Authentication and Authorization

This page is only for customers with a previous Maps APIs for Work or Maps API for Business license. This page is not applicable to customers with the new Google Maps APIs Premium Plan, which became available in January 2016.

Client IDs and signatures

For Google Maps APIs for Work customers, the image APIs (Maps Static API and Street View API) accept a client ID and unique signature for authentication.

Client ID and signature

When using the image APIs with a Google Maps APIs for Work license, two authentication parameters are required in addition to the standard parameters:

  • Your client ID. To access the special features of Google Maps APIs for Work, you must provide a client ID when accessing any of the API libraries or services. When registering for Google Maps APIs for Work, you will receive this client ID from the Google Cloud Support Portal. All client IDs begin with a gme- prefix. Pass your client ID as the value of the client parameter.

  • A unique signature, generated using your private cryptographic key. Pass this signature as the value of the signature parameter. You can find more information about generating a signature below, in the section on digital signatures.

Maps Static API:

    <img src="https://maps.googleapis.com/maps/api/staticmap
      ?center=-15.800513,-47.91378
      &zoom=11
      &size=300x300
      &client=YOUR_CLIENT_ID
      &signature=SIGNATURE">

Street View API:

    <img src="https://maps.googleapis.com/maps/api/streetview
      ?location=40.720032,-73.988354
      &size=400x400
      &fov=90&heading=235&pitch=10
      &client=YOUR_CLIENT_ID
      &signature=SIGNATURE">

You must not include a key parameter in your request.

Digital signatures, for Google Maps APIs for Work customers

Requests to the image APIs by Google Maps APIs for Work customers require a digital signature, generated using the private cryptographic key provided to you in your welcome email.

The signing process combines a URL and the key together using an encryption algorithm. The resulting unique signature allows our servers to verify that any site generating requests using your client ID are authorized to do so. The signature is also unique per URL, ensuring that requests that use your client ID cannot be modified without requiring a new signature to be generated.

Your private cryptographic key

Your private cryptographic URL-signing key will be issued with your client ID and is a "secret shared key" between you and Google. This signing key is yours alone and is unique to your client ID. For that reason, please keep your signing key secure. This key should not be passed within any requests, stored on any websites, or posted to any public forum. Anyone obtaining this signing key could spoof requests using your identity.

Note: This private cryptographic signing key is not the same as the API keys issued by the Google Cloud Platform Console.

If you've lost your private cryptographic key, log in to the Google Cloud Support Portal and click Maps: Manage Client ID to retrieve it.

Generate a digital signature

Attempting to access the image APIs with an invalid signature will result in a HTTP 403 (Forbidden) error. As you convert your applications to use URL signing, make sure to test your signatures to ensure they initiate a valid request. You should first test whether the original URL is valid as well as test whether you generate the correct signatures.

Follow these steps to create a digital signature for your request:

  1. Construct the request URL without the signature, making sure to include your client parameter. Note that any non-standard characters will need to be URL-encoded:

    Maps Static API: https://maps.googleapis.com/maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&client=clientID

    Street View API: https://maps.googleapis.com/maps/api/streetview?location=41.403609,2.174448&size=456x456&client=clientID

    Note: All Google services require UTF-8 character encoding (which implicitly includes ASCII). If your applications operate using other character sets, make sure they construct URLs using UTF-8 and properly URL-encode them.

  2. Strip off the domain portion of the request, leaving only the path and the query:

    Maps Static API: /maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&client=clientID

    Street View API: /maps/api/streetview?location=41.403609,2.174448&size=456x456&client=clientID

  3. Retrieve your private key, which is encoded in a modified Base64 for URLs, and sign the URL above using the HMAC-SHA1 algorithm. You may need to decode this key into its original binary format. Note that in most cryptographic libraries, the resulting signature will be in binary format.

    Note: Modified Base64 for URLs replaces the + and / characters of standard Base64 with - and _ respectively, so that these Base64 signatures no longer need to be URL-encoded.

  4. Encode the resulting binary signature using the modified Base64 for URLs to convert this signature into something that can be passed within a URL.

  5. Attach this signature to the URL within a signature parameter:

    Maps Static API:https://maps.googleapis.com/maps/api/staticmap?center=40.714%2c%20-73.998&zoom=12&size=400x400&client=clientID&signature=base64signature

    Street View API:https://maps.googleapis.com/maps/api/streetview?location=41.403609,2.174448&size=456x456&client=clientID&signature=base64signature

For samples showing ways to implement URL signing using server-side code, see Sample code for URL signing.

Sample code for URL signing

The following sections show ways to implement URL signing using server-side code. URLs should always be signed server-side to avoid exposing your cryptographic key to users.

Python

The example below uses standard Python libraries to sign a URL. (Download the code.)

