1 files changed, 115 insertions, 0 deletions
diff --git a/gnu/java/security/provider/DERReader.java b/gnu/java/security/provider/DERReader.java
new file mode 100644
index 000000000..66645e69e
--- /dev/null
+++ b/gnu/java/security/provider/DERReader.java
@@ -0,0 +1,115 @@
+package gnu.java.security.provider;
+
+import java.math.BigInteger;
+import gnu.java.security.der.DEREncodingException;
+
+public class DERReader
+{
+byte source[];
+int pos;
+
+static final int UNIVERSAL = 1;
+static final int APPLICATION = 2;
+static final int CONTEXT_SPECIFIC = 3;
+static final int PRIVATE = 4;
+
+
+public DERReader()
+{
+	source = null;
+	pos = 0;
+}
+
+public DERReader( byte source[] )
+{
+	init( source );
+}
+
+public void init( String source )
+{
+	init( source.getBytes() );
+}
+
+public void init( byte source[] )
+{
+	this.source = source;
+	pos = 0;
+}
+
+public BigInteger getBigInteger() throws DEREncodingException
+{
+	return new BigInteger( getPrimitive() );
+}
+
+//Reads Primitive, definite-length method
+private byte[] getPrimitive() throws DEREncodingException
+{
+	int tmp = pos;
+	
+	//Read Identifier
+	byte identifier = source[tmp++];
+	if( (0x20 & identifier) != 0)
+		throw new DEREncodingException();
+	int type = translateLeadIdentifierByte(identifier);
+	//System.out.println("Type: " + type);
+
+	//get tag
+	int tag = (0x1f & identifier);
+	//if( tag == 0x1f)
+	//	tag = getIdentifier(tmp);
+	//System.out.println("Tag: " + tag);
+
+	//get length
+	byte len = source[tmp]; //may be length of length parameter
+	long length =  0x7f & len;
+	int i;
+	if( (0x80 & len) != 0 ) {
+		//System.out.println("Extra Long Length");
+		len &= 0x7f;
+		//System.out.println("Length of Length: " + len);
+		//get length here
+		length = 0;
+		for( i = 0; i < len; i++ ) {
+			tmp++;
+			length <<= 8;
+			length += (source[tmp] < 0 ) ? 
+				(256 + source[tmp]) : 
+				source[tmp];
+		//System.out.println("Length of Length: " + length);
+		}
+		tmp++;
+	} else
+		tmp++;
+
+	/*System.out.println("Position: " + tmp);
+	System.out.println("Length: " + length);
+	for( i = 0; i < 10; i++)
+		System.out.print(source[tmp + i] + " ");
+	System.out.println();*/
+
+	byte tmpb[] = new byte[ (int)length ];
+	System.arraycopy( source, tmp, tmpb, 0, (int)length);
+	pos = (int)(tmp + length);
+	return tmpb;	
+}
+
+private int translateLeadIdentifierByte(byte b)
+{
+	if( (0x3f & b ) == b)
+		return UNIVERSAL;
+	else if( (0x7f & b ) == b)
+		return APPLICATION;
+	else if( (0xbf & b ) == b)
+		return CONTEXT_SPECIFIC;
+	else 
+		return PRIVATE;
+}
+
+private int getIdentifier(int tpos)
+{
+	while( (0x80 & source[tpos]) != 0)
+		tpos++;
+	return tpos;
+}
+
+}