One-Time Password (OTP) Converting C # Code to Java

Question

Last year, I wrote a one-time password generator (OTP) in C #. Now I need to use the OTP generator in Java, but I could not find equivalent functions in Java.

Here is the code I wrote last year: (I know this OTP protection is low, but I don't need bulletproof)

SHA1CryptoServiceProvider hash = new SHA1CryptoServiceProvider(); //first hash with sha1 byte[] hashPass = hash.ComputeHash(Encoding.ASCII.GetBytes(pass)); //pass is entered by user HMACMD5 hma = new HMACMD5(hashPass); // use the hashed value as a key to hmac OTPass = hma.ComputeHash(Encoding.ASCII.GetBytes(email + Counter(email)));// generate OTPass, Counter(email) is the counter of the user taken from database increaseCounter(email); // updating the counter this.SetLog(this.GetLog() + Environment.NewLine + "OTPass Generated: " + BitConverter.ToString(OTPass)); // OTP 

Here is the Java code that I tried to convert C # to: (This is only part of SHA1, I could not find how to write HMAC-MD5 in Java)

 import java.io.*; import java.security.*; public class otp { /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException { System.out.println("Please enter your username:"); BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String username = br.readLine(); System.out.println("Please enter your password:"); String password = br.readLine(); try { MessageDigest md = MessageDigest.getInstance("SHA1"); String input = password; md.update(input.getBytes()); byte[] output = md.digest(); System.out.println(); System.out.println("SHA1(\""+input+"\") ="); System.out.println(" "+bytesToHex(output)); } catch (Exception e) { System.out.println("Exception: "+e); } } public static String bytesToHex(byte[] b) { char hexDigit[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; StringBuffer buf = new StringBuffer(); for (int j=0; j<b.length; j++) { buf.append(hexDigit[(b[j] >> 4) & 0x0f]); buf.append(hexDigit[b[j] & 0x0f]); } return buf.toString(); } } 

thanks for the help

Answer 1

I always used BouncyCastle

You can take a look at a few of these pages:

BouncyCastle HMac

BouncyCastle Features

Or stick with Java 6:

 Mac hmacMd5 = Mac.getInstance("HMACMD5");