我如何在Java中找到php md5（sha1（“ test”））

Question

In my existing system, i have hashed the password with the following algorithm in php.

$userId = "testusername";
$password = "testpassword";
echo md5(sha1($userId).sha1($password));

what will be the equivalent method in Java for the above, because i was migrating php to java.

when i tried to search in google, they are talking about MessageDigest method. In PHP i have used the inbuild md5() and sha1() function

in java, i found the following, but still, its not equivalent.

   public static String sha1(String input) {
    StringBuilder sb = null;
    try{
        MessageDigest md = MessageDigest.getInstance("SHA-1");
        md.reset();
        md.update(input.getBytes());
        byte[] bytes = md.digest();
        sb = new StringBuilder();
        for(int i=0; i< bytes.length ;i++)
        {
            sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
        }
    }catch(RuntimeException | NoSuchAlgorithmException e){
        throw new RuntimeException(e.getMessage());
    }
    return sb.toString();
}

public static String md5(String input) {

    StringBuilder sb = null;
    try {
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(input.getBytes());
        byte[] bytes = md.digest();
        sb = new StringBuilder();
        for (int i = 0; i < bytes.length; i++) {
            sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
        }
    } catch (RuntimeException | NoSuchAlgorithmException e) {
        throw new RuntimeException(e.getMessage());
    }
    return sb.toString();
}

}

Answer 1

You can try bellow example :

class Main {
    public static void main(String[] a) throws UnsupportedEncodingException, NoSuchAlgorithmException {
        String output, input = "ml";
        MessageDigest md = MessageDigest.getInstance("md5");
        byte[] digest = md.digest(input.getBytes("UTF-8"));
        BigInteger bigInt = new BigInteger(1, digest);
        output = bigInt.toString(16);
        System.out.println(""+output);
    }
}

In the same way you also can generate sha1 just pass "sha1" in MessageDigest.getInstance(); function.

Answer 2

sha1($userId)+sha1($password) completely wrong. To do string concatenation in PHP you need sha1($userId).sha1($password)

The result you're seeing in PHP is actually md5(8) or c9f0f895fb98ab9159f51fd0297e236d . This is because the SHA1 of $password begins with an 8. The rest of the hash is thrown away.

This can not be used as a secure hashing function because there are too many collisions. For example, a password of 12345 has the same hash. You should require users to reset their passwords and use a standard password hashing mechanism instead.