SFTPClient Component

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The SFTPClient component can be used to transfer files to and from secure file transfer protocol (SFTP) servers.

Syntax

TipfSFTPClient

Remarks

The SFTPClient component is the Secure Shell (SSH)-enabled equivalent of the IPWorks FTP component. The SSHHost and SSHPort properties specify which Secure Shell (SSH) server to use. The SSHUser and SSHPassword properties allow the client to authenticate itself with the server. The SSHServerAuthentication event or SSHAcceptServerHostKey property allow you to check the server identity. Finally, the SSHStatus event provides information about the SSH handshake.

The SFTPClient component implements a standard SSH file transfer client.

The first step in using the component is specifying the SSHHost, SSHUser, and SSHPassword. The file to upload to or download from is given by the RemoteFile property. The file to download to or upload from is specified by LocalFile. The current path in the server is specified by the RemotePath property.

If LocalFile is set to something other than an empty string, then files are received in LocalFile; otherwise, the data are received through the Transfer event. StartTransfer and EndTransfer are fired at the beginning and end of transmission.

Directory listings are received through the DirList event.

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

Connected Property (SFTPClient Component)

Whether the component is connected.

Syntax

property Connected: Boolean read get_Connected;

Default Value

false

Remarks

This property is used to determine whether or not the component is connected to the remote host. Use the Connect and Disconnect methods to manage the connection.

This property is read-only and not available at design time.

DirList Property (SFTPClient Component)

Collection of entries resulting in the last directory listing.

Syntax

property DirList: TipfDirEntryList read get_DirList;

Remarks

This collection of entries is returned after a response is received from the server after a call to ListDirectory. The collection is made up of entries for each listing in the current directory, which is specified by the RemotePath property.

MaxDirEntries can be used to control the number of directory listings saved.

This property is read-only and not available at design time.

FileAttributes Property (SFTPClient Component)

The attributes of the RemoteFile .

Syntax

property FileAttributes: TipfSFTPFileAttributes read get_FileAttributes write set_FileAttributes;

Remarks

This property holds the attributes for the file specified by RemoteFile. Before querying this property, first call QueryFileAttributes to retrieve the attributes from the server.

To modify the attributes of the file, you may set FileAttributes and then call UpdateFileAttributes.

This property is not available at design time.

Firewall Property (SFTPClient Component)

A set of properties related to firewall access.

Syntax

property Firewall: TipfFirewall read get_Firewall write set_Firewall;

Remarks

This is a Firewall-type property, which contains fields describing the firewall through which the component will attempt to connect.

Idle Property (SFTPClient Component)

The current status of the component.

Syntax

property Idle: Boolean read get_Idle;

Default Value

true

Remarks

This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.

This property is read-only.

LocalFile Property (SFTPClient Component)

The path to a local file for upload or download.

Syntax

property LocalFile: String read get_LocalFile write set_LocalFile;

Default Value

''

Remarks

The LocalFile property is used by the Upload and Download methods. The file will be overwritten only if the Overwrite property is set to True.

Example. Setting LocalFile:

SFTPControl.Localfile = "C:\localfile.txt" SFTPControl.RemoteFile = "remotefile.txt" SFTPControl.Download() SFTPControl.Localfile = "C:\localfile2.txt" SFTPControl.RemoteFile = "folder/remotefile2.txt" SFTPControl.Download()

LocalHost Property (SFTPClient Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

property LocalHost: String read get_LocalHost write set_LocalHost;

Default Value

''

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (SFTPClient Component)

The TCP port in the local host where the component binds.

Syntax

property LocalPort: Integer read get_LocalPort write set_LocalPort;

Default Value

0

Remarks

This property must be set before a connection is attempted. It instructs the component to bind to a specific port (or communication endpoint) in the local machine.

Setting this property to 0 (default) enables the system to choose an open port at random. The chosen port will be returned by the LocalPort property after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this property when a connection is active will generate an error.

This property is useful when trying to connect to services that require a trusted port on the client side.

Overwrite Property (SFTPClient Component)

The value indicating whether or not the component should overwrite files during transfer.

