CkoSsh Objective-C Reference Documentation

CkoSsh

A client-side SSH2 implementation for executing commands and shell sessions on Unix/Windows SSH servers.

Properties

@property (nonatomic) BOOL AbortCurrent;

Introduced in version 9.5.0.58

When set to YES, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to NO when the next method is called. When the abort occurs, this property is reset to NO. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

@property (nonatomic, readonly, copy) NSNumber *AuthFailReason;

Introduced in version 9.5.0.52

Set to one of the following values if a call to AuthenticatePw, AuthenticatePk, or AuthenticatePwPk returns a failed status.

  • 1: Transport failure. This is a failure to communicate with the server (i.e. the connection was lost, or a read or write failed or timed out).
  • 2: Invalid key for public key authentication. The key was not a valid format, not a valid key, not a private key, or not the right type of key.
  • 3: No matching authentication methods were available.
  • 4: SSH authentication protocol error - an unexpected or invalid message was received.
  • 5: The incorrect password or private key was provided.
  • 6: Already authenticated. The SSH session is already authenticated.
  • 7: Password change request: The server requires the password to be changed.

@property (nonatomic) BOOL CaretControl;

Introduced in version 9.5.0.49

Controls whether the caret character '^' is interpreted as indicating a control character. The default value of this property is NO. If set to YES, then the following sequences are interpreted as control characters in any string passed to SendReqExec or ChannelSendString.

^@ 	00 	00 	NUL  	Null
^A 	01 	01 	SOH  	Start of Heading
^B 	02 	02 	STX  	Start of Text
^C 	03 	03 	ETX  	End of Text
^D 	04 	04 	EOT  	End of Transmission
^E 	05 	05 	ENQ  	Enquiry
^F 	06 	06 	ACK  	Acknowledge
^G 	07 	07 	BEL  	Bell
^H 	08 	08 	BS  	Backspace
^I 	09 	09 	HT  	Character Tabulation, Horizontal Tabulation
^J 	10 	0A 	LF  	Line Feed
^K 	11 	0B 	VT  	Line Tabulation, Vertical Tabulation
^L 	12 	0C 	FF  	Form Feed
^M 	13 	0D 	CR  	Carriage Return
^N 	14 	0E 	SO  	Shift Out
^O 	15 	0F 	SI  	Shift In
^P 	16 	10 	DLE  	Data Link Escape
^Q 	17 	11 	DC1  	Device Control One (XON)
^R 	18 	12 	DC2  	Device Control Two
^S 	19 	13 	DC3  	Device Control Three (XOFF)
^T 	20 	14 	DC4  	Device Control Four
^U 	21 	15 	NAK  	Negative Acknowledge
^V 	22 	16 	SYN  	Synchronous Idle
^W 	23 	17 	ETB  	End of Transmission Block
^X 	24 	18 	CAN  	Cancel
^Y 	25 	19 	EM  	End of medium
^Z 	26 	1A 	SUB  	Substitute
^[ 	27 	1B 	ESC  	Escape
^\ 	28 	1C 	FS  	File Separator
^] 	29 	1D 	GS  	Group Separator
^^ 	30 	1E 	RS  	Record Separator
^_ 	31 	1F 	US  	Unit Separator
^? 	127 	7F 	DEL  	Delete

@property (nonatomic, readonly, copy) NSNumber *ChannelOpenFailCode;

If a request to open a channel fails, this property contains a code that identifies the reason for failure. The reason codes are defined in RFC 4254 and are reproduced here:

             Symbolic name                           reason code
             -------------                           -----------
            SSH_OPEN_ADMINISTRATIVELY_PROHIBITED          1
            SSH_OPEN_CONNECT_FAILED                       2
            SSH_OPEN_UNKNOWN_CHANNEL_TYPE                 3
            SSH_OPEN_RESOURCE_SHORTAGE                    4

@property (nonatomic, readonly, copy) NSString *ChannelOpenFailReason;

The descriptive text corresponding to the ChannelOpenFailCode property.

@property (nonatomic, copy) NSString *ClientIdentifier;

The client-identifier string to be used when connecting to an SSH/SFTP server. Defaults to "SSH-2.0-PuTTY_Release_0.63". (This string is used to mimic PuTTY because some servers are known to disconnect from clients with unknown client identifiers.)

@property (nonatomic, copy) NSString *ClientIpAddress;

The IP address to use for computers with multiple network interfaces or IP addresses. For computers with a single network interface (i.e. most computers), this property should not be set. For multihoming computers, the default IP address is automatically used if this property is not set.

The IP address is a string such as in dotted notation using numbers, not domain names, such as "165.164.55.124".

@property (nonatomic, copy) NSNumber *ConnectTimeoutMs;

Maximum number of milliseconds to wait when connecting to an SSH server.

@property (nonatomic, copy) NSString *DebugLogFilePath;

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

@property (nonatomic, readonly, copy) NSNumber *DisconnectCode;

If the SSH server sent a DISCONNECT message when closing the connection, this property contains the "reason code" as specified in RFC 4253:

           Symbolic name                                reason code
           -------------                                -----------
      SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT             1
      SSH_DISCONNECT_PROTOCOL_ERROR                          2
      SSH_DISCONNECT_KEY_EXCHANGE_FAILED                     3
      SSH_DISCONNECT_RESERVED                                4
      SSH_DISCONNECT_MAC_ERROR                               5
      SSH_DISCONNECT_COMPRESSION_ERROR                       6
      SSH_DISCONNECT_SERVICE_NOT_AVAILABLE                   7
      SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED          8
      SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE                 9
      SSH_DISCONNECT_CONNECTION_LOST                        10
      SSH_DISCONNECT_BY_APPLICATION                         11
      SSH_DISCONNECT_TOO_MANY_CONNECTIONS                   12
      SSH_DISCONNECT_AUTH_CANCELLED_BY_USER                 13
      SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE         14
      SSH_DISCONNECT_ILLEGAL_USER_NAME                      15

@property (nonatomic, readonly, copy) NSString *DisconnectReason;

If the SSH/ server sent a DISCONNECT message when closing the connection, this property contains a descriptive string for the "reason code" as specified in RFC 4253.

@property (nonatomic) BOOL EnableCompression;

Introduced in version 9.5.0.56

Enables or disables the use of compression w/ the SSH connection. The default value is YES, meaning that compression is used if the server supports it.

