darwinssl: fix crash that started happening in Lion

Something (a recent security update maybe?) changed in Lion, and now it
has changed SSLCopyPeerTrust such that it may return noErr but also give
us a null trust, which caught us off guard and caused an eventual crash.

diff --git a/lib/curl_darwinssl.c b/lib/curl_darwinssl.c
index d03f3cc..82a339b 100644 (file)
--- a/lib/curl_darwinssl.c
+++ b/lib/curl_darwinssl.c
@@ -1363,11 +1363,11 @@ darwinssl_connect_step3(struct connectdata *conn,
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
   CFStringRef server_cert_summary;
   char server_cert_summary_c[128];
-  CFArrayRef server_certs;
+  CFArrayRef server_certs = NULL;
   SecCertificateRef server_cert;
   OSStatus err;
   CFIndex i, count;
-  SecTrustRef trust;
+  SecTrustRef trust = NULL;
 
   /* There is no step 3!
    * Well, okay, if verbose mode is on, let's print the details of the
@@ -1376,7 +1376,9 @@ darwinssl_connect_step3(struct connectdata *conn,
 #if CURL_BUILD_IOS
 #pragma unused(server_certs)
   err = SSLCopyPeerTrust(connssl->ssl_ctx, &trust);
-  if(err == noErr) {
+  /* For some reason, SSLCopyPeerTrust() can return noErr and yet return
+     a null trust, so be on guard for that: */
+  if(err == noErr && trust) {
     count = SecTrustGetCertificateCount(trust);
     for(i = 0L ; i < count ; i++) {
       server_cert = SecTrustGetCertificateAtIndex(trust, i);
@@ -1402,7 +1404,9 @@ darwinssl_connect_step3(struct connectdata *conn,
   if(SecTrustEvaluateAsync != NULL) {
 #pragma unused(server_certs)
     err = SSLCopyPeerTrust(connssl->ssl_ctx, &trust);
-    if(err == noErr) {
+    /* For some reason, SSLCopyPeerTrust() can return noErr and yet return
+       a null trust, so be on guard for that: */
+    if(err == noErr && trust) {
       count = SecTrustGetCertificateCount(trust);
       for(i = 0L ; i < count ; i++) {
         server_cert = SecTrustGetCertificateAtIndex(trust, i);
@@ -1422,7 +1426,8 @@ darwinssl_connect_step3(struct connectdata *conn,
   else {
 #if CURL_SUPPORT_MAC_10_8
     err = SSLCopyPeerCertificates(connssl->ssl_ctx, &server_certs);
-    if(err == noErr) {
+    /* Just in case SSLCopyPeerCertificates() returns null too... */
+    if(err == noErr && server_certs) {
       count = CFArrayGetCount(server_certs);
       for(i = 0L ; i < count ; i++) {
         server_cert = (SecCertificateRef)CFArrayGetValueAtIndex(server_certs,