Syntax

property Overwrite: Boolean read get_Overwrite write set_Overwrite;

Default Value

false

Remarks

This property is a value indicating whether or not the component should overwrite LocalFile when downloading and RemoteFile when uploading. If Overwrite is False, an error will be thrown whenever LocalFile exists before a download operation.

RemoteFile Property (SFTPClient Component)

The name of the remote file for uploading or downloading.

Syntax

property RemoteFile: String read get_RemoteFile write set_RemoteFile;

Default Value

''

Remarks

The RemoteFile is either an absolute file path or a relative path based on RemotePath.

A number of methods use RemoteFile as an argument.

Example 1. Setting RemoteFile:

SFTPControl.Localfile = "C:\localfile.txt" SFTPControl.RemoteFile = "remotefile.txt" SFTPControl.Download() SFTPControl.Localfile = "C:\localfile2.txt" SFTPControl.RemoteFile = "folder/remotefile2.txt" SFTPControl.Download()

Note: This property will also act as a file mask when performing ListDirectory.

Example 2. Using RemoteFile as a File Mask: SFTPControl.RemoteFile = "*.txt" SFTPControl.ListDirectory()

The following special characters are supported for pattern matching:

If these characters need to be used as a literal in a pattern, then they must be escaped by surrounding them with brackets []. Note: "]" and "-" do not need to be escaped. See below for the escape sequences:

For example, to match the value [Something].txt, specify the pattern [[]Something].txt.

RemotePath Property (SFTPClient Component)

The current path in the secure file transfer protocol (SFTP) server.

Syntax

property RemotePath: String read get_RemotePath;

Default Value

''

Remarks

The RemotePath shows the current working directory on the SFTP server. The ChangeRemotePath method can be used to change the working directory to an absolute directory path or to a relative path with respect to the current value of RemotePath.

Example. Changing Directory:

sftp1.SSHLogon("sftp.server.net", 22); sftp1.ChangeRemotePath("/home/user");

This property is read-only.

SSHAcceptServerHostKey Property (SFTPClient Component)

Instructs the component to accept the server host key that matches the supplied key.

Syntax

property SSHAcceptServerHostKey: TipfCertificate read get_SSHAcceptServerHostKey write set_SSHAcceptServerHostKey;

Remarks

If the host key that will be used by the server is known in advance, this property may be set to accept the expected key. Otherwise, the SSHServerAuthentication event should be trapped, and the key should be accepted or refused in the event.

If this property is not set and the SSHServerAuthentication event is not trapped, the server will not be authenticated and the connection will be terminated by the client.

SSHAuthMode Property (SFTPClient Component)

The authentication method to be used with the component when calling SSHLogon .

Syntax

property SSHAuthMode: TipfTSSHAuthModes read get_SSHAuthMode write set_SSHAuthMode;

TipfTSSHAuthModes = (
  amNone,
  amMultiFactor,
  amPassword,
  amPublicKey,
  amKeyboardInteractive,
  amGSSAPIWithMic,
  amGSSAPIKeyex,
  amCustom
);

Default Value

amPassword

Remarks

The Secure Shell (SSH) Authentication specification (RFC 4252) specifies multiple methods by which a user can be authenticated by an SSH server. When a call is made to SSHLogon, the component will connect to the SSH server and establish the security layer. After the connection has been secured, the client will send an authentication request to the SSHHost containing the SSHUser. The server will respond containing a list of methods by which that user may be authenticated.

The component will attempt to authenticate the user by one of those methods based on the value of SSHAuthMode and other property values supplied by the user. Currently, the component supports the following authentication methods:

Example 1. User/Password Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example 2. Public Key Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

SSHCert Property (SFTPClient Component)

A certificate to be used for authenticating the SSHUser .

Syntax

property SSHCert: TipfCertificate read get_SSHCert write set_SSHCert;

Remarks

To use public key authentication, SSHCert must contain a Certificate with a valid private key. The certificate's public key value is sent to the server along with a signature produced using the private key. The server will first check to see if the public key values match what is known for the user, and then it will attempt to use those values to verify the signature.

Example 1. User/Password Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example 2. Public Key Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

SSHCompressionAlgorithms Property (SFTPClient Component)

The comma-separated list containing all allowable compression algorithms.

