Google OAuth 2.0 / JWT认证举例(iOS)

Question

我正在构建一个iOS应用程序，需要使用下面链接中概述的OAuth 2.0/JWT工作流与Google进行身份验证。

Google OAuth 2.0 JWT示例

我有私钥文件和client_id。我正在使用谷歌API Objective-C客户端库来尝试和认证。但是，我不知道如何继续。

是否可以使用iOS客户端库进行此身份验证工作流?

Answer 1

我刚刚完成了类似你的问题。我需要使用JWT将数据发布到GCP IoT。以下是我使用RSAWithSHA256所做的:

使用MIHCrypto库(在Podfile pod "MIHCrypto"， "~> 0.4.1")

#import "MIHAESKeyFactory.h"
#import "MIHRSAPrivateKey.h"

  (void) createJWT {
  NSMutableDictionary *headerDict = [NSMutableDictionary new];
  headerDict[@"alg"] = @"RS256";
  headerDict[@"typ"] = @"JWT";
  NSMutableDictionary *payloadDict = [NSMutableDictionary new];
  payloadDict[@"aud"] = @"my project";
  NSDate *now = [NSDate new];
  payloadDict[@"iat"] = [NSNumber numberWithInt:[now timeIntervalSince1970]];
  payloadDict[@"exp"] = [NSNumber numberWithInt:[now timeIntervalSince1970] + 20 * 60];
  NSError *error;
  NSData *headerData = [NSJSONSerialization dataWithJSONObject:headerDict
                                                       options:NSJSONWritingPrettyPrinted
                                                         error:&error];

  NSData *payloadData = [NSJSONSerialization dataWithJSONObject:payloadDict
                                                        options:NSJSONWritingPrettyPrinted
                                                          error:&error];

  NSString *base64UrlMessage = [NSString stringWithFormat:@"%@.%@", [self base64UrlforData:headerData ], [self base64UrlforData:payloadData]];
  NSData *privateKeyData = [[self pemKeyStringFromFileWithName:@"myPrivateKey" extension:@"pem"] dataUsingEncoding:NSUTF8StringEncoding];
  MIHRSAPrivateKey *privateKey = [[MIHRSAPrivateKey alloc] initWithData:privateKeyData];
  NSError *signingError = nil;
  NSData *signedData = [privateKey signWithSHA256:[base64UrlMessage dataUsingEncoding:NSUTF8StringEncoding] error:&signingError];
  NSString *signedBase64UrlMessage = [self base64UrlforData: signedData];

  NSString *jwt = [NSString stringWithFormat:@"%@.%@", base64UrlMessage, signedBase64UrlMessage];
  NSLog(@"jwt = %@", jwt);
}

 (NSString*)base64UrlforData:(NSData*)data {
  // base64 to base64URL
  // 1 - remove all '='
  // 2 - replace all '+' by '-'
  // 3 - replace all '/' by '_'
  NSString *base64 = [data base64EncodedStringWithOptions:0];
  NSString *base64_1 = [base64 stringByReplacingOccurrencesOfString:@"=" withString:@""];
  NSString *base64_2 = [base64_1 stringByReplacingOccurrencesOfString:@"+" withString:@"-"];
  NSString *base64_3 = [base64_2 stringByReplacingOccurrencesOfString:@"/" withString:@"_"];
  return base64_3;
}
  (NSString *)pemKeyStringFromFileWithName:(NSString *)name extension: (NSString*) extension {
  NSBundle *bundle = [NSBundle mainBundle];
  NSURL *fileURL = [bundle URLForResource:name withExtension:extension];
  NSError *error = nil;
  NSString *fileContent = [NSString stringWithContentsOfURL:fileURL encoding:NSUTF8StringEncoding error:&error];
  if (error) {
    NSLog(@"%@ error: %@", self.debugDescription, error);
    return nil;
  }
  return fileContent;
}