/*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2018 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
#include <stdlib.h>
#include "ssl_locl.h"
+#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include <openssl/kdf.h>
static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
/*
- * 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.
+ * Given a |secret|; a |label| of length |labellen|; and |data| of length
+ * |datalen| (e.g. typically a hash of the handshake messages), derive a new
+ * secret |outlen| bytes long and store it in the location pointed to be |out|.
+ * The |data| value may be zero length. Returns 1 on success 0 on failure.
*/
int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
const unsigned char *label, size_t labellen,
- const unsigned char *hash,
+ const unsigned char *data, size_t datalen,
unsigned char *out, size_t outlen)
{
- const unsigned char label_prefix[] = "TLS 1.3, ";
+ const unsigned char label_prefix[] = "tls13 ";
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
int ret;
size_t hkdflabellen;
|| !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_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
|| !WPACKET_get_total_written(&pkt, &hkdflabellen)
|| !WPACKET_finish(&pkt)) {
EVP_PKEY_CTX_free(pctx);
WPACKET_cleanup(&pkt);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
+ ERR_R_INTERNAL_ERROR);
return 0;
}
EVP_PKEY_CTX_free(pctx);
+ if (ret != 0)
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
+ ERR_R_INTERNAL_ERROR);
+
return ret == 0;
}
static const unsigned char keylabel[] = "key";
return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
- NULL, key, keylen);
+ NULL, 0, key, keylen);
}
/*
static const unsigned char ivlabel[] = "iv";
return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
- NULL, iv, ivlen);
+ NULL, 0, iv, ivlen);
}
int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
static const unsigned char finishedlabel[] = "finished";
return tls13_hkdf_expand(s, md, secret, finishedlabel,
- sizeof(finishedlabel) - 1, NULL, fin, finlen);
+ sizeof(finishedlabel) - 1, NULL, 0, fin, finlen);
}
/*
unsigned char *outsecret)
{
size_t mdlen, prevsecretlen;
+ int mdleni;
int ret;
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
+ static const char derived_secret_label[] = "derived";
+ unsigned char preextractsec[EVP_MAX_MD_SIZE];
- if (pctx == NULL)
+ if (pctx == NULL) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
+ ERR_R_INTERNAL_ERROR);
return 0;
+ }
- mdlen = EVP_MD_size(md);
+ mdleni = EVP_MD_size(md);
+ /* Ensure cast to size_t is safe */
+ if (!ossl_assert(mdleni >= 0)) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
+ ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ mdlen = (size_t)mdleni;
if (insecret == NULL) {
insecret = default_zeros;
prevsecret = default_zeros;
prevsecretlen = 0;
} else {
+ EVP_MD_CTX *mctx = EVP_MD_CTX_new();
+ unsigned char hash[EVP_MAX_MD_SIZE];
+
+ /* The pre-extract derive step uses a hash of no messages */
+ if (mctx == NULL
+ || EVP_DigestInit_ex(mctx, md, NULL) <= 0
+ || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
+ ERR_R_INTERNAL_ERROR);
+ EVP_MD_CTX_free(mctx);
+ EVP_PKEY_CTX_free(pctx);
+ return 0;
+ }
+ EVP_MD_CTX_free(mctx);
+
+ /* Generate the pre-extract secret */
+ if (!tls13_hkdf_expand(s, md, prevsecret,
+ (unsigned char *)derived_secret_label,
+ sizeof(derived_secret_label) - 1, hash, mdlen,
+ preextractsec, mdlen)) {
+ /* SSLfatal() already called */
+ EVP_PKEY_CTX_free(pctx);
+ return 0;
+ }
+
+ prevsecret = preextractsec;
prevsecretlen = mdlen;
}
|| EVP_PKEY_derive(pctx, outsecret, &mdlen)
<= 0;
+ if (ret != 0)
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
+ ERR_R_INTERNAL_ERROR);
+
EVP_PKEY_CTX_free(pctx);
+ if (prevsecret == preextractsec)
+ OPENSSL_cleanse(preextractsec, mdlen);
return ret == 0;
}
int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
size_t insecretlen)
{
+ /* Calls SSLfatal() if required */
return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
insecret, insecretlen,
(unsigned char *)&s->handshake_secret);
const EVP_MD *md = ssl_handshake_md(s);
*secret_size = EVP_MD_size(md);
+ /* Calls SSLfatal() if required */
return tls13_generate_secret(s, md, prev, NULL, 0, out);
}
EVP_PKEY *key = NULL;
EVP_MD_CTX *ctx = EVP_MD_CTX_new();
- if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen))
+ if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
+ /* SSLfatal() already called */
goto err;
+ }
- if (str == s->method->ssl3_enc->server_finished_label)
- key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL,
- s->server_finished_secret, hashlen);
- else
- key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL,
- s->client_finished_secret, hashlen);
+ if (str == s->method->ssl3_enc->server_finished_label) {
+ key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
+ s->server_finished_secret, hashlen);
+ } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
+ key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
+ s->client_finished_secret, hashlen);
+ } else {
+ unsigned char finsecret[EVP_MAX_MD_SIZE];
