TLS 1.3: Implement TLSInnerPlaintext parsing/building
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index e5331a7..e739e2f 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -341,7 +341,8 @@
* Encryption/decryption functions
*/
-#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) || \
+ defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
/* This functions transforms a (D)TLS plaintext fragment and a record content
* type into an instance of the (D)TLSInnerPlaintext structure. This is used
* in DTLS 1.2 + CID and within TLS 1.3 to allow flexible padding and to protect
@@ -418,7 +419,8 @@
return( 0 );
}
-#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID ||
+ MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
/* `add_data` must have size 13 Bytes if the CID extension is disabled,
* and 13 + 1 + CID-length Bytes if the CID extension is enabled. */
@@ -576,6 +578,28 @@
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+ if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
+ {
+ /*
+ * Wrap plaintext into TLSInnerPlaintext structure.
+ * See ssl_build_inner_plaintext() for more information.
+ *
+ * Note that this changes `rec->data_len`, and hence
+ * `post_avail` needs to be recalculated afterwards.
+ */
+ if( ssl_build_inner_plaintext( data,
+ &rec->data_len,
+ post_avail,
+ rec->type ) != 0 )
+ {
+ return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+ }
+
+ rec->type = MBEDTLS_SSL_MSG_APPLICATION_DATA;
+ }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
+
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
/*
* Add CID information
@@ -1551,6 +1575,18 @@
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+ if( transform->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
+ {
+ /* Remove inner padding and infer true content type. */
+ ret = ssl_parse_inner_plaintext( data, &rec->data_len,
+ &rec->type );
+
+ if( ret != 0 )
+ return( MBEDTLS_ERR_SSL_INVALID_RECORD );
+ }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
+
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
if( rec->cid_len != 0 )
{
