dercoder.java

JAVA开源LDAP浏览器jxplorer的源码!

        }
        offset = encodeLength(content.length, stream, offset);
        stream[offset++] = (byte) o.getASN1Type().getTag();
        return offset;
    }
    
    /**
     * Encodes NULL.
     */
    private int encodeNULL(ASN1Object o, byte [] stream, int offset)
    {
        stream[offset++] = 0;
        stream[offset++] = (byte) o.getASN1Type().getTag();
        return offset;
    }
    
    /**
     * Encodes ContextSpecific.
     */
    private int encodeCONTEXT(ASN1Object o, byte [] stream, int offset)
    throws ASN1Exception
    {
    
        ASN1Object v = (ASN1Object) (o.getValue());
        int start = offset;
        
        //System.out.println("TYPE:" + v.getASN1Type().getName());
        
        if (o.implicit())
        {
        
            if ((o.getTag() & 0x20) == 0)
            {
            
                byte[] data = null;
                
                if ( v.getASN1Type().equals(ASN1Type.BOOLEAN))
                {
                
                    boolean b = ((Boolean) v.getValue()).booleanValue();
                    stream[offset++] = (byte) (b?1:0);
                    stream[offset++] = 1;
                }
                
                if ( v.getASN1Type().equals(ASN1Type.OCTET_STRING))
                {
                
                    data = (byte []) (v.getValue());
                    
                    for (int i = data.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = data[i];
                    }
                    offset = encodeLength(data.length, stream, offset);
                }
                
                if ( v.getASN1Type().equals(ASN1Type.IA5String))
                {
                
                    String s = (String) (v.getValue());
                    data = s.getBytes();
                    for (int i = data.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = data[i];
                    }
                    offset = encodeLength(data.length, stream, offset);
                }
                
                if ( v.getASN1Type().equals(ASN1Type.INTEGER))
                {
                    BigInteger tmp = (BigInteger) v.getValue();
                    data =  tmp.toByteArray();
                    
                    for (int i = data.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = data[i];
                    }
                    offset = encodeLength(data.length, stream, offset);
                }
                
                if (v.getASN1Type().equals(ASN1Type.UTCTime))
                {
                
                    String time = (String) (v.getValue());
                    //System.out.println("time:" + time);
                    
                    byte [] t = time.getBytes();
                    for (int i = t.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = t[i];
                    }
                    
                    offset = encodeLength(t.length, stream, offset);
                } // End of IF ... UTCTime
                
                if ( v.getASN1Type().equals(ASN1Type.GENERALIZEDTIME))
                {
                
                    String time = (String) (v.getValue());
                    //System.out.println("time:" + time);
                    
                    byte [] t = time.getBytes();
                    for (int i = t.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = t[i];
                    }
                    
                    offset = encodeLength(t.length, stream, offset);
                }
                
                if ( v.getASN1Type().equals(ASN1Type.BIT_STRING))
                {
                
                    byte [] content = (byte []) (v.getValue());
                    for (int i = content.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = content[i];
                    }
                    stream[offset++] = 0;
                    offset = encodeLength(content.length + 1, stream, offset);
                }
                
                if ( v.getASN1Type().equals(ASN1Type.ENUMERATED))
                {
                    BigInteger tmp = (BigInteger) v.getValue();
                    data =  tmp.toByteArray();
                    
                    for (int i = data.length - 1; i >= 0; i--)
                    {
                        stream[offset++] = data[i];
                    }
                    offset = encodeLength(data.length, stream, offset);
                }
                
                if ( v.getASN1Type().equals(ASN1Type.OBJECT_ID))
                {
                
                    String id = (String) (v.getValue());
                    StringTokenizer st = new StringTokenizer(id, " ");
                    String [] subid = new String[st.countTokens()];
                    //start = offset;
                    
                    for (int i = 0; i < subid.length; i++)
                    {
                        subid[i] = st.nextToken();
                    }
                    for (int i = subid.length - 1; i > 1; i--)
                    {
                        long s = Long.parseLong(subid[i]);
                        stream[offset++] = (byte) (s & 0x7f);
                        s >>>= 7;
                        
                        while (s != 0)
                        {
                            stream[offset++] = (byte) (s | 0x80);
                            s >>>= 7;
                        }
                    }
                    
                    long l = Long.parseLong(subid[0]) * 40 + Long.parseLong(subid[1]);
                    stream[offset++] = (byte) l;
                    offset = encodeLength(offset - start, stream, offset);
                    //stream[offset++] = (byte) o.getASN1Type().getTag();
                    //return offset;
                }
                
                if ( (v.getASN1Type().equals(ASN1Type.SEQUENCE)== true) ||
                        ( v.getASN1Type().equals(ASN1Type.SET) == true) )
                {
                
