Quero criar e verificar JWTs

A biblioteca JWT do Tink permite a criação e verificação de JSON Web Tokens (JWTs).

Criar JWTs

Recomendamos as primitivas JwtPublicKeySign com o tipo de chave JWT_ES256 para a maioria dos casos de uso.

Os exemplos a seguir mostram como criar JWTs e como converter o conjunto de chaves públicas no formato de conjunto JWK.

C++

// An example for signing JSON Web Tokens (JWT).
#include <iostream>
#include <memory>
#include <ostream>
#include <string>
#include <utility>

#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/log/check.h"
#include "absl/strings/string_view.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "tink/config/global_registry.h"
#include "util/util.h"
#include "tink/jwt/jwt_public_key_sign.h"
#include "tink/jwt/jwt_signature_config.h"
#include "tink/jwt/raw_jwt.h"
#include "tink/keyset_handle.h"
#include "tink/util/status.h"

ABSL_FLAG(std::string, keyset_filename, "", "Keyset file in JSON format");
ABSL_FLAG(std::string, audience, "", "Expected audience in the token");
ABSL_FLAG(std::string, token_filename, "", "Path to the token file");

namespace {

using ::crypto::tink::JwtPublicKeySign;
using ::crypto::tink::KeysetHandle;
using ::crypto::tink::RawJwt;
using ::crypto::tink::RawJwtBuilder;
using ::crypto::tink::util::Status;
using ::crypto::tink::util::StatusOr;

void ValidateParams() {
  // ...
}

}  // namespace

namespace tink_cc_examples {

// JWT sign example CLI implementation.
Status JwtSign(const std::string& keyset_filename, absl::string_view audience,
               const std::string& token_filename) {
  Status result = crypto::tink::JwtSignatureRegister();
  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();
  StatusOr<RawJwt> raw_jwt =
      RawJwtBuilder()
          .AddAudience(audience)
          .SetExpiration(absl::Now() + absl::Seconds(100))
          .Build();
  if (!raw_jwt.ok()) return raw_jwt.status();
  StatusOr<std::unique_ptr<JwtPublicKeySign>> jwt_signer =
      (*keyset_handle)
          ->GetPrimitive<crypto::tink::JwtPublicKeySign>(
              crypto::tink::ConfigGlobalRegistry());
  if (!jwt_signer.ok()) return jwt_signer.status();

  StatusOr<std::string> token = (*jwt_signer)->SignAndEncode(*raw_jwt);
  if (!token.ok()) return token.status();

  return WriteToFile(*token, token_filename);
}

}  // namespace tink_cc_examples

int main(int argc, char** argv) {
  absl::ParseCommandLine(argc, argv);

  ValidateParams();

  std::string keyset_filename = absl::GetFlag(FLAGS_keyset_filename);
  std::string audience = absl::GetFlag(FLAGS_audience);
  std::string token_filename = absl::GetFlag(FLAGS_token_filename);

  std::clog << "Using keyset in " << keyset_filename << " to ";
  std::clog << " generate and sign a token using audience '" << audience
            << "'; the resulting signature is written to " << token_filename
            << '\n';

  CHECK_OK(
      tink_cc_examples::JwtSign(keyset_filename, audience, token_filename));
  return 0;
}
jwt_sign.cc

Go

func Example_signAndVerify() {
	// A private keyset created with
	// "tinkey create-keyset --key-template=JWT_ES256 --out private_keyset.cfg".
	// Note that this keyset has the secret key information in cleartext.
	privateJSONKeyset := `{
		"primaryKeyId": 1742360595,
		"key": [
			{
				"keyData": {
					"typeUrl": "type.googleapis.com/google.crypto.tink.JwtEcdsaPrivateKey",
					"value": "GiBgVYdAPg3Fa2FVFymGDYrI1trHMzVjhVNEMpIxG7t0HRJGIiBeoDMF9LS5BDCh6YgqE3DjHwWwnEKEI3WpPf8izEx1rRogbjQTXrTcw/1HKiiZm2Hqv41w7Vd44M9koyY/+VsP+SAQAQ==",
					"keyMaterialType": "ASYMMETRIC_PRIVATE"
				},
				"status": "ENABLED",
				"keyId": 1742360595,
				"outputPrefixType": "TINK"
			}
		]
	}`

