Add binders writer
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 547651d..babbbbd 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -718,6 +718,22 @@
return( 0 );
}
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_session_tickets_get_psk( mbedtls_ssl_context *ssl,
+ psa_algorithm_t *psa_alg,
+ const unsigned char **psk,
+ size_t *psk_len )
+{
+
+ mbedtls_ssl_session *session = ssl->session_negotiate;
+
+ *psa_alg = ssl_tls13_ciphersuite_to_alg( ssl, session->ciphersuite );
+ *psk = session->resumption_key;
+ *psk_len = session->resumption_key_len;
+
+ return( 0 );
+}
+
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
MBEDTLS_CHECK_RETURN_CRITICAL
@@ -733,6 +749,18 @@
return( 0 );
}
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_psk_get_psk( mbedtls_ssl_context *ssl,
+ psa_algorithm_t *psa_alg,
+ const unsigned char **psk,
+ size_t *psk_len )
+{
+ *psa_alg = PSA_ALG_SHA_256;
+ *psk = ssl->conf->psk;
+ *psk_len = ssl->conf->psk_len;
+ return( 0 );
+}
+
/*
* mbedtls_ssl_tls13_write_identities_of_pre_shared_key_ext() structure:
*
@@ -910,12 +938,124 @@
return( 0 );
}
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_write_binder( mbedtls_ssl_context *ssl,
+ unsigned char *buf,
+ unsigned char *end,
+ int psk_type,
+ size_t *out_len )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ unsigned char *p = buf;
+ const unsigned char *psk;
+ psa_algorithm_t psa_alg = PSA_ALG_NONE;
+ size_t psk_len;
+ unsigned char binder_len;
+ unsigned char transcript[MBEDTLS_MD_MAX_SIZE];
+ size_t transcript_len = 0;
+
+ *out_len = 0;
+
+ switch( psk_type )
+ {
+#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_HAVE_TIME)
+ case MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION:
+ if( ssl_tls13_session_tickets_get_psk(
+ ssl, &psa_alg, &psk, &psk_len ) != 0 )
+ {
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+ break;
+#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_HAVE_TIME*/
+ case MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL:
+ if( ssl_tls13_psk_get_psk( ssl, &psa_alg, &psk, &psk_len ) != 0 )
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ break;
+ default:
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ binder_len = PSA_HASH_LENGTH( psa_alg );
+ if( binder_len == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ /*
+ * - binder_len (1 bytes)
+ * - binder (binder_len bytes)
+ */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 + binder_len );
+
+ p[0] = binder_len;
+
+ /* Get current state of handshake transcript. */
+ ret = mbedtls_ssl_get_handshake_transcript(
+ ssl, mbedtls_hash_info_md_from_psa( psa_alg ),
+ transcript, MBEDTLS_MD_MAX_SIZE, &transcript_len );
+ if( ret != 0 )
+ return( ret );
+
+
+
+ ret = mbedtls_ssl_tls13_create_psk_binder( ssl, psa_alg,
+ psk, psk_len, psk_type,
+ transcript, p + 1 );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_create_psk_binder", ret );
+ return( ret );
+ }
+ MBEDTLS_SSL_DEBUG_BUF( 4, "write binder", p, 1 + binder_len );
+
+ *out_len = 1 + binder_len;
+
+ return( ret );
+}
+
int mbedtls_ssl_tls13_write_binders_of_pre_shared_key_ext(
mbedtls_ssl_context *ssl, unsigned char *buf, unsigned char *end )
{
- ((void) ssl);
- ((void) buf);
- ((void) end);
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ unsigned char *p = buf;
+
+ /* Check if we have space to write binders_len.
+ * - binders_len (2 bytes)
+ */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
+ p += 2;
+
+ if( ssl_tls13_has_configured_ticket( ssl ) )
+ {
+ size_t output_len;
+ ret = ssl_tls13_write_binder( ssl, p, end,
+ MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION,
+ &output_len );
+ if( ret != 0 )
+ return( ret );
+ p += output_len;
+ }
+
+ if( ssl_tls13_has_configured_psk( ssl ) )
+ {
+ size_t output_len;
+ ret = ssl_tls13_write_binder( ssl, p, end,
+ MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL,
+ &output_len );
+ if( ret != 0 )
+ return( ret );
+ p += output_len;
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding PSK binder list." ) );
+
+ /*
+ * - binders_len (2 bytes)
+ */
+ MBEDTLS_PUT_UINT16_BE( p - buf - 2, buf, 0 );
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "pre_shared_key binders", buf, p - buf );
return( 0 );
}
