darwinsssl: add support for TLS False Start

TLS False Start support requires iOS 7.0 or later, or OS X 10.9 or later.

lib/vtls/darwinssl.c

@@ -1459,9 +1459,12 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
 #if CURL_BUILD_MAC_10_9 || CURL_BUILD_IOS_7
   /* We want to enable 1/n-1 when using a CBC cipher unless the user
      specifically doesn't want us doing that: */
-  if(SSLSetSessionOption != NULL)
+  if(SSLSetSessionOption != NULL) {
     SSLSetSessionOption(connssl->ssl_ctx, kSSLSessionOptionSendOneByteRecord,
                       !data->set.ssl_enable_beast);
+    SSLSetSessionOption(connssl->ssl_ctx, kSSLSessionOptionFalseStart,
+                      data->set.ssl.falsestart); /* false start support */
+  }
 #endif /* CURL_BUILD_MAC_10_9 || CURL_BUILD_IOS_7 */
 
   /* Check if there's a cached ID we can/should use here! */
@@ -2364,6 +2367,14 @@ void Curl_darwinssl_md5sum(unsigned char *tmp, /* input */
   (void)CC_MD5(tmp, (CC_LONG)tmplen, md5sum);
 }
 
+bool Curl_darwinssl_false_start(void) {
+#if CURL_BUILD_MAC_10_9 || CURL_BUILD_IOS_7
+  if(SSLSetSessionOption != NULL)
+    return TRUE;
+#endif
+  return FALSE;
+}
+
 static ssize_t darwinssl_send(struct connectdata *conn,
                               int sockindex,
                               const void *mem,

lib/vtls/darwinssl.h

@@ -48,6 +48,7 @@ void Curl_darwinssl_md5sum(unsigned char *tmp, /* input */
                            size_t tmplen,
                            unsigned char *md5sum, /* output */
                            size_t md5len);
+bool Curl_darwinssl_false_start(void);
 
 /* Set the API backend definition to SecureTransport */
 #define CURL_SSL_BACKEND CURLSSLBACKEND_DARWINSSL
@@ -69,6 +70,7 @@ void Curl_darwinssl_md5sum(unsigned char *tmp, /* input */
 #define curlssl_data_pending(x,y) Curl_darwinssl_data_pending(x, y)
 #define curlssl_random(x,y,z) ((void)x, Curl_darwinssl_random(y,z))
 #define curlssl_md5sum(a,b,c,d) Curl_darwinssl_md5sum(a,b,c,d)
+#define curlssl_false_start() Curl_darwinssl_false_start()
 
 #endif /* USE_DARWINSSL */
 #endif /* HEADER_CURL_DARWINSSL_H */