	// The corresponding public keyset created with
	// "tinkey create-public-keyset --in private_keyset.cfg"
	publicJSONKeyset := `{
		"primaryKeyId": 1742360595,
		"key": [
			{
				"keyData": {
					"typeUrl": "type.googleapis.com/google.crypto.tink.JwtEcdsaPublicKey",
					"value": "EAEaIG40E1603MP9RyoomZth6r+NcO1XeODPZKMmP/lbD/kgIiBeoDMF9LS5BDCh6YgqE3DjHwWwnEKEI3WpPf8izEx1rQ==",
					"keyMaterialType": "ASYMMETRIC_PUBLIC"
				},
				"status": "ENABLED",
				"keyId": 1742360595,
				"outputPrefixType": "TINK"
			}
		]
	}`

	// 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 JWT Signer primitive from privateKeysetHandle.
	signer, err := jwt.NewSigner(privateKeysetHandle)
	if err != nil {
		log.Fatal(err)
	}

	// Use the primitive to create and sign a token. In this case, the primary key of the
	// keyset will be used (which is also the only key in this example).
	expiresAt := time.Now().Add(time.Hour)
	audience := "example audience"
	subject := "example subject"
	rawJWT, err := jwt.NewRawJWT(&jwt.RawJWTOptions{
		Audience:  &audience,
		Subject:   &subject,
		ExpiresAt: &expiresAt,
	})
	if err != nil {
		log.Fatal(err)
	}
	token, err := signer.SignAndEncode(rawJWT)
	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 := jwt.NewVerifier(publicKeysetHandle)
	if err != nil {
		log.Fatal(err)
	}

	// Verify the signed token.
	validator, err := jwt.NewValidator(&jwt.ValidatorOpts{ExpectedAudience: &audience})
	if err != nil {
		log.Fatal(err)
	}
	verifiedJWT, err := verifier.VerifyAndDecode(token, validator)
	if err != nil {
		log.Fatal(err)
	}

	// Extract subject claim from the token.
	if !verifiedJWT.HasSubject() {
		log.Fatal(err)
	}
	extractedSubject, err := verifiedJWT.Subject()
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(extractedSubject)
	// Output: example subject
}
jwt_test.go

Java

package jwt;

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.RegistryConfiguration;
import com.google.crypto.tink.TinkJsonProtoKeysetFormat;
import com.google.crypto.tink.jwt.JwtPublicKeySign;
import com.google.crypto.tink.jwt.JwtSignatureConfig;
import com.google.crypto.tink.jwt.RawJwt;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Instant;

/**
 * A command-line utility for signing JSON Web Tokens (JWTs).
 *
 * <p>It loads cleartext private keys from disk - this is not recommended!
 *
 * <p>It requires the following arguments:
 *
 * <ul>
 *   <li>private-keyset-file: Name of the input file containing the private keyset.
 *   <li>audience: The audience claim to be used in the token
 *   <li>token-file: name of the output file containing the signed JWT.
 */
public final class JwtSign {
  public static void main(String[] args) throws Exception {
    if (args.length != 3) {
      System.err.printf("Expected 3 parameters, got %d\n", args.length);
      System.err.println("Usage: java JwtSign private-keyset-file audience token-file");
      System.exit(1);
    }

    Path privateKeysetFile = Paths.get(args[0]);
    String audience = args[1];
    Path tokenFile = Paths.get(args[2]);

    // Register all JWT signature key types with the Tink runtime.
    JwtSignatureConfig.register();

    // Read the private keyset into a KeysetHandle.
    KeysetHandle privateKeysetHandle =
        TinkJsonProtoKeysetFormat.parseKeyset(
            new String(Files.readAllBytes(privateKeysetFile), UTF_8),
            InsecureSecretKeyAccess.get());

    // Get the primitive.
    JwtPublicKeySign signer =
        privateKeysetHandle.getPrimitive(RegistryConfiguration.get(), JwtPublicKeySign.class);

    // Use the primitive to sign a token that expires in 100 seconds.
    RawJwt rawJwt =
        RawJwt.newBuilder()
            .addAudience(audience)
            .setExpiration(Instant.now().plusSeconds(100))
            .build();
    String signedToken = signer.signAndEncode(rawJwt);
    Files.write(tokenFile, signedToken.getBytes(UTF_8));
  }

  private JwtSign() {}
}
JwtSign.java

Python

"""A utility for creating and signing JSON Web Tokens (JWT).