#!/usr/bin/python
# -*- coding: utf-8 -*-
""" Signs a URL using a URL signing secret """

import hashlib
import hmac
import base64
import urlparse

def sign_url(input_url=None, secret=None):
  """ Sign a request URL with a URL signing secret.

      Usage:
      from urlsigner import sign_url

      signed_url = sign_url(input_url=my_url, secret=SECRET)

      Args:
      input_url - The URL to sign
      secret    - Your URL signing secret

      Returns:
      The signed request URL
  """

  if not input_url or not secret:
    raise Exception("Both input_url and secret are required")

  url = urlparse.urlparse(input_url)

  # We only need to sign the path+query part of the string
  url_to_sign = url.path + "?" + url.query

  # Decode the private key into its binary format
  # We need to decode the URL-encoded private key
  decoded_key = base64.urlsafe_b64decode(secret)

  # Create a signature using the private key and the URL-encoded
  # string using HMAC SHA1. This signature will be binary.
  signature = hmac.new(decoded_key, url_to_sign, hashlib.sha1)

  # Encode the binary signature into base64 for use within a URL
  encoded_signature = base64.urlsafe_b64encode(signature.digest())

  original_url = url.scheme + "://" + url.netloc + url.path + "?" + url.query

  # Return signed URL
  return original_url + "&signature=" + encoded_signature

if __name__ == "__main__":
  input_url = raw_input("URL to Sign: ")
  secret = raw_input("URL signing secret: ")
  print "Signed URL: " + sign_url(input_url, secret)

Java

The example below uses the java.util.Base64 class available since JDK 1.8 - older versions may need to use Apache Commons or similar. (Download the code.)

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;  // JDK 1.8 only - older versions may need to use Apache Commons or similar.
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.net.URL;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class UrlSigner {

  // Note: Generally, you should store your private key someplace safe
  // and read them into your code

  private static String keyString = "YOUR_PRIVATE_KEY";
  
  // The URL shown in these examples is a static URL which should already
  // be URL-encoded. In practice, you will likely have code
  // which assembles your URL from user or web service input
  // and plugs those values into its parameters.
  private static String urlString = "YOUR_URL_TO_SIGN";

  // This variable stores the binary key, which is computed from the string (Base64) key
  private static byte[] key;
  
  public static void main(String[] args) throws IOException,
    InvalidKeyException, NoSuchAlgorithmException, URISyntaxException {
    
    BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
    
    String inputUrl, inputKey = null;

    // For testing purposes, allow user input for the URL.
    // If no input is entered, use the static URL defined above.    
    System.out.println("Enter the URL (must be URL-encoded) to sign: ");
    inputUrl = input.readLine();
    if (inputUrl.equals("")) {
      inputUrl = urlString;
    }
    
    // Convert the string to a URL so we can parse it
    URL url = new URL(inputUrl);
 
    // For testing purposes, allow user input for the private key.
    // If no input is entered, use the static key defined above.   
    System.out.println("Enter the Private key to sign the URL: ");
    inputKey = input.readLine();
    if (inputKey.equals("")) {
      inputKey = keyString;
    }
    
    UrlSigner signer = new UrlSigner(inputKey);
    String request = signer.signRequest(url.getPath(),url.getQuery());
    
    System.out.println("Signed URL :" + url.getProtocol() + "://" + url.getHost() + request);
  }
  
  public UrlSigner(String keyString) throws IOException {
    // Convert the key from 'web safe' base 64 to binary
    keyString = keyString.replace('-', '+');
    keyString = keyString.replace('_', '/');
    System.out.println("Key: " + keyString);
    // Base64 is JDK 1.8 only - older versions may need to use Apache Commons or similar.
    this.key = Base64.getDecoder().decode(keyString);
  }

  public String signRequest(String path, String query) throws NoSuchAlgorithmException,
    InvalidKeyException, UnsupportedEncodingException, URISyntaxException {
    
    // Retrieve the proper URL components to sign
    String resource = path + '?' + query;
    
    // Get an HMAC-SHA1 signing key from the raw key bytes
    SecretKeySpec sha1Key = new SecretKeySpec(key, "HmacSHA1");

    // Get an HMAC-SHA1 Mac instance and initialize it with the HMAC-SHA1 key
    Mac mac = Mac.getInstance("HmacSHA1");
    mac.init(sha1Key);

    // compute the binary signature for the request
    byte[] sigBytes = mac.doFinal(resource.getBytes());

    // base 64 encode the binary signature
    // Base64 is JDK 1.8 only - older versions may need to use Apache Commons or similar.
    String signature = Base64.getEncoder().encodeToString(sigBytes);
    
    // convert the signature to 'web safe' base 64
    signature = signature.replace('+', '-');
    signature = signature.replace('/', '_');
    
    return resource + "&signature=" + signature;
  }
}

Node JS

The example below uses native Node modules to sign a URL. (Download the code.)

