iOS - Auth驗證jwt解析(decode)token原生方法

• 一個方法搞定
• 參數jwtStr是從Auth獲取的token字符串
• 返回內容jsonDict是字典.

-(id)jwtDecodeWithJwtString:(NSString *)jwtStr{

    NSArray * segments = [jwtStr componentsSeparatedByString:@"."];
    NSString * base64String = [segments objectAtIndex:1];
    
    int requiredLength = (int)(4 *ceil((float)[base64String length]/4.0));
    int nbrPaddings = requiredLength - (int)[base64String length];
    if(nbrPaddings > 0){
        NSString * pading = [[NSString string] stringByPaddingToLength:nbrPaddings withString:@"=" startingAtIndex:0];
        base64String = [base64String stringByAppendingString:pading];
    }
    base64String = [base64String stringByReplacingOccurrencesOfString:@"-" withString:@"+"];
    base64String = [base64String stringByReplacingOccurrencesOfString:@"_" withString:@"/"];
    NSData * decodeData = [[NSData alloc] initWithBase64EncodedData:base64String options:0];
    NSString * decodeString = [[NSString alloc] initWithData:decodeData encoding:NSUTF8StringEncoding];
    NSDictionary * jsonDict = [NSJSONSerialization JSONObjectWithData:[decodeString dataUsingEncoding:NSUTF8StringEncoding] options:0 error:nil];
    return jsonDict;
}

參考來源: http://popdevelop.com/2013/12/decode-json-web-token-jwt-in-ios-objective-c/