It loads cleartext keys from disk - this is not recommended!
"""

import datetime

from absl import app
from absl import flags
from absl import logging
import tink
from tink import jwt
from tink import secret_key_access


_PRIVATE_KEYSET_PATH = flags.DEFINE_string(
    'private_keyset_path', None,
    'Path to the keyset used for the JWT signature operation.')
_AUDIENCE = flags.DEFINE_string('audience', None,
                                'Audience to be used in the token')
_TOKEN_PATH = flags.DEFINE_string('token_path', None, 'Path to the token file.')


def main(argv):
  del argv  # Unused.

  # Initialise Tink
  jwt.register_jwt_signature()

  # Read the keyset into a KeysetHandle
  with open(_PRIVATE_KEYSET_PATH.value, 'rt') as keyset_file:
    try:
      text = keyset_file.read()
      keyset_handle = tink.json_proto_keyset_format.parse(
          text, secret_key_access.TOKEN
      )
    except tink.TinkError as e:
      logging.exception('Error reading keyset: %s', e)
      return 1

  now = datetime.datetime.now(tz=datetime.timezone.utc)

  # Get the JwtPublicKeySign primitive
  try:
    jwt_sign = keyset_handle.primitive(jwt.JwtPublicKeySign)
  except tink.TinkError as e:
    logging.exception('Error creating JwtPublicKeySign: %s', e)
    return 1

  # Create token
  raw_jwt = jwt.new_raw_jwt(
      audiences=[_AUDIENCE.value],
      expiration=now + datetime.timedelta(seconds=100))
  token = jwt_sign.sign_and_encode(raw_jwt)
  with open(_TOKEN_PATH.value, 'wt') as token_file:
    token_file.write(token)
  logging.info('Token has been written to %s', _TOKEN_PATH.value)


if __name__ == '__main__':
  flags.mark_flags_as_required(
      ['private_keyset_path', 'audience', 'token_path'])
  app.run(main)
jwt_sign_cli.py

Uma maneira comum de compartilhar o conjunto de chaves públicas é o formato de conjunto JWK. O exemplo a seguir mostra como converter o conjunto de chaves públicas no formato de conjunto JWK.

C++

// An example for converting a Tink keyset with public keys into a JWK set.
#include <iostream>
#include <memory>
#include <ostream>
#include <string>

#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/log/check.h"
#include "util/util.h"
#include "tink/jwt/jwk_set_converter.h"
#include "tink/jwt/jwt_signature_config.h"
#include "tink/keyset_handle.h"
#include "tink/util/status.h"

ABSL_FLAG(std::string, public_keyset_filename, "",
          "Public keyset file in Tink's JSON format");
ABSL_FLAG(std::string, public_jwk_set_filename, "",
          "Path to the output public JWK set file");

namespace {

using ::crypto::tink::JwkSetFromPublicKeysetHandle;
using ::crypto::tink::KeysetHandle;
using ::crypto::tink::util::Status;
using ::crypto::tink::util::StatusOr;

void ValidateParams() {
  // ...
}

}  // namespace

namespace tink_cc_examples {

Status JwtGeneratePublicJwkSet(const std::string& public_keyset_filename,
                               const std::string& public_jwk_set_filename) {
  Status result = crypto::tink::JwtSignatureRegister();
  if (!result.ok()) return result;

  StatusOr<std::unique_ptr<KeysetHandle>> keyset_handle =
      ReadJsonCleartextKeyset(public_keyset_filename);
  if (!keyset_handle.ok()) return keyset_handle.status();

