Después de crear una clave en un KMS externo y recuperar su URI y sus credenciales, puedes usar las APIs de Tink o Tinkey para generar un conjunto de claves, encriptarlo con el KMS externo y almacenarlo en algún lugar.
Llave de tinto
tinkey create-keyset --key-template AES128_GCM \
--out-format json --out encrypted_aead_keyset.json \
--master-key-uri gcp-kms://projects/tink-examples/locations/global/keyRings/foo/cryptoKeys/bar \
--credential gcp_credentials.json
Java
Para este ejemplo, necesitas la extensión tink-java-gcpkms de Google Cloud KMS.
package encryptedkeyset;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.crypto.tink.Aead;
import com.google.crypto.tink.KeysetHandle;
import com.google.crypto.tink.TinkJsonProtoKeysetFormat;
import com.google.crypto.tink.aead.AeadConfig;
import com.google.crypto.tink.aead.PredefinedAeadParameters;
import com.google.crypto.tink.integration.gcpkms.GcpKmsClient;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
/**
* A command-line utility for working with encrypted keysets.
*
* <p>It requires the following arguments:
*
* <ul>
* <li>mode: Can be "generate", "encrypt" or "decrypt". If mode is "generate", it will generate a
* keyset, encrypt it and store it in the key-file argument. If mode is "encrypt" or
* "decrypt", it will read and decrypt an keyset from the key-file argument, and use it to
* encrypt or decrypt the input-file argument.
* <li>kek-uri: Use this Cloud KMS' key as the key-encrypting-key for envelope encryption.
* <li>gcp-credential-file: Use this JSON credential file to connect to Cloud KMS.
* <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 EncryptedKeysetExample {
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 != 4 && args.length != 6) {
System.err.printf("Expected 4 or 6 parameters, got %d\n", args.length);
System.err.println(
"Usage: java EncryptedKeysetExample generate/encrypt/decrypt key-file kek-uri"
+ " gcp-credential-file input-file output-file");
System.exit(1);
}
String mode = args[0];
if (!mode.equals(MODE_ENCRYPT) && !mode.equals(MODE_DECRYPT) && !mode.equals(MODE_GENERATE)) {
System.err.print("The first argument should be either encrypt, decrypt or generate");
System.exit(1);
}
Path keyFile = Paths.get(args[1]);
String kekUri = args[2];
String gcpCredentialFilename = args[3];
// Initialise Tink: register all AEAD key types with the Tink runtime
AeadConfig.register();
// From the key-encryption key (KEK) URI, create a remote AEAD primitive for encrypting Tink
// keysets.
Aead kekAead = new GcpKmsClient().withCredentials(gcpCredentialFilename).getAead(kekUri);
if (mode.equals(MODE_GENERATE)) {
KeysetHandle handle = KeysetHandle.generateNew(PredefinedAeadParameters.AES128_GCM);
String serializedEncryptedKeyset =
TinkJsonProtoKeysetFormat.serializeEncryptedKeyset(
handle, kekAead, EMPTY_ASSOCIATED_DATA);
Files.write(keyFile, serializedEncryptedKeyset.getBytes(UTF_8));
return;
}
// Use the primitive to encrypt/decrypt files
// Read the encrypted keyset
KeysetHandle handle =
TinkJsonProtoKeysetFormat.parseEncryptedKeyset(
new String(Files.readAllBytes(keyFile), UTF_8), kekAead, EMPTY_ASSOCIATED_DATA);
// Get the primitive
Aead aead = handle.getPrimitive(Aead.class);
Path inputFile = Paths.get(args[4]);
Path outputFile = Paths.get(args[5]);
if (mode.equals(MODE_ENCRYPT)) {
byte[] plaintext = Files.readAllBytes(inputFile);
byte[] ciphertext = aead.encrypt(plaintext, EMPTY_ASSOCIATED_DATA);
Files.write(outputFile, ciphertext);
} else if (mode.equals(MODE_DECRYPT)) {
byte[] ciphertext = Files.readAllBytes(inputFile);
byte[] plaintext = aead.decrypt(ciphertext, EMPTY_ASSOCIATED_DATA);
Files.write(outputFile, plaintext);
}
}
private EncryptedKeysetExample() {}
}
Go
import (
"bytes"
"fmt"
"log"
"github.com/tink-crypto/tink-go/v2/aead"
"github.com/tink-crypto/tink-go/v2/keyset"
"github.com/tink-crypto/tink-go/v2/testing/fakekms"
)
// The fake KMS should only be used in tests. It is not secure.
