Remove spurious whitespace
[openssl.git] / ssl / tls13_enc.c
index 9fdd61e..fe817f8 100644 (file)
@@ -9,6 +9,7 @@
 
 #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;
@@ -53,11 +54,13 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
             || !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;
     }
 
@@ -71,6 +74,10 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
 
     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;
 }
 
@@ -84,7 +91,7 @@ int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
     static const unsigned char keylabel[] = "key";
 
     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
-                             NULL, key, keylen);
+                             NULL, 0, key, keylen);
 }
 
 /*
@@ -97,7 +104,7 @@ int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
     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,
@@ -107,7 +114,7 @@ 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);
 }
 
 /*
@@ -124,9 +131,14 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
     size_t mdlen, prevsecretlen;
     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);
 
@@ -138,6 +150,32 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
         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;
     }
 
@@ -151,7 +189,13 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
             || 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;
 }
 
@@ -163,6 +207,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
 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);
@@ -180,6 +225,7 @@ int tls13_generate_master_secret(SSL *s, unsigned char *out,
     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);
 }
 
@@ -196,8 +242,10 @@ size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
     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,
@@ -210,8 +258,11 @@ size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
             || 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:
@@ -233,7 +284,8 @@ int tls13_setup_key_block(SSL *s)
     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;
     }
 
@@ -243,7 +295,7 @@ int tls13_setup_key_block(SSL *s)
     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,
@@ -255,9 +307,9 @@ static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md,
     size_t ivlen, keylen, taglen;
     size_t hashlen = EVP_MD_size(md);
 
-    if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret,
-                           hashlen)) {
-        SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
+    if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
+                           secret, hashlen)) {
+        /* SSLfatal() already called */
         goto err;
     }
 
@@ -284,33 +336,20 @@ static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md,
 
     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));
@@ -319,18 +358,13 @@ static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md,
 
 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";
     unsigned char *iv;
     unsigned char secret[EVP_MAX_MD_SIZE];
     unsigned char hashval[EVP_MAX_MD_SIZE];
@@ -352,7 +386,8 @@ int tls13_change_cipher_state(SSL *s, int which)
         } 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;
             }
         }
@@ -366,7 +401,8 @@ int tls13_change_cipher_state(SSL *s, int which)
         } 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;
             }
         }
@@ -392,12 +428,33 @@ int tls13_change_cipher_state(SSL *s, int which)
 
             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;
             }
 
@@ -408,7 +465,8 @@ int tls13_change_cipher_state(SSL *s, int which)
              */
             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));
@@ -416,7 +474,8 @@ int tls13_change_cipher_state(SSL *s, int which)
             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;
             }
@@ -430,7 +489,7 @@ int tls13_change_cipher_state(SSL *s, int which)
             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
@@ -474,7 +533,7 @@ int tls13_change_cipher_state(SSL *s, int which)
         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;
         }
     }
@@ -497,16 +556,28 @@ int tls13_change_cipher_state(SSL *s, int which)
         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->session->master_key,
+                               hashlen)) {
+            /* SSLfatal() already called */
             goto err;
         }
         s->session->master_key_length = hashlen;
+
+        /* 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 (!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;
     }
 
@@ -516,14 +587,14 @@ int tls13_change_cipher_state(SSL *s, int which)
         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;
     }
 
@@ -533,10 +604,9 @@ int tls13_change_cipher_state(SSL *s, int which)
     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;
@@ -544,12 +614,12 @@ int tls13_update_key(SSL *s, int send)
     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) {
         iv = s->write_iv;
         ciph_ctx = s->enc_write_ctx;
         RECORD_LAYER_reset_write_sequence(&s->rlayer);
@@ -559,12 +629,14 @@ int tls13_update_key(SSL *s, int send)
         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);
 
@@ -576,8 +648,46 @@ int tls13_update_key(SSL *s, int send)
 
 int tls13_alert_code(int code)
 {
-    if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_END_OF_EARLY_DATA)
+    if (code == SSL_AD_MISSING_EXTENSION)
         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 || !SSL_is_init_finished(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;
+}