ssl_tls13_client.c: alpn: Miscellanous minor improvements
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 0c26b2d..5c07bc0 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -113,7 +113,10 @@
#if defined(MBEDTLS_SSL_ALPN)
/*
- * ssl_tls13_write_alpn_ext( ) structure:
+ * ssl_tls13_write_alpn_ext()
+ *
+ * Structure of the application_layer_protocol_negotiation extension in
+ * ClientHello:
*
* opaque ProtocolName<1..2^8-1>;
*
@@ -123,15 +126,13 @@
*
*/
static int ssl_tls13_write_alpn_ext( mbedtls_ssl_context *ssl,
- unsigned char *buf,
- const unsigned char *end,
- size_t *olen )
+ unsigned char *buf,
+ const unsigned char *end,
+ size_t *out_len )
{
unsigned char *p = buf;
- size_t protocol_name_len;
- const char **cur;
- *olen = 0;
+ *out_len = 0;
if( ssl->conf->alpn_list == NULL )
return( 0 );
@@ -154,26 +155,27 @@
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*/
- for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
+ for( const char **cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
{
/*
* mbedtls_ssl_conf_set_alpn_protocols() checked that the length of
* protocol names is less than 255.
*/
- protocol_name_len = strlen( *cur );
+ size_t protocol_name_len = strlen( *cur );
+
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 + protocol_name_len );
*p++ = (unsigned char)protocol_name_len;
memcpy( p, *cur, protocol_name_len );
p += protocol_name_len;
}
- *olen = p - buf;
+ *out_len = p - buf;
- /* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
- MBEDTLS_PUT_UINT16_BE( *olen - 6, buf, 4 );
+ /* List length = *out_len - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
+ MBEDTLS_PUT_UINT16_BE( *out_len - 6, buf, 4 );
- /* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
- MBEDTLS_PUT_UINT16_BE( *olen - 4, buf, 2 );
+ /* Extension length = *out_len - 2 (ext_type) - 2 (ext_len) */
+ MBEDTLS_PUT_UINT16_BE( *out_len - 4, buf, 2 );
return( 0 );
}