Some older SSH servers have been found that claim to support compression, but actually fail when compression is used. PuTTY does not enable compression by default. If trouble is encountered where the SSH server disconnects immediately after the connection is seemingly established (i.e. during authentication), then check to see if disabling compression resolves the problem.

@property (nonatomic, copy) NSString *ForceCipher;

Set to one of the following encryption algorithms to force that cipher to be used. By default, the component will automatically choose the first cipher supported by the server in the order listed here: "aes256-ctr", "aes128-ctr", "aes256-cbc", "aes128-cbc", "twofish256-cbc", "twofish128-cbc", "blowfish-cbc", "3des-cbc", "arcfour128", "arcfour256". (If blowfish is chosen, the encryption strength is 128 bits.)

Important: If this is property is set and the server does NOT support then encryption algorithm, then the Connect will fail.

@property (nonatomic, copy) NSNumber *HeartbeatMs;

This is the number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any SSH operation prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

@property (nonatomic, copy) NSString *HostKeyAlg;

Indicates the preferred host key algorithm to be used in establishing the SSH secure connection. The default is "DSS". It may be changed to "RSA" if needed. Chilkat recommends not changing this unless a problem warrants the change.

@property (nonatomic, readonly, copy) NSString *HostKeyFingerprint;

Set after connecting to an SSH server. The format of the fingerprint looks like this: "ssh-rsa 1024 68:ff:d1:4e:6c:ff:d7:b0:d6:58:73:85:07:bc:2e:d5"

@property (nonatomic, copy) NSString *HttpProxyAuthMethod;

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy authentication method name. Valid choices are "Basic" or "NTLM".

@property (nonatomic, copy) NSString *HttpProxyDomain;

The NTLM authentication domain (optional) if NTLM authentication is used w/ the HTTP proxy.

@property (nonatomic, copy) NSString *HttpProxyHostname;

If an HTTP proxy is to be used, set this property to the HTTP proxy hostname or IPv4 address (in dotted decimal notation).

SSH using HTTP Proxy

@property (nonatomic, copy) NSString *HttpProxyPassword;

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy password.

@property (nonatomic, copy) NSNumber *HttpProxyPort;

If an HTTP proxy is to be used, set this property to the HTTP proxy port number. (Two commonly used HTTP proxy ports are 8080 and 3128.)

@property (nonatomic, copy) NSString *HttpProxyUsername;

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy login name.

SSH using HTTP Proxy

@property (nonatomic, copy) NSNumber *IdleTimeoutMs;

Causes SSH operations to fail when progress for sending or receiving data halts for more than this number of milliseconds. Setting IdleTimeoutMs = 0 (the default) allows the application to wait indefinitely.

@property (nonatomic, readonly) BOOL IsConnected;

Returns YES if the component is connected to an SSH server.

Note: The IsConnected property is set to YES after successfully completing the Connect method call. The IsConnected property will only be set to NO by calling Disconnect, or by the failure of another method call such that the disconnection is detected.

Check SSH Connection (IsConnected)

@property (nonatomic) BOOL KeepSessionLog;

Controls whether communications to/from the SSH server are saved to the SessionLog property. The default value is NO. If this property is set to YES, the contents of the SessionLog property will continuously grow as SSH activity transpires. The purpose of the KeepSessionLog / SessionLog properties is to help in debugging any future problems that may arise.

@property (nonatomic, readonly, copy) NSString *LastErrorHtml;

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

@property (nonatomic, readonly, copy) NSString *LastErrorText;

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

@property (nonatomic, readonly, copy) NSString *LastErrorXml;

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

@property (nonatomic) BOOL LastMethodSuccess;

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of YES indicates success, a value of NO indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = YES and failure = NO.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to YES. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

@property (nonatomic, copy) NSNumber *MaxPacketSize;

The maximum packet length to be used in the SSH transport protocol. The default value is 8192.

Note: If a large amount of data is to be flowing to/from the SSH server, then setting the MaxPacketSize equal to 32768 may improve performance. For those familiar with the inner workings of the SSH protocol, this is the "maximum packet size" value that is sent in the SSH_MSG_CHANNEL_OPEN message as defined in RFC 4254.

@property (nonatomic, readonly, copy) NSNumber *NumOpenChannels;

The number of currently open channels.

@property (nonatomic, readonly) BOOL PasswordChangeRequested;

Set by the AuthenticatePw and AuthenticatePwPk methods. If the authenticate method returns a failed status, and this property is set to YES, then it indicates the server requested a password change. In this case, re-call the authenticate method, but provide both the old and new passwords in the following format, where vertical bar characters encapsulate the old and new passwords:

|oldPassword|newPassword|

@property (nonatomic) BOOL PreferIpv6;

If YES, then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is NO, which will choose IPv4 over IPv6.

@property (nonatomic, copy) NSNumber *ReadTimeoutMs;

The maximum amount of time to allow for reading messages/data from the SSH server. This is different from the IdleTimeoutMs property. The IdleTimeoutMs is the maximum amount of time to wait while no incoming data is arriving. The ReadTimeoutMs is the maximum amount of time to allow for reading data even if data is continuing to arrive. The default value of 0 indicates an infinite timeout value.

@property (nonatomic, copy) NSString *ReqExecCharset;

Introduced in version 9.5.0.47

Indicates the charset to be used for the command sent via the SendReqExec method. The default is "ANSI". A likely alternate value would be "utf-8".

@property (nonatomic, readonly, copy) NSString *ServerIdentifier;

Introduced in version 9.5.0.71

The server-identifier string received from the server during connection establishment. For example, a typical value would be similar to "SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.2".

@property (nonatomic, readonly, copy) NSString *SessionLog;

Contains a log of the messages sent to/from the SSH server. To enable session logging, set the KeepSessionLog property = YES. Note: This property is not a filename -- it is a string property that contains the session log data.

@property (nonatomic, copy) NSString *SocksHostname;

The SOCKS4/SOCKS5 hostname or IPv4 address (in dotted decimal notation). This property is only used if the SocksVersion property is set to 4 or 5).

@property (nonatomic, copy) NSString *SocksPassword;

The SOCKS5 password (if required). The SOCKS4 protocol does not include the use of a password, so this does not apply to SOCKS4.

@property (nonatomic, copy) NSNumber *SocksPort;

The SOCKS4/SOCKS5 proxy port. The default value is 1080. This property only applies if a SOCKS proxy is used (if the SocksVersion property is set to 4 or 5).

@property (nonatomic, copy) NSString *SocksUsername;

The SOCKS4/SOCKS5 proxy username. This property is only used if the SocksVersion property is set to 4 or 5).

