| /** |
| * 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 cleartext-keyset-example] |
| package cleartextkeyset; |
| |
| import com.google.crypto.tink.Aead; |
| import com.google.crypto.tink.CleartextKeysetHandle; |
| import com.google.crypto.tink.JsonKeysetReader; |
| import com.google.crypto.tink.JsonKeysetWriter; |
| import com.google.crypto.tink.KeyTemplates; |
| import com.google.crypto.tink.KeysetHandle; |
| import com.google.crypto.tink.aead.AeadConfig; |
| import java.io.File; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.nio.file.Paths; |
| import java.security.GeneralSecurityException; |
| |
| /** |
| * A command-line utility for generating, storing and using cleartext AES128_GCM keysets. |
| * |
| * <h1>WARNING: It loads cleartext keys from disk - this is not recommended! |
| * |
| * <p>It requires the following arguments: |
| * |
| * <ul> |
| * <li>mode: Can be "generate", "encrypt" or "decrypt". If mode is "generate" it will generate, |
| * encrypt a keyset, store it in key-file. If mode is "encrypt" or "decrypt" it will read and |
| * decrypt an keyset from key-file, and use it to encrypt or decrypt input-file. |
| * <li>key-file: Read the encrypted key material from this file. |
| * <li>input-file: If mode is "encrypt" or "decrypt", read the input from this file. |
| * <li>output-file: If mode is "encrypt" or "decrypt", write the result to this file. |
| */ |
| public final class CleartextKeysetExample { |
| private static final String MODE_ENCRYPT = "encrypt"; |
| private static final String MODE_DECRYPT = "decrypt"; |
| private static final String MODE_GENERATE = "generate"; |
| private static final byte[] EMPTY_ASSOCIATED_DATA = new byte[0]; |
| |
| public static void main(String[] args) throws Exception { |
| if (args.length != 2 && args.length != 4) { |
| System.err.printf("Expected 2 or 4 parameters, got %d\n", args.length); |
| System.err.println( |
| "Usage: java CleartextKeysetExample generate/encrypt/decrypt key-file input-file" |
| + " output-file"); |
| System.exit(1); |
| } |
| String mode = args[0]; |
| if (!MODE_ENCRYPT.equals(mode) && !MODE_DECRYPT.equals(mode) && !MODE_GENERATE.equals(mode)) { |
| System.err.print("The first argument should be either encrypt, decrypt or generate"); |
| System.exit(1); |
| } |
| File keyFile = new File(args[1]); |
| |
| // Initialise Tink: register all AEAD key types with the Tink runtime |
| AeadConfig.register(); |
| |
| if (MODE_GENERATE.equals(mode)) { |
| // [START generate-a-new-keyset] |
| KeysetHandle handle = KeysetHandle.generateNew(KeyTemplates.get("AES128_GCM")); |
| // [END generate-a-new-keyset] |
| |
| // [START store-a-cleartext-keyset] |
| CleartextKeysetHandle.write(handle, JsonKeysetWriter.withFile(keyFile)); |
| // [END store-a-cleartext-keyset] |
| System.exit(0); |
| } |
| |
| // Use the primitive to encrypt/decrypt files |
| |
| // Read the cleartext keyset |
| KeysetHandle handle = null; |
| try { |
| handle = CleartextKeysetHandle.read(JsonKeysetReader.withFile(keyFile)); |
| } catch (GeneralSecurityException | IOException ex) { |
| System.err.println("Error reading key: " + ex); |
| System.exit(1); |
| } |
| |
| // Get the primitive |
| Aead aead = null; |
| try { |
| aead = handle.getPrimitive(Aead.class); |
| } catch (GeneralSecurityException ex) { |
| System.err.println("Error creating primitive: %s " + ex); |
| System.exit(1); |
| } |
| |
| byte[] input = Files.readAllBytes(Paths.get(args[2])); |
| File outputFile = new File(args[3]); |
| |
| if (MODE_ENCRYPT.equals(mode)) { |
| byte[] ciphertext = aead.encrypt(input, EMPTY_ASSOCIATED_DATA); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(ciphertext); |
| } |
| } else if (MODE_DECRYPT.equals(mode)) { |
| byte[] plaintext = aead.decrypt(input, EMPTY_ASSOCIATED_DATA); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(plaintext); |
| } |
| } |
| |
| System.exit(0); |
| } |
| |
| private CleartextKeysetExample() {} |
| } |
| // [END cleartext-keyset-example] |