  StatusOr<std::string> public_jwk_set =
      JwkSetFromPublicKeysetHandle(**keyset_handle);
  if (!public_jwk_set.ok()) return keyset_handle.status();

  return WriteToFile(*public_jwk_set, public_jwk_set_filename);
}

}  // namespace tink_cc_examples

int main(int argc, char** argv) {
  absl::ParseCommandLine(argc, argv);

  ValidateParams();

  std::string public_keyset_filename =
      absl::GetFlag(FLAGS_public_keyset_filename);
  std::string public_jwk_set_filename =
      absl::GetFlag(FLAGS_public_jwk_set_filename);

  std::clog << "Convert public keyset in " << public_keyset_filename << " to ";
  std::clog << " to JWK set format; the result is written to "
            << public_jwk_set_filename << '\n';

  CHECK_OK(tink_cc_examples::JwtGeneratePublicJwkSet(public_keyset_filename,
                                                     public_jwk_set_filename));
  return 0;
}
jwt_generate_public_jwk_set.cc

Go

func Example_generateJWKS() {
	// A Tink keyset in JSON format with one JWT public key.
	publicJSONKeyset := `{
		"primaryKeyId": 1742360595,
		"key": [
			{
				"keyData": {
					"typeUrl": "type.googleapis.com/google.crypto.tink.JwtEcdsaPublicKey",
					"value": "EAEaIG40E1603MP9RyoomZth6r+NcO1XeODPZKMmP/lbD/kgIiBeoDMF9LS5BDCh6YgqE3DjHwWwnEKEI3WpPf8izEx1rQ==",
					"keyMaterialType": "ASYMMETRIC_PUBLIC"
				},
				"status": "ENABLED",
				"keyId": 1742360595,
				"outputPrefixType": "TINK"
			}
		]
	}`

	// 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)
	}

	// Create a publicJWKset from publicKeysetHandle.
	publicJWKset, err := jwt.JWKSetFromPublicKeysetHandle(publicKeysetHandle)
	if err != nil {
		log.Fatal(err)
	}

	// Remove whitespace so that we can compare it to the expected string.
	compactPublicJWKset := &bytes.Buffer{}
	err = json.Compact(compactPublicJWKset, publicJWKset)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(compactPublicJWKset.String())
	// Output:
	// {"keys":[{"alg":"ES256","crv":"P-256","key_ops":["verify"],"kid":"Z9pQEw","kty":"EC","use":"sig","x":"bjQTXrTcw_1HKiiZm2Hqv41w7Vd44M9koyY_-VsP-SA","y":"XqAzBfS0uQQwoemIKhNw4x8FsJxChCN1qT3_IsxMda0"}]}
}
jwt_test.go

Java

package jwt;

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.TinkJsonProtoKeysetFormat;
import com.google.crypto.tink.jwt.JwkSetConverter;
import com.google.crypto.tink.jwt.JwtSignatureConfig;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

/**
 * A command-line example for generating the public JWT keyset in JWK set format.
 *
 * <p>It loads cleartext private keys from disk - this is not recommended!
 *
 * <p>It requires the following arguments:
 *
 * <ul>
 *   <li>private-keyset-file: Name of the input file containing the private keyset.
 *   <li>public-jwkset-file: Name of the output file containing the public key in JWK set format.
 */
public final class JwtGeneratePublicJwkSet {
  public static void main(String[] args) throws Exception {
    if (args.length != 2) {
      System.err.printf("Expected 2 parameters, got %d\n", args.length);
      System.err.println(
          "Usage: java JwtGeneratePublicJwkSet private-keyset-file public-jwk-set-file");
      System.exit(1);
    }

    Path privateKeysetFile = Paths.get(args[0]);
    Path publicJwkSetFile = Paths.get(args[1]);

    // Register all JWT signature key types with the Tink runtime.
    JwtSignatureConfig.register();

    // Read the keyset into a KeysetHandle.
    KeysetHandle privateKeysetHandle =
        TinkJsonProtoKeysetFormat.parseKeyset(
            new String(Files.readAllBytes(privateKeysetFile), UTF_8),
            InsecureSecretKeyAccess.get());