+
+ if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
+ s->client_app_traffic_secret,
+ finsecret, hashlen))
+ goto err;
+
+ key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
+ hashlen);
+ OPENSSL_cleanse(finsecret, sizeof(finsecret));
+ }
if (key == NULL
|| ctx == NULL
|| EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
|| EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
- || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0)
+ || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
+ ERR_R_INTERNAL_ERROR);
goto err;
+ }
ret = hashlen;
err:
s->session->cipher = s->s3->tmp.new_cipher;
if (!ssl_cipher_get_evp
(s->session, &c, &hash, &mac_type, NULL, NULL, 0)) {
- SSLerr(SSL_F_TLS13_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
+ SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
return 0;
}
return 1;
}
-static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md,
+static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
const EVP_CIPHER *ciph,
const unsigned char *insecret,
const unsigned char *hash,
{
unsigned char key[EVP_MAX_KEY_LENGTH];
size_t ivlen, keylen, taglen;
- size_t hashlen = EVP_MD_size(md);
+ int hashleni = EVP_MD_size(md);
+ size_t hashlen;
- if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret,
- hashlen)) {
- SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
+ /* Ensure cast to size_t is safe */
+ if (!ossl_assert(hashleni >= 0)) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
+ ERR_R_EVP_LIB);
+ goto err;
+ }
+ hashlen = (size_t)hashleni;
+
+ if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
+ secret, hashlen)) {
+ /* SSLfatal() already called */
goto err;
}
if (!tls13_derive_key(s, md, secret, key, keylen)
|| !tls13_derive_iv(s, md, secret, iv, ivlen)) {
- SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
+ /* SSLfatal() already called */
goto err;
}
- if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, send) <= 0
+ if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
|| !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
|| (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
taglen, NULL))
|| EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
- SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_EVP_LIB);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
+ ERR_R_EVP_LIB);
goto err;
}
-#ifdef OPENSSL_SSL_TRACE_CRYPTO
- if (s->msg_callback) {
- int wh = send ? TLS1_RT_CRYPTO_WRITE : 0;
-
- if (ciph->key_len)
- s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY,
- key, ciph->key_len, s, s->msg_callback_arg);
-
- wh |= TLS1_RT_CRYPTO_IV;
- s->msg_callback(2, s->version, wh, iv, ivlen, s,
- s->msg_callback_arg);
- }
-#endif
-
return 1;
err:
OPENSSL_cleanse(key, sizeof(key));
int tls13_change_cipher_state(SSL *s, int which)
{
- static const unsigned char client_early_traffic[] =
- "client early traffic secret";
- static const unsigned char client_handshake_traffic[] =
- "client handshake traffic secret";
- static const unsigned char client_application_traffic[] =
- "client application traffic secret";
- static const unsigned char server_handshake_traffic[] =
- "server handshake traffic secret";
- static const unsigned char server_application_traffic[] =
- "server application traffic secret";
- static const unsigned char resumption_master_secret[] =
- "resumption master secret";
+ static const unsigned char client_early_traffic[] = "c e traffic";
+ static const unsigned char client_handshake_traffic[] = "c hs traffic";
+ static const unsigned char client_application_traffic[] = "c ap traffic";
+ static const unsigned char server_handshake_traffic[] = "s hs traffic";
+ static const unsigned char server_application_traffic[] = "s ap traffic";
+ static const unsigned char exporter_master_secret[] = "exp master";
+ static const unsigned char resumption_master_secret[] = "res master";
+ static const unsigned char early_exporter_master_secret[] = "e exp master";
unsigned char *iv;
unsigned char secret[EVP_MAX_MD_SIZE];
unsigned char hashval[EVP_MAX_MD_SIZE];
} else {
s->enc_read_ctx = EVP_CIPHER_CTX_new();
if (s->enc_read_ctx == NULL) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
goto err;
}
}
RECORD_LAYER_reset_read_sequence(&s->rlayer);
} else {
+ s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
if (s->enc_write_ctx != NULL) {
EVP_CIPHER_CTX_reset(s->enc_write_ctx);
} else {
s->enc_write_ctx = EVP_CIPHER_CTX_new();
if (s->enc_write_ctx == NULL) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
goto err;
}
}
handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
if (handlen <= 0) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE,
- SSL_R_BAD_HANDSHAKE_LENGTH);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE,
+ SSL_R_BAD_HANDSHAKE_LENGTH);
goto err;
}
+
+ if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
+ && s->max_early_data > 0
+ && s->session->ext.max_early_data == 0) {
+ /*
+ * If we are attempting to send early data, and we've decided to
+ * actually do it but max_early_data in s->session is 0 then we
+ * must be using an external PSK.
