Use the TLSv1.3 record header as AAD
[openssl.git] / ssl / record / ssl3_record_tls13.c
index 9dc7075cc2da0e663a88dc8e306d10cd4ffc6d27..21073b637de6c5447520a9a69141f2cc5d97862a 100644 (file)
@@ -9,9 +9,11 @@
 
 #include "../ssl_locl.h"
 #include "record_locl.h"
+#include "internal/cryptlib.h"
 
 /*-
- * tls13_enc encrypts/decrypts |n_recs| in |recs|.
+ * tls13_enc encrypts/decrypts |n_recs| in |recs|. Will call SSLfatal() for
+ * internal errors, but not otherwise.
  *
  * Returns:
  *    0: (in non-constant time) if the record is publically invalid (i.e. too
  *   -1: if the record's AEAD-authenticator is invalid or, if sending,
  *       an internal error occurred.
  */
-int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
+int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
 {
     EVP_CIPHER_CTX *ctx;
-    unsigned char iv[EVP_MAX_IV_LENGTH];
-    size_t ivlen, taglen, offset, loop;
+    unsigned char iv[EVP_MAX_IV_LENGTH], recheader[SSL3_RT_HEADER_LENGTH];
+    size_t ivlen, taglen, offset, loop, hdrlen;
     unsigned char *staticiv;
     unsigned char *seq;
     int lenu, lenf;
     SSL3_RECORD *rec = &recs[0];
-    uint32_t alg_enc = s->s3->tmp.new_cipher->algorithm_enc;
+    uint32_t alg_enc;
+    WPACKET wpkt;
 
     if (n_recs != 1) {
         /* Should not happen */
         /* TODO(TLS1.3): Support pipelining */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                 ERR_R_INTERNAL_ERROR);
         return -1;
     }
 
-    if (send) {
+    if (sending) {
         ctx = s->enc_write_ctx;
         staticiv = s->write_iv;
         seq = RECORD_LAYER_get_write_sequence(&s->rlayer);
@@ -52,25 +57,57 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
         rec->input = rec->data;
         return 1;
     }
+
     ivlen = EVP_CIPHER_CTX_iv_length(ctx);
 
+    if (s->early_data_state == SSL_EARLY_DATA_WRITING
+            || s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
+        if (s->session != NULL && s->session->ext.max_early_data > 0) {
+            alg_enc = s->session->cipher->algorithm_enc;
+        } else {
+            if (!ossl_assert(s->psksession != NULL
+                             && s->psksession->ext.max_early_data > 0)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                         ERR_R_INTERNAL_ERROR);
+                return -1;
+            }
+            alg_enc = s->psksession->cipher->algorithm_enc;
+        }
+    } else {
+        /*
+         * To get here we must have selected a ciphersuite - otherwise ctx would
+         * be NULL
+         */
+        if (!ossl_assert(s->s3->tmp.new_cipher != NULL)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                     ERR_R_INTERNAL_ERROR);
+            return -1;
+        }
+        alg_enc = s->s3->tmp.new_cipher->algorithm_enc;
+    }
+
     if (alg_enc & SSL_AESCCM) {
         if (alg_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
             taglen = EVP_CCM8_TLS_TAG_LEN;
          else
             taglen = EVP_CCM_TLS_TAG_LEN;
-         if (send && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
-                                         NULL) <= 0)
+         if (sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
+                                         NULL) <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                     ERR_R_INTERNAL_ERROR);
             return -1;
+        }
     } else if (alg_enc & SSL_AESGCM) {
         taglen = EVP_GCM_TLS_TAG_LEN;
     } else if (alg_enc & SSL_CHACHA20) {
         taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
     } else {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                 ERR_R_INTERNAL_ERROR);
         return -1;
     }
 
-    if (!send) {
+    if (!sending) {
         /*
          * Take off tag. There must be at least one byte of content type as
          * well as the tag
@@ -83,6 +120,8 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
     /* Set up IV */
     if (ivlen < SEQ_NUM_SIZE) {
         /* Should not happen */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                 ERR_R_INTERNAL_ERROR);
         return -1;
     }
     offset = ivlen - SEQ_NUM_SIZE;
@@ -102,21 +141,48 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
     }
 
     /* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
-    if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, send) <= 0
-            || (!send && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
+    if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, sending) <= 0
+            || (!sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
                                              taglen,
-                                             rec->data + rec->length) <= 0)
+                                             rec->data + rec->length) <= 0)) {
+        return -1;
+    }
+
+    /* Set up the AAD */
+    if (!WPACKET_init_static_len(&wpkt, recheader, sizeof(recheader), 0)
+            || !WPACKET_put_bytes_u8(&wpkt, rec->type)
+            || !WPACKET_put_bytes_u16(&wpkt, rec->rec_version)
+            || !WPACKET_put_bytes_u16(&wpkt, rec->length + taglen)
+            || !WPACKET_get_total_written(&wpkt, &hdrlen)
+            || hdrlen != SSL3_RT_HEADER_LENGTH
+            || !WPACKET_finish(&wpkt)) {
+        WPACKET_cleanup(&wpkt);
+        return -1;
+    }
+
+    /*
+     * For CCM we must explicitly set the total plaintext length before we add
+     * any AAD.
+     */
+    if (((alg_enc & SSL_AESCCM) != 0
+                 && EVP_CipherUpdate(ctx, NULL, &lenu, NULL,
+                                     (unsigned int)rec->length) <= 0)
+            || EVP_CipherUpdate(ctx, NULL, &lenu, recheader,
+                                sizeof(recheader)) <= 0
             || EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
                                 (unsigned int)rec->length) <= 0
             || EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
             || (size_t)(lenu + lenf) != rec->length) {
         return -1;
     }
-    if (send) {
+    if (sending) {
         /* Add the tag */
         if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
-                                rec->data + rec->length) <= 0)
+                                rec->data + rec->length) <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
+                     ERR_R_INTERNAL_ERROR);
             return -1;
+        }
         rec->length += taglen;
     }