Syntax

property SSHCompressionAlgorithms: String read get_SSHCompressionAlgorithms write set_SSHCompressionAlgorithms;

Default Value

'none,zlib'

Remarks

During the Secure Shell (SSH) handshake, this list will be used to negotiate the compression algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports. Therefore, it is important to list multiple algorithms in preferential order. If no algorithm can be agreed on, the component will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following compression algorithms are supported by the component:

• zlib
• zlib@openssh.com
• none

SSHEncryptionAlgorithms Property (SFTPClient Component)

The comma-separated list containing all allowable encryption algorithms.

Syntax

property SSHEncryptionAlgorithms: String read get_SSHEncryptionAlgorithms write set_SSHEncryptionAlgorithms;

Default Value

'aes256-ctr,aes192-ctr,aes128-ctr,3des-ctr,arcfour256,arcfour128,arcfour,aes256-gcm@openssh.com,aes128-gcm@openssh.com,chacha20-poly1305@openssh.com'

Remarks

During the Secure Shell (SSH) handshake, this list will be used to negotiate the encryption algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports. Therefore, it is important to list multiple algorithms in preferential order. If no algorithm can be agreed on, the component will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following encryption algorithms are supported by the component:

SSHHost Property (SFTPClient Component)

The address of the Secure Shell (SSH) host.

Syntax

property SSHHost: String read get_SSHHost write set_SSHHost;

Default Value

''

Remarks

The SSHHost property specifies the IP address (IP number in dotted internet format) or domain name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If the SSHHost property is set to a domain name, a DNS request is initiated, and upon successful termination of the request, the SSHHost property is set to the corresponding address. If the search is not successful, an error is returned.

The SSHHost must be the same host that will be assumed for SSH as for the remote service being connected to.

SSHPassword Property (SFTPClient Component)

The password for Secure Shell (SSH) password-based authentication.

Syntax

property SSHPassword: String read get_SSHPassword write set_SSHPassword;

Default Value

''

Remarks

SSHPassword specifies the password that is used to authenticate the client to the SSH server.

SSHPort Property (SFTPClient Component)

The port on the Secure Shell (SSH) server where the SSH service is running; by default, 22.

Syntax

property SSHPort: Integer read get_SSHPort write set_SSHPort;

Default Value

22

Remarks

The SSHPort specifies a service port on the SSH host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

SSHUser Property (SFTPClient Component)

The username for Secure Shell (SSH) authentication.

Syntax

property SSHUser: String read get_SSHUser write set_SSHUser;

Default Value

''

Remarks

SSHUser specifies the username that is used to authenticate the client to the SSH server. This property is required.

Example 1. User/Password Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example 2. Public Key Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

StartByte Property (SFTPClient Component)

The offset in bytes at which to begin the upload or download.

Syntax

property StartByte: Int64 read get_StartByte write set_StartByte;

Default Value

0

Remarks

The StartByte property is used by the Upload and Download methods to determine at what offset to begin the transfer. This allows for resuming both uploads and downloads. The value of this property is reset to 0 after a successful transfer. StartByte is not valid for use with Append.

When downloading, this property can be used in conjunction with the TransferredDataLimit configuration setting to download only a specific range of data from the current RemoteFile.

Timeout Property (SFTPClient Component)

The timeout for the component.

Syntax

property Timeout: Integer read get_Timeout write set_Timeout;

Default Value

60

Remarks

If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If Timeout is set to a positive value, the component will wait for the operation to complete before returning control.

The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If Timeout expires, and the operation is not yet complete, the component raises an exception.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

Append Method (SFTPClient Component)

Append data from LocalFile to a remote file RemoteFile on a Secure File Transfer Protocol (SFTP) server.

Syntax

procedure Append();

Remarks

This method is similar to the Upload method, but the local file specified by LocalFile is appended to RemoteFile on the server as opposed to replacing it as with the Upload method. RemoteFile is either an absolute path on the server, or a path relative to RemotePath. The server will create a file with that name if it does not already exist (similar to upload).

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

ChangeRemotePath Method (SFTPClient Component)

Changes the current path on the server.

