| /** |
| * 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 hybrid-example] |
| package hybrid; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.crypto.tink.CleartextKeysetHandle; |
| import com.google.crypto.tink.HybridDecrypt; |
| import com.google.crypto.tink.HybridEncrypt; |
| import com.google.crypto.tink.JsonKeysetReader; |
| import com.google.crypto.tink.KeysetHandle; |
| import com.google.crypto.tink.hybrid.HybridConfig; |
| 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 digitally signing and verifying a file. |
| * |
| * <p>It loads cleartext keys from disk - this is not recommended! |
| * |
| * <p>It requires the following arguments: |
| * |
| * <ul> |
| * <li>mode: either 'encrypt' or 'decrypt'. |
| * <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] contex-info: Bind the encryption to this context info. |
| */ |
| public final class HybridExample { |
| 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 HybridExample encrypt/decrypt key-file input-file output-file context-info"); |
| System.exit(1); |
| } |
| |
| String mode = args[0]; |
| if (!mode.equals("encrypt") && !mode.equals("decrypt")) { |
| System.err.println("Incorrect mode. Please select encrypt or decrypt."); |
| System.exit(1); |
| } |
| File keyFile = new File(args[1]); |
| File inputFile = new File(args[2]); |
| byte[] input = Files.readAllBytes(inputFile.toPath()); |
| File outputFile = new File(args[3]); |
| byte[] contextInfo = new byte[0]; |
| if (args.length == 5) { |
| contextInfo = args[4].getBytes(UTF_8); |
| } |
| |
| // Register all hybrid encryption key types with the Tink runtime. |
| HybridConfig.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); |
| } |
| |
| if (mode.equals("encrypt")) { |
| // Get the primitive. |
| HybridEncrypt encryptor = null; |
| try { |
| encryptor = handle.getPrimitive(HybridEncrypt.class); |
| } catch (GeneralSecurityException ex) { |
| System.err.println("Cannot create primitive, got error: " + ex); |
| System.exit(1); |
| } |
| |
| // Use the primitive to encrypt data. |
| byte[] ciphertext = encryptor.encrypt(input, contextInfo); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(ciphertext); |
| } |
| System.exit(0); |
| } |
| |
| // Get the primitive. |
| HybridDecrypt decryptor = null; |
| try { |
| decryptor = handle.getPrimitive(HybridDecrypt.class); |
| } catch (GeneralSecurityException ex) { |
| System.err.println("Cannot create primitive, got error: " + ex); |
| System.exit(1); |
| } |
| |
| // Use the primitive to decrypt data. |
| byte[] plaintext = decryptor.decrypt(input, contextInfo); |
| try (FileOutputStream stream = new FileOutputStream(outputFile)) { |
| stream.write(plaintext); |
| } |
| System.exit(0); |
| } |
| |
| private HybridExample() {} |
| } |
| // [END hybrid-example] |