1 files changed, 29 insertions, 17 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/asn1/ConstructedOctetStream.java b/bcprov/src/main/java/org/bouncycastle/asn1/ConstructedOctetStream.java
index f247b11f..fd261787 100644
--- a/bcprov/src/main/java/org/bouncycastle/asn1/ConstructedOctetStream.java
+++ b/bcprov/src/main/java/org/bouncycastle/asn1/ConstructedOctetStream.java
@@ -26,15 +26,14 @@ class ConstructedOctetStream
                 return -1;
             }
 
-            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
-
-            if (s == null)
+            ASN1OctetStringParser next = getNextParser();
+            if (next == null)
             {
                 return -1;
             }
 
             _first = false;
-            _currentStream = s.getOctetStream();
+            _currentStream = next.getOctetStream();
         }
 
         int totalRead = 0;
@@ -54,15 +53,14 @@ class ConstructedOctetStream
             }
             else
             {
-                ASN1OctetStringParser aos = (ASN1OctetStringParser)_parser.readObject();
-
-                if (aos == null)
+                ASN1OctetStringParser next = getNextParser();
+                if (next == null)
                 {
                     _currentStream = null;
                     return totalRead < 1 ? -1 : totalRead;
                 }
 
-                _currentStream = aos.getOctetStream();
+                _currentStream = next.getOctetStream();
             }
         }
     }
@@ -77,15 +75,14 @@ class ConstructedOctetStream
                 return -1;
             }
 
-            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
-    
-            if (s == null)
+            ASN1OctetStringParser next = getNextParser();
+            if (next == null)
             {
                 return -1;
             }
-    
+
             _first = false;
-            _currentStream = s.getOctetStream();
+            _currentStream = next.getOctetStream();
         }
 
         for (;;)
@@ -97,15 +94,30 @@ class ConstructedOctetStream
                 return b;
             }
 
-            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
-
-            if (s == null)
+            ASN1OctetStringParser next = getNextParser();
+            if (next == null)
             {
                 _currentStream = null;
                 return -1;
             }
 
-            _currentStream = s.getOctetStream();
+            _currentStream = next.getOctetStream();
         }
     }
+
+    private ASN1OctetStringParser getNextParser() throws IOException
+    {
+        ASN1Encodable asn1Obj = _parser.readObject();
+        if (asn1Obj == null)
+        {
+            return null;
+        }
+
+        if (asn1Obj instanceof ASN1OctetStringParser)
+        {
+            return (ASN1OctetStringParser)asn1Obj;
+        }
+
+        throw new IOException("unknown object encountered: " + asn1Obj.getClass());
+    }
 }