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App mit signierten Headern sichern

Sie können Ihre Anwendung mit signierten IAP-Headern (Identity-Aware Proxy) schützen.

Weitere Informationen

Eine ausführliche Dokumentation, die dieses Codebeispiel enthält, finden Sie hier:

App mit signierten Headern sichern

Codebeispiel

C#

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.


using Google.Apis.Auth;
using Google.Apis.Auth.OAuth2;
using System;
using System.Threading;
using System.Threading.Tasks;

public class IAPTokenVerification
{
    /// <summary>
    /// Verifies a signed jwt token and returns its payload.
    /// </summary>
    /// <param name="signedJwt">The token to verify.</param>
    /// <param name="expectedAudience">The audience that the token should be meant for.
    /// Validation will fail if that's not the case.</param>
    /// <param name="cancellationToken">The cancellation token to propagate cancellation requests.</param>
    /// <returns>A task that when completed will have as its result the payload of the verified token.</returns>
    /// <exception cref="InvalidJwtException">If verification failed. The message of the exception will contain
    /// information as to why the token failed.</exception>
    public async Task<JsonWebSignature.Payload> VerifyTokenAsync(
        string signedJwt, string expectedAudience, CancellationToken cancellationToken = default)
    {
        SignedTokenVerificationOptions options = new SignedTokenVerificationOptions
        {
            // Use clock tolerance to account for possible clock differences
            // between the issuer and the verifier.
            IssuedAtClockTolerance = TimeSpan.FromMinutes(1),
            ExpiryClockTolerance = TimeSpan.FromMinutes(1),
            TrustedAudiences = { expectedAudience },
            TrustedIssuers = { "https://cloud.google.com/iap" },
            CertificatesUrl = GoogleAuthConsts.IapKeySetUrl,
        };

        return await JsonWebSignature.VerifySignedTokenAsync(signedJwt, options, cancellationToken: cancellationToken);
    }
}

Go

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

import (
	"context"
	"fmt"
	"io"

	"google.golang.org/api/idtoken"
)

// validateJWTFromAppEngine validates a JWT found in the
// "x-goog-iap-jwt-assertion" header.
func validateJWTFromAppEngine(w io.Writer, iapJWT, projectNumber, projectID string) error {
	// iapJWT := "YmFzZQ==.ZW5jb2RlZA==.and0" // req.Header.Get("X-Goog-IAP-JWT-Assertion")
	// projectNumber := "123456789"
	// projectID := "your-project-id"
	ctx := context.Background()
	aud := fmt.Sprintf("/projects/%s/apps/%s", projectNumber, projectID)

	payload, err := idtoken.Validate(ctx, iapJWT, aud)
	if err != nil {
		return fmt.Errorf("idtoken.Validate: %w", err)
	}

	// payload contains the JWT claims for further inspection or validation
	fmt.Fprintf(w, "payload: %v", payload)

	return nil
}

// validateJWTFromComputeEngine validates a JWT found in the
// "x-goog-iap-jwt-assertion" header.
func validateJWTFromComputeEngine(w io.Writer, iapJWT, projectNumber, backendServiceID string) error {
	// iapJWT := "YmFzZQ==.ZW5jb2RlZA==.and0" // req.Header.Get("X-Goog-IAP-JWT-Assertion")
	// projectNumber := "123456789"
	// backendServiceID := "backend-service-id"
	ctx := context.Background()
	aud := fmt.Sprintf("/projects/%s/global/backendServices/%s", projectNumber, backendServiceID)

	payload, err := idtoken.Validate(ctx, iapJWT, aud)
	if err != nil {
		return fmt.Errorf("idtoken.Validate: %w", err)
	}

	// payload contains the JWT claims for further inspection or validation
	fmt.Fprintf(w, "payload: %v", payload)

	return nil
}

Java

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.


import com.google.api.client.http.HttpRequest;
import com.google.api.client.json.webtoken.JsonWebToken;
import com.google.auth.oauth2.TokenVerifier;