+ */
+ if (!ossl_assert(s->psksession != NULL
+ && s->max_early_data ==
+ s->psksession->ext.max_early_data)) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE,
+ ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ sslcipher = SSL_SESSION_get0_cipher(s->psksession);
+ }
if (sslcipher == NULL) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
goto err;
}
*/
mdctx = EVP_MD_CTX_new();
if (mdctx == NULL) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
goto err;
}
cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
|| !EVP_DigestUpdate(mdctx, hdata, handlen)
|| !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
EVP_MD_CTX_free(mdctx);
goto err;
}
hashlen = hashlenui;
EVP_MD_CTX_free(mdctx);
+
+ if (!tls13_hkdf_expand(s, md, insecret,
+ early_exporter_master_secret,
+ sizeof(early_exporter_master_secret) - 1,
+ hashval, hashlen,
+ s->early_exporter_master_secret, hashlen)) {
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+ SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
+ s->early_exporter_master_secret, hashlen)) {
+ /* SSLfatal() already called */
+ goto err;
+ }
} else if (which & SSL3_CC_HANDSHAKE) {
insecret = s->handshake_secret;
finsecret = s->client_finished_secret;
labellen = sizeof(client_handshake_traffic) - 1;
log_label = CLIENT_HANDSHAKE_LABEL;
/*
- * The hanshake hash used for the server read/client write handshake
+ * The handshake hash used for the server read/client write handshake
* traffic secret is the same as the hash for the server
* write/client read handshake traffic secret. However, if we
* processed early data then we delay changing the server
cipher = s->s3->tmp.new_sym_enc;
if (!ssl3_digest_cached_records(s, 1)
|| !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ /* SSLfatal() already called */;
goto err;
}
}
if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
resumption_master_secret,
sizeof(resumption_master_secret) - 1,
- hashval, s->session->master_key, hashlen)) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ hashval, hashlen, s->resumption_master_secret,
+ hashlen)) {
+ /* SSLfatal() already called */
goto err;
}
- s->session->master_key_length = hashlen;
}
if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
insecret, hash, label, labellen, secret, iv,
ciph_ctx)) {
+ /* SSLfatal() already called */
goto err;
}
- if (label == server_application_traffic)
+ if (label == server_application_traffic) {
memcpy(s->server_app_traffic_secret, secret, hashlen);
- else if (label == client_application_traffic)
+ /* Now we create the exporter master secret */
+ if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
+ exporter_master_secret,
+ sizeof(exporter_master_secret) - 1,
+ hash, hashlen, s->exporter_master_secret,
+ hashlen)) {
+ /* SSLfatal() already called */
+ goto err;
+ }
+
+ if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
+ hashlen)) {
+ /* SSLfatal() already called */
+ goto err;
+ }
+ } else if (label == client_application_traffic)
memcpy(s->client_app_traffic_secret, secret, hashlen);
if (!ssl_log_secret(s, log_label, secret, hashlen)) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ /* SSLfatal() already called */
goto err;
}
if (finsecret != NULL
&& !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
finsecret, finsecretlen)) {
- SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ /* SSLfatal() already called */
goto err;
}
+ if (!s->server && label == client_early_traffic)
+ s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
+ else
+ s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
ret = 1;
err:
OPENSSL_cleanse(secret, sizeof(secret));
return ret;
}
-int tls13_update_key(SSL *s, int send)
+int tls13_update_key(SSL *s, int sending)
{
- static const unsigned char application_traffic[] =
- "application traffic secret";
+ static const unsigned char application_traffic[] = "traffic upd";
const EVP_MD *md = ssl_handshake_md(s);
size_t hashlen = EVP_MD_size(md);
unsigned char *insecret, *iv;
EVP_CIPHER_CTX *ciph_ctx;
int ret = 0;
- if (s->server == send)
+ if (s->server == sending)
