Objective-C

URL Signing for Google Maps API

See more Encryption Examples

Demonstrates how to sign a URL for the Google Maps API. Objective-C

#import <CkoCrypt2.h>
#import <NSString.h>

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];

//  The output will be modified Base64.
//  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.
crypt.EncodingMode = @"modBase64";

//  Set the hash algorithm to sha-1
crypt.HashAlgorithm = @"sha-1";
crypt.MacAlgorithm = @"hmac";

NSString *sig = 0;

//  Set the HMAC key (this is the private key provided by Google)
[crypt SetMacKeyEncoded: @"vNIXE0xscrmjlyV-12Nj_BvUPaw=" encoding: @"modBase64"];

//  Compute the URL signature
sig = [crypt MacStringENC: @"/maps/api/geocode/json?address=New+York&sensor=false&client=clientID"];

//  The result should be KrU1TzVQM7Ur0i8i7K3huiw3MsA=
NSLog(@"%@",sig);