From 59067bc95140f2bc3a8bcb22ae18206ca8d72328 Mon Sep 17 00:00:00 2001
From: KarthikeyanKumar <karthikeyan.cse.skcet@gmail.com>
Date: Thu, 7 Feb 2019 16:58:24 +0530
Subject: [PATCH] Create ComputeTransHashSHA2.java

This is sample code to compute hmac sha 512 for a transaction for Authorize.net
---
 .../sample/Sha512/ComputeTransHashSHA2.java   | 99 +++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 src/main/java/net/authorize/sample/Sha512/ComputeTransHashSHA2.java

diff --git a/src/main/java/net/authorize/sample/Sha512/ComputeTransHashSHA2.java b/src/main/java/net/authorize/sample/Sha512/ComputeTransHashSHA2.java
new file mode 100644
index 00000000..2a3a146e
--- /dev/null
+++ b/src/main/java/net/authorize/sample/Sha512/ComputeTransHashSHA2.java
@@ -0,0 +1,99 @@
+package net.authorize.sample.Sha512;
+
+import java.security.*;
+import java.util.Formatter;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class ComputeTransHashSHA2 {
+
+    public static void main(String[] args) throws Exception {
+        String signatureKey = "56E529FE6C63D60E545F84686096E6AA01D5E18A119F18A130F7CFB3983104216979E95D84C91BDD382AA0875264A63940A2D0AA5548F6023B4C78A9D52C18DA";
+        String transId = "60115868980";
+        String apiLogin = "5T9cRn9FK";
+        String amount = "15.00";
+        //transHashSHA2 represents the computed TransHash2 using SignatureKey for the given transaction
+        //textToHash is formed by concatenating apilogin id , transId for the given transaction and transaction amount.
+        // For more details please visit https://developer.authorize.net/support/hash_upgrade/?utm_campaign=19Q2%20MD5%20Hash%20EOL%20Partner&utm_medium=email&utm_source=Eloqua for implementation details.
+        String transHashSHA2=getHMACSHA512(signatureKey, "^"+ apiLogin+"^"+ transId +"^"+ amount+"^");
+    }
+
+    /**
+     * This is method to generate HMAC512 key for a given signature key and Text to Hash
+     * @param signatureKey
+     * @param textToHash
+     * @return
+     * @throws Exception
+     */
+    public static String getHMACSHA512(String signatureKey, String textToHash)throws Exception
+    {
+        // Check if Key is null or empty
+        if (signatureKey==null||signatureKey.isEmpty())
+            throw new IllegalArgumentException("HMACSHA512: key Parameter cannot be empty.");
+        //Check if texttoHash is null or empty
+        if (textToHash==null||textToHash.isEmpty())
+            throw new IllegalArgumentException("HMACSHA512: textToHash Parameter cannot be empty.");
+
+        // Signature Key size cannot be less than 2 or odd
+        if (signatureKey.length() % 2 != 0 || signatureKey.trim().length() < 2)
+        {
+            throw new IllegalArgumentException("HMACSHA512: key Parameter cannot be odd or less than 2 characters.");
+        }
+
+        // Convert Hex string to byte array
+        byte signatureKeyInByteArray[]=hexStringToByteArray(signatureKey);
+        // Calculate hmac 512 for the byte array contents and text to hash.
+        String hashedValue=calculateHMAC(signatureKeyInByteArray,textToHash);
+        if(hashedValue==null)
+            throw new NullPointerException("For Signature Key :["+signatureKey+"] And Text To Hash ["+textToHash+"] the generated HMAC512 Key is null .Please contact Authorize.net for more information");
+
+        return hashedValue.toUpperCase();
+    }
+
+    /**
+     * This is the method to Calculate Hmac sha512 for given signature signatureKey  in byte array and text to hash in byte array
+     * @param signatureKey
+     * @param textToHash
+     * @return
+     * @throws SignatureException
+     * @throws NoSuchAlgorithmException
+     * @throws InvalidKeyException
+     */
+    public static String calculateHMAC(byte signatureKey[], String textToHash)
+            throws SignatureException, NoSuchAlgorithmException, InvalidKeyException
+    {
+        SecretKeySpec secretKeySpec = new SecretKeySpec(signatureKey, "HmacSHA512");
+        Mac mac = Mac.getInstance("HmacSHA512");
+        mac.init(secretKeySpec);
+        return toHexString(mac.doFinal(textToHash.getBytes()));
+    }
+
+    /**
+     * This is the method to convert byte array into hexadecimal string
+     * @param bytes
+     * @return hexadecimal string.
+     */
+    private static String toHexString(byte[] bytes) {
+        Formatter formatter = new Formatter();
+        for (byte b : bytes) {
+            formatter.format("%02x", b);
+        }
+        return formatter.toString();
+    }
+
+    /**
+     * This is the method convert hexadecimal string to byte array
+     * @param str
+     * @return byte array
+     */
+    public static byte[] hexStringToByteArray(String str) {
+        int len = str.length();
+        byte[] data = new byte[len / 2];
+        for (int i = 0; i < len; i += 2) {
+            data[i / 2] = (byte) ((Character.digit(str.charAt(i), 16) << 4)
+                    + Character.digit(str.charAt(i+1), 16));
+        }
+        return data;
+    }
+}