                    start = offset;
                    //System.out.println("SIZE:" + v.size());
                    for (int i = v.size() - 1; i >= 0; i--)
                    {
                        offset = encode(v.getComponent(i), stream, offset);
                    }
                    
                    offset = encodeLength(offset - start, stream, offset);
                    stream[offset++] = (byte) (0xa0 | o.getTag());
                    return offset;
                } // End of IF ... sequence
                
                stream[offset++] = (byte) (0x80 | o.getTag()); // For all other types
                
            }
            else
            {
            
                offset = encode(v, stream, offset);
                stream[offset - 1] = (byte) (0xa0 | o.getTag());
            }
        }
        else
        {
        
            offset = encode(v, stream, offset);
            offset = encodeLength(offset - start, stream, offset);
            stream[offset++] = (byte) (0xa0 | o.getTag());
        }
        return offset;
    }
    
    
    /********************************/
    /*		DER Decoding			*/
    /********************************/
    
    /**
     * DER decoding -- decodes a byte array to an ASN1Object
     * @param	buffer the byte array to be decoded
     * @return	the decoded ASN1Object
     * @exception iss.security.asn1.ASN1Exception if any error
     * occurred in the decoding process
     */
    public ASN1Object decode(byte [] buffer)
    throws ASN1Exception
    {
        int [] offset = new int [1];
        offset[0] = 0;
        return decode(buffer, offset);
    }
    
    /**
     * DER decoding -- decodes a byte array to an ASN1Object
     * @param	buffer the byte array to be decoded
     * @param	offset the starting index of the buffer
     * @return	the decoded ASN1Object
     * @exception iss.security.asn1.ASN1Exception if any error
     * occurred in the decoding process
     */
    public ASN1Object decode(byte [] buffer, int [] offset)
    throws ASN1Exception
    {
        int start = offset[0];
        int tag = buffer[offset[0]++];
        int oldTag = 0;
        if ((tag & 0x80) != 0 && (tag & 0x40) == 0)
        {// context-specific tag
            oldTag = tag;
            tag = 0x80;
        }
        
        ASN1Type type = new ASN1Type(tag);
        ASN1Object object = ASN1Object.create(type);
        int length = decodeLength(buffer, offset);
        if (length < 0 && length != -1)
        {
            throw new ASN1Exception(
                "Invalid object length (" + length + ")");
        }
        switch (tag)
        {
        case 1:
            decodeBOOLEAN(object, buffer, offset, length);
            break;
        case 2:
            decodeINTEGER(object, buffer, offset, length);
            break;
        case 3:
            decodeBITSTRING(object, buffer, offset, length);
            break;
        case 4:
            decodeOCTETSTRING(object, buffer, offset, length);
            break;
        case 5:
            decodeNULL(object, buffer, offset, length);
            break;
        case 6:
            decodeOBJECTID(object, buffer, offset, length);
            break;
        case 10:
            decodeENUMERATED(object, buffer, offset, length);
            break;
        case 19:
            decodePrintableString(object, buffer, offset, length);
            break;
        case 20:
            //		case 20: decodeT61String(object, buffer, offset, length);
            //				break;
        case 22:
            decodeIA5String(object, buffer, offset, length);
            break;
        case 23:
            decodeUTCTime(object, buffer, offset, length);
            break;
        case 24:
            decodeGeneralizedTime(object, buffer, offset, length);
            break;
        case 28:
            decodeUniversalString(object, buffer, offset, length);
            break;
        case 30:
            decodeBMPSTRING(object, buffer, offset, length);
            break;
        case 48:
        case 49:
            decodeSEQUENCE(object, buffer, offset, length);
            break;
            //		case 49: decodeSET(object, buffer, offset, length);
            //				break;
        case 128:
            decodeCONTEXT(object, buffer, offset, length, oldTag);
            break;
        default:
            throw new ASN1Exception("Unknow ASN.1 tag --" + tag);
        }
        
        //	offset[0] = offset[0] + length;
        byte [] der = new byte[offset[0]-start];
        System.arraycopy(buffer, start, der, 0, offset[0] - start);
        object.setByteArray(der);
        return object;
    }
    
    /**
     * Decodes the length.
     */
    private int decodeLength(byte [] stream, int [] offset)
    throws ASN1Exception
    {
        int length = stream[offset[0]++] & 0xff;
        if ((length & 0x80) != 0)
        {
            int count = length & 0x7f;
            if (count > 4)
            {
                throw new ASN1Exception("ASN.1 Object too large");
            }
            if (count == 0)
            { // indefinite length
                return -1;
            }
            length = stream[offset[0]++] & 0xff;
            for (int i = 1; i < count; i++)
            {
                length <<= 8;
                length |= (stream[offset[0]++] & 0xff);
            }
        }
        return length;
    }
    
    /**
     * Decodes BOOLEAN. Definite-length only.
     */
    private void decodeBOOLEAN(ASN1Object o, byte [] stream, int [] offset,