The following examples show how to create a keyset with a single key and store it in plaintext on disk.
Tinkey
tinkey create-keyset \
--key-template AES128_GCM \
--out-format json \
--out aead_keyset.json
Java
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.FileInputStream;
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)) {
KeysetHandle handle = KeysetHandle.generateNew(KeyTemplates.get("AES128_GCM"));
try (FileOutputStream outputStream = new FileOutputStream(keyFile)) {
CleartextKeysetHandle.write(handle, JsonKeysetWriter.withOutputStream(outputStream));
}
System.exit(0);
}
// Use the primitive to encrypt/decrypt files
// Read the cleartext keyset
KeysetHandle handle = null;
try (FileInputStream inputStream = new FileInputStream(keyFile)) {
handle = CleartextKeysetHandle.read(JsonKeysetReader.withInputStream(inputStream));
} 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() {}
}
Go
import (
"bytes"
"fmt"
"log"
"github.com/tink-crypto/tink-go/v2/aead"
"github.com/tink-crypto/tink-go/v2/insecurecleartextkeyset"
"github.com/tink-crypto/tink-go/v2/keyset"
)
func Example_cleartextKeysetInBinary() {
// Generate a new keyset handle for the primitive we want to use.
handle, err := keyset.NewHandle(aead.AES256GCMKeyTemplate())
if err != nil {
log.Fatal(err)
}
// Serialize the keyset.
buff := &bytes.Buffer{}
err = insecurecleartextkeyset.Write(handle, keyset.NewBinaryWriter(buff))
if err != nil {
log.Fatal(err)
}
serializedKeyset := buff.Bytes()
// serializedKeyset can now be stored at a secure location.
// WARNING: Storing the keyset in cleartext to disk is not recommended!
// Parse the keyset.
parsedHandle, err := insecurecleartextkeyset.Read(
keyset.NewBinaryReader(bytes.NewBuffer(serializedKeyset)))
if err != nil {
log.Fatal(err)
}
// Get the primitive.
primitive, err := aead.New(parsedHandle)
if err != nil {
log.Fatal(err)
}
// Use the primitive.
plaintext := []byte("message")
associatedData := []byte("example encryption")
ciphertext, err := primitive.Encrypt(plaintext, associatedData)
if err != nil {
log.Fatal(err)
}
decrypted, err := primitive.Decrypt(ciphertext, associatedData)
if err != nil {
log.Fatal(err)
}
fmt.Println(string(decrypted))
// Output: message
}
Python
"""A command-line utility for generating, storing and using cleartext AES128_GCM keysets.
It loads cleartext keys from disk - this is not recommended!
"""
from absl import app
from absl import flags
from absl import logging
import tink
from tink import aead
from tink import cleartext_keyset_handle
FLAGS = flags.FLAGS
flags.DEFINE_enum('mode', None, ['generate', 'encrypt', 'decrypt'],
'The operation to perform.')
flags.DEFINE_string('keyset_path', None,
'Path to the keyset used for encryption.')
flags.DEFINE_string('input_path', None, 'Path to the input file.')
flags.DEFINE_string('output_path', None, 'Path to the output file.')
def main(argv):
del argv # Unused.
# Initialise Tink
aead.register()
if FLAGS.mode == 'generate':
# Generate a new keyset
try:
key_template = aead.aead_key_templates.AES128_GCM
keyset_handle = tink.new_keyset_handle(key_template)
except tink.TinkError as e:
logging.exception('Error creating primitive: %s', e)
return 1
with open(FLAGS.keyset_path, 'wt') as keyset_file:
try:
cleartext_keyset_handle.write(
tink.JsonKeysetWriter(keyset_file), keyset_handle)
except tink.TinkError as e:
logging.exception('Error writing key: %s', e)
return 1
return 0
# Use the input keyset to encrypt/decrypt data
# Read the keyset into a keyset_handle
with open(FLAGS.keyset_path, 'rt') as keyset_file:
try:
text = keyset_file.read()
keyset_handle = cleartext_keyset_handle.read(tink.JsonKeysetReader(text))
except tink.TinkError as e:
logging.exception('Error reading key: %s', e)
return 1
# Get the primitive
try:
cipher = keyset_handle.primitive(aead.Aead)
except tink.TinkError as e:
logging.error('Error creating primitive: %s', e)
return 1
with open(FLAGS.input_path, 'rb') as input_file:
input_data = input_file.read()
if FLAGS.mode == 'decrypt':
output_data = cipher.decrypt(input_data, b'envelope_example')
elif FLAGS.mode == 'encrypt':
output_data = cipher.encrypt(input_data, b'envelope_example')
else:
logging.error(
'Error mode not supported. Please choose "encrypt" or "decrypt".')
return 1
with open(FLAGS.output_path, 'wb') as output_file:
output_file.write(output_data)
if __name__ == '__main__':
flags.mark_flags_as_required(['mode', 'keyset_path'])
app.run(main)