Security-55471.14.4.tar.gz

[apple/security.git] / libsecurity_transform / lib / SecTransformReadTransform.cpp

diff --git a/libsecurity_transform/lib/SecTransformReadTransform.cpp b/libsecurity_transform/lib/SecTransformReadTransform.cpp
index 902bfb1dc4f1fb81456e80e30963cb5df3477034..5d998cf3d281dc159e549730bcabfd486d9d82a9 100644 (file)
--- a/libsecurity_transform/lib/SecTransformReadTransform.cpp
+++ b/libsecurity_transform/lib/SecTransformReadTransform.cpp
@@ -41,15 +41,42 @@ static SecTransformInstanceBlock StreamTransformImplementation(CFStringRef name,
                        }
                        
                        CFArrayRef array = (CFArrayRef) value;
-                       CFReadStreamRef input = (CFReadStreamRef) CFArrayGetValueAtIndex(array, 0);
-                       
-                       // open the stream
-                       if (!CFReadStreamOpen(input))
+                       CFTypeRef item = (CFTypeRef) CFArrayGetValueAtIndex(array, 0);
+
+                       // Ensure that indeed we do have a CFReadStreamRef
+                       if (NULL == item || CFReadStreamGetTypeID() != CFGetTypeID(item))
                        {
-                               // We didn't open properly.  Error out
-                               return (CFTypeRef) CreateSecTransformErrorRef(kSecTransformErrorInvalidInput, "An error occurred while opening the stream.");
+                               return (CFTypeRef) CreateSecTransformErrorRef(kSecTransformErrorInvalidInput, "The input attribute item was nil or not a read stream");
                        }
                        
+                       // This now is a safe cast
+                       CFReadStreamRef input = (CFReadStreamRef)item;
+
+                       // Get the state of the stream
+                       CFStreamStatus streamStatus = CFReadStreamGetStatus(input);
+                       switch (streamStatus)
+                       {
+                               case kCFStreamStatusNotOpen:
+                               {
+                                       if (!CFReadStreamOpen(input))
+                                       {
+                                               // We didn't open properly.  Error out
+                                               return (CFTypeRef) CreateSecTransformErrorRef(kSecTransformErrorInvalidInput, "An error occurred while opening the stream.");
+                                       }
+                               }
+                               break;
+
+                               case kCFStreamStatusError:
+                               {
+                                       return (CFTypeRef) CreateSecTransformErrorRef(kSecTransformErrorInvalidInput, "The read stream is in an error state");
+                               }
+                               break;
+
+                               default:
+                                       // The assumption is that the stream is ready to go as is.
+                               break;
+                       }               
+                       
                        // allocate the read buffer on the heap
                        u_int8_t* buffer = (u_int8_t*) malloc(blockSize);