@property (nonatomic, copy) NSNumber *SocksVersion;

SocksVersion May be set to one of the following integer values:

0 - No SOCKS proxy is used. This is the default.
4 - Connect via a SOCKS4 proxy.
5 - Connect via a SOCKS5 proxy.

@property (nonatomic, copy) NSNumber *SoRcvBuf;

Sets the receive buffer size socket option. Normally, this property should be left unchanged. The default value is 4194304.

This property can be increased if download performance seems slow. It is recommended to be a multiple of 4096.

More Information about TCP performance and Buffer Sizes

@property (nonatomic, copy) NSNumber *SoSndBuf;

Sets the send buffer size socket option. Normally, this property should be left unchanged. The default value is 262144.

This property can be increased if upload performance seems slow. It is recommended to be a multiple of 4096. Testing with sizes such as 512K and 1MB is reasonable.

More Information about TCP performance and Buffer Sizes

@property (nonatomic) BOOL StderrToStdout;

If YES, then stderr is redirected to stdout. In this case, channel output for both stdout and stderr is combined and retrievable via the following methods: GetReceivedData, GetReceivedDataN, GetReceivedText, GetReceivedTextS. If this property is NO, then stderr is available separately via the GetReceivedStderr method.

The default value of this property is YES.

Note: Most SSH servers do not send stderr output as "extended data" packets as specified in RFC 4254. The SessionLog may be examined to see if any CHANNEL_EXTENDED_DATA messages exist. If not, then all of the output (stdout + stderr) was sent via CHANNEL_DATA messages, and therefore it is not possible to differentiate stderr output from stdout. In summary: This feature will not work for most SSH servers.

@property (nonatomic) BOOL StripColorCodes;

Introduced in version 9.5.0.67

If YES, then terminal color codes are stripped from the received text. The default value of this property is YES. (Color codes are non-printable escape sequences that provide information about color for text in a terminal.)

@property (nonatomic) BOOL TcpNoDelay;

Controls whether the TCP_NODELAY socket option is used for the underlying TCP/IP socket. The default value is YES. This disables the Nagle algorithm and allows for better performance when small amounts of data are sent to/from the SSH server.

@property (nonatomic, copy) NSString *UserAuthBanner;

Introduced in version 9.5.0.46

If a user authentication banner message is received during authentication, it will be made available here. An application can check to see if this property contains a banner string after calling StartKeyboardAuth. It is only possible for an application to display this message if it is doing keyboard-interactive authentication via the StartKeyboardAuth and ContinueKeyboardAuth methods.

@property (nonatomic) BOOL VerboseLogging;

If set to YES, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is NO. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

@property (nonatomic, readonly, copy) NSString *Version;

Version of the component/library, such as "9.5.0.63"

Methods

- (BOOL)AuthenticatePk:(NSString *)username
    privateKey:(CkoSshKey *)privateKey;

Authenticates with the SSH server using public-key authentication. The corresponding public key must have been installed on the SSH server for the username. Authentication will succeed if the matching privateKey is provided.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

Returns YES for success, NO for failure.

Beware of too much time between connect and authentication.

Use PuTTY Key for SSH Authentication

- (CkoTask *)AuthenticatePkAsync:(NSString *)username
    privateKey:(CkoSshKey *)privateKey;

Creates an asynchronous task to call the AuthenticatePk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)AuthenticatePw:(NSString *)login
    password:(NSString *)password;

Authenticates with the SSH server using a login and password.

An SSH session always begins by first calling Connect to connect to the SSH server, and then calling either AuthenticatePw or AuthenticatePk to login.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.
Note: To learn about how to handle password change requests, see the PasswordChangeRequested property (above).

Returns YES for success, NO for failure.

Beware of too much time between connect and authentication.

- (CkoTask *)AuthenticatePwAsync:(NSString *)login
    password:(NSString *)password;

Creates an asynchronous task to call the AuthenticatePw method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)AuthenticatePwPk:(NSString *)username
    password:(NSString *)password
    privateKey:(CkoSshKey *)privateKey;

Authentication for SSH servers that require both a password and private key. (Most SSH servers are configured to require one or the other, but not both.)

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

Returns YES for success, NO for failure.

- (CkoTask *)AuthenticatePwPkAsync:(NSString *)username
    password:(NSString *)password
    privateKey:(CkoSshKey *)privateKey;

Creates an asynchronous task to call the AuthenticatePwPk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)AuthenticateSecPw:(CkoSecureString *)login
    password:(CkoSecureString *)password;

Introduced in version 9.5.0.71

The same as AuthenticatePw, except the login and passwords strings are passed in secure string objects.

Returns YES for success, NO for failure.

SSH Authenticate Secure

- (CkoTask *)AuthenticateSecPwAsync:(CkoSecureString *)login
    password:(CkoSecureString *)password;

Introduced in version 9.5.0.71

Creates an asynchronous task to call the AuthenticateSecPw method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)AuthenticateSecPwPk:(CkoSecureString *)username
    password:(CkoSecureString *)password
    privateKey:(CkoSshKey *)privateKey;

Introduced in version 9.5.0.71

The same as AuthenticatePwPk, except the login and passwords strings are passed in secure string objects.

Returns YES for success, NO for failure.

- (CkoTask *)AuthenticateSecPwPkAsync:(CkoSecureString *)username
    password:(CkoSecureString *)password
    privateKey:(CkoSshKey *)privateKey;

Introduced in version 9.5.0.71

Creates an asynchronous task to call the AuthenticateSecPwPk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelIsOpen:(NSNumber *)channelNum;

Returns YES if the channel indicated by channelNum is open. Otherwise returns NO.

- (NSNumber *)ChannelPoll:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs;

Polls for incoming data on an open channel. This method will read a channel, waiting at most pollTimeoutMs milliseconds for data to arrive. Return values are as follows:

-1 -- Error. Check the IsConnected property to see if the connection to the SSH server is still valid. Also, call ChannelIsOpen to see if the channel remains open. The LastErrorText property will contain more detailed information regarding the error.

-2 -- No additional data was received prior to the poll timeout.

>0 -- Additional data was received and the return value indicates how many bytes are available to be "picked up". Methods that read data on a channel do not return the received data directly. Instead, they return an integer to indicate how many bytes are available to be "picked up". An application picks up the available data by calling GetReceivedData or GetReceivedText.

=0 -- A zero can be returned if the channel EOF has already been received, or if the channel had already been closed.