    // Export the public keyset as JWK set.
    String publicJwkSet =
        JwkSetConverter.fromPublicKeysetHandle(privateKeysetHandle.getPublicKeysetHandle());
    Files.write(publicJwkSetFile, publicJwkSet.getBytes(UTF_8));
  }

  private JwtGeneratePublicJwkSet() {}
}
JwtGeneratePublicJwkSet.java

Python

"""A utility for generating the public JWK set from the public keyset.
"""

from absl import app
from absl import flags
from absl import logging
import tink
from tink import jwt


_PUBLIC_KEYSET_PATH = flags.DEFINE_string(
    'public_keyset_path', None,
    'Path to the public keyset in Tink JSON format.')
_PUBLIC_JWK_SET_PATH = flags.DEFINE_string(
    'public_jwk_set_path', None, 'Path to public keyset in JWK format.')


def main(argv):
  del argv  # Unused.

  # Initialise Tink
  jwt.register_jwt_signature()

  # Read the keyset into a KeysetHandle
  with open(_PUBLIC_KEYSET_PATH.value, 'rt') as keyset_file:
    try:
      text = keyset_file.read()
      public_keyset_handle = tink.json_proto_keyset_format.parse_without_secret(
          text
      )
    except tink.TinkError as e:
      logging.exception('Error reading keyset: %s', e)
      return 1

  # Export Public Keyset as JWK set
  public_jwk_set = jwt.jwk_set_from_public_keyset_handle(public_keyset_handle)
  with open(_PUBLIC_JWK_SET_PATH.value, 'wt') as public_jwk_set_file:
    public_jwk_set_file.write(public_jwk_set)
  logging.info('The public JWK set has been written to %s',
               _PUBLIC_JWK_SET_PATH.value)


if __name__ == '__main__':
  flags.mark_flags_as_required(['public_keyset_path', 'public_jwk_set_path'])
  app.run(main)
jwt_generate_public_jwk_set.py

Verificar JWTs

Recomendamos as primitivas JwtPublicKeyVerify com o tipo de chave JWT_ES256 para a maioria dos casos de uso.

Os exemplos a seguir mostram como verificar JWTs usando um conjunto de chaves públicas no formato de conjunto JWK, que é um formato comumente usado para compartilhar conjuntos de chaves públicas com outras partes.

C++

// A utility for creating, signing and verifying JSON Web Tokens (JWT).
#include <iostream>
#include <memory>
#include <ostream>
#include <string>
#include <utility>

#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/jwt/jwk_set_converter.h"
#include "tink/jwt/jwt_public_key_verify.h"
#include "tink/jwt/jwt_signature_config.h"
#include "tink/jwt/jwt_validator.h"
#include "tink/keyset_handle.h"
#include "tink/util/status.h"

ABSL_FLAG(std::string, jwk_set_filename, "", "Path to the JWK set file");
ABSL_FLAG(std::string, audience, "", "Expected audience in the token");
ABSL_FLAG(std::string, token_filename, "", "Path to the token file");

namespace {

using ::crypto::tink::JwkSetToPublicKeysetHandle;
using ::crypto::tink::JwtPublicKeyVerify;
using ::crypto::tink::JwtValidator;
using ::crypto::tink::KeysetHandle;
using ::crypto::tink::util::Status;
using ::crypto::tink::util::StatusOr;

void ValidateParams() {
  // ...
}

}  // namespace

namespace tink_cc_examples {

// JWT verify example CLI implementation.
Status JwtVerify(const std::string& jwk_set_filename,
                 absl::string_view audience,
                 const std::string& token_filename) {
  Status result = crypto::tink::JwtSignatureRegister();
  if (!result.ok()) return result;

  // Read the JWK set from file and convert it.
  StatusOr<std::string> jwk_set = ReadFile(jwk_set_filename);
  if (!jwk_set.ok()) return jwk_set.status();
  StatusOr<std::unique_ptr<KeysetHandle>> keyset_handle =
      JwkSetToPublicKeysetHandle(*jwk_set);

  // Read the token.
  StatusOr<std::string> token = ReadFile(token_filename);
  if (!token.ok()) return token.status();