Syntax

procedure ChangeRemotePath(RemotePath: String);

Remarks

This method changes the current path on the server to the specified RemotePath. When called, the component will issue a command to the server to change the directory. The RemotePath parameter may hold an absolute or relative path.

Absolute Paths

If the path begins with a /, it is considered an absolute path and must specify the entire path from the root of the server. For example:

component.ChangeRemotePath("/home/testuser/myfolder");

Relative Paths

If the path does not begin with a /, it is considered a relative path and is resolved in relation to the current directory. For instance, a value of myfolder will indicate a subfolder of the current directory. The special value .. refers to the parent directory of the current path. For example:

//Change to the 'myfolder' sub-directory component.ChangeRemotePath("myfolder"); //Navigate up two levels and then into the 'another/folder' path. component.ChangeRemotePath("../../another/folder");

CheckFileExists Method (SFTPClient Component)

Returns if the file specified by RemoteFile exists on the remote server.

Syntax

function CheckFileExists(): Boolean;

Remarks

This property returns True if the file exists on the remote server. It returns False if the file does not exist. You must specify the file you wish to check by setting the RemoteFile before calling this method.

If no session is in place, the value of this property will always be False.

Config Method (SFTPClient Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Connect Method (SFTPClient Component)

Connects to the Secure Shell (SSH) host without logging in.

Syntax

procedure Connect();

Remarks

This method establishes a connection with the SSHHost but does not log in. In most cases, it is recommended to use the SSHLogon method, which will both establish a connection and log in to the server.

This method may be useful in cases in which it is desirable to separate the connection and logon operations--for instance, confirming a host is available by first creating the connection.

CreateFile Method (SFTPClient Component)

Creates a file on the Secure File Transfer Protocol (SFTP) server.

Syntax

procedure CreateFile(FileName: String);

Remarks

This method creates an empty file on the server with the name specified by the FileName parameter.

To upload a file with content, use Upload instead.

DecodePacket Method (SFTPClient Component)

Decodes a hex-encoded Secure Shell (SSH) packet.

Syntax

function DecodePacket(EncodedPacket: String): TBytes;

Remarks

This method is used to decode an SSH packet created by EncodePacket.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the SSHCustomAuth event.

DeleteFile Method (SFTPClient Component)

Delete a file specified by FileName from a Secure File Transfer Protocol (SFTP) server.

Syntax

procedure DeleteFile(FileName: String);

Remarks

The remote file or directory specified by FileName is deleted. FileName is either an absolute path on the server or a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

Disconnect Method (SFTPClient Component)

Disconnects from the server without first logging off.

Syntax

procedure Disconnect();

Remarks

This method immediately disconnects from the server without first logging off.

In most cases, the SSHLogoff method should be used to log off and disconnect from the server. Call the Disconnect method in cases in which it is desirable to immediately disconnect without first logging off.

DoEvents Method (SFTPClient Component)

This method processes events from the internal message queue.

Syntax

procedure DoEvents();

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Download Method (SFTPClient Component)

Download a RemoteFile from a Secure File Transfer Protocol (SFTP) server.

Syntax

procedure Download();

Remarks

The remote file specified by RemoteFile is downloaded to the local file specified by LocalFile, or it is retrieved through the Transfer event, if the LocalFile property is '' (empty string). RemoteFile is either an absolute path on the server or is a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

Example. Download a File:

SFTPControl.Localfile = "C:\localfile.txt" SFTPControl.RemoteFile = "remotefile.txt" SFTPControl.Download() SFTPControl.Localfile = "C:\localfile2.txt" SFTPControl.RemoteFile = "folder/remotefile2.txt" SFTPControl.Download()

DownloadRange Method (SFTPClient Component)

DownloadRange facilitates the partial downloading of a remote file from a Secure File Transfer Protocol (SFTP) server.

Syntax

function DownloadRange(Path: String; FileName: String; StartByte: Int64; Count: Integer; var Buffer: TBytes): Integer;

Remarks

This method enables downloading a specific segment of a remote file specified by Path and FileName. StartByte is the offset (in bytes) relative to the beginning of the file from where to start reading, and Count is the number of bytes to read into the specified Buffer.