- (CkoTask *)ChannelPollAsync:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs;

Creates an asynchronous task to call the ChannelPoll method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)ChannelRead:(NSNumber *)channelNum;

Reads incoming data on an open channel. This method will read a channel, waiting at most IdleTimeoutMs milliseconds for data to arrive. Return values are as follows:

-1 -- Error. Check the IsConnected property to see if the connection to the SSH server is still valid. Also, call ChannelIsOpen to see if the channel remains open. The LastErrorText property will contain more detailed information regarding the error.

-2 -- No additional data was received prior to the IdleTimeoutMs timeout.

>0 -- Additional data was received and the return value indicates how many bytes are available to be "picked up". Methods that read data on a channel do not return the received data directly. Instead, they return an integer to indicate how many bytes are available to be "picked up". An application picks up the available data by calling GetReceivedData or GetReceivedText.

=0 -- A zero can be returned if the channel EOF has already been received, or if the channel had already been closed.

- (CkoTask *)ChannelReadAsync:(NSNumber *)channelNum;

Creates an asynchronous task to call the ChannelRead method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)ChannelReadAndPoll:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs;

Reads incoming data on an open channel and continues reading until no data arrives for pollTimeoutMs milliseconds. The first read will wait a max of IdleTimeoutMs milliseconds before timing out. Subsequent reads wait a max of pollTimeoutMs milliseconds before timing out.

The idea behind ChannelReadAndPoll is to capture the output of a shell command. One might imagine the typical sequence of events when executing a shell command to be like this: (1) client sends command to server, (2) server executes the command (i.e. it's computing...), potentially taking some amount of time, (3) output is streamed back to the client. It makes sense for the client to wait a longer period of time for the first data to arrive, but once it begins arriving, the timeout can be shortened. This is exactly what ChannelReadAndPoll does -- the first timeout is controlled by the IdleTimeoutMs property, while the subsequent reads (once output starts flowing) is controlled by pollTimeoutMs.

Return values are as follows:
-1 -- Error. Check the IsConnected property to see if the connection to the SSH server is still valid. Also, call ChannelIsOpen to see if the channel remains open. The LastErrorText property will contain more detailed information regarding the error.

-2 -- No additional data was received prior to the IdleTimeoutMs timeout.

>0 -- Additional data was received and the return value indicates how many bytes are available to be "picked up". Methods that read data on a channel do not return the received data directly. Instead, they return an integer to indicate how many bytes are available to be "picked up". An application picks up the available data by calling GetReceivedData or GetReceivedText.

=0 -- A zero can be returned if the channel EOF has already been received, or if the channel had already been closed.

- (CkoTask *)ChannelReadAndPollAsync:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs;

Creates an asynchronous task to call the ChannelReadAndPoll method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)ChannelReadAndPoll2:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs
    maxNumBytes:(NSNumber *)maxNumBytes;

The same as ChannelReadAndPoll, except this method will return as soon as maxNumBytes is exceeded, which may be as large as the MaxPacketSize property setting.

- (CkoTask *)ChannelReadAndPoll2Async:(NSNumber *)channelNum
    pollTimeoutMs:(NSNumber *)pollTimeoutMs
    maxNumBytes:(NSNumber *)maxNumBytes;

Creates an asynchronous task to call the ChannelReadAndPoll2 method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelReceivedClose:(NSNumber *)channelNum;

YES if a CLOSE message has been received on the channel indicated by channelNum. When a CLOSE is received, no subsequent data should be sent in either direction -- the channel is closed in both directions.

- (BOOL)ChannelReceivedEof:(NSNumber *)channelNum;

YES if an EOF message has been received on the channel indicated by channelNum. When an EOF is received, no more data will be forthcoming on the channel. However, data may still be sent in the opposite direction.

- (BOOL)ChannelReceivedExitStatus:(NSNumber *)channelNum;

YES if an exit status code was received on the channel. Otherwise NO.

- (BOOL)ChannelReceiveToClose:(NSNumber *)channelNum;

Reads incoming data on an open channel until the channel is closed by the server. If successful, the number of bytes available to be "picked up" can be determined by calling GetReceivedNumBytes. The received data may be retrieved by calling GetReceivedData or GetReceivedText.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelReceiveToCloseAsync:(NSNumber *)channelNum;

Creates an asynchronous task to call the ChannelReceiveToClose method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelReceiveUntilMatch:(NSNumber *)channelNum
    matchPattern:(NSString *)matchPattern
    charset:(NSString *)charset
    caseSensitive:(BOOL)caseSensitive;

Reads incoming text data on an open channel until the received data matches the matchPattern. For example, to receive data until the string "Hello World" arrives, set matchPattern equal to "*Hello World*". charset indicates the character encoding of the text being received ("iso-8859-1" for example). caseSensitive may be set to YES for case sensitive matching, or NO for case insensitive matching.

Returns YES if text data matching matchPattern was received and is available to be picked up by calling GetReceivedText (or GetReceivedTextS). IMPORTANT: This method may read beyond the matching text. Call GetReceivedTextS to extract only the data up-to and including the matching text.

Important Notes:

  • It's wise to set the ReadTimeoutMs property to a non-zero value to prevent an infinite wait if the matchPattern never arrives.
  • If using a shell session and SendReqPty was called, set the termType = "dumb". If terminal control codes get mixed into the output stream, it could disrupt matching.
  • Be aware of the StderrToStdout property setting. The default value is true, which means that stderr is mixed with stdout in the output stream. This could disrupt matching. Set StderrToStdout to false to prevent this possibility.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelReceiveUntilMatchAsync:(NSNumber *)channelNum
    matchPattern:(NSString *)matchPattern
    charset:(NSString *)charset
    caseSensitive:(BOOL)caseSensitive;

Creates an asynchronous task to call the ChannelReceiveUntilMatch method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelReceiveUntilMatchN:(NSNumber *)channelNum
    matchPatterns:(CkoStringArray *)matchPatterns
    charset:(NSString *)charset
    caseSensitive:(BOOL)caseSensitive;

The same as ChannelReceiveUntilMatch except that the method returns when any one of the match patterns specified in matchPatterns are received on the channel.

Important: It's wise to set the ReadTimeoutMs property to a non-zero value to prevent an infinite wait if of the matchPatterns ever arrives.

Returns YES for success, NO for failure.

