NSURLCredentialStorage sharedCredentialStorage does not return valid credential

I have a problem with the sharedCredentialStorage. It won't return the expected credential, even having all parameters of protection space (host, port,...) the same as the one I have set before.

Code to set the defaultCredential:

NSURLCredential* credential = [NSURLCredential credentialWithUser:[self.username text] password:[self.password text] persistence:NSURLCredentialPersistencePermanent];
NSURLProtectionSpace *protectionSpace = [[NSURLProtectionSpace alloc]initWithHost:@"localhost" port:0 protocol:NSURLProtectionSpaceHTTP realm:nil authenticationMethod:NSURLAuthenticationMethodDefault];
[[NSURLCredentialStorage sharedCredentialStorage] setDefaultCredential:credential forProtectionSpace:protectionSpace];

After running this piece of code and going to gdb window, the result for the allCredentials (at sharedCredentialStorage) gives:

(lldb) po [[NSURLCredentialStorage sharedCredentialStorage] allCredentials]
(id) $10 = 0x07546d60 {
    "<NSURLProtectionSpace: 0x7550530>" =     {
        lauro = "<NSURLCredential: 0x7573490>: lauro";
    };
}

That means the credential has been correctly added to the sharedCredentialStorage.

But when the http request operation happens and the authentication challange pops out and this code is ran:

credential = [[NSURLCredentialStorage sharedCredentialStorage] defaultCredentialForProtectionSpace:[challenge protectionSpace]];

Nothing is returned to credential variable. Do you have any clue why is this happening?

The output of the gdb gives:

(lldb) po [[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0]
(id) $13 = 0x0754c1b0 <NSURLProtectionSpace: 0x754c1b0>
(lldb) po [[[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0] host]
// Host for the credential @ sharedCredentialStorage
(id) $14 = 0x0a8b8000 localhost
(lldb) po [[[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0] port]
// Port for the credential @ sharedCredentialStorage (0 matches any)
(id) $15 = 0x00000000 <nil>
(lldb) po [[[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0] realm]
// Realm for the credential @ sharedCredentialStorage (nil matches any)
(id) $16 = 0x00000000 <nil>
(lldb) po [[[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0] authenticationMethod]
// Authentication method for the credential @ sharedCredentialStorage (this gets converted to HTTP basic)
(id) $17 = 0x0159c094 NSURLAuthenticationMethodDefault
(lldb) po [[[[[NSURLCredentialStorage sharedCredentialStorage] allCredentials] allKeys] objectAtIndex:0] protocol]
// Protocol for the credential @ sharedCredentialStorage
(id) $18 = 0x0159b504 http
(lldb) po [[challenge protectionSpace] host]
// Host for the credential @ challange
(id) $19 = 0x0754e6c0 localhost
(lldb) po [[challenge protectionSpace] port]
// Port for the credential @ challange
(id) $20 = 0x00000050 [no Objective-C description available]
// Realm for the credential @ challange
(lldb) po [[challenge protectionSpace] realm]
(id) $21 = 0x01bde844 <object returned empty description>
// Authentication method for the credential @ challange
(lldb) po [[challenge protectionSpace] authenticationMethod]
(id) $22 = 0x0159c094 NSURLAuthenticationMethodDefault

// And finally, the check again to see if we have credentials @ sharedCredentialStorage
(lldb) po [[NSURLCredentialStorage sharedCredentialStorage] allCredentials]
(id) $25 = 0x0756f2b0 {
    "<NSURLProtectionSpace: 0x7574a80>" =     {
        lauro = "<NSURLCredential: 0x7574b00>: lauro";
    };
}

One more thing, even if I use some string for realm (and set it properly also at my REST web service) it does not work.

When you get the challenge the port provided in the protection space is probably 80 (or 443). When you are storing the credential you are giving a port of 0. Set it to the correct port (80 for http, 443 for https, unless you know the server you are connecting to is not using the default ports - your lldv output seems to show port 50?) and try that.