ConnectionKit and SFTP: How to authenticate CK2FileManager - objective-c

Question

For my Mac OS X Cocoa app, I am trying to
connect to a SFTP server that only accepts username/password credentials
get the contents of a remote directory
upload files
and find it surprisingly complicated.
After trying ConnectionKit (nearly no documentation), NMSSH (crashed once too often with simultaneous uploads), rsync (not supported by the server), sftp (needs key authentication if scripted, doesn't work with username/password), I am now back to ConnectionKit: https://github.com/karelia/ConnectionKit
However, I am struggling with the authentication challenge, as I don’t know what to do with my credential in the delegate method.
I downloaded and compiled ConnectionKit (apparently version 2).
I am trying to use CK2FileManager as the Readme indicates (is this the right approach at all? Or should I use the libssh2_sftp-Cocoa-wrapper instead?… however I had troubles with libssh2 blocking methods in NMSSH before)
I am successfully setting up my connection URL and
my delegates' -didReceiveAuthenticationChallenge is called
But this is where I struggle: I know how to create a NSURLCredential, however, I can’t figure out what to do with it =>
- (void)fileManager:(CK2FileManager *)manager
didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
NSURLCredential *credentials = [NSURLCredential
credentialWithUser:self.username
password:[self getPassword]
persistence:NSURLCredentialPersistenceForSession];
// what to do now?
// [manager useCredential:] doesn’t exist, nor is there a manager.connection?
// ...
}
I already read the header, I searched the archives of this list, but all answers seem to be outdated.
I also searched Google, Bing and StackOverflow and found one promising example from 2011 using CKFTPConnection, which doesn’t seem to be included in the current framework anymore.
Thanks so much for any pointer to the right direction.
tl;dr
I don't know how to respond to ConnectionKit's CK2FileManager authenticationChallenge:
see the comment in the code example

Answer 1

For CK2:
- (void)listDirectoryAtPath:(NSString *)path
{
// path is here #"download"
NSURL *ftpServer = [NSURL URLWithString:#"sftp://companyname.topLevelDomain"];
NSURL *directory = [CK2FileManager URLWithPath:path isDirectory:YES hostURL:ftpServer];
CK2FileManager *fileManager = [[CK2FileManager alloc] init];
fileManager.delegate = self;
[fileManager contentsOfDirectoryAtURL:directory
includingPropertiesForKeys:nil
options:NSDirectoryEnumerationSkipsHiddenFiles
completionHandler:^(NSArray *contents, NSError *error) {
if (!error) {
NSLog(#"%#", contents);
} else {
NSLog(#"ERROR: %#", error.localizedDescription);
}
}];
}
and than you have to implement the following protocol
- (void)fileManager:(CK2FileManager *)manager operation:(CK2FileOperation *)operation
didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
completionHandler:(void (^)(CK2AuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler
{
if (![challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodDefault]) {
completionHandler(CK2AuthChallengePerformDefaultHandling, nil);
return;
}
NSString * username = #"<username>";
NSString * pathToPrivateSSHKey = #"</Users/myNameOnLocalMaschine/.ssh/id_rsa>"
NSURLCredential *cred = [NSURLCredential ck2_credentialWithUser:username
publicKeyURL:nil
privateKeyURL:[NSURL fileURLWithPath:pathToPrivateSSHKey]
password:nil
persistence:NSURLCredentialPersistenceForSession];
completionHandler(CK2AuthChallengeUseCredential, cred);
}
That's it.
Call -listDirectoryAtPath: and then you will get in the Completion Handler Block in contents array all the files located on the given path :)

Answer 2

Okay, that was easy and I could have found out that on my own; just for the reference: [[challenge sender] useCredential:credentials forAuthenticationChallenge:challenge];
Sorry to reward myself for my own question, but maybe this code snippet helps filling the missing docs, this is how I connect to my SFTP server with ConnectionKit:
- (void)connectWithCompletionBlock:(void (^)(void))completionBlock {
if(!self.cFileManager) {
self.cFileManager = [[CK2FileManager alloc] init];
self.cFileManager.delegate = self;
}
NSURL *sftpServer = [NSURL URLWithString:[#"sftp://" stringByAppendingString:self.server]];
self.remoteFolder = [CK2FileManager URLWithPath:self.remotePath relativeToURL:sftpServer];
// try to get the contents of the current directory
[self.cFileManager contentsOfDirectoryAtURL:self.remoteFolder
includingPropertiesForKeys:nil
options:NSDirectoryEnumerationSkipsHiddenFiles
completionHandler:^(NSArray *contents, NSError *error)
{
NSLog(#"remote folder contents: \n%#", contents);
// invoke completion block
completionBlock();
}];
}
- (void)fileManager:(CK2FileManager *)manager
didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
NSURLCredential *credentials = [NSURLCredential
credentialWithUser:self.username
password:[self getPassword]
persistence:NSURLCredentialPersistenceForSession];
[[challenge sender] useCredential:credentials forAuthenticationChallenge:challenge]
}