This functionality is particularly useful for efficient management of large files and targeted data retrieval within them.

Note: If the requested range extends beyond the end of the file, only the available bytes will be returned.

EncodePacket Method (SFTPClient Component)

Hex encodes a Secure Shell (SSH) packet.

Syntax

function EncodePacket(Packet: TBytes): String;

Remarks

This method is used to encode a raw SSH packet created by SetSSHParam.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the SSHCustomAuth event.

GetSSHParam Method (SFTPClient Component)

Reads a field from a Secure Shell (SSH) packet's payload.

Syntax

function GetSSHParam(Payload: TBytes; Field: String): String;

Remarks

This method is used to read the value of a particular field from an SSH packet's payload. Payload should contain the full payload of a packet received by an event such as SSHChannelRequest. Field is the name of a field to be read out of the packet.

The following is a list of the names of well-known channel request field names and their encodings:

The remaining fields that are available in the payload are dependent on the value of RequestType.

pty-req

Pty-req is a request to open a pseudo terminal on the specified channel. The following fields are available:

x11-req

X11-req is a request to forward x11 sessions over a channel. The following fields are available:

env

Env is a request to set an environment variable to be passed into a shell that may be started later. The following fields are available:

exec

Exec is a request to execute a command on the channel using the authenticated user's shell. The following field is available:

subsystem

Subsystem is a request to start a subsystem on the specified channel. The following field is available:

xon-xoff

Xon-xoff instructs the server to allow or disallow control-S/control-Q style flow control. The following field is available:

signal

Sends a signal to the remote process/service. The following field is available:

If the packet type is not well known, Field should start with the special character "%" and contain a comma-separated list of field types as defined in SetSSHParam. For example, reading out the X11AuthProtocol of an x11-req payload, you can use "%s,f".

Note: The return value is a string encoded the same way as the FieldValue param in SetSSHParam.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the SSHCustomAuth event.

GetSSHParamBytes Method (SFTPClient Component)

Reads a field from a Secure Shell (SSH) packet's payload.

Syntax

function GetSSHParamBytes(Payload: TBytes; Field: String): TBytes;

Remarks

This method is the same as calling GetSSHParam, but it returns raw bytes instead of strings.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the SSHCustomAuth event.

Interrupt Method (SFTPClient Component)

This method interrupts the current method.

Syntax

procedure Interrupt();

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

ListDirectory Method (SFTPClient Component)

List the current directory specified by RemotePath on a Secure File Transfer Protocol (SFTP) server.

Syntax

procedure ListDirectory();

Remarks

A listing is requested for the directory (or file mask) specified in RemoteFile. RemoteFile is either an absolute path on the server or is a path relative to RemotePath. The file listing is received through the DirList event.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

MakeDirectory Method (SFTPClient Component)

Creates a directory on a Secure File Transfer Protocol (SFTP) server.

Syntax

procedure MakeDirectory(NewDir: String);

Remarks

A directory with a path specified by NewDir is created on the SFTP server. NewDir is either an absolute path on the server or is a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

QueryFileAttributes Method (SFTPClient Component)

Queries the server for the attributes of RemoteFile .

Syntax

procedure QueryFileAttributes();

Remarks

This method queries the server for attributes of RemoteFile. After calling this method, FileAttributes will be populated with the values returned by the server.

To update attributes, modify the desired values in FileAttributes and call UpdateFileAttributes.

QueueFile Method (SFTPClient Component)

Adds a file to the transfer queue.

Syntax

procedure QueueFile(LocalFile: String; RemoteFile: String);

Remarks

This method adds a file to the queue of files that will be transferred.

It is not required to use this method; however, this method extends the ability of the component to allow for multiple simultaneous file transfers.

To simply transfer a file without using this method, you need only to set LocalFile and RemoteFile and to call Upload or Download, as appropriate. This method allows you to instead queue multiple files before beginning a transfer.

When a file is queued, it will not be transferred until the Upload or Download method is called. If multiple files are queued, the files will be transferred simultaneously. The SimultaneousTransferLimit setting controls the maximum number of simultaneous transfers.

