
*
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
+ * where hash is SHA-256 for all cipher suites defined in RFC 5246 as well as
+ * those published prior to TLS v1.2 while the TLS v1.2 protocol is in effect,
+ * unless defined otherwise by the cipher suite.
*
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ * P_<hash> is an expansion function that uses a single hash function to expand
+ * a secret and seed into an arbitrary quantity of output:
*
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
+ * P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
+ * HMAC_<hash>(secret, A(2) + seed) +
+ * HMAC_<hash>(secret, A(3) + seed) + ...
*
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
+ * where + indicates concatenation. P_<hash> can be iterated as many times as
+ * is necessary to produce the required quantity of data.
*
+ * A(i) is defined as:
+ * A(0) = seed
+ * A(i) = HMAC_<hash>(secret, A(i-1))
*/
-
#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
#include "internal/cryptlib.h"
-#include <openssl/kdf.h>
#include <openssl/evp.h>
+#include <openssl/kdf.h>
+#include <openssl/core_names.h>
+#include <openssl/params.h>
#include "internal/evp_int.h"
+#include "kdf_local.h"
+static void kdf_tls1_prf_reset(EVP_KDF_IMPL *impl);
static int tls1_prf_alg(const EVP_MD *md,
const unsigned char *sec, size_t slen,
const unsigned char *seed, size_t seed_len,
#define TLS1_PRF_MAXBUF 1024
-/* TLS KDF pkey context structure */
+/* TLS KDF kdf context structure */
-typedef struct {
+struct evp_kdf_impl_st {
/* Digest to use for PRF */
const EVP_MD *md;
/* Secret value to use for PRF */
/* Buffer of concatenated seed data */
unsigned char seed[TLS1_PRF_MAXBUF];
size_t seedlen;
-} TLS1_PRF_PKEY_CTX;
+};
-static int pkey_tls1_prf_init(EVP_PKEY_CTX *ctx)
+static EVP_KDF_IMPL *kdf_tls1_prf_new(void)
{
- TLS1_PRF_PKEY_CTX *kctx;
+ EVP_KDF_IMPL *impl;
- kctx = OPENSSL_zalloc(sizeof(*kctx));
- if (kctx == NULL)
- return 0;
- ctx->data = kctx;
+ if ((impl = OPENSSL_zalloc(sizeof(*impl))) == NULL)
+ KDFerr(KDF_F_KDF_TLS1_PRF_NEW, ERR_R_MALLOC_FAILURE);
+ return impl;
+}
- return 1;
+static void kdf_tls1_prf_free(EVP_KDF_IMPL *impl)
+{
+ kdf_tls1_prf_reset(impl);
+ OPENSSL_free(impl);
}
-static void pkey_tls1_prf_cleanup(EVP_PKEY_CTX *ctx)
+static void kdf_tls1_prf_reset(EVP_KDF_IMPL *impl)
{
- TLS1_PRF_PKEY_CTX *kctx = ctx->data;
- OPENSSL_clear_free(kctx->sec, kctx->seclen);
- OPENSSL_cleanse(kctx->seed, kctx->seedlen);
- OPENSSL_free(kctx);
+ OPENSSL_clear_free(impl->sec, impl->seclen);
+ OPENSSL_cleanse(impl->seed, impl->seedlen);
+ memset(impl, 0, sizeof(*impl));
}
-static int pkey_tls1_prf_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
+static int kdf_tls1_prf_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
{
- TLS1_PRF_PKEY_CTX *kctx = ctx->data;
- switch (type) {
- case EVP_PKEY_CTRL_TLS_MD:
- kctx->md = p2;
- return 1;
+ const unsigned char *p;
+ size_t len;
+ const EVP_MD *md;
- case EVP_PKEY_CTRL_TLS_SECRET:
- if (p1 < 0)
+ switch (cmd) {
+ case EVP_KDF_CTRL_SET_MD:
+ md = va_arg(args, const EVP_MD *);
+ if (md == NULL)
return 0;
- if (kctx->sec != NULL)
- OPENSSL_clear_free(kctx->sec, kctx->seclen);
- OPENSSL_cleanse(kctx->seed, kctx->seedlen);
- kctx->seedlen = 0;
- kctx->sec = OPENSSL_memdup(p2, p1);
