Pithos_GSS » Java GSS CLI Client

package gssclient;

import java.io.File;

import java.io.UnsupportedEncodingException;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Locale;

import java.util.TimeZone;

import javax.crypto.Mac;

import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

import org.apache.commons.httpclient.HttpMethod;

import org.apache.commons.httpclient.methods.FileRequestEntity;

import org.apache.commons.httpclient.methods.GetMethod;

import org.apache.commons.httpclient.methods.PutMethod;

public class HttpMethodGenerator {

    public static final String HOST = "http://pithos.grnet.gr";

    public static final String REST_PREFIX = "/pithos/rest";

    public static final String PATH_PREFIX = HOST + REST_PREFIX;

    private static final String HMAC_SHA1 = "HmacSHA1";

    private static final String AUTHORIZATION_HEADER = "Authorization";

    private static final String DATE_HEADER = "X-GSS-Date";

    private static final String DATE_FORMAT = "EEE, d MMM yyyy HH:mm:ss z";

    private static final SimpleDateFormat DATE_FORMATER = new SimpleDateFormat(

            DATE_FORMAT, Locale.US);

    static {

        DATE_FORMATER.setTimeZone(TimeZone.getTimeZone("GMT"));

    }

    protected static String sign(String httpMethod, String timestamp, String path,

            String token) {

        String input = httpMethod + timestamp + path;

        String signed = null;

        try {

            System.err.println("Token:" + token);

            // Get an HMAC-SHA1 key from the authentication token.

            System.err.println("Input: " + input);

            byte[] unencodedToken = Base64.decodeBase64(token.getBytes());

            SecretKeySpec signingKey = new SecretKeySpec(unencodedToken,

                    HMAC_SHA1);

            // Get an HMAC-SHA1 Mac instance and initialize with the signing

            // key.

            Mac hmac = Mac.getInstance(HMAC_SHA1);

            hmac.init(signingKey);

            // Compute the HMAC on the input data bytes.

            byte[] rawMac = hmac.doFinal(input.getBytes());

            // Do base 64 encoding.

            signed = new String(Base64.encodeBase64(rawMac), "US-ASCII");

        } catch (InvalidKeyException ikex) {

            System.err.println("Fatal key exception: " + ikex.getMessage());

            ikex.printStackTrace();

        } catch (UnsupportedEncodingException ueex) {

            System.err

                    .println("Fatal encoding exception: " + ueex.getMessage());

        } catch (NoSuchAlgorithmException nsaex) {

            System.err.println("Fatal algorithm exception: "

                    + nsaex.getMessage());

            nsaex.printStackTrace();

        }

        if (signed == null) {

            System.exit(-1);

        }

        System.err.println("Signed: " + signed);

        return signed;

    }

    protected static void fillRequestHeaders(HttpMethod request, Date timestamp,

                    UserInfo userInfo) {

        String path = request.getPath().substring(REST_PREFIX.length());

        String strTimestamp = DATE_FORMATER.format(timestamp);

        String signature = sign(request.getName(), strTimestamp, path, userInfo

                .getToken());

        request.addRequestHeader(AUTHORIZATION_HEADER, userInfo.getUsername()

                + " " + signature);

        request.addRequestHeader(DATE_HEADER, strTimestamp);

    }

    public static GetMethod generateGetMethod(String uri, Date timestamp, 

            UserInfo userInfo) {

        GetMethod request = new GetMethod(uri);

        fillRequestHeaders(request, timestamp, userInfo);

        return request;

    }

    public static PutMethod generatePutMethod(String uri, Date timestamp, 

            UserInfo userInfo, String filename, String path) {

        File file = new File(filename);

        PutMethod request = new PutMethod(uri + "files/" + path + file.getName());

        fillRequestHeaders(request, timestamp, userInfo);

        request.setRequestEntity(new FileRequestEntity(file, ""));

        return request;

    }

}