  StatusOr<JwtValidator> validator =
      crypto::tink::JwtValidatorBuilder().ExpectAudience(audience).Build();
  if (!validator.ok()) return validator.status();

  StatusOr<std::unique_ptr<JwtPublicKeyVerify>> jwt_verifier =
      (*keyset_handle)
          ->GetPrimitive<crypto::tink::JwtPublicKeyVerify>(
              crypto::tink::ConfigGlobalRegistry());
  if (!jwt_verifier.ok()) return jwt_verifier.status();

  return (*jwt_verifier)->VerifyAndDecode(*token, *validator).status();
}

}  // namespace tink_cc_examples

int main(int argc, char** argv) {
  absl::ParseCommandLine(argc, argv);

  ValidateParams();

  std::string jwk_set_filename = absl::GetFlag(FLAGS_jwk_set_filename);
  std::string audience = absl::GetFlag(FLAGS_audience);
  std::string token_filename = absl::GetFlag(FLAGS_token_filename);

  std::clog << "Using keyset in " << jwk_set_filename << " to ";
  std::clog << " verify a token with expected audience '" << audience << '\n';

  CHECK_OK(
      tink_cc_examples::JwtVerify(jwk_set_filename, audience, token_filename));
  return 0;
}
jwt_verify.cc

Go

func Example_verifyWithJWKS() {
	// A signed token with the subject 'example subject', audience 'example audience'.
	// and expiration on 2023-03-23.
	token := `eyJhbGciOiJFUzI1NiIsICJraWQiOiJaOXBRRXcifQ.eyJhdWQiOiJleGFtcGxlIGF1ZGllbmNlIiwgImV4cCI6MTY3OTUzMzIwMCwgInN1YiI6ImV4YW1wbGUgc3ViamVjdCJ9.ZvI0T84fJ1aouiB7n62kHOmbm0Hpfiz0JtYs15XVDT8KyoVYZ8hu_DGJUN47BqZIbuOI-rdu9TxJvutj8uF3Ow`

	// A public keyset in the JWK set format.
	publicJWKset := `{
		"keys":[
			{
				"alg":"ES256",
				"crv":"P-256",
				"key_ops":["verify"],
				"kid":"Z9pQEw",
				"kty":"EC",
				"use":"sig",
				"x":"bjQTXrTcw_1HKiiZm2Hqv41w7Vd44M9koyY_-VsP-SA",
				"y":"XqAzBfS0uQQwoemIKhNw4x8FsJxChCN1qT3_IsxMda0"
			}
		]
	}`

	// Create a keyset handle from publicJWKset.
	publicKeysetHandle, err := jwt.JWKSetToPublicKeysetHandle([]byte(publicJWKset))
	if err != nil {
		log.Fatal(err)
	}

	// Retrieve the Verifier primitive from publicKeysetHandle.
	verifier, err := jwt.NewVerifier(publicKeysetHandle)
	if err != nil {
		log.Fatal(err)
	}

	// Verify the signed token. For this example, we use a fixed date. Usually, you would
	// either not set FixedNow, or set it to the current time.
	audience := "example audience"
	validator, err := jwt.NewValidator(&jwt.ValidatorOpts{
		ExpectedAudience: &audience,
		FixedNow:         time.Date(2023, 3, 23, 0, 0, 0, 0, time.UTC),
	})
	if err != nil {
		log.Fatal(err)
	}
	verifiedJWT, err := verifier.VerifyAndDecode(token, validator)
	if err != nil {
		log.Fatal(err)
	}

	// Extract subject claim from the token.
	if !verifiedJWT.HasSubject() {
		log.Fatal(err)
	}
	extractedSubject, err := verifiedJWT.Subject()
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(extractedSubject)
	// Output: example subject
}
jwt_test.go

Java

package jwt;

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.crypto.tink.KeysetHandle;
import com.google.crypto.tink.RegistryConfiguration;
import com.google.crypto.tink.jwt.JwkSetConverter;
import com.google.crypto.tink.jwt.JwtPublicKeyVerify;
import com.google.crypto.tink.jwt.JwtSignatureConfig;
import com.google.crypto.tink.jwt.JwtValidator;
import com.google.crypto.tink.jwt.VerifiedJwt;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.List;

