Fix client handling of 0-RTT rejects with cipher mismatch.
Servers can only accept 0-RTT if the ciphers match. If they reject
0-RTT, however, they may change the cipher suite and even the PRF hash.
This is tricky, however, because the 0-RTT accept or reject signal comes
in EncryptedExtensions, which is *after* the new cipher suite is
installed. (Although a client could infer 0-RTT is rejected based on the
cipher suite if it wanted.)
While we correctly handled the PRF hash switch, we get the cipher suite
mixed up due to dependency on SSL_get_session and incorrectly decrypt
EncryptedExtensions. Fix this and add some tests.
Change-Id: Ia20f2ed665cf601d30a38f0c8d4786c4c111019f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/40005
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/ssl/internal.h b/ssl/internal.h
index 4a93e15..a6b58c5 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -1356,9 +1356,11 @@
bool tls13_advance_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> in);
// tls13_set_traffic_key sets the read or write traffic keys to
-// |traffic_secret|. It returns true on success and false on error.
+// |traffic_secret|. The version and cipher suite are determined from |session|.
+// It returns true on success and false on error.
bool tls13_set_traffic_key(SSL *ssl, enum ssl_encryption_level_t level,
enum evp_aead_direction_t direction,
+ const SSL_SESSION *session,
Span<const uint8_t> traffic_secret);
// tls13_derive_early_secret derives the early traffic secret. It returns true