SSH ReceiveUntilMatchN

- (CkoTask *)ChannelReceiveUntilMatchNAsync:(NSNumber *)channelNum
    matchPatterns:(CkoStringArray *)matchPatterns
    charset:(NSString *)charset
    caseSensitive:(BOOL)caseSensitive;

Creates an asynchronous task to call the ChannelReceiveUntilMatchN method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (void)ChannelRelease:(NSNumber *)channelNum;

Introduced in version 9.5.0.44

Releases the internal memory resources for a channel previously opened by OpenSessionChannel, OpenCustomChannel, or OpenDirectTcpIpChannel. It is not absolutely necessary to call this method because the internal memory resources for all channels are automatically released when the SSH object instance is deleted/disposed. This method becomes necessary only when an extremely large number of channels within the same SSH object instance are opened, used, and closed over a long period of time.

- (BOOL)ChannelSendClose:(NSNumber *)channelNum;

Sends a CLOSE message to the server for the channel indicated by channelNum. This closes both directions of the bidirectional channel.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelSendCloseAsync:(NSNumber *)channelNum;

Creates an asynchronous task to call the ChannelSendClose method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelSendData:(NSNumber *)channelNum
    data:(NSData *)data;

Sends byte data on the channel indicated by channelNum.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelSendDataAsync:(NSNumber *)channelNum
    data:(NSData *)data;

Creates an asynchronous task to call the ChannelSendData method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelSendEof:(NSNumber *)channelNum;

Sends an EOF for the channel indicated by channelNum. Once an EOF is sent, no additional data may be sent on the channel. However, the channel remains open and additional data may still be received from the server.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelSendEofAsync:(NSNumber *)channelNum;

Creates an asynchronous task to call the ChannelSendEof method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ChannelSendString:(NSNumber *)channelNum
    strData:(NSString *)strData
    charset:(NSString *)charset;

Sends character data on the channel indicated by channelNum. The text is converted to the charset indicated by charset prior to being sent. A list of supported charset values may be found on this page: Supported Charsets.

Returns YES for success, NO for failure.

- (CkoTask *)ChannelSendStringAsync:(NSNumber *)channelNum
    strData:(NSString *)strData
    charset:(NSString *)charset;

Creates an asynchronous task to call the ChannelSendString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)CheckConnection;

Introduced in version 9.5.0.46

Returns YES if the underlying TCP socket is connected to the SSH server.

- (void)ClearTtyModes;

Clears the collection of TTY modes that are sent with the SendReqPty method.

- (BOOL)Connect:(NSString *)hostname
    port:(NSNumber *)port;

Connects to the SSH server at domainName:port

The domainName may be a domain name or an IPv4 or IPv6 address in string format.

Important: All TCP-based Internet communications, regardless of the protocol (such as HTTP, FTP, SSH, IMAP, POP3, SMTP, etc.), and regardless of SSL/TLS, begin with establishing a TCP connection to a remote host:port. External security-related infrastructure such as software firewalls (Windows Firewall), hardware firewalls, anti-virus, at either source or destination (or both) can block the connection. If the connection fails, make sure to check all potential external causes of blockage.

Returns YES for success, NO for failure.

- (CkoTask *)ConnectAsync:(NSString *)hostname
    port:(NSNumber *)port;

Creates an asynchronous task to call the Connect method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ConnectThroughSsh:(CkoSsh *)ssh
    hostname:(NSString *)hostname
    port:(NSNumber *)port;

Introduced in version 9.5.0.55

Connects to an SSH server through an existing SSH connection. The ssh is an existing connected and authenticated SSH object. The connection to hostname:port is made through the existing SSH connection via port-forwarding. If successful, the connection is as follows: application => ServerSSH1 => ServerSSH2. (where ServerSSH1 is the ssh and ServerSSH2 is the SSH server at hostname:port) Once connected in this way, all communications are routed through ServerSSH1 to ServerSSH2. This includes authentication -- which means the application must still call one of the Authenticate* methods to authenticate with ServerSSH2.

Returns YES for success, NO for failure.

Multi-Hop SSH (SSH Through SSH)

- (CkoTask *)ConnectThroughSshAsync:(CkoSsh *)ssh
    hostname:(NSString *)hostname
    port:(NSNumber *)port;

Introduced in version 9.5.0.55

Creates an asynchronous task to call the ConnectThroughSsh method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSString *)ContinueKeyboardAuth:(NSString *)response;

Introduced in version 9.5.0.46

Continues keyboard-interactive authentication with the SSH server. The response is typically the password. If multiple responses are required (because there were multiple prompts in the infoRequest XML returned by StartKeyboardAuth), then the response should be formatted as XML (as shown below) otherwise the response simply contains the single response string.

<response>
    <response1>response to first prompt</response1>
    <response2>response to second prompt</response2>
    ...
    <responseN>response to Nth prompt</responseN>
</response>

If the interactive authentication completed with success or failure, the XML response will be:

<success>success_message</success>

or

<error>error_message</error>
If additional steps are required to complete the interactive authentication, then an XML string that provides the name, instruction, and prompts is returned. The XML has the following format:
 	<infoRequest numPrompts="N">
	    <name>name_string</name>
	    <instruction>instruction_string</instruction>
	    <prompt1 echo="1_or_0">prompt_string</prompt1>
	    ...
	    <promptN echo="1_or_0">prompt_string</promptN>
	</infoRequest>

Returns nil on failure

SSH Keyboard Authentication

- (CkoTask *)ContinueKeyboardAuthAsync:(NSString *)response;

Introduced in version 9.5.0.46

Creates an asynchronous task to call the ContinueKeyboardAuth method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (void)Disconnect;

Disconnects from the SSH server.

- (NSNumber *)GetChannelExitStatus:(NSNumber *)channelNum;

Returns the exit status code for a channel. This method should only be called if an exit status has been received. You may check to see if the exit status was received by calling ChannelReceivedExitStatus.

- (NSNumber *)GetChannelNumber:(NSNumber *)index;

Returns the channel number for the Nth open channel. Indexing begins at 0, and the number of currently open channels is indicated by the NumOpenChannels property. Returns -1 if the index is out of range.

- (NSString *)GetChannelType:(NSNumber *)index;

Returns a string describing the channel type for the Nth open channel. Channel types are: "session", "x11", "forwarded-tcpip", and "direct-tcpip".

Returns nil on failure

- (NSData *)GetReceivedData:(NSNumber *)channelNum;

Returns the accumulated data received on the channel indicated by channelNum and clears the channel's internal receive buffer.

Returns nil on failure

- (NSData *)GetReceivedDataN:(NSNumber *)channelNum
    numBytes:(NSNumber *)numBytes;

Same as GetReceivedData, but a maximum of maxNumBytes bytes is returned.

