Update copyright year
[openssl.git] / ssl / tls13_enc.c
index aa933b2..1f956e6 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2019 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
@@ -13,7 +13,7 @@
 #include <openssl/evp.h>
 #include <openssl/kdf.h>
 
-#define TLS13_MAX_LABEL_LEN     246
+#define TLS13_MAX_LABEL_LEN     249
 
 /* Always filled with zeros */
 static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
@@ -22,30 +22,47 @@ static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
  * 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.
+ * The |data| value may be zero length. Any errors will be treated as fatal if
+ * |fatal| is set. 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 *data, size_t datalen,
-                             unsigned char *out, size_t outlen)
+                             unsigned char *out, size_t outlen, int fatal)
 {
-    const unsigned char label_prefix[] = "tls13 ";
+    static const unsigned char label_prefix[] = "tls13 ";
     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
+     * 2 bytes for length of derived secret + 1 byte for length of combined
+     * prefix and label + bytes for the label itself + 1 byte length of hash
+     * + bytes for the hash itself
      */
     unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
-                            + sizeof(label_prefix) + TLS13_MAX_LABEL_LEN
-                            + EVP_MAX_MD_SIZE];
+                            + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
+                            + 1 + EVP_MAX_MD_SIZE];
     WPACKET pkt;
 
     if (pctx == NULL)
         return 0;
 
+    if (labellen > TLS13_MAX_LABEL_LEN) {
+        if (fatal) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
+                     ERR_R_INTERNAL_ERROR);
+        } else {
+            /*
+             * Probably we have been called from SSL_export_keying_material(),
+             * or SSL_export_keying_material_early().
+             */
+            SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
+        }
+        EVP_PKEY_CTX_free(pctx);
+        return 0;
+    }
+
     hashlen = EVP_MD_size(md);
 
     if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
@@ -59,8 +76,11 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
             || !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);
+        if (fatal)
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
+                     ERR_R_INTERNAL_ERROR);
+        else
+            SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
         return 0;
     }
 
@@ -74,9 +94,13 @@ 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);
+    if (ret != 0) {
+        if (fatal)
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
+                     ERR_R_INTERNAL_ERROR);
+        else
+            SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
+    }
 
     return ret == 0;
 }
@@ -91,7 +115,7 @@ 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, 0, key, keylen);
+                             NULL, 0, key, keylen, 1);
 }
 
 /*
@@ -104,7 +128,7 @@ 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, 0, iv, ivlen);
+                             NULL, 0, iv, ivlen, 1);
 }
 
 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
@@ -114,7 +138,7 @@ 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, 0, fin, finlen);
+                             sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
 }
 
 /*
@@ -129,6 +153,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
                           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";
@@ -140,7 +165,14 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
         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;
@@ -169,7 +201,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
         if (!tls13_hkdf_expand(s, md, prevsecret,
                                (unsigned char *)derived_secret_label,
                                sizeof(derived_secret_label) - 1, hash, mdlen,
-                               preextractsec, mdlen)) {
+                               preextractsec, mdlen, 1)) {
             /* SSLfatal() already called */
             EVP_PKEY_CTX_free(pctx);
             return 0;
@@ -242,22 +274,39 @@ 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,
-                                   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:
@@ -274,11 +323,9 @@ int tls13_setup_key_block(SSL *s)
 {
     const EVP_CIPHER *c;
     const EVP_MD *hash;
-    int mac_type = NID_undef;
 
     s->session->cipher = s->s3->tmp.new_cipher;
-    if (!ssl_cipher_get_evp
-        (s->session, &c, &hash, &mac_type, NULL, NULL, 0)) {
+    if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
                  SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
         return 0;
@@ -300,10 +347,19 @@ static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
 {
     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;
+
+    /* 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)) {
+                           secret, hashlen, 1)) {
         /* SSLfatal() already called */
         goto err;
     }
@@ -360,6 +416,7 @@ int tls13_change_cipher_state(SSL *s, int which)
     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];
@@ -391,6 +448,7 @@ int tls13_change_cipher_state(SSL *s, int which)
 
         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 {
@@ -476,6 +534,23 @@ int tls13_change_cipher_state(SSL *s, int which)
             }
             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,
+                                   1)) {
+                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;
@@ -551,19 +626,8 @@ 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, 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)) {
+                               hashval, hashlen, s->resumption_master_secret,
+                               hashlen, 1)) {
             /* SSLfatal() already called */
             goto err;
         }
@@ -576,9 +640,24 @@ int tls13_change_cipher_state(SSL *s, int which)
         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, 1)) {
+            /* 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)) {
@@ -593,6 +672,10 @@ int tls13_change_cipher_state(SSL *s, int which)
         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));
@@ -615,6 +698,7 @@ int tls13_update_key(SSL *s, int sending)
         insecret = s->client_app_traffic_secret;
 
     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);
@@ -635,6 +719,7 @@ int tls13_update_key(SSL *s, int sending)
 
     memcpy(insecret, secret, hashlen);
 
+    s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
     ret = 1;
  err:
     OPENSSL_cleanse(secret, sizeof(secret));
@@ -643,7 +728,8 @@ int tls13_update_key(SSL *s, int sending)
 
 int tls13_alert_code(int code)
 {
-    if (code == SSL_AD_MISSING_EXTENSION)
+    /* 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);
@@ -662,7 +748,7 @@ int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
     unsigned int hashsize, datalen;
     int ret = 0;
 
-    if (ctx == NULL || !SSL_is_init_finished(s))
+    if (ctx == NULL || !ossl_statem_export_allowed(s))
         goto err;
 
     if (!use_context)
@@ -675,10 +761,69 @@ int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
             || 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)
+                                  data, datalen, exportsecret, hashsize, 0)
+            || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
+                                  sizeof(exporterlabel) - 1, hash, hashsize,
+                                  out, olen, 0))
+        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, 0)
             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
                                   sizeof(exporterlabel) - 1, hash, hashsize,
-                                  out, olen))
+                                  out, olen, 0))
         goto err;
 
     ret = 1;