Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import android.util.Base64;
import java.security.SignatureException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

public class Main {
    /***
     * Computes RFC 2104-compliant HMAC signature. This can be used to sign the Amazon S3
     * request urls
     * 
     * @param data The data to be signed.
     * @param key The signing key.
     * @return The Base64-encoded RFC 2104-compliant HMAC signature.
     * @throws SignatureException when signature generation fails
     */
    public static String getHMac(String data, String key) throws SignatureException {

        if (data == null) {
            throw new NullPointerException("Data to be signed cannot be null");
        }

        String result = null;
        try {

            final String HMAC_SHA1_ALGORITHM = "HmacSHA1";

            // get an hmac_sha1 key from the raw key bytes
            SecretKeySpec signingKey = new SecretKeySpec(key.getBytes(), HMAC_SHA1_ALGORITHM);

            // get an hmac_sha1 Mac instance &
            // initialize with the signing key
            Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
            mac.init(signingKey);

            // compute the hmac on input data bytes
            byte[] digest = mac.doFinal(data.getBytes());

            if (digest != null) {
                // Base 64 Encode the results
                result = Base64.encodeToString(digest, Base64.NO_WRAP);
            }

        } catch (Exception e) {
            throw new SignatureException("Failed to generate HMAC : " + e.getMessage());
        }

        return result;
    }
}