const keyURI = "fake-kms://CM2b3_MDElQKSAowdHlwZS5nb29nbGVhcGlzLmNvbS9nb29nbGUuY3J5cHRvLnRpbmsuQWVzR2NtS2V5EhIaEIK75t5L-adlUwVhWvRuWUwYARABGM2b3_MDIAE"
func Example_encryptedKeyset() {
// Get a KEK (key encryption key) AEAD. This is usually a remote AEAD to a KMS. In this example,
// we use a fake KMS to avoid making RPCs.
client, err := fakekms.NewClient(keyURI)
if err != nil {
log.Fatal(err)
}
kekAEAD, err := client.GetAEAD(keyURI)
if err != nil {
log.Fatal(err)
}
// Generate a new keyset handle for the primitive we want to use.
newHandle, err := keyset.NewHandle(aead.AES256GCMKeyTemplate())
if err != nil {
log.Fatal(err)
}
// Choose some associated data. This is the context in which the keyset will be used.
keysetAssociatedData := []byte("keyset encryption example")
// Encrypt the keyset with the KEK AEAD and the associated data.
buf := new(bytes.Buffer)
writer := keyset.NewBinaryWriter(buf)
err = newHandle.WriteWithAssociatedData(writer, kekAEAD, keysetAssociatedData)
if err != nil {
log.Fatal(err)
}
encryptedKeyset := buf.Bytes()
// The encrypted keyset can now be stored.
// To use the primitive, we first need to decrypt the keyset. We use the same
// KEK AEAD and the same associated data that we used to encrypt it.
reader := keyset.NewBinaryReader(bytes.NewReader(encryptedKeyset))
handle, err := keyset.ReadWithAssociatedData(reader, kekAEAD, keysetAssociatedData)
if err != nil {
log.Fatal(err)
}
// Get the primitive.
primitive, err := aead.New(handle)
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, encrypting and storing keysets."""
from absl import app
from absl import flags
from absl import logging
import tink
from tink import aead
from tink.integration import gcpkms
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('kek_uri', None,
'The Cloud KMS URI of the key encryption key.')
flags.DEFINE_string('gcp_credential_path', None,
'Path to the GCP credentials JSON file.')
flags.DEFINE_string('input_path', None, 'Path to the input file.')
flags.DEFINE_string('output_path', None, 'Path to the output file.')
flags.DEFINE_string('associated_data', None,
'Optional associated data to use with the '
'encryption operation.')
def main(argv):
del argv # Unused.
associated_data = b'' if not FLAGS.associated_data else bytes(
FLAGS.associated_data, 'utf-8')
# Initialise Tink
aead.register()
try:
# Read the GCP credentials and setup client
client = gcpkms.GcpKmsClient(FLAGS.kek_uri, FLAGS.gcp_credential_path)
except tink.TinkError as e:
logging.exception('Error creating GCP KMS client: %s', e)
return 1
# Create envelope AEAD primitive using AES256 GCM for encrypting the data
try:
remote_aead = client.get_aead(FLAGS.kek_uri)
except tink.TinkError as e:
logging.exception('Error creating primitive: %s', e)
return 1
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
# Encrypt the keyset_handle with the remote key-encryption key (KEK)
with open(FLAGS.keyset_path, 'wt') as keyset_file:
try:
keyset_encryption_associated_data = 'encrypted keyset example'
serialized_encrypted_keyset = (
tink.json_proto_keyset_format.serialize_encrypted(
keyset_handle, remote_aead, keyset_encryption_associated_data
)
)
keyset_file.write(serialized_encrypted_keyset)
except tink.TinkError as e:
logging.exception('Error writing key: %s', e)
return 1
return 0
# Use the keyset to encrypt/decrypt data
# Read the encrypted keyset into a keyset_handle
with open(FLAGS.keyset_path, 'rt') as keyset_file:
try:
serialized_encrypted_keyset = keyset_file.read()
keyset_encryption_associated_data = 'encrypted keyset example'
keyset_handle = tink.json_proto_keyset_format.parse_encrypted(
serialized_encrypted_keyset,
remote_aead,
keyset_encryption_associated_data,
)
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.exception('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, associated_data)
elif FLAGS.mode == 'encrypt':
output_data = cipher.encrypt(input_data, associated_data)
else:
logging.error(
'Unsupported mode %s. Please choose "encrypt" or "decrypt".',
FLAGS.mode,
)
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', 'kek_uri', 'gcp_credential_path'])
app.run(main)