The Upload or Download method will not return until the queue has been completely processed. This method may be called from within events to add additional files to the queue before processing is complete.

To clear the queue, call ResetQueue. This will not affect current transfers.

To cancel an individual file transfer, set the Cancel parameter of the Transfer event to True. The rest of the queue will continue to process as normal.

The Interrupt method may be called to immediately stop all current transfers.

In the event of a file-specific error, the Error event will fire and the LocalFile and RemoteFile event parameters can be used to identify the file to which the error applies.

RemoveDirectory Method (SFTPClient Component)

Remove a directory specified by DirName from a secure file transfer protocol (SFTP) server.

Syntax

procedure RemoveDirectory(DirName: String);

Remarks

A directory with a path specified by DirName is deleted on the SFTP server. DirName is either an absolute path on the server or a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

RenameFile Method (SFTPClient Component)

Change the name of RemoteFile to NewName .

Syntax

procedure RenameFile(NewName: String);

Remarks

The name of the remote file or the folder specified by RemoteFile is changed to NewName. RemoteFile and NewName are either absolute paths on the server or a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

Reset Method (SFTPClient Component)

This method will reset the component.

Syntax

procedure Reset();

Remarks

This method will reset the component's properties to their default values.

ResetQueue Method (SFTPClient Component)

Resets the queue of files to be transferred.

Syntax

procedure ResetQueue();

Remarks

This method will remove all files from the transfer queue.

Calling this method will clear all files that were queued by QueueFile. Calling this method will not affect current transfers.

SetDownloadStream Method (SFTPClient Component)

Sets the stream to which the downloaded data from the server will be written.

Syntax

procedure SetDownloadStream(DownloadStream: TStream);

Remarks

If a download stream is set before the Download method is called, the downloaded data will be written to the stream. The stream should be open and normally set to position 0.

The component will automatically close this stream if CloseStreamAfterTransfer is True (default). If the stream is closed, you will need to call SetDownloadStream again before calling Download again.

The downloaded content will be written starting at the current position in the stream.

Note: SetDownloadStream and LocalFile will reset the other.

SetSSHParam Method (SFTPClient Component)

Writes a field to the end of a payload.

Syntax

function SetSSHParam(Payload: TBytes; FieldType: String; FieldValue: String): TBytes;

Remarks

This method is used to build the payload portion of a Secure Shell (SSH) packet to be sent later by a call to SendSSHPacket. Payload should contain the result of a previous call to SetSSHParam. FieldType is a string defining the type of field to be written to the packet. FieldValue should be the string representation of the field to be written.

The following is a list of supported field types and a description of how FieldValue should be encoded:

Note: Integer values may be hexadecimal encoded by prefixing "0x" to the beginning of the string; otherwise, the value is assumed to be Base10.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the SSHCustomAuth event.

SetUploadStream Method (SFTPClient Component)

Sets the stream from which the component will read data to upload to the server.

Syntax

procedure SetUploadStream(UploadStream: TStream);

Remarks

If an upload stream is set before the Upload method is called, the content of the stream will be read by the component and uploaded to the server. The stream should be open and normally set to position 0. The component will automatically close this stream if CloseStreamAfterTransfer is True (default). If the stream is closed, you will need to call SetUploadStream again before calling Upload again. The content of the stream will be read from the current position all the way to the end and no bytes will be skipped.

Note: SetUploadStream and LocalFile will reset the other.

SSHLogoff Method (SFTPClient Component)

Logs off from the Secure Shell (SSH) server.

Syntax

procedure SSHLogoff();

Remarks

Logs off from the SSH server. If that fails, the connection is terminated by the local host.

SSHLogon Method (SFTPClient Component)

Logs on to the SSHHost using the current SSHUser and SSHPassword .

Syntax

procedure SSHLogon(SSHHost: String; SSHPort: Integer);

Remarks

Logs on to the Secure Shell (SSH) server using the current SSHUser and SSHPassword. This will perform the SSH handshake and authentication.

Example. Logging On:

SSHClient.SSHUser = "username" SSHClient.SSHPassword = "password" SSHClient.SSHLogon("sshHost", sshPort)

UpdateFileAttributes Method (SFTPClient Component)

Instructs the component to send the FileAttributes to the server.

