co.runrightfast.core.security.crypto.impl.EncryptionServiceImpl.java Source code

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Here is the source code for co.runrightfast.core.security.crypto.impl.EncryptionServiceImpl.java

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/*
 Copyright 2015 Alfio Zappala
    
 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 co.runrightfast.core.security.crypto.impl;

import co.runrightfast.core.security.crypto.CipherFunctions;
import co.runrightfast.core.security.crypto.Decryption;
import co.runrightfast.core.security.crypto.Encryption;
import co.runrightfast.core.security.crypto.EncryptionService;
import co.runrightfast.core.security.crypto.EncryptionServiceException;
import co.runrightfast.core.security.crypto.UnknownSecretKeyException;
import co.runrightfast.core.security.messages.SecretKeys;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.collect.ImmutableMap;
import java.security.Key;
import java.util.Map;
import java.util.Set;
import lombok.NonNull;
import org.apache.commons.collections4.MapUtils;
import org.apache.commons.lang3.SerializationUtils;
import org.apache.shiro.crypto.CipherService;

/**
 *
 * @author alfio
 */
public final class EncryptionServiceImpl implements EncryptionService {

    public static Map<String, Key> toKeyMap(@NonNull final SecretKeys keys) {
        final ImmutableMap.Builder<String, Key> mapBuilder = ImmutableMap.builder();
        keys.getKeys().entrySet().stream().forEach(entry -> mapBuilder.put(entry.getKey(),
                SerializationUtils.deserialize(entry.getValue().toByteArray())));
        return mapBuilder.build();
    }

    private final Map<String, CipherFunctions> cipherFunctions;

    public EncryptionServiceImpl(@NonNull final CipherService cipherService, final Map<String, Key> secretKeys) {
        checkSecretKeys(secretKeys);
        this.cipherFunctions = cipherFunctions(cipherService, secretKeys);
    }

    public EncryptionServiceImpl(@NonNull final CipherService cipherService, @NonNull final SecretKeys secretKeys) {
        final Map<String, Key> secretKeysMap = toKeyMap(secretKeys);
        checkSecretKeys(secretKeysMap);
        this.cipherFunctions = cipherFunctions(cipherService, secretKeysMap);
    }

    private Map<String, CipherFunctions> cipherFunctions(@NonNull final CipherService cipherService,
            final Map<String, Key> secretKeys) {
        final ImmutableMap.Builder<String, CipherFunctions> map = ImmutableMap.builder();
        secretKeys.entrySet().stream().forEach(entry -> {
            final byte[] secretKey = entry.getValue().getEncoded();
            final Encryption encryption = data -> {
                try {
                    return cipherService.encrypt(data, secretKey).getBytes();
                } catch (final Exception e) {
                    throw new EncryptionServiceException(e);
                }
            };
            final Decryption decryption = data -> {
                try {
                    return cipherService.decrypt(data, secretKey).getBytes();
                } catch (final Exception e) {
                    throw new EncryptionServiceException(e);
                }
            };
            map.put(entry.getKey(), new CipherFunctions(encryption, decryption));
        });

        return map.build();
    }

    private void checkSecretKeys(final Map<String, Key> secretKeys) {
        checkArgument(MapUtils.isNotEmpty(secretKeys));
        checkArgument(!secretKeys.values().stream().filter(key -> key == null).findFirst().isPresent());
    }

    @Override
    public Set<String> getEncryptionKeys() {
        return cipherFunctions.keySet();
    }

    @Override
    public byte[] encrypt(@NonNull final byte[] data, @NonNull final String secretKey) {
        final CipherFunctions cipher = cipherFunctions.get(secretKey);
        checkExists(secretKey, cipher);
        return cipher.getEncryption().apply(data);
    }

    private void checkExists(final String secretKey, final CipherFunctions cipher) {
        if (cipher == null) {
            throw new UnknownSecretKeyException(secretKey);
        }
    }

    @Override
    public byte[] decrypt(@NonNull final byte[] data, @NonNull final String secretKey) {
        final CipherFunctions cipher = cipherFunctions.get(secretKey);
        checkExists(secretKey, cipher);
        return cipher.getDecryption().apply(data);
    }

    @Override
    public Encryption encryption(@NonNull final String secretKey) {
        final CipherFunctions cipher = cipherFunctions.get(secretKey);
        checkExists(secretKey, cipher);
        return cipher.getEncryption();
    }

    @Override
    public Decryption decryption(@NonNull final String secretKey) {
        return cipherFunctions(secretKey).getDecryption();
    }

    @Override
    public CipherFunctions cipherFunctions(@NonNull final String secretKey) {
        final CipherFunctions cipher = cipherFunctions.get(secretKey);
        checkExists(secretKey, cipher);
        return cipher;
    }

}