/**
 * A command-line utility for verifying JSON Web Tokens (JWTs).
 *
 * <p>It requires the following arguments:
 *
 * <ul>
 *   <li>public-jwkset-file: Name of the input file containing the public keyset in JWK set format.
 *   <li>audience: The audience claim to be used in the token
 *   <li>token-file: name of the input file containing the signed JWT.
 */
public final class JwtVerify {
  public static void main(String[] args) throws Exception {
    if (args.length != 3) {
      System.err.printf("Expected 3 parameters, got %d\n", args.length);
      System.err.println(
          "Usage: java JwtVerify public-jwk-set-file audience token-file");
      System.exit(1);
    }

    Path publicJwkSetFile = Paths.get(args[0]);
    String audience = args[1];
    Path tokenFile = Paths.get(args[2]);

    // Register all JWT signature key types with the Tink runtime.
    JwtSignatureConfig.register();

    // Read the public keyset in JWK set format into a KeysetHandle.
    KeysetHandle publicKeysetHandle =
        JwkSetConverter.toPublicKeysetHandle(
            new String(Files.readAllBytes(publicJwkSetFile), UTF_8));

    List<String> lines = Files.readAllLines(tokenFile, UTF_8);
    if (lines.size() != 1) {
      System.err.printf("The signature file should contain only one line,  got %d", lines.size());
      System.exit(1);
    }
    String signedToken = lines.get(0).trim();

    // Get the primitive.
    JwtPublicKeyVerify verifier =
        publicKeysetHandle.getPrimitive(RegistryConfiguration.get(), JwtPublicKeyVerify.class);

    // Use the primitive to verify a token.
    JwtValidator validator = JwtValidator.newBuilder().expectAudience(audience).build();
    VerifiedJwt verifiedJwt = verifier.verifyAndDecode(signedToken, validator);
    long seconds = ChronoUnit.SECONDS.between(Instant.now(), verifiedJwt.getExpiration());
    System.out.println("Token is valid and expires in " + seconds + " seconds.");
  }

  private JwtVerify() {}
}
JwtVerify.java

Python

"""A utility for verifying Json Web Tokens (JWT)."""

import datetime

from absl import app
from absl import flags
from absl import logging
import tink
from tink import jwt


FLAGS = flags.FLAGS

_PUBLIC_JWK_SET_PATH = flags.DEFINE_string(
    'public_jwk_set_path', None, 'Path to public keyset in JWK set format.')
_AUDIENCE = flags.DEFINE_string('audience', None,
                                'Audience to be used in the token')
_TOKEN_PATH = flags.DEFINE_string('token_path', None,
                                  'Path to the signature file.')


def main(argv):
  del argv  # Unused.

  # Initialise Tink
  jwt.register_jwt_signature()

  with open(_PUBLIC_JWK_SET_PATH.value, 'rt') as public_jwk_set_file:
    try:
      text = public_jwk_set_file.read()
      keyset_handle = jwt.jwk_set_to_public_keyset_handle(text)
    except tink.TinkError as e:
      logging.exception('Error reading public JWK set: %s', e)
      return 1

  now = datetime.datetime.now(tz=datetime.timezone.utc)
  try:
    jwt_verify = keyset_handle.primitive(jwt.JwtPublicKeyVerify)
  except tink.TinkError as e:
    logging.exception('Error creating JwtPublicKeyVerify: %s', e)
    return 1

  # Verify token
  with open(_TOKEN_PATH.value, 'rt') as token_file:
    token = token_file.read()
  validator = jwt.new_validator(expected_audience=_AUDIENCE.value)
  try:
    verified_jwt = jwt_verify.verify_and_decode(token, validator)
    expires_in = verified_jwt.expiration() - now
    logging.info('Token is valid and expires in %s seconds', expires_in.seconds)
    return 0
  except tink.TinkError as e:
    logging.info('JWT verification failed: %s', e)
    return 1


if __name__ == '__main__':
  flags.mark_flags_as_required(['audience', 'token_path'])
  app.run(main)
jwt_verify_cli.py

JSON Web Tokens (JWTs)

A Tink oferece suporte à geração e verificação de JWTs, um padrão amplamente usado na Web. A implementação de JWT da Tink oferece um subconjunto do padrão JWT definido na RFC 7519 que a equipe da Tink considera seguro para uso e que se encaixa bem na biblioteca Tink.