/** Verify IAP authorization JWT token in incoming request. */
public class VerifyIapRequestHeader {

  private static final String IAP_ISSUER_URL = "https://cloud.google.com/iap";

  // Verify jwt tokens addressed to IAP protected resources on App Engine.
  // The project *number* for your Google Cloud project via 'gcloud projects describe $PROJECT_ID'
  // The project *number* can also be retrieved from the Project Info card in Cloud Console.
  // projectId is The project *ID* for your Google Cloud Project.
  boolean verifyJwtForAppEngine(HttpRequest request, long projectNumber, String projectId)
      throws Exception {
    // Check for iap jwt header in incoming request
    String jwt = request.getHeaders().getFirstHeaderStringValue("x-goog-iap-jwt-assertion");
    if (jwt == null) {
      return false;
    }
    return verifyJwt(
        jwt,
        String.format("/projects/%s/apps/%s", Long.toUnsignedString(projectNumber), projectId));
  }

  boolean verifyJwtForComputeEngine(HttpRequest request, long projectNumber, long backendServiceId)
      throws Exception {
    // Check for iap jwt header in incoming request
    String jwtToken = request.getHeaders().getFirstHeaderStringValue("x-goog-iap-jwt-assertion");
    if (jwtToken == null) {
      return false;
    }
    return verifyJwt(
        jwtToken,
        String.format(
            "/projects/%s/global/backendServices/%s",
            Long.toUnsignedString(projectNumber), Long.toUnsignedString(backendServiceId)));
  }

  private boolean verifyJwt(String jwtToken, String expectedAudience) {
    TokenVerifier tokenVerifier =
        TokenVerifier.newBuilder().setAudience(expectedAudience).setIssuer(IAP_ISSUER_URL).build();
    try {
      JsonWebToken jsonWebToken = tokenVerifier.verify(jwtToken);

      // Verify that the token contain subject and email claims
      JsonWebToken.Payload payload = jsonWebToken.getPayload();
      return payload.getSubject() != null && payload.get("email") != null;
    } catch (TokenVerifier.VerificationException e) {
      System.out.println(e.getMessage());
      return false;
    }
  }
}

Node.js

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const iapJwt = 'SOME_ID_TOKEN'; // JWT from the "x-goog-iap-jwt-assertion" header

let expectedAudience = null;
if (projectNumber && projectId) {
  // Expected Audience for App Engine.
  expectedAudience = `/projects/${projectNumber}/apps/${projectId}`;
} else if (projectNumber && backendServiceId) {
  // Expected Audience for Compute Engine
  expectedAudience = `/projects/${projectNumber}/global/backendServices/${backendServiceId}`;
}

const oAuth2Client = new OAuth2Client();

async function verify() {
  // Verify the id_token, and access the claims.
  const response = await oAuth2Client.getIapPublicKeys();
  const ticket = await oAuth2Client.verifySignedJwtWithCertsAsync(
    iapJwt,
    response.pubkeys,
    expectedAudience,
    ['https://cloud.google.com/iap']
  );
  // Print out the info contained in the IAP ID token
  console.log(ticket);
}

verify().catch(console.error);

PHP

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

namespace Google\Cloud\Samples\Iap;

# Imports Google auth libraries for IAP validation
use Google\Auth\AccessToken;

/**
 * Validate a JWT passed to your App Engine app by Identity-Aware Proxy.
 *
 * @param string $iapJwt The contents of the X-Goog-IAP-JWT-Assertion header.
 * @param string $cloudProjectNumber The project *number* for your Google
 *     Cloud project. This is returned by 'gcloud projects describe $PROJECT_ID',
 *     or in the Project Info card in Cloud Console.
 * @param string $cloudProjectId Your Google Cloud Project ID.
 */
function validate_jwt_from_app_engine(
    string $iapJwt,
    string $cloudProjectNumber,
    string $cloudProjectId
): void {
    $expectedAudience = sprintf(
        '/projects/%s/apps/%s',
        $cloudProjectNumber,
        $cloudProjectId
    );
    validate_jwt($iapJwt, $expectedAudience);
}

