Nous vous recommandons d'utiliser la primitive de signature numérique avec le type de clé ECDSA_P256 pour la plupart des cas d'utilisation.
Une signature numérique garantit que personne ne falsifie vos données et prouve qu'elles proviennent de vous. Elle est asymétrique : la clé privée est utilisée pour signer les données, et la clé publique les vérifie.
Les exemples suivants vous aident à utiliser la primitive de signature numérique:
C++
// A utility for signing and verifying files using digital signatures.
#include <iostream>
#include <memory>
#include <ostream>
#include <string>
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/log/check.h"
#include "absl/strings/string_view.h"
#include "tink/config/global_registry.h"
#include "util/util.h"
#include "tink/keyset_handle.h"
#include "tink/public_key_sign.h"
#include "tink/public_key_verify.h"
#include "tink/signature/signature_config.h"
#include "tink/util/status.h"
ABSL_FLAG(std::string, keyset_filename, "", "Keyset file in JSON format");
ABSL_FLAG(std::string, mode, "", "Mode of operation (sign|verify)");
ABSL_FLAG(std::string, input_filename, "", "Filename to operate on");
ABSL_FLAG(std::string, signature_filename, "", "Path to the signature file");
namespace {
using ::crypto::tink::KeysetHandle;
using ::crypto::tink::PublicKeySign;
using ::crypto::tink::PublicKeyVerify;
using ::crypto::tink::util::Status;
using ::crypto::tink::util::StatusOr;
constexpr absl::string_view kSign = "sign";
constexpr absl::string_view kVerify = "verify";
void ValidateParams() {
// ...
}
} // namespace
namespace tink_cc_examples {
// Digital signature example CLI implementation.
Status DigitalSignatureCli(absl::string_view mode,
const std::string& keyset_filename,
const std::string& input_filename,
const std::string& signature_filename) {
Status result = crypto::tink::SignatureConfig::Register();
if (!result.ok()) return result;
// Read the keyset from file.
StatusOr<std::unique_ptr<KeysetHandle>> keyset_handle =
ReadJsonCleartextKeyset(keyset_filename);
if (!keyset_handle.ok()) return keyset_handle.status();
// Read the input.
StatusOr<std::string> input_file_content = ReadFile(input_filename);
if (!input_file_content.ok()) return input_file_content.status();
if (mode == kSign) {
StatusOr<std::unique_ptr<PublicKeySign>> public_key_sign =
(*keyset_handle)
->GetPrimitive<crypto::tink::PublicKeySign>(
crypto::tink::ConfigGlobalRegistry());
if (!public_key_sign.ok()) return public_key_sign.status();
StatusOr<std::string> signature =
(*public_key_sign)->Sign(*input_file_content);
if (!signature.ok()) return signature.status();
return WriteToFile(*signature, signature_filename);
} else { // mode == kVerify
StatusOr<std::unique_ptr<PublicKeyVerify>> public_key_verify =
(*keyset_handle)
->GetPrimitive<crypto::tink::PublicKeyVerify>(
crypto::tink::ConfigGlobalRegistry());
if (!public_key_verify.ok()) return public_key_verify.status();
// Read the signature.
StatusOr<std::string> signature_file_content = ReadFile(signature_filename);
if (!signature_file_content.ok()) return signature_file_content.status();
return (*public_key_verify)
->Verify(*signature_file_content, *input_file_content);
}
}
} // namespace tink_cc_examples
int main(int argc, char** argv) {
absl::ParseCommandLine(argc, argv);
ValidateParams();
std::string mode = absl::GetFlag(FLAGS_mode);
std::string keyset_filename = absl::GetFlag(FLAGS_keyset_filename);
std::string input_filename = absl::GetFlag(FLAGS_input_filename);
std::string signature_filename = absl::GetFlag(FLAGS_signature_filename);
std::clog << "Using keyset in " << keyset_filename << " to " << mode;
if (mode == kSign) {
std::clog << " file " << input_filename
<< "; the resulting signature is written to "
<< signature_filename << '\n';
} else { // mode == kVerify
std::clog << " the signature in " << signature_filename
<< " over the content of " << input_filename << '\n';
}
CHECK_OK(tink_cc_examples::DigitalSignatureCli(
mode, keyset_filename, input_filename, signature_filename));
return 0;
}
Go
import (
"bytes"
"fmt"
"log"
"github.com/tink-crypto/tink-go/v2/insecurecleartextkeyset"
"github.com/tink-crypto/tink-go/v2/keyset"
"github.com/tink-crypto/tink-go/v2/signature"
)
func Example() {
// A private keyset created with
// "tinkey create-keyset --key-template=ECDSA_P256 --out private_keyset.cfg".
