* be 'copied' into these ones
*/
uint32_t mac_flags;
+ /*
+ * The TLS1.3 early_secret and handshake_secret. The master_secret is stored
+ * in the session.
+ */
+ unsigned char early_secret[EVP_MAX_MD_SIZE];
+ unsigned char handshake_secret[EVP_MAX_MD_SIZE];
EVP_CIPHER_CTX *enc_read_ctx; /* cryptographic state */
EVP_MD_CTX *read_hash; /* used for mac generation */
COMP_CTX *compress; /* compression */
__owur int tls1_generate_master_secret(SSL *s, unsigned char *out,
unsigned char *p, size_t len,
size_t *secret_size);
+__owur int tls13_derive_secret(SSL *s, const unsigned char *insecret,
+ const unsigned char *label, size_t labellen,
+ unsigned char *secret);
+__owur int tls13_derive_key(SSL *s, const unsigned char *secret,
+ unsigned char *key, size_t keylen);
+__owur int tls13_derive_iv(SSL *s, const unsigned char *secret,
+ unsigned char *iv, size_t ivlen);
+__owur int tls13_generate_early_secret(SSL *s, const unsigned char *insecret,
+ size_t insecretlen);
+__owur int tls13_generate_handshake_secret(SSL *s,
+ const unsigned char *insecret,
+ size_t insecretlen);
+__owur int tls13_generate_master_secret(SSL *s, unsigned char *out,
+ unsigned char *prev, size_t prevlen,
+ size_t *secret_size);
__owur int tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen,
const char *label, size_t llen,
const unsigned char *p, size_t plen,
--- /dev/null
+/*
+ * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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
+ */
+
+#include <stdlib.h>
+#include "ssl_locl.h"
+#include <openssl/evp.h>
+#include <openssl/kdf.h>
+
+#define TLS13_MAX_LABEL_LEN 246
+
+/* Always filled with zeros */
+static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
+
+const unsigned char keylabel[] = "key";
+const unsigned char ivlabel[] = "iv";
+
+/*
+ * Given a |secret|; a |label| of length |labellen|; and a |hash| of the
+ * handshake messages, derive a new secret |outlen| bytes long and store it in
+ * the location pointed to be |out|. The |hash| value may be NULL.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+static int tls13_hkdf_expand(SSL *s, const unsigned char *secret,
+ const unsigned char *label, size_t labellen,
+ const unsigned char *hash,
+ unsigned char *out, size_t outlen)
+{
+ const unsigned char label_prefix[] = "TLS 1.3, ";
+ const EVP_MD *md = ssl_handshake_md(s);
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
+ int ret;
+ size_t hkdflabellen;
+ size_t hashlen;
+ /*
+ * 2 bytes for length of whole HkdfLabel + 1 byte for length of combined
+ * prefix and label + bytes for the label itself + bytes for the hash
+ */
+ unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
+ + sizeof(label_prefix) + TLS13_MAX_LABEL_LEN
+ + EVP_MAX_MD_SIZE];
+ WPACKET pkt;
+
+ if (pctx == NULL)
+ return 0;
+
+ hashlen = EVP_MD_size(md);
+
+ if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
+ || !WPACKET_put_bytes_u16(&pkt, outlen)
+ || !WPACKET_start_sub_packet_u8(&pkt)
+ || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
+ || !WPACKET_memcpy(&pkt, label, labellen)
+ || !WPACKET_close(&pkt)
+ || !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen)
+ || !WPACKET_get_total_written(&pkt, &hkdflabellen)
+ || !WPACKET_finish(&pkt)) {
+ WPACKET_cleanup(&pkt);
+ return 0;
+ }
+
+ ret = EVP_PKEY_derive_init(pctx) <= 0
+ || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
+ <= 0
+ || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
+ || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
+ || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
+ || EVP_PKEY_derive(pctx, out, &outlen) <= 0;
+
+ EVP_PKEY_CTX_free(pctx);
+
+ return ret == 0;
+}
+