/**
 * Validate a JWT passed to your Compute / Container Engine app by Identity-Aware Proxy.
 *
 * @param string $iapJwt The contents of the X-Goog-IAP-JWT-Assertion header.
 * @param string $cloudProjectNumber The project *number* for your Google
 *     Cloud project. This is returned by 'gcloud projects describe $PROJECT_ID',
 *     or in the Project Info card in Cloud Console.
 * @param string $backendServiceId The ID of the backend service used to access the
 *     application. See https://cloud.google.com/iap/docs/signed-headers-howto
 *     for details on how to get this value.
 */
function validate_jwt_from_compute_engine(
    string $iapJwt,
    string $cloudProjectNumber,
    string $backendServiceId
): void {
    $expectedAudience = sprintf(
        '/projects/%s/global/backendServices/%s',
        $cloudProjectNumber,
        $backendServiceId
    );
    validate_jwt($iapJwt, $expectedAudience);
}

/**
 * Validate a JWT passed to your app by Identity-Aware Proxy.
 *
 * @param string $iapJwt The contents of the X-Goog-IAP-JWT-Assertion header.
 * @param string $expectedAudience The expected audience of the JWT with the following formats:
 *     App Engine:     /projects/{PROJECT_NUMBER}/apps/{PROJECT_ID}
 *     Compute Engine: /projects/{PROJECT_NUMBER}/global/backendServices/{BACKEND_SERVICE_ID}
 */
function validate_jwt(string $iapJwt, string $expectedAudience): void
{
    // Validate the signature using the IAP cert URL.
    $token = new AccessToken();
    $jwt = $token->verify($iapJwt, [
        'certsLocation' => AccessToken::IAP_CERT_URL
    ]);

    if (!$jwt) {
        print('Failed to validate JWT: Invalid JWT');
        return;
    }

    // Validate token by checking issuer and audience fields.
    assert($jwt['iss'] == 'https://cloud.google.com/iap');
    assert($jwt['aud'] == $expectedAudience);

    print('Printing user identity information from ID token payload:');
    printf('sub: %s', $jwt['sub']);
    printf('email: %s', $jwt['email']);
}

Python

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

from google.auth.transport import requests
from google.oauth2 import id_token


def validate_iap_jwt(iap_jwt, expected_audience):
    """Validate an IAP JWT.

    Args:
      iap_jwt: The contents of the X-Goog-IAP-JWT-Assertion header.
      expected_audience: The Signed Header JWT audience. See
          https://cloud.google.com/iap/docs/signed-headers-howto
          for details on how to get this value.

    Returns:
      (user_id, user_email, error_str).
    """

    try:
        decoded_jwt = id_token.verify_token(
            iap_jwt,
            requests.Request(),
            audience=expected_audience,
            certs_url="https://www.gstatic.com/iap/verify/public_key",
        )
        return (decoded_jwt["sub"], decoded_jwt["email"], "")
    except Exception as e:
        return (None, None, f"**ERROR: JWT validation error {e}**")

Ruby

Richten Sie zur Authentifizierung bei IAP die Standardanmeldedaten für Anwendungen ein. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

# iap_jwt = "The contents of the X-Goog-Iap-Jwt-Assertion header"
# project_number = "The project *number* for your Google Cloud project"
# project_id = "Your Google Cloud project ID"
# backend_service_id = "Your Compute Engine backend service ID"
require "googleauth"

audience = nil
if project_number && project_id
  # Expected audience for App Engine
  audience = "/projects/#{project_number}/apps/#{project_id}"
elsif project_number && backend_service_id
  # Expected audience for Compute Engine
  audience = "/projects/#{project_number}/global/backendServices/#{backend_service_id}"
end

# The client ID as the target audience for IAP
payload = Google::Auth::IDTokens.verify_iap iap_jwt, aud: audience

puts payload

if audience.nil?
  puts "Audience not verified! Supply a project_number and project_id to verify"
end

Nächste Schritte

Informationen zum Suchen und Filtern von Codebeispielen für andere Google Cloud-Produkte finden Sie im Google Cloud-Beispielbrowser.