- if (kctx->sec == NULL)
+
+ impl->md = md;
+ return 1;
+
+ case EVP_KDF_CTRL_SET_TLS_SECRET:
+ p = va_arg(args, const unsigned char *);
+ len = va_arg(args, size_t);
+ OPENSSL_clear_free(impl->sec, impl->seclen);
+ impl->sec = OPENSSL_memdup(p, len);
+ if (impl->sec == NULL)
return 0;
- kctx->seclen = p1;
+
+ impl->seclen = len;
+ return 1;
+
+ case EVP_KDF_CTRL_RESET_TLS_SEED:
+ OPENSSL_cleanse(impl->seed, impl->seedlen);
+ impl->seedlen = 0;
return 1;
- case EVP_PKEY_CTRL_TLS_SEED:
- if (p1 == 0 || p2 == NULL)
+ case EVP_KDF_CTRL_ADD_TLS_SEED:
+ p = va_arg(args, const unsigned char *);
+ len = va_arg(args, size_t);
+ if (len == 0 || p == NULL)
return 1;
- if (p1 < 0 || p1 > (int)(TLS1_PRF_MAXBUF - kctx->seedlen))
+
+ if (len > (TLS1_PRF_MAXBUF - impl->seedlen))
return 0;
- memcpy(kctx->seed + kctx->seedlen, p2, p1);
- kctx->seedlen += p1;
+
+ memcpy(impl->seed + impl->seedlen, p, len);
+ impl->seedlen += len;
return 1;
default:
return -2;
-
}
}
-static int pkey_tls1_prf_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
- size_t *keylen)
+static int kdf_tls1_prf_ctrl_str(EVP_KDF_IMPL *impl,
+ const char *type, const char *value)
{
- TLS1_PRF_PKEY_CTX *kctx = ctx->data;
- if (kctx->md == NULL || kctx->sec == NULL || kctx->seedlen == 0)
+ if (value == NULL) {
+ KDFerr(KDF_F_KDF_TLS1_PRF_CTRL_STR, KDF_R_VALUE_MISSING);
return 0;
- return tls1_prf_alg(kctx->md, kctx->sec, kctx->seclen,
- kctx->seed, kctx->seedlen,
- key, *keylen);
-}
-
-const EVP_PKEY_METHOD tls1_prf_pkey_meth = {
- EVP_PKEY_TLS1_PRF,
- 0,
- pkey_tls1_prf_init,
- 0,
- pkey_tls1_prf_cleanup,
-
- 0, 0,
- 0, 0,
+ }
+ if (strcmp(type, "digest") == 0)
+ return kdf_md2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_SET_MD, value);
- 0,
- 0,
+ if (strcmp(type, "secret") == 0)
+ return kdf_str2ctrl(impl, kdf_tls1_prf_ctrl,
+ EVP_KDF_CTRL_SET_TLS_SECRET, value);
- 0,
- 0,
+ if (strcmp(type, "hexsecret") == 0)
+ return kdf_hex2ctrl(impl, kdf_tls1_prf_ctrl,
+ EVP_KDF_CTRL_SET_TLS_SECRET, value);
- 0, 0,
+ if (strcmp(type, "seed") == 0)
+ return kdf_str2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_ADD_TLS_SEED,
+ value);
- 0, 0, 0, 0,
+ if (strcmp(type, "hexseed") == 0)
+ return kdf_hex2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_ADD_TLS_SEED,
+ value);
- 0, 0,
+ return -2;
+}
- 0, 0,
+static int kdf_tls1_prf_derive(EVP_KDF_IMPL *impl, unsigned char *key,
+ size_t keylen)
+{
+ if (impl->md == NULL) {
+ KDFerr(KDF_F_KDF_TLS1_PRF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
+ return 0;
+ }
+ if (impl->sec == NULL) {
+ KDFerr(KDF_F_KDF_TLS1_PRF_DERIVE, KDF_R_MISSING_SECRET);
+ return 0;
+ }
+ if (impl->seedlen == 0) {
+ KDFerr(KDF_F_KDF_TLS1_PRF_DERIVE, KDF_R_MISSING_SEED);
+ return 0;
+ }
+ return tls1_prf_alg(impl->md, impl->sec, impl->seclen,
+ impl->seed, impl->seedlen,
+ key, keylen);
+}
- 0,
- pkey_tls1_prf_derive,
- pkey_tls1_prf_ctrl,
- 0
+const EVP_KDF tls1_prf_kdf_meth = {
+ EVP_KDF_TLS1_PRF,
+ kdf_tls1_prf_new,
+ kdf_tls1_prf_free,
+ kdf_tls1_prf_reset,
+ kdf_tls1_prf_ctrl,
+ kdf_tls1_prf_ctrl_str,
+ NULL,
+ kdf_tls1_prf_derive
};
+/*
+ * Refer to "The TLS Protocol Version 1.0" Section 5
+ * (https://tools.ietf.org/html/rfc2246#section-5) and
+ * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
+ * (https://tools.ietf.org/html/rfc5246#section-5).
