libshh2 Password Authentication Error

[jaxian]

Hi. I am trying to connect to a Mac via remote login using only the password for the authentication method on an iPhone. I want to establish a connection to the computer and then authenticate using the password and username. Then if this is successfull, I want the user to be presented with a new UIView where they can execute only one command. Thats it. Now, I used a source somebody made and it works obviously but the password and username authentication has not been implemented. I have been trying to implement it but could not do so. I get so many errors. Heres the code:

//
//  Request.m
//  Port Scanner
//
//  Created by Matthew Wilkinson on 18/11/2009.
//  Copyright 2009 __MyCompanyName__. All rights reserved.
//

#import "Request.h"
#import "Port_ScannerAppDelegate.h"

// SSH Librarys 
#include "libssh2_config.h"
#include "libssh2.h"
#include "libssh2_sftp.h"

#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
# ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>



@implementation Request

@synthesize userName;
@synthesize password;
@synthesize ip;

- (id)initWithUserName:(NSString *)someUserName andPassword:(NSString *)somePassword andIp:(NSString *)someIp {
	[super init];
	self.userName = someUserName;
	self.password = somePassword;
	self.ip = someIp;
	return self;
}


- (void)connect {	
	
	
	Port_ScannerAppDelegate *delegate = (Port_ScannerAppDelegate *)[[UIApplication sharedApplication] delegate];
	
	const char *username = [self.userName UTF8String];
	const char *password = [self.password UTF8String];
	const char *host = [self.ip UTF8String];
	
	unsigned long hostaddr;
	int sock, i, auth_pw = 0;
	struct sockaddr_in sin;
	const char *fingerprint;
	char *userauthlist;
	LIBSSH2_SESSION *session;
	LIBSSH2_CHANNEL *channel;
	hostaddr = inet_addr(host);
	sock = socket(AF_INET, SOCK_STREAM, 0);
	sin.sin_family = AF_INET;
	sin.sin_port = htons(22);
	sin.sin_addr.s_addr = hostaddr;
	
	
	if (connect(sock, (struct sockaddr*)(&sin),
				sizeof(struct sockaddr_in)) != 0) {
		[delegate sendText:@"Connection Failed"];
		
	} 
		
	else { 
		
		/* We could authenticate via password */ 
        if (libssh2_userauth_password(session, username, password)) {
			
            printf("\tAuthentication by password failed!\n");
		
        } else {
            printf("\tAuthentication by password succeeded.\n");
        }
		
	 [delegate sendText:@"Connection to IP success, username/password check not implemented (yet)"]; 
		
	} 
	
	
	NSLog(@"All done!");		
}

@end

The error I get is:

"_libssh2_userauth_password_ex", referenced from:
-[Request connect] in Request.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

Please help!