no.digipost.android.authentication.ConcealAdapter.java Source code

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Here is the source code for no.digipost.android.authentication.ConcealAdapter.java

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/**
 * Copyright (C) Posten Norge AS
 *
 * 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 no.digipost.android.authentication;

import android.content.Context;
import android.util.Base64;
import android.util.Log;
import com.facebook.android.crypto.keychain.AndroidConceal;
import com.facebook.android.crypto.keychain.SharedPrefsBackedKeyChain;
import com.facebook.crypto.CryptoConfig;
import com.facebook.crypto.Entity;
import com.facebook.crypto.exception.CryptoInitializationException;
import com.facebook.crypto.exception.KeyChainException;
import com.facebook.crypto.keychain.KeyChain;
import org.apache.commons.io.output.ByteArrayOutputStream;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class ConcealAdapter implements CryptoAdapter {

    private final com.facebook.crypto.Crypto crypto;
    Entity entity = Entity.create("refresh_token");

    public ConcealAdapter(final Context context) {
        KeyChain keyChain = new SharedPrefsBackedKeyChain(context, CryptoConfig.KEY_256);
        crypto = AndroidConceal.get().createCrypto256Bits(keyChain);
    }

    public boolean isAvailable() {
        return crypto.isAvailable();
    }

    public String decrypt(final String cipherText) {
        try {
            InputStream inputStream = crypto.getCipherInputStream(
                    new ByteArrayInputStream(Base64.decode(cipherText.getBytes(), Base64.DEFAULT)), entity);

            int read;
            byte[] buffer = new byte[1024];
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            while ((read = inputStream.read(buffer)) != -1) {
                out.write(buffer, 0, read);
            }
            inputStream.close();
            out.close();
            return new String(out.toByteArray());
        } catch (Exception e) {
            Log.w("Crypto", e);
        }
        return null;
    }

    public String encrypt(final String plaintext) {
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            OutputStream outputStream = crypto.getCipherOutputStream(out, entity);
            outputStream.write(plaintext.getBytes());
            outputStream.close();
            return Base64.encodeToString(out.toByteArray(), Base64.DEFAULT);
        } catch (CryptoInitializationException e) {
            e.printStackTrace();
            return null;
        } catch (KeyChainException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }
}