O Tink não oferece suporte a partes do padrão que são raramente usadas ou difíceis de usar corretamente. Estas são as limitações:

• A Tink só é compatível com o formato JWS Compact Serialization. JWS JSON Serialization e JWE não são compatíveis.
• A Tink não aceita o valor None no cabeçalho alg.
• O Tink só aceita os cabeçalhos typ, alg e kid. Todos os outros cabeçalhos não são compatíveis.
• A Tink não permite que os tokens sejam analisados antes que a assinatura ou o MAC seja verificado.

Assinaturas JWT

Se os tokens forem gerados e verificados por entidades diferentes, use chaves assimétricas com as primitivas JwtPublicKeySign e JwtPublicKeyVerify. A chave privada é usada para gerar tokens, e a chave pública é usada para verificar tokens. Os algoritmos compatíveis com essas primitivas são: ES256, ES384, ES512, RS256, RS384, RS512, PS256, PS384 e PS512.

Escolher um tipo de chave

As assinaturas JWT usam tipos de chave diferentes da assinatura digital normal no Tink. Isso é necessário porque alguns metadados (como alg e kid) precisam ser armazenados com a chave.

Recomendamos usar JWT_ES256 na maioria dos casos de uso. Os tokens gerados com esse tipo de chave sempre têm um cabeçalho kid. Se você preferir tokens um pouco mais curtos sem um cabeçalho kid, escolha o tipo de chave JWT_ES256_RAW. Para todos os tipos de chaves compatíveis, consulte Tipos de chaves compatíveis.

Distribuição de conjunto de chaves públicas

O Tink permite que conjuntos de chaves públicas sejam convertidos para e do formato de conjuntos JWK definido na RFC 7517, que a maioria das bibliotecas JWT entende.

Observação: o formato de serialização do conjunto de chaves JSON do Tink não é um conjunto JWK, e outras bibliotecas provavelmente não poderão lê-lo.

A Tink não aceita a exportação de chaves JWT públicas em nenhum outro formato. O motivo é que outros formatos não contêm os metadados alg e kid para serem usados na verificação, o que torna o uso deles mais propenso a erros e pode dificultar a rotação de chaves.

É preferível não compartilhar o conjunto de chaves públicas apenas uma vez, mas fornecer uma maneira de atualizar automaticamente o conjunto de chaves públicas. Caso contrário, a rotação para uma nova chave é muito difícil. Isso geralmente é feito publicando o conjunto de chaves públicas em um URL confiável e seguro. Um servidor que verifica tokens precisa buscar novamente o conjunto de chaves públicas periodicamente no URL, por exemplo, uma vez por dia. Para fazer a rotação, a nova chave pública precisa ser adicionada ao conjunto de chaves públicas pelo menos um dia antes de ser usada para assinar tokens. Caso contrário, os novos tokens assinados com a nova chave privada serão rejeitados por servidores que ainda usam o conjunto de chaves públicas antigo.

Observação: algumas implementações buscam novamente a chave pública assim que um token com um cabeçalho kid desconhecido é recebido. Não é possível implementar essa lógica no Tink, porque o token não é analisado antes de ser verificado. Não recomendamos fazer isso, já que pode resultar em muitas solicitações extras para o URL do conjunto de chaves se tokens maliciosos com cabeçalhos kid aleatórios forem enviados.

JWT MAC

A Tink também é compatível com JWT com chaves simétricas usando a primitiva JwtMac. Use essa primitiva somente se os tokens forem gerados e verificados pela mesma entidade. Os algoritmos compatíveis com essa primitiva são HS256, HS384 e HS512.

Escolher um tipo de chave

Os tipos de chave MAC JWT são diferentes dos tipos de chave MAC normais. Recomendamos usar JWT_HS256 na maioria dos casos de uso.