Returns nil on failure

- (NSNumber *)GetReceivedNumBytes:(NSNumber *)channelNum;

Returns the number of bytes available in the internal receive buffer for the specified channelNum. The received data may be retrieved by calling GetReceivedData or GetReceivedText.

- (NSData *)GetReceivedStderr:(NSNumber *)channelNum;

Introduced in version 9.5.0.48

Returns the accumulated stderr bytes received on the channel indicated by channelNum and clears the channel's internal stderr receive buffer.

Note: If the StderrToStdout property is set to YES, then stderr is automatically redirected to stdout. This is the default behavior. The following methods can be called to retrieve the channel's stdout: GetReceivedData, GetReceivedDataN, GetReceivedText, and GetReceivedTextS.

Returns nil on failure

- (NSString *)GetReceivedStderrText:(NSNumber *)channelNum
    charset:(NSString *)charset;

Returns the accumulated stderr text received on the channel indicated by channelNum and clears the channel's internal receive buffer. The charset indicates the charset of the character data in the internal receive buffer. A list of supported charset values may be found on this page: Supported Charsets.

Returns nil on failure

- (NSString *)GetReceivedText:(NSNumber *)channelNum
    charset:(NSString *)charset;

Returns the accumulated text received on the channel indicated by channelNum and clears the channel's internal receive buffer. The charset indicates the charset of the character data in the internal receive buffer. A list of supported charset values may be found on this page: Supported Charsets.

Returns nil on failure

- (NSString *)GetReceivedTextS:(NSNumber *)channelNum
    substr:(NSString *)substr
    charset:(NSString *)charset;

The same as GetReceivedText, except only the text up to and including substr is returned. The text returned is removed from the internal receive buffer. If the substr was not found in the internal receive buffer, an empty string is returned and the internal receive buffer is not modified.

Returns nil on failure

- (NSNumber *)OpenCustomChannel:(NSString *)channelType;

Opens a custom channel with a custom server that uses the SSH protocol. The channelType is application-defined.

If successful, the channel number is returned. This is the number that should be passed to any method requiring a channel number. A -1 is returned upon failure.

- (CkoTask *)OpenCustomChannelAsync:(NSString *)channelType;

Creates an asynchronous task to call the OpenCustomChannel method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)OpenDirectTcpIpChannel:(NSString *)hostname
    port:(NSNumber *)port;

Open a direct-tcpip channel for port forwarding. Data sent on the channel via ChannelSend* methods is sent to the SSH server and then forwarded to targetHostname:targetPort. The SSH server automatically forwards data received from targetHostname:targetPort to the SSH client. Therefore, calling ChannelRead* and ChannelReceive* methods is equivalent to reading directly from targetHostname:targetPort.

If successful, the channel number is returned. This is the number that should be passed to any method requiring a channel number. A -1 is returned upon failure.

SSH Tunnel (Port Forwarding via direct-tcpip channel)

- (CkoTask *)OpenDirectTcpIpChannelAsync:(NSString *)hostname
    port:(NSNumber *)port;

Creates an asynchronous task to call the OpenDirectTcpIpChannel method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)OpenSessionChannel;

Opens a new session channel. Almost everything you will do with the Chilkat SSH component will involve opening a session channel. The normal sequence of operation is typically this: 1) Connect to the SSH server. 2) Authenticate. 3) Open a session channel. 4) do something on the channel such as opening a shell, execute a command, etc.

If successful, the channel number is returned. This is the number that should be passed to any method requiring a channel number. A -1 is returned upon failure.

- (CkoTask *)OpenSessionChannelAsync;

Creates an asynchronous task to call the OpenSessionChannel method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSString *)PeekReceivedText:(NSNumber *)channelNum
    charset:(NSString *)charset;

This is the same as GetReceivedText, except the internal receive buffer is not cleared.

Returns nil on failure

- (NSNumber *)QuickCmdCheck:(NSNumber *)pollTimeoutMs;

Introduced in version 9.5.0.65

Returns a channel number for a completed command that was previously sent via QuickCmdSend. Returns -1 if no commands have yet completed. The pollTimeoutMs indicates how long to wait (in milliseconds) for any command in progress (on any channel) to complete before returning -1.

Returns -2 if an error occurred (for example, if the connection to the SSH server was lost while checking for responses).

SSH Parallel Remote Commands on Single Server

SSH Parallel Remote Commands on Multiple Servers

- (CkoTask *)QuickCmdCheckAsync:(NSNumber *)pollTimeoutMs;

Introduced in version 9.5.0.65

Creates an asynchronous task to call the QuickCmdCheck method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)QuickCmdSend:(NSString *)command;

Introduced in version 9.5.0.65

Sends a command and returns the channel number for the command that has started. This is the equivalent of calling OpenSessionChannel, followed by SendReqExec. A value of -1 is returned on failure.

The ReqExecCharset property controls the charset used for the command that is sent.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

SSH Parallel Remote Commands on Single Server

SSH Parallel Remote Commands on Multiple Servers

- (CkoTask *)QuickCmdSendAsync:(NSString *)command;

Introduced in version 9.5.0.65

Creates an asynchronous task to call the QuickCmdSend method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSString *)QuickCommand:(NSString *)command
    charset:(NSString *)charset;

Introduced in version 9.5.0.65

Simplified method for executing a remote command and getting the complete output. This is the equivalent of calling OpenSessionChannel, followed by SendReqExec, then ChannelReceiveToClose, and finally GetReceivedText.

The charset indicates the charset of the command's output (such as "utf-8" or "ansi"). A list of supported charset values may be found on this page: Supported Charsets.

The ReqExecCharset property controls the charset used for the command that is sent.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

Returns nil on failure

SSH Execute Remote Commands

- (CkoTask *)QuickCommandAsync:(NSString *)command
    charset:(NSString *)charset;

Introduced in version 9.5.0.65

Creates an asynchronous task to call the QuickCommand method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (NSNumber *)QuickShell;

Introduced in version 9.5.0.65

Simplified method for starting a remote shell session. It is the equivalent of calling OpenSessionChannel, followed by SendReqPty, and finally SendReqShell.

Returns the SSH channel number for the session, or -1 if not successful.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

SSH Quick/Simple Shell Session

- (CkoTask *)QuickShellAsync;

Introduced in version 9.5.0.65

Creates an asynchronous task to call the QuickShell method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)ReKey;

Initiates a re-key with the SSH server. The ReKey method does not return until the key re-exchange is complete.

