HMACSHA1.java

/**
 * @author conmind
 */
public class HMACSHA1 {
        public static byte[] getHmacSHA1( String data,String key){
                byte[] ipadArray = new byte[64];
                byte[] opadArray = new byte[64];
                byte[] keyArray = new byte[64];
                int ex = key.length();
                SHA1 sha1= new SHA1();
                if (key.length() > 64) {
                        byte[] temp = sha1.getDigestOfBytes(key.getBytes());
                        ex = temp.length;
                        for (int i = 0; i < ex; i++) {
                                keyArray[i] = temp[i];
                        }
                }else{
                        byte[] temp = key.getBytes();
                        for (int i = 0; i < temp.length; i++) {
                                keyArray[i] = temp[i];
                        }
                }
                for (int i = ex; i < 64; i++) {
                        keyArray[i] = 0;
                }
                for (int j = 0; j < 64; j++) {
                        ipadArray[j] = (byte) (keyArray[j] ^ 0x36);
                        opadArray[j] = (byte) (keyArray[j] ^ 0x5C);
                }
                byte[] tempResult = sha1.getDigestOfBytes(join(ipadArray,data.getBytes()));
                
                return sha1.getDigestOfBytes(join(opadArray,tempResult));
        }
        
        private static byte[] join(byte[] b1,byte[] b2){
                int length = b1.length + b2.length;
                byte[] newer = new byte[length];
                for (int i = 0; i < b1.length; i++) {
                        newer[i] = b1[i];
                }
                for (int i = 0; i < b2.length; i++) {
                        newer[i+b1.length] = b2[i];
                }
                return newer;
        }
}