+/*
+ * Given a input secret |insecret| and a |label| of length |labellen|, derive a
+ * new |secret|. This will be the length of the current hash output size and
+ * will be based on the current state of the handshake hashes.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_derive_secret(SSL *s, const unsigned char *insecret,
+ const unsigned char *label, size_t labellen,
+ unsigned char *secret)
+{
+ unsigned char hash[EVP_MAX_MD_SIZE];
+ size_t hashlen;
+
+ if (!ssl3_digest_cached_records(s, 1))
+ return 0;
+
+ if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen))
+ return 0;
+
+ return tls13_hkdf_expand(s, insecret, label, labellen, hash, secret,
+ hashlen);
+}
+
+/*
+ * Given a |secret| generate a |key| of length |keylen| bytes.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_derive_key(SSL *s, const unsigned char *secret, unsigned char *key,
+ size_t keylen)
+{
+ return tls13_hkdf_expand(s, secret, keylabel, sizeof(keylabel) - 1, NULL,
+ key, keylen);
+}
+
+/*
+ * Given a |secret| generate an |iv| of length |ivlen| bytes.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_derive_iv(SSL *s, const unsigned char *secret, unsigned char *iv,
+ size_t ivlen)
+{
+ return tls13_hkdf_expand(s, secret, ivlabel, sizeof(ivlabel) - 1, NULL,
+ iv, ivlen);
+}
+
+/*
+ * Given the previous secret |prevsecret| and a new input secret |insecret| of
+ * length |insecretlen|, generate a new secret and store it in the location
+ * pointed to by |outsecret|.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+static int tls13_generate_secret(SSL *s, const unsigned char *prevsecret,
+ const unsigned char *insecret,
+ size_t insecretlen,
+ unsigned char *outsecret)
+{
+ const EVP_MD *md = ssl_handshake_md(s);
+ size_t mdlen, prevsecretlen;
+ int ret;
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
+
+ if (pctx == NULL)
+ return 0;
+
+ mdlen = EVP_MD_size(md);
+
+ if (insecret == NULL) {
+ insecret = default_zeros;
+ insecretlen = mdlen;
+ }
+ if (prevsecret == NULL) {
+ prevsecret = default_zeros;
+ prevsecretlen = 0;
+ } else {
+ prevsecretlen = mdlen;
+ }
+
+ ret = EVP_PKEY_derive_init(pctx) <= 0
+ || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY)
+ <= 0
+ || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
+ || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0
+ || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen)
+ <= 0
+ || EVP_PKEY_derive(pctx, outsecret, &mdlen)
+ <= 0;
+
+ EVP_PKEY_CTX_free(pctx);
+ return ret == 0;
+}
+
+/*
+ * Given an input secret |insecret| of length |insecretlen| generate the early
+ * secret.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_generate_early_secret(SSL *s, const unsigned char *insecret,
+ size_t insecretlen)
+{
+ return tls13_generate_secret(s, NULL, insecret, insecretlen,
+ (unsigned char *)&s->early_secret);
+}
+
+/*
+ * Given an input secret |insecret| of length |insecretlen| generate the
+ * handshake secret. This requires the early secret to already have been
+ * generated.
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
+ size_t insecretlen)
+{
+ return tls13_generate_secret(s, s->early_secret, insecret, insecretlen,
+ (unsigned char *)&s->handshake_secret);
+}
+
+/*
+ * Given the handshake secret |prev| of length |prevlen| generate the master
+ * secret and store its length in |*secret_size|
+ *
+ * Returns 1 on success 0 on failure.
+ */
+int tls13_generate_master_secret(SSL *s, unsigned char *out,
+ unsigned char *prev, size_t prevlen,
+ size_t *secret_size)
+{
+ *secret_size = EVP_MD_size(ssl_handshake_md(s));
+ return tls13_generate_secret(s, prev, NULL, 0, out);
+}
+
+
projects / openssl.git / commitdiff