package org.scribe.services;
import javax.crypto.*;
import javax.crypto.spec.*;
import org.apache.commons.codec.binary.*;
import org.scribe.exceptions.*;
import org.scribe.utils.*;
/**
* HMAC-SHA1 implementation of {@SignatureService}
*
* @author Pablo Fernandez
*
*/
public class HMACSha1SignatureService implements SignatureService
{
private static final String EMPTY_STRING = "";
private static final String CARRIAGE_RETURN = "\r\n";
private static final String UTF8 = "UTF-8";
private static final String HMAC_SHA1 = "HmacSHA1";
private static final String METHOD = "HMAC-SHA1";
/**
* {@inheritDoc}
*/
public String getSignature(String baseString, String apiSecret, String tokenSecret)
{
try
{
Preconditions.checkEmptyString(baseString, "Base string cant be null or empty string");
Preconditions.checkEmptyString(apiSecret, "Api secret cant be null or empty string");
return doSign(baseString, URLUtils.percentEncode(apiSecret) + '&' + URLUtils.percentEncode(tokenSecret));
}
catch (Exception e)
{
throw new OAuthSignatureException(baseString, e);
}
}
private String doSign(String toSign, String keyString) throws Exception
{
SecretKeySpec key = new SecretKeySpec((keyString).getBytes(UTF8), HMAC_SHA1);
Mac mac = Mac.getInstance(HMAC_SHA1);
mac.init(key);
byte[] bytes = mac.doFinal(toSign.getBytes(UTF8));
return new String(Base64.encodeBase64(bytes)).replace(CARRIAGE_RETURN, EMPTY_STRING);
}
/**
* {@inheritDoc}
*/
public String getSignatureMethod()
{
return METHOD;
}
}