SHA256 in Java Ruby C# PHP Phython

gistfile1.txt

*SHA256–Bit Hash Java Example*

import java.security.MessageDigest;
import java.security.SignatureException;
String sourceString = ...; // shared secret + fields in correct format
String hash = sha256Digest(sourceString);

public String sha256Digest (String data) throws SignatureException {
 return getDigest(“SHA-256”, data, true);
}

private String getDigest(String algorithm, String data, boolean toLower) 
 throws SignatureException {
  try {
 MessageDigest mac = MessageDigest.getInstance(algorithm);
 mac.update(data.getBytes(“UTF-8”));
 return toLower ? 
  new String(toHex(mac.digest())).toLowerCase() : new String(toHex(mac.digest()));
  } catch (Exception e) {
 throw new SignatureException(e);
  }
}

private String toHex(byte[] bytes) {
 BigInteger bi = new BigInteger(1, bytes);
 return String.format(“%0” + (bytes.length << 1) + “X”, bi);
}

Note: org.apache.commons.code.digest is a useful library for generating the SHA256 hash.

*SHA256–Bit Hash PHP Example*

$hash = hash('sha256',$sourceString);

*SHA256–Bit Hash Ruby Example*

require ‘digest’
hash = Digest::SHA256.hexdigest(sourceString)

*SHA256–Bit Hash Python Example*

hash = hashlib.sha256(sourceString).hexdigest()

*SHA256–Bit Hash C# Example*

import System.Security.Cryptography.SHA256;

public string GetHashSha256(string text)
{
  byte[] bytes = Encoding.ASCII.GetBytes(text);
  SHA256Managed hashstring = new SHA256Managed();
  byte[] hash = hashstring.ComputeHash(bytes);
  string hashString = string.Empty;

  foreach (byte x in hash)
  {
 hashString += String.Format("{0:x2}", x);
  }
  return hashString;
}

From: https://developer.visa.com/vme/merchant/documents/Mobile_SDKs/ios/SHA256_Bit_Hashing.html