Send POST request with special characters iOS - ios

Question

My app calls a web service to login. Usually the service works without any problems, but when I've a password with a special characters (example: !*'\"();:#&=+$,/?%#[]%), the web server doesn't allow me to login because on server side I receive the password without special characters for example:
password insert on my app: test+test
password receive to web server: testtest
As you see the request delete the special characters actually I'm sending the login credential by using the following code:
- (id)sendRequestToURL:(NSString *)url withMethod:(NSString *)method withUsername:(NSString*)username withPassword:(NSString*)password andInstallationId:(NSString*)installationId {
NSURL *finalURL = [[NSURL alloc]init];
if ([method isEqualToString:#"POST"]) {
finalURL = [NSURL URLWithString:url];
} else {
NSLog(#"Metodo no previsto");
}
NSString *post = [NSString stringWithFormat:#"username=%#&password=%#&installationId=%#", username, password, installationId];
NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding];
NSString *postLength = [NSString stringWithFormat:#"%lu", (unsigned long)postData.length];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]init];
[request setURL:finalURL];
[request setHTTPMethod:method];
[request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self];
if (connection) {
[connection start];
}
return connection;
}
How I can fix this issue? I looked at the NSString class reference, I saw there's the method - stringByAddingPercentEncodingWithAllowedCharacters: to don't delete the special characters, does anyone know how to use this method? Can you show me a code snippet?
Thank you

Answer 1

I found a way to solve this issue, below is my code, maybe it should be useful for someone:
- (id)sendRequestToURL:(NSString *)url withMethod:(NSString *)method withUsername:(NSString*)username withPassword:(NSString*)password andInstallationId:(NSString*)installationId {
NSURL *finalURL = [[NSURL alloc]init];
if ([method isEqualToString:#"POST"]) {
finalURL = [NSURL URLWithString:url];
} else {
NSLog(#"Metodo no previsto");
}
NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:#"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789"];
NSString *encodedPassword = [password stringByAddingPercentEncodingWithAllowedCharacters:set];
NSString *post = [NSString stringWithFormat:#"username=%#&password=%#&installationId=%#", username, encodedPassword, installationId];
NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding];
NSString *postLength = [NSString stringWithFormat:#"%lu", (unsigned long)postData.length];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]init];
[request setURL:finalURL];
[request setHTTPMethod:method];
[request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self];
if (connection) {
[connection start];
}
return connection;
}
In this way I search in the password string the special characters and if it found it change this character with the percent encoding. In that way I can log in with plain password and with password with special characters. I hope it will be useful for someone.

Answer 2

Just encode every parmeter with the - stringByAddingPercentEscapesUsingEncoding:.
NSString *encodeUsername = [username stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *encodePassword = [password stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *encodeInstallationId = [installationId stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *post = [NSString stringWithFormat:#"username=%#&password=%#&installationId=%#", encodeUsername, encodePassword, ins encodeInstallationId allationId];
And use this encoded paramater in your request.

Answer 3

Url encode your string and POST to web service. Please use below method for url encoding.
+(NSString *) urlencode: (NSString *) str {
NSString * encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(
NULL,
(CFStringRef)str,
NULL,
(CFStringRef)#" ",
kCFStringEncodingUTF8 );
return [encodedString autorelease];
}