it.infn.mw.iam.util.ssh.RSAPublicKeyUtils.java Source code

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Here is the source code for it.infn.mw.iam.util.ssh.RSAPublicKeyUtils.java

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/**
 * Copyright (c) Istituto Nazionale di Fisica Nucleare (INFN). 2016-2018
 *
 * 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 it.infn.mw.iam.util.ssh;

import java.security.MessageDigest;
import java.util.Base64;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.MessageDigestAlgorithms;

public class RSAPublicKeyUtils {

    private RSAPublicKeyUtils() {
    }

    public static String getMD5Fingerprint(String key) {

        return buildMD5Fingerprint(key);
    }

    public static String getFormattedMD5Fingerprint(String key) {

        return String.join(":", buildMD5Fingerprint(key).split("(?<=\\G..)"));
    }

    public static String getSHA256Fingerprint(String key) {

        return buildSHA256Fingerprint(key);
    }

    private static String buildMD5Fingerprint(String key) throws InvalidSshKeyException {

        String fingerprint = null;

        try {

            byte[] decodedKey = Base64.getDecoder().decode(key);
            byte[] digest = MessageDigest.getInstance(MessageDigestAlgorithms.MD5).digest(decodedKey);
            fingerprint = Hex.encodeHexString(digest);

        } catch (Exception e) {

            throw new InvalidSshKeyException("Error during fingerprint generation: RSA key is not base64 encoded",
                    e);
        }

        return fingerprint;
    }

    private static String buildSHA256Fingerprint(String key) throws InvalidSshKeyException {

        String fingerprint = null;

        try {

            byte[] decodedKey = Base64.getDecoder().decode(key);
            byte[] digest = MessageDigest.getInstance(MessageDigestAlgorithms.SHA_256).digest(decodedKey);
            fingerprint = Base64.getEncoder().encodeToString(digest);

        } catch (Exception e) {

            throw new InvalidSshKeyException("Error during fingerprint generation: RSA key is not base64 encoded",
                    e);
        }

        return fingerprint;
    }
}