// Note that this keyset has the secret key information in cleartext.
privateJSONKeyset := `{
"key": [{
"keyData": {
"keyMaterialType":
"ASYMMETRIC_PRIVATE",
"typeUrl":
"type.googleapis.com/google.crypto.tink.EcdsaPrivateKey",
"value":
"EkwSBggDEAIYAhogEiSZ9u2nDtvZuDgWgGsVTIZ5/V08N4ycUspTX0RYRrkiIHpEwHxQd1bImkyMvV2bqtUbgMh5uPSTdnUEGrPXdt56GiEA3iUi+CRN71qy0fOCK66xAW/IvFyjOGtxjppRhSFUneo="
},
"keyId": 611814836,
"outputPrefixType": "TINK",
"status": "ENABLED"
}],
"primaryKeyId": 611814836
}`
// The corresponding public keyset created with
// "tinkey create-public-keyset --in private_keyset.cfg"
publicJSONKeyset := `{
"key": [{
"keyData": {
"keyMaterialType":
"ASYMMETRIC_PUBLIC",
"typeUrl":
"type.googleapis.com/google.crypto.tink.EcdsaPublicKey",
"value":
"EgYIAxACGAIaIBIkmfbtpw7b2bg4FoBrFUyGef1dPDeMnFLKU19EWEa5IiB6RMB8UHdWyJpMjL1dm6rVG4DIebj0k3Z1BBqz13beeg=="
},
"keyId": 611814836,
"outputPrefixType": "TINK",
"status": "ENABLED"
}],
"primaryKeyId": 611814836
}`
// Create a keyset handle from the cleartext private keyset in the previous
// step. The keyset handle provides abstract access to the underlying keyset to
// limit the access of the raw key material. WARNING: In practice,
// it is unlikely you will want to use a insecurecleartextkeyset, as it implies
// that your key material is passed in cleartext, which is a security risk.
// Consider encrypting it with a remote key in Cloud KMS, AWS KMS or HashiCorp Vault.
// See https://github.com/google/tink/blob/master/docs/GOLANG-HOWTO.md#storing-and-loading-existing-keysets.
privateKeysetHandle, err := insecurecleartextkeyset.Read(
keyset.NewJSONReader(bytes.NewBufferString(privateJSONKeyset)))
if err != nil {
log.Fatal(err)
}
// Retrieve the Signer primitive from privateKeysetHandle.
signer, err := signature.NewSigner(privateKeysetHandle)
if err != nil {
log.Fatal(err)
}
// Use the primitive to sign a message. In this case, the primary key of the
// keyset will be used (which is also the only key in this example).
data := []byte("data")
sig, err := signer.Sign(data)
if err != nil {
log.Fatal(err)
}
// Create a keyset handle from the keyset containing the public key. Because the
// public keyset does not contain any secrets, we can use [keyset.ReadWithNoSecrets].
publicKeysetHandle, err := keyset.ReadWithNoSecrets(
keyset.NewJSONReader(bytes.NewBufferString(publicJSONKeyset)))
if err != nil {
log.Fatal(err)
}
// Retrieve the Verifier primitive from publicKeysetHandle.
verifier, err := signature.NewVerifier(publicKeysetHandle)
if err != nil {
log.Fatal(err)
}
if err = verifier.Verify(sig, data); err != nil {
log.Fatal(err)
}
fmt.Printf("sig is valid")
// Output: sig is valid
}
Java
package signature;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.crypto.tink.InsecureSecretKeyAccess;
import com.google.crypto.tink.KeysetHandle;
import com.google.crypto.tink.PublicKeySign;
import com.google.crypto.tink.PublicKeyVerify;
import com.google.crypto.tink.TinkJsonProtoKeysetFormat;
import com.google.crypto.tink.signature.SignatureConfig;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
/**
* 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 'sign' or 'verify'.
* <li>key-file: Read the key material from this file.
* <li>input-file: Read the input from this file.
* <li>signature-file: name of the file containing a hexadecimal signature of the input file.
*/
public final class SignatureExample {
public static void main(String[] args) throws Exception {
if (args.length != 4) {
System.err.printf("Expected 4 parameters, got %d\n", args.length);
System.err.println(
"Usage: java SignatureExample sign/verify key-file input-file signature-file");
System.exit(1);
}
String mode = args[0];
if (!mode.equals("sign") && !mode.equals("verify")) {
System.err.println("Incorrect mode. Please select sign or verify.");
System.exit(1);
}
Path keyFile = Paths.get(args[1]);
byte[] msg = Files.readAllBytes(Paths.get(args[2]));
Path signatureFile = Paths.get(args[3]);
// Register all signature key types with the Tink runtime.
