1 files changed, 105 insertions, 0 deletions
diff --git a/gnu/java/security/provider/DERWriter.java b/gnu/java/security/provider/DERWriter.java
new file mode 100644
index 000000000..037274d1e
--- /dev/null
+++ b/gnu/java/security/provider/DERWriter.java
@@ -0,0 +1,105 @@
+package gnu.java.security.provider;
+
+import java.math.BigInteger;
+
+public class DERWriter
+{
+
+static final int UNIVERSAL = 1;
+static final int APPLICATION = 2;
+static final int CONTEXT_SPECIFIC = 3;
+static final int PRIVATE = 4;
+
+public DERWriter()
+{}
+
+public byte[] writeBigInteger( BigInteger i)
+{
+	return writePrimitive( 0x02, UNIVERSAL, (int)Math.ceil((double)i.bitLength() / 8), i.toByteArray() );
+}
+
+private byte[] writePrimitive( int identifier, int identifierencoding,
+	 int length, byte contents[])
+{
+	return joinarrays( generateIdentifier( identifier, identifierencoding ), generateLength( length ), contents);
+}
+
+public byte[] joinarrays( byte a[], byte b[])
+{
+	byte d[] = new byte[ a.length + b.length];
+	System.arraycopy( a, 0, d, 0, a.length);
+	System.arraycopy( b, 0, d, a.length, b.length);
+	return d;
+}
+
+public byte[] joinarrays( byte a[], byte b[], byte c[])
+{
+	byte d[] = new byte[ a.length + b.length + c.length];
+	System.arraycopy( a, 0, d, 0, a.length);
+	System.arraycopy( b, 0, d, a.length, b.length);
+	System.arraycopy( c, 0, d, a.length + b.length, c.length);
+	return d;
+}
+
+private byte[] generateIdentifier(int identifier, 
+	int identifierencoding)
+{
+	byte b[];
+	if( identifier > 31 ) {
+		int count = (int)(Math.log( identifier ) / Math.log( 256 ));
+		b = new byte[ count + 1 ];
+		b[0] = (byte)(translateLeadIdentifierByte(identifierencoding) 
+			| 0x1f);
+		int i;
+		for( i = 1; i < (count + 1); i++) {
+			b[i] = (byte)(0x7f & ( identifier >> (7 * (count - i)) ));
+			b[i] |= 0x80;
+		}
+		b[i - 1] ^= 0x80;
+		//System.out.println("Identifier1: " + b[0]);
+		return b;
+	} else {
+		b = new byte[1];
+		b[0] = (byte)((translateLeadIdentifierByte(identifierencoding)
+		| (byte)( identifier & 0x1f )) & 0xdf);
+		//System.out.println("Identifier2: " + b[0]);
+		return b;
+	}
+}
+
+private byte translateLeadIdentifierByte(int b)
+{
+	if( b == UNIVERSAL)
+		return (byte)0x3f;
+	else if( b == APPLICATION)
+		return (byte)0x7f;
+	else if( b == CONTEXT_SPECIFIC)
+		return (byte)0xbf;
+	else 
+		return (byte)0xC0;
+}
+
+private byte[] generateLength( int length )
+{
+	byte b[];
+	if( length > 127 ) {
+		int count = (int)Math.ceil(Math.log( length ) / Math.log( 256 ));
+		//System.out.println("Length byte count: " + count);
+		b = new byte[ count + 1 ];
+		b[0] = (byte)((count & 0x7f) | 0x80);
+		for( int i = 1; i < (count + 1); i++) {
+			b[i] = (byte)( length >>> (8 * ( count - i) ));
+			//System.out.println("Length1 byte1: " + (length >>> (8 * ( count - i) )));
+			//System.out.println("Length1 byte2: " + b[i]);
+		}
+
+		//System.out.println("Length1: " + length);
+		return b;
+	} else {
+		b = new byte[1];
+		b[0] = (byte)( length & 0x7f );
+		//System.out.println("Length2: " + length);
+		return b;
+	}
+}
+}