RFC 4253 (the SSH Transport Layer Protocol) recommends that keys be changed after each gigabyte of transmitted data or after each hour of connection time, whichever comes sooner. Key re-exchange is a public-key operation and requires a fair amount of processing power and should not be performed too often. Either side (client or server) may initiate a key re-exchange at any time.

In most cases, a server will automatically initiate key re-exchange whenever it deems necessary, and the Chilkat SSH component handles these transparently. For example, if the Chilkat SSH component receives a re-key message from the server while in the process of receiving data on a channel, it will automatically handle the key re-exchange and the application will not even realize that an underlying key re-exchange occurred.

Returns YES for success, NO for failure.

- (CkoTask *)ReKeyAsync;

Creates an asynchronous task to call the ReKey method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SaveLastError:(NSString *)path;

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns YES for success, NO for failure.

- (BOOL)SendIgnore;

Sends an IGNORE message to the SSH server. This is one way of verifying that the connection to the SSH server is open and valid. The SSH server does not respond to an IGNORE message. It simply ignores it. IGNORE messages are not associated with a channel (in other words, you do not need to first open a channel prior to sending an IGNORE message).

Returns YES for success, NO for failure.

- (CkoTask *)SendIgnoreAsync;

Creates an asynchronous task to call the SendIgnore method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqExec:(NSNumber *)channelNum
    command:(NSString *)command;

Initiates execution of a command on the channel specified by channelNum. The commandLine contains the full command line including any command-line parameters (just as you would type the command at a shell prompt).

The user's default shell (typically defined in /etc/password in UNIX systems) is started on the SSH server to execute the command.

Important: A channel only exists for a single request. You may not call SendReqExec multiple times on the same open channel. The reason is that the SSH server automatically closes the channel at the end of the exec. The solution is to call OpenSessionChannel to get a new channel, and then call SendReqExec using the new channel. It is OK to have more than one channel open simultaneously.

Charset: The ReqExecCharset property has been added in version 9.5.0.47. This can be set to control the character encoding of the command sent to the server. The default is ANSI. A likely alternative value is "utf-8".

Returns YES for success, NO for failure.

Note about sending commands that produce no output.

Note about sending interactive commands such as "more"

SSH Exec (Execute Command Line)

Multiple SendReqExec on Same Connection

Understanding SSH Automation

- (CkoTask *)SendReqExecAsync:(NSNumber *)channelNum
    command:(NSString *)command;

Creates an asynchronous task to call the SendReqExec method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqPty:(NSNumber *)channelNum
    xTermEnvVar:(NSString *)xTermEnvVar
    widthInChars:(NSNumber *)widthInChars
    heightInRows:(NSNumber *)heightInRows
    pixWidth:(NSNumber *)pixWidth
    pixHeight:(NSNumber *)pixHeight;

Requests a pseudo-terminal for a session channel. If the termType is a character oriented terminal ("vt100" for example), then widthInChars and heightInChars would be set to non-zero values, while widthInPixels and heightInPixels may be set to 0. If termType is pixel-oriented, such as "xterm", the reverse is true (i.e. set widthInPixels and heightInPixels, but set widthInChars and heightInChars equal to 0).

In most cases, you probably don't even want terminal emulation. In that case, try setting termType = "dumb". Terminal emulation causes terminal escape sequences to be included with shell command output. A "dumb" terminal should have no escape sequences.

Some SSH servers allow a shell to be started (via the SendReqShell method) without the need to first request a pseudo-terminal. The normal sequence for starting a remote shell is as follows:

1) Connect
2) Authenticate
3) OpenSessionChannel
4) Request a PTY via this method if necessary.
5) Start a shell by calling SendReqShell

Returns YES for success, NO for failure.

Understanding SSH Automation

- (CkoTask *)SendReqPtyAsync:(NSNumber *)channelNum
    xTermEnvVar:(NSString *)xTermEnvVar
    widthInChars:(NSNumber *)widthInChars
    heightInRows:(NSNumber *)heightInRows
    pixWidth:(NSNumber *)pixWidth
    pixHeight:(NSNumber *)pixHeight;

Creates an asynchronous task to call the SendReqPty method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqSetEnv:(NSNumber *)channelNum
    name:(NSString *)name
    value:(NSString *)value;

Sets an environment variable in the remote shell.

Returns YES for success, NO for failure.

- (CkoTask *)SendReqSetEnvAsync:(NSNumber *)channelNum
    name:(NSString *)name
    value:(NSString *)value;

Creates an asynchronous task to call the SendReqSetEnv method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqShell:(NSNumber *)channelNum;

Starts a shell on an open session channel. Some SSH servers require that a PTY (pseudo-terminal) first be requested prior to starting a shell. In that case, call SendReqPty prior to calling this method. Once a shell is started, commands may be sent by calling ChannelSendString. (Don't forget to terminate commands with a CRLF).

Returns YES for success, NO for failure.

SSH Remote Shell

Understanding SSH Automation

- (CkoTask *)SendReqShellAsync:(NSNumber *)channelNum;

Creates an asynchronous task to call the SendReqShell method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqSignal:(NSNumber *)channelNum
    signalName:(NSString *)signalName;

Delivers a signal to the remote process/service. signalName is one of the following: ABRT, ALRM, FPE, HUP, ILL, INT, KILL, PIPE, QUIT, SEGV, TERM, USR1, USR2. (Obviously, these are UNIX signals, so the remote SSH server would need to be a Unix/Linux system.)

Returns YES for success, NO for failure.

- (CkoTask *)SendReqSignalAsync:(NSNumber *)channelNum
    signalName:(NSString *)signalName;

Creates an asynchronous task to call the SendReqSignal method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqSubsystem:(NSNumber *)channelNum
    subsystemName:(NSString *)subsystemName;

Executes a pre-defined subsystem. The SFTP protocol (Secure File Transfer Protocol) is started by the Chilkat SFTP component by starting the "sftp" subsystem.

Returns YES for success, NO for failure.

- (CkoTask *)SendReqSubsystemAsync:(NSNumber *)channelNum
    subsystemName:(NSString *)subsystemName;

Creates an asynchronous task to call the SendReqSubsystem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqWindowChange:(NSNumber *)channelNum
    widthInChars:(NSNumber *)widthInChars
    heightInRows:(NSNumber *)heightInRows
    pixWidth:(NSNumber *)pixWidth
    pixHeight:(NSNumber *)pixHeight;

When the client-side window (terminal) size changes, this message may be sent to the server to inform it of the new size.

