1 files changed, 194 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/asn1/ASN1OutputStream.java b/core/src/main/java/org/spongycastle/asn1/ASN1OutputStream.java
new file mode 100644
index 00000000..8e663ac1
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/asn1/ASN1OutputStream.java
@@ -0,0 +1,194 @@
+package org.spongycastle.asn1;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Stream that produces output based on the default encoding for the passed in objects.
+ */
+public class ASN1OutputStream
+{
+    private OutputStream os;
+
+    public ASN1OutputStream(
+        OutputStream    os)
+    {
+        this.os = os;
+    }
+
+    void writeLength(
+        int length)
+        throws IOException
+    {
+        if (length > 127)
+        {
+            int size = 1;
+            int val = length;
+
+            while ((val >>>= 8) != 0)
+            {
+                size++;
+            }
+
+            write((byte)(size | 0x80));
+
+            for (int i = (size - 1) * 8; i >= 0; i -= 8)
+            {
+                write((byte)(length >> i));
+            }
+        }
+        else
+        {
+            write((byte)length);
+        }
+    }
+
+    void write(int b)
+        throws IOException
+    {
+        os.write(b);
+    }
+
+    void write(byte[] bytes)
+        throws IOException
+    {
+        os.write(bytes);
+    }
+
+    void write(byte[] bytes, int off, int len)
+        throws IOException
+    {
+        os.write(bytes, off, len);
+    }
+
+    void writeEncoded(
+        int     tag,
+        byte[]  bytes)
+        throws IOException
+    {
+        write(tag);
+        writeLength(bytes.length);
+        write(bytes);
+    }
+
+    void writeTag(int flags, int tagNo)
+        throws IOException
+    {
+        if (tagNo < 31)
+        {
+            write(flags | tagNo);
+        }
+        else
+        {
+            write(flags | 0x1f);
+            if (tagNo < 128)
+            {
+                write(tagNo);
+            }
+            else
+            {
+                byte[] stack = new byte[5];
+                int pos = stack.length;
+
+                stack[--pos] = (byte)(tagNo & 0x7F);
+
+                do
+                {
+                    tagNo >>= 7;
+                    stack[--pos] = (byte)(tagNo & 0x7F | 0x80);
+                }
+                while (tagNo > 127);
+
+                write(stack, pos, stack.length - pos);
+            }
+        }
+    }
+
+    void writeEncoded(int flags, int tagNo, byte[] bytes)
+        throws IOException
+    {
+        writeTag(flags, tagNo);
+        writeLength(bytes.length);
+        write(bytes);
+    }
+
+    protected void writeNull()
+        throws IOException
+    {
+        os.write(BERTags.NULL);
+        os.write(0x00);
+    }
+
+    public void writeObject(
+        ASN1Encodable obj)
+        throws IOException
+    {
+        if (obj != null)
+        {
+            obj.toASN1Primitive().encode(this);
+        }
+        else
+        {
+            throw new IOException("null object detected");
+        }
+    }
+
+    void writeImplicitObject(ASN1Primitive obj)
+        throws IOException
+    {
+        if (obj != null)
+        {
+            obj.encode(new ImplicitOutputStream(os));
+        }
+        else
+        {
+            throw new IOException("null object detected");
+        }
+    }
+
+    public void close()
+        throws IOException
+    {
+        os.close();
+    }
+
+    public void flush()
+        throws IOException
+    {
+        os.flush();
+    }
+
+    ASN1OutputStream getDERSubStream()
+    {
+        return new DEROutputStream(os);
+    }
+
+    ASN1OutputStream getDLSubStream()
+    {
+        return new DLOutputStream(os);
+    }
+
+    private class ImplicitOutputStream
+        extends ASN1OutputStream
+    {
+        private boolean first = true;
+
+        public ImplicitOutputStream(OutputStream os)
+        {
+            super(os);
+        }
+
+        public void write(int b)
+            throws IOException
+        {
+            if (first)
+            {
+                first = false;
+            }
+            else
+            {
+                super.write(b);
+            }
+        }
+    }
+}