Base64 API Signature in iOS - ios

Question

For Single Platform Integration i need to create a Base64 Signature https://singleplatform.jira.com/wiki/display/PubDocs/SinglePlatform+Publisher+Integration#SinglePlatformPublisherIntegration-BuildingValidURLs
here is ruby script to create Base64 Signature, which work now i want to create it in iOS.
require 'hmac-sha1'
require 'base64'
def make_signature(uri_path, params, client_id, secret)
padding_factor = (4 - secret.length % 4) % 4
secret += "=" * padding_factor
secret = secret.gsub(/[-_]/, {"-" => "+", "_" => "/"})
binary_key = Base64.decode64(secret)
params.update({"client" => client_id})
path = uri_path + "?" + params.collect{|k,v| "#{k}=#{v}"}.inject{|initial,cur| initial + "&" + cur}
digest = HMAC::SHA1.new(binary_key).update(path).digest
digest = Base64.encode64(digest).gsub(/[+\/]/, {"+" => "-", "/" => "_"}).delete("=")
return "#{path}&sig=#{digest}"
end
puts 'http://api.singleplatform.co' + make_signature('/locations/haru-7', {}, "YOUR CLIENT ID", "YOUR SECRET")
What I have tried
I have tried https://github.com/MealCatcher/objc-singleplatform it not working.
I have also tried Base64 & iOS 7 CommonHMAC.h framework.
//To HMAC-SHA1 Signing
static NSData *HMAC_SHA1(NSString *data, NSString *key) {
unsigned char buf[CC_SHA1_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA1, [key UTF8String], [key length], [data UTF8String], [data length], buf);
return [NSData dataWithBytes:buf length:CC_SHA1_DIGEST_LENGTH];
}
//To Retrieve your private key For URL
NSString *uri_path = [NSString stringWithFormat:#"%#?client=%#",#"/locations/haru-7",#"clientID"];
NSMutableString *secret = [NSMutableString stringWithFormat:#"%#=",signingKey];
[secret stringByReplacingOccurrencesOfString:#"-" withString:#"+"];
[secret stringByReplacingOccurrencesOfString:#"_" withString:#"/"];
NSData *signature = HMAC_SHA1(uri_path, [secret base64DecodedString]);
NSString *base64Signature = [signature base64EncodedString];
[base64Signature stringByReplacingOccurrencesOfString:#"+" withString:#"-"];
[base64Signature stringByReplacingOccurrencesOfString:#"/" withString:#"_"];
Thanks in advance.
Full Solution:
https://github.com/ronakjangir47/SinglePlatformSignature

Answer 1

Here is an example as Objective-C methods. Note the separation of tasks into individual methods, each can be easily written & tested individually.
- (NSString *)signatureBase64 {
NSString *uri_path = [NSString stringWithFormat:#"%#?client=%#",#"/locations/haru-7",#"clientID"];
NSData *signature = [uri_path dataUsingEncoding:NSUTF8StringEncoding];
NSLog(#"signature Data: %#", signature);
NSString *signingKeyBase64 = #"c2lnbmluZ0tleQ==";
NSData *signingKey = [self decodeURLBase64String:signingKeyBase64];
NSLog(#"signingKey Data: %#", signingKey);
NSLog(#"signingKeyAscii: '%#'", [[NSString alloc] initWithData:signingKey encoding:NSUTF8StringEncoding]);
NSData *digest = [self hmacSha1:signature key:signingKey];
NSLog(#"digest Data: %#", digest);
NSString *signatureBase64 = [self encodeURLBase64Data:digest];
NSLog(#"signatureBase64: '%#'", signatureBase64);
return signatureBase64;
}
- (NSData *)decodeURLBase64String:(NSString *)string {
string = [string stringByReplacingOccurrencesOfString:#"-" withString:#"+"];
string = [string stringByReplacingOccurrencesOfString:#"_" withString:#"/"];
NSData *data = [[NSData alloc] initWithBase64Encoding:string];
return data;
}
- (NSString *)encodeURLBase64Data:(NSData *)data {
NSString *signatureBase64 = [data base64EncodedStringWithOptions:0];
signatureBase64 = [signatureBase64 stringByReplacingOccurrencesOfString:#"+" withString:#"-"];
signatureBase64 = [signatureBase64 stringByReplacingOccurrencesOfString:#"?" withString:#"_"];
return signatureBase64;
}
// Note there is no intermediate buffer, this is a simple pattern.
- (NSData *)hmacSha1:(NSData *)data key:(NSData *)key {
NSMutableData *hmac = [NSMutableData dataWithLength:CC_SHA1_DIGEST_LENGTH];
CCHmac( kCCHmacAlgSHA1,
key.bytes, key.length,
data.bytes, data.length,
hmac.mutableBytes);
return hmac;
}
NSLog output:
signatureData: <2f6c6f63 6174696f 6e732f68 6172752d 373f636c 69656e74 3d636c69 656e7449 44>
signingKeyBase64: 'c2lnbmluZ0tleQ=='
signingKey Data: <7369676e 696e674b 6579>
signingKeyAscii: 'signingKey'
digest Data: <8e4b88b6 111e3151 3b5d35d0 04e60cf9 8a984fb3>
signatureBase64: 'jkuIthEeMVE7XTXQBOYM-YqYT7M='