- (CkoTask *)SendReqWindowChangeAsync:(NSNumber *)channelNum
    widthInChars:(NSNumber *)widthInChars
    heightInRows:(NSNumber *)heightInRows
    pixWidth:(NSNumber *)pixWidth
    pixHeight:(NSNumber *)pixHeight;

Creates an asynchronous task to call the SendReqWindowChange method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqX11Forwarding:(NSNumber *)channelNum
    singleConnection:(BOOL)singleConnection
    authProt:(NSString *)authProt
    authCookie:(NSString *)authCookie
    screenNum:(NSNumber *)screenNum;

Allows the client to send an X11 forwarding request to the server. Chilkat only provides this functionality because it is a message defined in the SSH connection protocol. Chilkat has no advice for when or why it would be needed.

- (CkoTask *)SendReqX11ForwardingAsync:(NSNumber *)channelNum
    singleConnection:(BOOL)singleConnection
    authProt:(NSString *)authProt
    authCookie:(NSString *)authCookie
    screenNum:(NSNumber *)screenNum;

Creates an asynchronous task to call the SendReqX11Forwarding method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SendReqXonXoff:(NSNumber *)channelNum
    clientCanDo:(BOOL)clientCanDo;

This method should be ignored and not used.

- (CkoTask *)SendReqXonXoffAsync:(NSNumber *)channelNum
    clientCanDo:(BOOL)clientCanDo;

Creates an asynchronous task to call the SendReqXonXoff method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)SetTtyMode:(NSString *)name
    value:(NSNumber *)value;

Sets a TTY mode that is included in the SendReqPty method call. Most commonly, it is not necessary to call this method at all. Chilkat has no recommendations or expertise as to why or when a particular mode might be useful. This capability is provided because it is defined in the SSH connection protocol specification.

This method can be called multiple times to set many terminal mode flags (one per call).

The ttyValue is an integer, typically 0 or 1. Valid ttyName flag names include: VINTR, VQUIT, VERASE, VKILL, VEOF, VEOL, VEOL2, VSTART, VSTOP, VSUSP, VDSUSP, VREPRINT, VWERASE, VLNEXT, VFLUSH, VSWTCH, VSTATUS, VDISCARD, IGNPAR, PARMRK, INPCK, ISTRIP, INLCR, IGNCR, ICRNL, IUCLC, IXON, IXANY, IXOFF, IMAXBEL, ISIG, ICANON, XCASE, ECHO, ECHOE, ECHOK, ECHONL, NOFLSH, TOSTOP, IEXTEN, ECHOCTL, ECHOKE, PENDIN, OPOST, OLCUC, ONLCR, OCRNL, ONOCR, ONLRET, CS7, CS8, PARENB, PARODD, TTY_OP_ISPEED, TTY_OP_OSPEED

- (NSString *)StartKeyboardAuth:(NSString *)login;

Introduced in version 9.5.0.46

Begins keyboard-interactive authentication with the SSH server. Returns an XML string providing the name, instruction, and prompts. The XML has the following format:

 	<infoRequest numPrompts="N">
	    <name>name_string</name>
	    <instruction>instruction_string</instruction>
	    <prompt1 echo="1_or_0">prompt_string</prompt1>
	    ...
	    <promptN echo="1_or_0">prompt_string</promptN>
	</infoRequest>

If the authentication immediately succeeds because no password is required, or immediately fails, the XML response can be:

<success>success_message</success>

or

<error>error_message</error>

Returns nil on failure

SSH Keyboard Authentication

- (CkoTask *)StartKeyboardAuthAsync:(NSString *)login;

Introduced in version 9.5.0.46

Creates an asynchronous task to call the StartKeyboardAuth method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

- (BOOL)UnlockComponent:(NSString *)unlockCode;

Unlocks the component. This must be called once prior to calling any other method. A fully-functional 30-day trial is automatically started when an arbitrary string is passed to this method. For example, passing "Hello", or "abc123" will unlock the component for the 1st thirty days after the initial install.

Returns YES for success, NO for failure.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Purchased Unlock Code

LastErrorText Standard Information

- (NSNumber *)WaitForChannelMessage:(NSNumber *)pollTimeoutMs;

Introduced in version 9.5.0.48

The pollTimeoutMs is the number of milliseconds to wait. To poll, pass a value of 0 in pollTimeoutMs. Waits for an incoming message on any channel. This includes data, EOF, CLOSE, etc. If a message arrives in the alotted time, the channel number is returned. A value of -1 is returned for a timeout, and -2 for any other errors such as if the connection is lost.

Note: If a channel number is returned, the message must still be read by calling a method such as ChannelRead, ChannelReceiveUntilMatch, etc. Once the message is actually received, it may be collected by calling GetReceivedText, GetReceivedData, etc.

- (CkoTask *)WaitForChannelMessageAsync:(NSNumber *)pollTimeoutMs;

Introduced in version 9.5.0.48

Creates an asynchronous task to call the WaitForChannelMessage method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

Events

To implement an event callback, your application would define and implement a class that inherits from CkoBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkoBaseProgress base class.

For example:

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

  MySshProgress *callbackObj = [[MySshProgress alloc] init];

  [ssh setEventCallbackObject:callbackObj];

MySshProgress interface example:

#import "CkoSshProgress.h"

@interface MySshProgress : CkoBaseProgress {

}

    - (id)init;
    - (void)dealloc;
    - (void)dispose;

    - (void)AbortCheck:(BOOL *)abort;

    - (void)BinaryData:(NSData *)data 
        length:(NSNumber *)length;

    - (void)PercentDone:(NSNumber *)pctDone 
        abort:(BOOL *)abort;

    - (void)ProgressInfo:(NSString *)name 
        value:(NSString *)value;

    - (void)TaskCompleted:(CkoTask *)task;

    - (void)TextData:(NSString *)data;

@end

- (void)AbortCheck:(BOOL *)abort;

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

- (void)BinaryData:(NSData *)data
    length:(NSNumber *)length;

Binary data provided by certain methods.

- (void)PercentDone:(NSNumber *)pctDone
    abort:(BOOL *)abort;

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to YES will cause the method to abort and return a failed status (or whatever return value indicates failure).

- (void)ProgressInfo:(NSString *)name
    value:(NSString *)value;

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

- (void)TaskCompleted:(CkoTask *)task;

Called in the background thread when an asynchronous task completes.

- (void)TextData:(NSString *)data;

Text data provided by certain methods.