如何通过NSURLConnection从app向web服务器提交带有特殊字符的密码

Question

我必须登录我的网络服务器。一切正常，但没有生成密码，如|％<“> {}¥^〜。我怎么编码这样的密码？

我创建一个用户密码= |％<“> {}¥^〜不起作用（例如像”user1234“这样的密码工作正常）

NSString *userName = self.usernameOutlet.text;
NSString *userPassword = self.passwordOutlet.text;
NSString *escapedString = [self.passwordOutlet.text stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];
userPassword = escapedString;
NSString *post = [NSString stringWithFormat:@"login=%@&password=%@",userName,userPassword];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:@"%lu",(unsigned long)[postData length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:@"http://XXXXXXXX/login"]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];

使用像“user1234”这样的密码我得到一个cookie

密码如“|％<”> {}¥^〜“我没有cookie

我究竟做错了什么？

Answer 1

想要使用URLQueryAllowedCharacterSet很诱人，但这对所有字符串都不起作用。值得注意的是&和+将无法通过。

如果你想知道我们为什么必须逃脱&和+的百分比，那是因为这两个字符在x-www-form-urlencoded请求中具有特殊含义。 &用于在x-www-form-urlencoded请求中分隔键值对，因此它会截断您的密码。并且大多数Web服务将+转换为空间，因此您也希望百分之百逃脱。

所以，让我们首先定义一个可以工作的字符集：

// NSCharacterSet+URLQueryValueAllowed.h

@interface NSCharacterSet (URLQueryValueAllowed)

@property (class, readonly, copy) NSCharacterSet *URLQueryValueAllowedCharacterSet;

@end

和

// NSCharacterSet+URLQueryValueAllowed.m

@implementation NSCharacterSet (URLQueryValueAllowed)

+ (NSCharacterSet *)URLQueryValueAllowedCharacterSet {
    static dispatch_once_t onceToken;
    static NSCharacterSet *queryValueAllowed;
    dispatch_once(&onceToken, ^{
        NSMutableCharacterSet *allowed = [[NSCharacterSet URLQueryAllowedCharacterSet] mutableCopy];
        NSString *generalDelimitersToEncode = @":#[]@";   // does not include "?" or "/" due to RFC 3986 - Section 3.4
        NSString *subDelimitersToEncode = @"!$&'()*+,;=";

        [allowed removeCharactersInString:generalDelimitersToEncode];
        [allowed removeCharactersInString:subDelimitersToEncode];

        queryValueAllowed = [allowed copy];
    });
    return queryValueAllowed;
}

@end

然后，为了让我们的生活更轻松，让我们为编码字典的百分比定义NSDictionary类别：

// NSDictionary+PercentEncoded.h

@interface NSDictionary (PercentEncoded)
- (NSString *)percentEncodedString;
- (NSData *)percentEncodedData;
@end

和

// NSDictionary+PercentEncoded.m

@implementation NSDictionary (PercentEncoded)
- (NSString *)percentEncodedString {
    NSMutableArray<NSString *> *results = [NSMutableArray array];
    NSCharacterSet *allowed = [NSCharacterSet URLQueryValueAllowedCharacterSet];

    for (NSString *key in self.allKeys) {
        NSString *encodedKey = [key stringByAddingPercentEncodingWithAllowedCharacters:allowed];
        NSString *value = [[self objectForKey:key] description];
        NSString *encodedValue = [value stringByAddingPercentEncodingWithAllowedCharacters:allowed];
        [results addObject:[NSString stringWithFormat:@"%@=%@", encodedKey, encodedValue]];
    }
    return [results componentsJoinedByString:@"&"];
}

- (NSData *)percentEncodedData {
    return [[self percentEncodedString] dataUsingEncoding:NSUTF8StringEncoding];
}
@end

然后，您的应用程序代码可以：

NSDictionary *dictionary = @{@"login": userName, @"password": userPassword};
NSData *body = [dictionary percentEncodedData];