de.desy.dcache.s3.Signature.java Source code

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Here is the source code for de.desy.dcache.s3.Signature.java

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/*
 * Copyright 2012 s0525775 / DESY / Amazon.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package de.desy.dcache.s3;

import java.security.SignatureException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;

/**
*
* @author Amazon
* http://docs.amazonwebservices.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/AuthJavaSampleHMACSignature.html
*/
/**
* This class defines common routines for generating
* authentication signatures for AWS requests.
*/
public class Signature {
    private static final String HMAC_SHA1_ALGORITHM = "HmacSHA1";

    /**
    * Computes RFC 2104-compliant HMAC signature.
    * * @param data
    * The data to be signed.
    * @param key
    * The signing key.
    * @return
    * The Base64-encoded RFC 2104-compliant HMAC signature.
    * @throws
    * java.security.SignatureException when signature generation fails
    */
    public static String calculateRFC2104HMAC(String data, String key) throws java.security.SignatureException {
        String result;
        try {
            // 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 and initialize with the signing key
            Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
            mac.init(signingKey);

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

            // base64-encode the hmac
            result = new String(Base64.encodeBase64(rawHmac));

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