+ *
+ * P_<hash> is an expansion function that uses a single hash function to expand
+ * a secret and seed into an arbitrary quantity of output:
+ *
+ * P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
+ * HMAC_<hash>(secret, A(2) + seed) +
+ * HMAC_<hash>(secret, A(3) + seed) + ...
+ *
+ * where + indicates concatenation. P_<hash> can be iterated as many times as
+ * is necessary to produce the required quantity of data.
+ *
+ * A(i) is defined as:
+ * A(0) = seed
+ * A(i) = HMAC_<hash>(secret, A(i-1))
+ */
static int tls1_prf_P_hash(const EVP_MD *md,
const unsigned char *sec, size_t sec_len,
const unsigned char *seed, size_t seed_len,
unsigned char *out, size_t olen)
{
- int chunk;
- EVP_MD_CTX *ctx = NULL, *ctx_tmp = NULL, *ctx_init = NULL;
- EVP_PKEY *mac_key = NULL;
- unsigned char A1[EVP_MAX_MD_SIZE];
- size_t A1_len;
+ size_t chunk;
+ EVP_MAC *mac = NULL;
+ EVP_MAC_CTX *ctx = NULL, *ctx_Ai = NULL, *ctx_init = NULL;
+ unsigned char Ai[EVP_MAX_MD_SIZE];
+ size_t Ai_len;
int ret = 0;
+ OSSL_PARAM params[4];
+ int mac_flags;
+ const char *mdname = EVP_MD_name(md);
- chunk = EVP_MD_size(md);
- OPENSSL_assert(chunk >= 0);
-
- ctx = EVP_MD_CTX_new();
- ctx_tmp = EVP_MD_CTX_new();
- ctx_init = EVP_MD_CTX_new();
- if (ctx == NULL || ctx_tmp == NULL || ctx_init == NULL)
+ mac = EVP_MAC_fetch(NULL, OSSL_MAC_NAME_HMAC, NULL); /* Implicit fetch */
+ ctx_init = EVP_MAC_CTX_new(mac);
+ if (ctx_init == NULL)
goto err;
- EVP_MD_CTX_set_flags(ctx_init, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
- mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, sec, sec_len);
- if (mac_key == NULL)
+
+ /* TODO(3.0) rethink "flags", also see hmac.c in providers */
+ mac_flags = EVP_MD_CTX_FLAG_NON_FIPS_ALLOW;
+ params[0] = OSSL_PARAM_construct_int(OSSL_MAC_PARAM_FLAGS, &mac_flags);
+ params[1] = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST,
+ (char *)mdname,
+ strlen(mdname) + 1);
+ params[2] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
+ (void *)sec, sec_len);
+ params[3] = OSSL_PARAM_construct_end();
+ if (!EVP_MAC_CTX_set_params(ctx_init, params))
goto err;
- if (!EVP_DigestSignInit(ctx_init, NULL, md, NULL, mac_key))
+ if (!EVP_MAC_init(ctx_init))
goto err;
- if (!EVP_MD_CTX_copy_ex(ctx, ctx_init))
+ chunk = EVP_MAC_size(ctx_init);
+ if (chunk == 0)
goto err;
- if (seed != NULL && !EVP_DigestSignUpdate(ctx, seed, seed_len))
+ /* A(0) = seed */
+ ctx_Ai = EVP_MAC_CTX_dup(ctx_init);
+ if (ctx_Ai == NULL)
goto err;
- if (!EVP_DigestSignFinal(ctx, A1, &A1_len))
+ if (seed != NULL && !EVP_MAC_update(ctx_Ai, seed, seed_len))
goto err;
for (;;) {
- /* Reinit mac contexts */
- if (!EVP_MD_CTX_copy_ex(ctx, ctx_init))
- goto err;
- if (!EVP_DigestSignUpdate(ctx, A1, A1_len))
+ /* calc: A(i) = HMAC_<hash>(secret, A(i-1)) */
+ if (!EVP_MAC_final(ctx_Ai, Ai, &Ai_len, sizeof(Ai)))
goto err;
- if (olen > (size_t)chunk && !EVP_MD_CTX_copy_ex(ctx_tmp, ctx))
+ EVP_MAC_CTX_free(ctx_Ai);
+ ctx_Ai = NULL;
+
+ /* calc next chunk: HMAC_<hash>(secret, A(i) + seed) */