insecret = s->server_app_traffic_secret;
else
insecret = s->client_app_traffic_secret;
- if (send) {
+ if (sending) {
+ s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
iv = s->write_iv;
ciph_ctx = s->enc_write_ctx;
RECORD_LAYER_reset_write_sequence(&s->rlayer);
RECORD_LAYER_reset_read_sequence(&s->rlayer);
}
- if (!derive_secret_key_and_iv(s, send, ssl_handshake_md(s),
+ if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
s->s3->tmp.new_sym_enc, insecret, NULL,
application_traffic,
sizeof(application_traffic) - 1, secret, iv,
- ciph_ctx))
+ ciph_ctx)) {
+ /* SSLfatal() already called */
goto err;
+ }
memcpy(insecret, secret, hashlen);
+ s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
ret = 1;
err:
OPENSSL_cleanse(secret, sizeof(secret));
int tls13_alert_code(int code)
{
- if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_END_OF_EARLY_DATA)
+ /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
+ if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
return code;
return tls1_alert_code(code);
}
+
+int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
+ const char *label, size_t llen,
+ const unsigned char *context,
+ size_t contextlen, int use_context)
+{
+ unsigned char exportsecret[EVP_MAX_MD_SIZE];
+ static const unsigned char exporterlabel[] = "exporter";
+ unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
+ const EVP_MD *md = ssl_handshake_md(s);
+ EVP_MD_CTX *ctx = EVP_MD_CTX_new();
+ unsigned int hashsize, datalen;
+ int ret = 0;
+
+ if (ctx == NULL || !ossl_statem_export_allowed(s))
+ goto err;
+
+ if (!use_context)
+ contextlen = 0;
+
+ if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
+ || EVP_DigestUpdate(ctx, context, contextlen) <= 0
+ || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
+ || EVP_DigestInit_ex(ctx, md, NULL) <= 0
+ || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
+ || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
+ (const unsigned char *)label, llen,
+ data, datalen, exportsecret, hashsize)
+ || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
+ sizeof(exporterlabel) - 1, hash, hashsize,
+ out, olen))
+ goto err;
+
+ ret = 1;
+ err:
+ EVP_MD_CTX_free(ctx);
+ return ret;
+}
+
+int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
+ const char *label, size_t llen,
+ const unsigned char *context,
+ size_t contextlen)
+{
+ static const unsigned char exporterlabel[] = "exporter";
+ unsigned char exportsecret[EVP_MAX_MD_SIZE];
+ unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
+ const EVP_MD *md;
+ EVP_MD_CTX *ctx = EVP_MD_CTX_new();
+ unsigned int hashsize, datalen;
+ int ret = 0;
+ const SSL_CIPHER *sslcipher;
+
+ if (ctx == NULL || !ossl_statem_export_early_allowed(s))
+ goto err;
+
+ if (!s->server && s->max_early_data > 0
+ && s->session->ext.max_early_data == 0)
+ sslcipher = SSL_SESSION_get0_cipher(s->psksession);
+ else
+ sslcipher = SSL_SESSION_get0_cipher(s->session);
+
+ md = ssl_md(sslcipher->algorithm2);
+
+ /*
+ * Calculate the hash value and store it in |data|. The reason why
+ * the empty string is used is that the definition of TLS-Exporter
+ * is like so:
+ *
+ * TLS-Exporter(label, context_value, key_length) =
+ * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
+ * "exporter", Hash(context_value), key_length)
+ *
+ * Derive-Secret(Secret, Label, Messages) =
+ * HKDF-Expand-Label(Secret, Label,
+ * Transcript-Hash(Messages), Hash.length)
+ *
+ * Here Transcript-Hash is the cipher suite hash algorithm.
+ */
+ if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
+ || EVP_DigestUpdate(ctx, context, contextlen) <= 0
+ || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
+ || EVP_DigestInit_ex(ctx, md, NULL) <= 0
+ || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
+ || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
+ (const unsigned char *)label, llen,
+ data, datalen, exportsecret, hashsize)
+ || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
+ sizeof(exporterlabel) - 1, hash, hashsize,
+ out, olen))
+ goto err;
+
+ ret = 1;
+ err:
+ EVP_MD_CTX_free(ctx);
+ return ret;
+}