SignatureConfig.register();
// Read the keyset into a KeysetHandle.
KeysetHandle handle =
TinkJsonProtoKeysetFormat.parseKeyset(
new String(Files.readAllBytes(keyFile), UTF_8), InsecureSecretKeyAccess.get());
if (mode.equals("sign")) {
// Get the primitive.
PublicKeySign signer = handle.getPrimitive(PublicKeySign.class);
// Use the primitive to sign data.
byte[] signature = signer.sign(msg);
Files.write(signatureFile, signature);
} else {
byte[] signature = Files.readAllBytes(signatureFile);
// Get the primitive.
PublicKeyVerify verifier = handle.getPrimitive(PublicKeyVerify.class);
verifier.verify(signature, msg);
}
}
private SignatureExample() {}
}
Obj-C
Python
import tink
from tink import secret_key_access
from tink import signature
def example():
"""Sign and verify using digital signatures."""
# Register the signature key managers. This is needed to create
# PublicKeySign and PublicKeyVerify primitives later.
signature.register()
# A private keyset created with
# "tinkey create-keyset --key-template=ECDSA_P256 --out private_keyset.cfg".
# Note that this keyset has the secret key information in cleartext.
private_keyset = r"""{
"key": [{
"keyData": {
"keyMaterialType":
"ASYMMETRIC_PRIVATE",
"typeUrl":
"type.googleapis.com/google.crypto.tink.EcdsaPrivateKey",
"value":
"EkwSBggDEAIYAhogEiSZ9u2nDtvZuDgWgGsVTIZ5/V08N4ycUspTX0RYRrkiIHpEwHxQd1bImkyMvV2bqtUbgMh5uPSTdnUEGrPXdt56GiEA3iUi+CRN71qy0fOCK66xAW/IvFyjOGtxjppRhSFUneo="
},
"keyId": 611814836,
"outputPrefixType": "TINK",
"status": "ENABLED"
}],
"primaryKeyId": 611814836
}"""
# The corresponding public keyset created with
# "tinkey create-public-keyset --in private_keyset.cfg"
public_keyset = r"""{
"key": [{
"keyData": {
"keyMaterialType":
"ASYMMETRIC_PUBLIC",
"typeUrl":
"type.googleapis.com/google.crypto.tink.EcdsaPublicKey",
"value":
"EgYIAxACGAIaIBIkmfbtpw7b2bg4FoBrFUyGef1dPDeMnFLKU19EWEa5IiB6RMB8UHdWyJpMjL1dm6rVG4DIebj0k3Z1BBqz13beeg=="
},
"keyId": 611814836,
"outputPrefixType": "TINK",
"status": "ENABLED"
}],
"primaryKeyId": 611814836
}"""
# Create a keyset handle from the cleartext keyset in the previous
# step. The keyset handle provides abstract access to the underlying keyset to
# limit the exposure of accessing the raw key material. WARNING: In practice,
# it is unlikely you will want to use tink.json_proto_keyset_format.parse, as
# it implies that your key material is passed in cleartext which is a security
# risk.
private_keyset_handle = tink.json_proto_keyset_format.parse(
private_keyset, secret_key_access.TOKEN
)
# Retrieve the PublicKeySign primitive we want to use from the keyset
# handle.
sign_primitive = private_keyset_handle.primitive(signature.PublicKeySign)
# Use the primitive to sign a message. In this case the primary key of the
# keyset will be used (which is also the only key in this example).
sig = sign_primitive.sign(b'msg')
# Create a keyset handle from the keyset containing the public key. Because
# this keyset does not contain any secrets, we can use
# `parse_without_secret`.
public_keyset_handle = tink.json_proto_keyset_format.parse_without_secret(
public_keyset
)
# Retrieve the PublicKeyVerify primitive we want to use from the keyset
# handle.
verify_primitive = public_keyset_handle.primitive(signature.PublicKeyVerify)
# Use the primitive to verify that `sig` is valid signature for the message.
# Verify finds the correct key in the keyset. If no key is found or
# verification fails, it raises an error.
verify_primitive.verify(sig, b'msg')
# Note that we can also get the public keyset handle from the private keyset
# handle. The verification works the same as above.
public_keyset_handle2 = private_keyset_handle.public_keyset_handle()
verify_primitive2 = public_keyset_handle2.primitive(signature.PublicKeyVerify)
verify_primitive2.verify(sig, b'msg')