1 files changed, 111 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/asn1/ConstructedOctetStream.java b/core/src/main/java/org/spongycastle/asn1/ConstructedOctetStream.java
new file mode 100644
index 00000000..21c3ac36
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/asn1/ConstructedOctetStream.java
@@ -0,0 +1,111 @@
+package org.spongycastle.asn1;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+class ConstructedOctetStream
+    extends InputStream
+{
+    private final ASN1StreamParser _parser;
+
+    private boolean                _first = true;
+    private InputStream            _currentStream;
+
+    ConstructedOctetStream(
+        ASN1StreamParser parser)
+    {
+        _parser = parser;
+    }
+
+    public int read(byte[] b, int off, int len) throws IOException
+    {
+        if (_currentStream == null)
+        {
+            if (!_first)
+            {
+                return -1;
+            }
+
+            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
+
+            if (s == null)
+            {
+                return -1;
+            }
+
+            _first = false;
+            _currentStream = s.getOctetStream();
+        }
+
+        int totalRead = 0;
+
+        for (;;)
+        {
+            int numRead = _currentStream.read(b, off + totalRead, len - totalRead);
+
+            if (numRead >= 0)
+            {
+                totalRead += numRead;
+
+                if (totalRead == len)
+                {
+                    return totalRead;
+                }
+            }
+            else
+            {
+                ASN1OctetStringParser aos = (ASN1OctetStringParser)_parser.readObject();
+
+                if (aos == null)
+                {
+                    _currentStream = null;
+                    return totalRead < 1 ? -1 : totalRead;
+                }
+
+                _currentStream = aos.getOctetStream();
+            }
+        }
+    }
+
+    public int read()
+        throws IOException
+    {
+        if (_currentStream == null)
+        {
+            if (!_first)
+            {
+                return -1;
+            }
+
+            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
+    
+            if (s == null)
+            {
+                return -1;
+            }
+    
+            _first = false;
+            _currentStream = s.getOctetStream();
+        }
+
+        for (;;)
+        {
+            int b = _currentStream.read();
+
+            if (b >= 0)
+            {
+                return b;
+            }
+
+            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
+
+            if (s == null)
+            {
+                _currentStream = null;
+                return -1;
+            }
+
+            _currentStream = s.getOctetStream();
+        }
+    }
+}