+ ctx = EVP_MAC_CTX_dup(ctx_init);
+ if (ctx == NULL)
goto err;
- if (seed && !EVP_DigestSignUpdate(ctx, seed, seed_len))
+ if (!EVP_MAC_update(ctx, Ai, Ai_len))
goto err;
-
- if (olen > (size_t)chunk) {
- size_t mac_len;
- if (!EVP_DigestSignFinal(ctx, out, &mac_len))
+ /* save state for calculating next A(i) value */
+ if (olen > chunk) {
+ ctx_Ai = EVP_MAC_CTX_dup(ctx);
+ if (ctx_Ai == NULL)
goto err;
- out += mac_len;
- olen -= mac_len;
- /* calc the next A1 value */
- if (!EVP_DigestSignFinal(ctx_tmp, A1, &A1_len))
- goto err;
- } else { /* last one */
-
- if (!EVP_DigestSignFinal(ctx, A1, &A1_len))
+ }
+ if (seed != NULL && !EVP_MAC_update(ctx, seed, seed_len))
+ goto err;
+ if (olen <= chunk) {
+ /* last chunk - use Ai as temp bounce buffer */
+ if (!EVP_MAC_final(ctx, Ai, &Ai_len, sizeof(Ai)))
goto err;
- memcpy(out, A1, olen);
+ memcpy(out, Ai, olen);
break;
}
+ if (!EVP_MAC_final(ctx, out, NULL, olen))
+ goto err;
+ EVP_MAC_CTX_free(ctx);
+ ctx = NULL;
+ out += chunk;
+ olen -= chunk;
}
ret = 1;
err:
- EVP_PKEY_free(mac_key);
- EVP_MD_CTX_free(ctx);
- EVP_MD_CTX_free(ctx_tmp);
- EVP_MD_CTX_free(ctx_init);
- OPENSSL_cleanse(A1, sizeof(A1));
+ EVP_MAC_CTX_free(ctx);
+ EVP_MAC_CTX_free(ctx_Ai);
+ EVP_MAC_CTX_free(ctx_init);
+ EVP_MAC_free(mac);
+ OPENSSL_cleanse(Ai, sizeof(Ai));
return ret;
}
+/*
+ * Refer to "The TLS Protocol Version 1.0" Section 5
+ * (https://tools.ietf.org/html/rfc2246#section-5) and
+ * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
+ * (https://tools.ietf.org/html/rfc5246#section-5).
+ *
+ * For TLS v1.0 and TLS v1.1:
+ *
+ * PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
+ * P_SHA-1(S2, label + seed)
+ *
+ * S1 is taken from the first half of the secret, S2 from the second half.
+ *
+ * L_S = length in bytes of secret;
+ * L_S1 = L_S2 = ceil(L_S / 2);
+ *
+ * For TLS v1.2:
+ *
+ * PRF(secret, label, seed) = P_<hash>(secret, label + seed)
+ */
static int tls1_prf_alg(const EVP_MD *md,
const unsigned char *sec, size_t slen,
const unsigned char *seed, size_t seed_len,
unsigned char *out, size_t olen)
{
-
if (EVP_MD_type(md) == NID_md5_sha1) {
+ /* TLS v1.0 and TLS v1.1 */
size_t i;
unsigned char *tmp;
- if (!tls1_prf_P_hash(EVP_md5(), sec, slen/2 + (slen & 1),
- seed, seed_len, out, olen))
+ /* calc: L_S1 = L_S2 = ceil(L_S / 2) */
+ size_t L_S1 = (slen + 1) / 2;
+ size_t L_S2 = L_S1;
+
+ if (!tls1_prf_P_hash(EVP_md5(), sec, L_S1,
+ seed, seed_len, out, olen))
return 0;
- tmp = OPENSSL_malloc(olen);
- if (tmp == NULL)
+ if ((tmp = OPENSSL_malloc(olen)) == NULL) {
+ KDFerr(KDF_F_TLS1_PRF_ALG, ERR_R_MALLOC_FAILURE);
return 0;
- if (!tls1_prf_P_hash(EVP_sha1(), sec + slen/2, slen/2 + (slen & 1),
- seed, seed_len, tmp, olen)) {
+ }
+ if (!tls1_prf_P_hash(EVP_sha1(), sec + slen - L_S2, L_S2,
+ seed, seed_len, tmp, olen)) {
OPENSSL_clear_free(tmp, olen);
return 0;
}
OPENSSL_clear_free(tmp, olen);
return 1;
}
+
+ /* TLS v1.2 */
if (!tls1_prf_P_hash(md, sec, slen, seed, seed_len, out, olen))
return 0;