Objective-C

SSH Public Key Authentication

Demonstrates authenticating with an SSH server using public-key authentication. A private key is loaded into an SshKey object and passed to AuthenticatePk. The matching public key must already be installed on the server for the account.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: Public-key authentication is the standard for unattended and automated SSH: the private key never leaves the client, the server merely trusts the corresponding public key, and no reusable password crosses the wire. SshKey imports several formats — OpenSSH PEM keys via FromOpenSshPrivateKey and PuTTY .ppk files via FromPuttyPrivateKey — encrypted or not. For an encrypted key, set the Password property before importing. Note that LoadText is only a convenience for reading a text file into a string; it does not itself load the key.

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Objective-C

#import <CkoSsh.h>
#import <NSString.h>
#import <CkoSshKey.h>

BOOL success = NO;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  Demonstrates authenticating with an SSH server using public-key authentication.  The matching
//  public key must already be installed on the SSH server for the account.

CkoSsh *ssh = [[CkoSsh alloc] init];

//  Timeouts, in milliseconds.
ssh.ConnectTimeoutMs = [NSNumber numberWithInt:5000];
ssh.ReadTimeoutMs = [NSNumber numberWithInt:15000];

NSString *hostname = @"ssh.example.com";
int port = 22;
success = [ssh Connect: hostname port: [NSNumber numberWithInt: port]];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

//  LoadText is a convenience method that reads any text file into a string.  It does not itself
//  load the key.
CkoSshKey *key = [[CkoSshKey alloc] init];
NSString *privKeyText = [key LoadText: @"qa_data/my_private_key.pem"];
if (key.LastMethodSuccess == NO) {
    NSLog(@"%@",key.LastErrorText);
    return;
}

//  Import the private key.  Both OpenSSH and PuTTY formats are supported, encrypted or not.
//  This example loads an unencrypted OpenSSH-format key; for a PuTTY .ppk file, call
//  FromPuttyPrivateKey instead.  For an encrypted key, set key.Password before importing.
success = [key FromOpenSshPrivateKey: privKeyText];
if (success == NO) {
    NSLog(@"%@",key.LastErrorText);
    return;
}

success = [ssh AuthenticatePk: @"mySshLogin" privateKey: key];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

NSLog(@"%@",@"Public-key authentication successful.");

[ssh Disconnect];