'use strict'

const crypto = require('crypto');
const url = require('url');

/**
 * Convert from 'web safe' base64 to true base64.
 *
 * @param  {string} safeEncodedString The code you want to translate
 *                                    from a web safe form.
 * @return {string}
 */
function removeWebSafe(safeEncodedString) {
  return safeEncodedString.replace(/-/g, '+').replace(/_/g, '/');
}

/**
 * Convert from true base64 to 'web safe' base64
 *
 * @param  {string} encodedString The code you want to translate to a
 *                                web safe form.
 * @return {string}
 */
function makeWebSafe(encodedString) {
  return encodedString.replace(/\+/g, '-').replace(/\//g, '_');
}

/**
 * Takes a base64 code and decodes it.
 *
 * @param  {string} code The encoded data.
 * @return {string}
 */
function decodeBase64Hash(code) {
  // "new Buffer(...)" is deprecated. Use Buffer.from if it exists.
  return Buffer.from ? Buffer.from(code, 'base64') : new Buffer(code, 'base64');
}

/**
 * Takes a key and signs the data with it.
 *
 * @param  {string} key  Your unique secret key.
 * @param  {string} data The url to sign.
 * @return {string}
 */
function encodeBase64Hash(key, data) {
  return crypto.createHmac('sha1', key).update(data).digest('base64');
}

/**
 * Sign a URL using a secret key.
 *
 * @param  {string} path   The url you want to sign.
 * @param  {string} secret Your unique secret key.
 * @return {string}
 */
function sign(path, secret) {
  const uri = url.parse(path);
  const safeSecret = decodeBase64Hash(removeWebSafe(secret));
  const hashedSignature = makeWebSafe(encodeBase64Hash(safeSecret, uri.path));
  return url.format(uri) + '&signature=' + hashedSignature;
}

C#

The example below uses the default System.Security.Cryptography library to sign a URL request. Note that we need to convert the default Base64 encoding to implement a URL-safe version. (Download the code.)

using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;

namespace SignUrl {

  public struct GoogleSignedUrl {

    public static string Sign(string url, string keyString) {
      ASCIIEncoding encoding = new ASCIIEncoding();

      // converting key to bytes will throw an exception, need to replace '-' and '_' characters first.
      string usablePrivateKey = keyString.Replace("-", "+").Replace("_", "/");
      byte[] privateKeyBytes = Convert.FromBase64String(usablePrivateKey);

      Uri uri = new Uri(url);
      byte[] encodedPathAndQueryBytes = encoding.GetBytes(uri.LocalPath + uri.Query);

      // compute the hash
      HMACSHA1 algorithm = new HMACSHA1(privateKeyBytes);
      byte[] hash = algorithm.ComputeHash(encodedPathAndQueryBytes);

      // convert the bytes to string and make url-safe by replacing '+' and '/' characters
      string signature = Convert.ToBase64String(hash).Replace("+", "-").Replace("/", "_");
            
      // Add the signature to the existing URI.
      return uri.Scheme+"://"+uri.Host+uri.LocalPath + uri.Query +"&signature=" + signature;
    }
  }

  class Program {

    static void Main() {
    
      // Note: Generally, you should store your private key someplace safe
      // and read them into your code

      const string keyString = "YOUR_PRIVATE_KEY";
  
      // The URL shown in these examples is a static URL which should already
      // be URL-encoded. In practice, you will likely have code
      // which assembles your URL from user or web service input
      // and plugs those values into its parameters.
      const  string urlString = "YOUR_URL_TO_SIGN";
      
      string inputUrl = null;
      string inputKey = null;
    
      Console.WriteLine("Enter the URL (must be URL-encoded) to sign: ");
      inputUrl = Console.ReadLine();
      if (inputUrl.Length == 0) {
        inputUrl = urlString;
      }     
    
      Console.WriteLine("Enter the Private key to sign the URL: ");
      inputKey = Console.ReadLine();
      if (inputKey.Length == 0) {
        inputKey = keyString;
      }
      
      Console.WriteLine(GoogleSignedUrl.Sign(inputUrl,inputKey));
    }
  }
}

Troubleshooting authentication issues

If your request is malformed or supplies an invalid signature, the image API returns an HTTP 403 (Forbidden) error.

To troubleshoot individual URLs, you can use the URL Signing Debugger. It allows you to quickly validate a URL and signature generated by your application.

Alternatively, Google Maps APIs for Work customers can troubleshoot individual URLs by logging in to the Google Cloud Support Portal and selecting Resources > Google Maps APIs for Work online tools > URL Signing Debugger for Web Service and Image APIs.