1 files changed, 28 insertions, 19 deletions

diff --git a/src/lib/libssl/tls12_record_layer.c b/src/lib/libssl/tls12_record_layer.c
index b45a625fd4..0104443286 100644
--- a/src/lib/libssl/tls12_record_layer.c
+++ b/src/lib/libssl/tls12_record_layer.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls12_record_layer.c,v 1.14 2021/01/20 07:05:25 tb Exp $ */
+/* $OpenBSD: tls12_record_layer.c,v 1.15 2021/01/26 14:22:20 jsing Exp $ */
 /*
  * Copyright (c) 2020 Joel Sing <jsing@openbsd.org>
  *
@@ -23,6 +23,7 @@
 
 struct tls12_record_protection {
         uint16_t epoch;
+        uint8_t seq_num[SSL3_SEQUENCE_SIZE];
 
         int stream_mac;
 
@@ -37,8 +38,6 @@ struct tls12_record_protection {
 
         EVP_CIPHER_CTX *cipher_ctx;
         EVP_MD_CTX *hash_ctx;
-
-        uint8_t *seq_num;
 };
 
 static struct tls12_record_protection *
@@ -48,12 +47,22 @@ tls12_record_protection_new(void)
 }
 
 static void
+tls12_record_protection_clear(struct tls12_record_protection *rp)
+{
+        memset(rp->seq_num, 0, sizeof(rp->seq_num));
+
+        freezero(rp->mac_key, rp->mac_key_len);
+        rp->mac_key = NULL;
+        rp->mac_key_len = 0;
+}
+
+static void
 tls12_record_protection_free(struct tls12_record_protection *rp)
 {
         if (rp == NULL)
                 return;
 
-        freezero(rp->mac_key, rp->mac_key_len);
+        tls12_record_protection_clear(rp);
 
         freezero(rp, sizeof(struct tls12_record_protection));
 }
@@ -294,32 +303,24 @@ void
 tls12_record_layer_clear_read_state(struct tls12_record_layer *rl)
 {
         tls12_record_layer_set_read_state(rl, NULL, NULL, NULL, 0);
-        tls12_record_layer_set_read_mac_key(rl, NULL, 0);
-        rl->read->seq_num = NULL;
+        tls12_record_protection_clear(rl->read);
 }
 
 void
 tls12_record_layer_clear_write_state(struct tls12_record_layer *rl)
 {
         tls12_record_layer_set_write_state(rl, NULL, NULL, NULL, 0);
-        rl->write->seq_num = NULL;
+        tls12_record_protection_clear(rl->write);
 
         tls12_record_protection_free(rl->write_previous);
         rl->write_previous = NULL;
 }
 
 void
-tls12_record_layer_set_read_seq_num(struct tls12_record_layer *rl,
-    uint8_t *seq_num)
+tls12_record_layer_reflect_seq_num(struct tls12_record_layer *rl)
 {
-        rl->read->seq_num = seq_num;
-}
-
-void
-tls12_record_layer_set_write_seq_num(struct tls12_record_layer *rl,
-    uint8_t *seq_num)
-{
-        rl->write->seq_num = seq_num;
+        memcpy(rl->write->seq_num, rl->read->seq_num,
+            sizeof(rl->write->seq_num));
 }
 
 int
@@ -391,6 +392,8 @@ tls12_record_layer_change_read_cipher_state(struct tls12_record_layer *rl,
         if ((read_new = tls12_record_protection_new()) == NULL)
                 goto err;
 
+        /* Read sequence number gets reset to zero. */
+
         /* XXX - change cipher state. */
 
         tls12_record_protection_free(rl->read_current);
@@ -416,6 +419,8 @@ tls12_record_layer_change_write_cipher_state(struct tls12_record_layer *rl,
         if ((write_new = tls12_record_protection_new()) == NULL)
                 goto err;
 
+        /* Write sequence number gets reset to zero. */
+
         /* XXX - change cipher state. */
 
         if (rl->dtls) {
@@ -434,6 +439,7 @@ tls12_record_layer_change_write_cipher_state(struct tls12_record_layer *rl,
 
         return ret;
 }
+
 static int
 tls12_record_layer_build_seq_num(struct tls12_record_layer *rl, CBB *cbb,
     uint16_t epoch, uint8_t *seq_num, size_t seq_num_len)
@@ -896,7 +902,7 @@ tls12_record_layer_open_record(struct tls12_record_layer *rl, uint8_t *buf,
         uint8_t content_type;
 
         CBS_init(&cbs, buf, buf_len);
-        CBS_init(&seq_num, rl->read->seq_num, SSL3_SEQUENCE_SIZE);
+        CBS_init(&seq_num, rl->read->seq_num, sizeof(rl->read->seq_num));
 
         if (!CBS_get_u8(&cbs, &content_type))
                 return 0;
@@ -912,6 +918,9 @@ tls12_record_layer_open_record(struct tls12_record_layer *rl, uint8_t *buf,
                  */
                 if (!CBS_get_bytes(&cbs, &seq_num, SSL3_SEQUENCE_SIZE))
                         return 0;
+                if (!CBS_write_bytes(&seq_num, rl->read->seq_num,
+                    sizeof(rl->read->seq_num), NULL))
+                        return 0;
         }
         if (!CBS_get_u16_length_prefixed(&cbs, &fragment))
                 return 0;
@@ -1096,7 +1105,7 @@ tls12_record_layer_seal_record(struct tls12_record_layer *rl,
         if (!CBB_init(&seq_num_cbb, SSL3_SEQUENCE_SIZE))
                 goto err;
         if (!tls12_record_layer_build_seq_num(rl, &seq_num_cbb, rl->write->epoch,
-            rl->write->seq_num, SSL3_SEQUENCE_SIZE))
+            rl->write->seq_num, sizeof(rl->write->seq_num)))
                 goto err;
         if (!CBB_finish(&seq_num_cbb, &seq_num_data, &seq_num_len))
                 goto err;