--- /dev/null
+/*
+ * 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
+ */
+
+/*
+ * 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 the TLS PRF algorithm is given by:
+ *
+ * PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
+ * P_SHA-1(S2, label + seed)
+ *
+ * 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.
+ *
+ * For TLS v1.2 the TLS PRF algorithm is given by:
+ *
+ * PRF(secret, label, seed) = P_<hash>(secret, label + seed)
+ *
+ * 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.
+ *
+ * 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))
+ */
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include "internal/cryptlib.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,
+ unsigned char *out, size_t olen);
+
+#define TLS1_PRF_MAXBUF 1024
+
+/* TLS KDF kdf context structure */
+
+struct evp_kdf_impl_st {
+ /* Digest to use for PRF */
+ const EVP_MD *md;
+ /* Secret value to use for PRF */
+ unsigned char *sec;
+ size_t seclen;
+ /* Buffer of concatenated seed data */
+ unsigned char seed[TLS1_PRF_MAXBUF];
+ size_t seedlen;
+};
+
+static EVP_KDF_IMPL *kdf_tls1_prf_new(void)
+{
+ EVP_KDF_IMPL *impl;
+
+ if ((impl = OPENSSL_zalloc(sizeof(*impl))) == NULL)
+ KDFerr(KDF_F_KDF_TLS1_PRF_NEW, ERR_R_MALLOC_FAILURE);
+ return impl;
+}
+
+static void kdf_tls1_prf_free(EVP_KDF_IMPL *impl)
+{
+ kdf_tls1_prf_reset(impl);
+ OPENSSL_free(impl);
+}
+
+static void kdf_tls1_prf_reset(EVP_KDF_IMPL *impl)
+{
+ OPENSSL_clear_free(impl->sec, impl->seclen);
+ OPENSSL_cleanse(impl->seed, impl->seedlen);
+ memset(impl, 0, sizeof(*impl));
+}
+
+static int kdf_tls1_prf_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
+{
+ const unsigned char *p;
+ size_t len;
+ const EVP_MD *md;
+
+ switch (cmd) {
+ case EVP_KDF_CTRL_SET_MD:
+ md = va_arg(args, const EVP_MD *);
+ if (md == NULL)
+ return 0;
+
+ 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;
+
+ impl->seclen = len;
+ return 1;
+
+ /* TODO: This is only ever called from pkey_kdf and only as part of setting the TLS secret
+ consider merging the twe two?? */
+ case EVP_KDF_CTRL_RESET_TLS_SEED:
+ OPENSSL_cleanse(impl->seed, impl->seedlen);
+ impl->seedlen = 0;
+ return 1;
+
+ 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 (len > (TLS1_PRF_MAXBUF - impl->seedlen))
+ return 0;
+
+ memcpy(impl->seed + impl->seedlen, p, len);
+ impl->seedlen += len;
+ return 1;
+
+ default:
+ return -2;
+ }
+}
+
+static int kdf_tls1_prf_ctrl_str(EVP_KDF_IMPL *impl,
+ const char *type, const char *value)
+{
+ if (value == NULL) {
+ KDFerr(KDF_F_KDF_TLS1_PRF_CTRL_STR, KDF_R_VALUE_MISSING);
+ return 0;
+ }
+ if (strcmp(type, "digest") == 0)
+ return kdf_md2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_SET_MD, value);
+
+ if (strcmp(type, "secret") == 0)
+ return kdf_str2ctrl(impl, kdf_tls1_prf_ctrl,
+ EVP_KDF_CTRL_SET_TLS_SECRET, value);
+
+ if (strcmp(type, "hexsecret") == 0)
+ return kdf_hex2ctrl(impl, kdf_tls1_prf_ctrl,
+ EVP_KDF_CTRL_SET_TLS_SECRET, value);
+
+ if (strcmp(type, "seed") == 0)
+ return kdf_str2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_ADD_TLS_SEED,
+ value);
+
+ if (strcmp(type, "hexseed") == 0)
+ return kdf_hex2ctrl(impl, kdf_tls1_prf_ctrl, EVP_KDF_CTRL_ADD_TLS_SEED,
+ value);
+
+ return -2;
+}
+
+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);
+}
+
+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)
+{
+ 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);
+
+ 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;
+
+ /* 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, 0);
+ 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_MAC_init(ctx_init))
+ goto err;
+ chunk = EVP_MAC_size(ctx_init);
+ if (chunk == 0)
+ goto err;
+ /* A(0) = seed */
+ ctx_Ai = EVP_MAC_CTX_dup(ctx_init);
+ if (ctx_Ai == NULL)
+ goto err;
+ if (seed != NULL && !EVP_MAC_update(ctx_Ai, seed, seed_len))
+ goto err;
+
+ for (;;) {
+ /* calc: A(i) = HMAC_<hash>(secret, A(i-1)) */
+ if (!EVP_MAC_final(ctx_Ai, Ai, &Ai_len, sizeof(Ai)))
+ goto err;
+ 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 (!EVP_MAC_update(ctx, Ai, Ai_len))
+ goto err;
+ /* save state for calculating next A(i) value */
+ if (olen > chunk) {
+ ctx_Ai = EVP_MAC_CTX_dup(ctx);
+ if (ctx_Ai == NULL)
+ goto err;
+ }
+ 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, 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_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;
+ /* 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;
+
+ 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 - L_S2, L_S2,
+ seed, seed_len, tmp, olen)) {
+ OPENSSL_clear_free(tmp, olen);
+ return 0;
+ }
+ for (i = 0; i < olen; i++)
+ out[i] ^= tmp[i];
+ 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;
+
+ return 1;
+}
projects / thirdparty / openssl.git / blobdiff