| /** |
| * Copyright 2021 Google LLC |
| * |
| * 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. |
| */ |
| // [START deterministic-aead-example] |
| package deterministicaead; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.crypto.tink.CleartextKeysetHandle; |
| import com.google.crypto.tink.DeterministicAead; |
| import com.google.crypto.tink.JsonKeysetReader; |
| import com.google.crypto.tink.KeysetHandle; |
| import com.google.crypto.tink.daead.DeterministicAeadConfig; |
| import java.io.File; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.security.GeneralSecurityException; |
| |
| /** |
| * A command-line utility for encrypting small files with Deterministic AEAD. |
| * |
| * <p>It loads cleartext keys from disk - this is not recommended! |
| * |
| * <p>It requires the following arguments: |
| * |
| * <ul> |
| * <li>mode: Can be "encrypt" or "decrypt" to encrypt/decrypt the input to the output. |
| * <li>key-file: Read the key material from this file. |
| * <li>input-file: Read the input from this file. |
| * <li>output-file: Write the result to this file. |
| * <li>[optional] associated-data: Associated data used for the encryption or decryption. |
| */ |
| public final class DeterministicAeadExample { |
| private static final String MODE_ENCRYPT = "encrypt"; |
| private static final String MODE_DECRYPT = "decrypt"; |
| |
| public static void main(String[] args) throws Exception { |
| if (args.length != 4 && args.length != 5) { |
| System.err.printf("Expected 4 or 5 parameters, got %d\n", args.length); |
| System.err.println( |
| "Usage: java DeterministicAeadExample encrypt/decrypt key-file input-file output-file" |
| + " [associated-data]"); |
| System.exit(1); |
| } |
| String mode = args[0]; |
| File keyFile = new File(args[1]); |
| File inputFile = new File(args[2]); |
| File outputFile = new File(args[3]); |
| byte[] associatedData = new byte[0]; |
| if (args.length == 5) { |
| associatedData = args[4].getBytes(UTF_8); |
| } |
| |
| // Initialise Tink: register all Deterministic AEAD key types with the Tink runtime |
| DeterministicAeadConfig.register(); |
| |
| // Read the keyset into a KeysetHandle |
| KeysetHandle handle = null; |
| try { |
| handle = CleartextKeysetHandle.read(JsonKeysetReader.withFile(keyFile)); |
| } catch (GeneralSecurityException | IOException ex) { |
| System.err.println("Cannot read keyset, got error: " + ex); |
| System.exit(1); |
| } |
| |
| // Get the primitive |
| DeterministicAead daead = null; |
| try { |
| daead = handle.getPrimitive(DeterministicAead.class); |
| } catch (GeneralSecurityException ex) { |
| System.err.println("Cannot create primitive, got error: " + ex); |
| System.exit(1); |
| } |
| |
| // Use the primitive to encrypt/decrypt files. |
| if (MODE_ENCRYPT.equals(mode)) { |
| byte[] plaintext = Files.readAllBytes(inputFile.toPath()); |
| byte[] ciphertext = daead.encryptDeterministically(plaintext, associatedData); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(ciphertext); |
| } |
| } else if (MODE_DECRYPT.equals(mode)) { |
| byte[] ciphertext = Files.readAllBytes(inputFile.toPath()); |
| byte[] plaintext = daead.decryptDeterministically(ciphertext, associatedData); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(plaintext); |
| } |
| } else { |
| System.err.println("The first argument must be either encrypt or decrypt, got: " + mode); |
| System.exit(1); |
| } |
| |
| System.exit(0); |
| } |
| |
| private DeterministicAeadExample() {} |
| } |
| // [END deterministic-aead-example] |