Syntax

procedure UpdateFileAttributes();

Remarks

When UpdateFileAttributes is called, the component will send the values of the following properties to the server:

• AccessTime
• ACL
• AllocationSize
• AttributeBits
• AttributeBitsValid
• CreationTime
• FileType
• GroupId
• IsDir
• ModifiedTime
• OwnerId
• Permissions
• Size

Upload Method (SFTPClient Component)

Upload a file specified by LocalFile to a secure file transfer protocol (SFTP) server.

Syntax

procedure Upload();

Remarks

The local file specified by LocalFile is uploaded to the remote file specified by RemoteFile. RemoteFile is either an absolute path on the server or a path relative to RemotePath.

If a Secure Shell (SSH) session is not in place, one is automatically created by the component first.

If you want to append to a server file, please refer to the Append method.

Example. Upload a File:

FTPControl.LocalFile = "C:\\localfile.txt" FTPControl.RemoteFile = "remotefile.txt" FTPControl.Upload() FTPControl.LocalFile = "C:\\localfile2.txt" FTPControl.RemoteFile = "folder/remotefile2.txt" FTPControl.Upload()

UploadRange Method (SFTPClient Component)

UploadRange inserts data into a remote file on a secure file transfer protocol (SFTP) server.

Syntax

procedure UploadRange(Path: String; FileName: String; StartByte: Int64; Count: Integer; Buffer: TBytes);

Remarks

This method enables uploading a buffer into the remote file specified by the Path and FileName. Count bytes will be updated from the provided Buffer starting in the remote file at the StartByte offset.

This functionality enables precise control over the insertion of data into a remote file, allowing for targeted modifications, overwriting, or additions starting from a specific position within the file.

Note: If the offset specified is beyond the file length, empty bytes will be created between the last file byte and the uploaded buffer.

Connected Event (SFTPClient Component)

Fired immediately after a connection completes (or fails).

Syntax

type TConnectedEvent = procedure (
  Sender: TObject;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnected: TConnectedEvent read FOnConnected write FOnConnected;

Remarks

If the connection is made normally, StatusCode is 0 and Description is 'OK'.

If the connection fails, StatusCode has the error code returned by the Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Please refer to the Error Codes section for more information.

ConnectionStatus Event (SFTPClient Component)

Fired to indicate changes in the connection state.

Syntax

type TConnectionStatusEvent = procedure (
  Sender: TObject;
  const ConnectionEvent: String;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnectionStatus: TConnectionStatusEvent read FOnConnectionStatus write FOnConnectionStatus;

Remarks

This event is fired when the connection state changes: for example, completion of a firewall or proxy connection or completion of a security handshake.

The ConnectionEvent parameter indicates the type of connection event. Values may include the following:

DirList Event (SFTPClient Component)

Fired when a directory entry is received.

Syntax

type TDirListEvent = procedure (
  Sender: TObject;
  const DirEntry: String;
  const FileName: String;
  IsDir: Boolean;
  FileSize: Int64;
  const FileTime: String;
  IsSymlink: Boolean
) of Object;

property OnDirList: TDirListEvent read FOnDirList write FOnDirList;

Remarks

The DirList events are fired when a directory listing is received as a response to a ListDirectory.

The StartTransfer and EndTransfer events mark the beginning and end of the event stream.

The DirEntry parameter contains the filename when ListDirectory is called.

The component tries to fill out the FileName, IsDir, FileSize, and FileTime parameters when calling the ListDirectory method.

The format of the FileTime parameter returned by the component can be controlled through the FileTimeFormat configuration setting. If no format is specified, the component will format the date dependent on the year. If the filetime is in the same year, it will be formatted as "MMM dd HH:mm"; otherwise, it will be formatted as "MMM dd yyyy".

IsSymlink indicates whether the entry is a symbolic link. When the entry is a symbolic link, the value of IsDir will always be False because this information is not returned in the directory listing. To inspect a symlink to determine if it is a link to a file or a folder, set RemoteFile and query the IsDir property.

Disconnected Event (SFTPClient Component)

Fired when a connection is closed.

Syntax

type TDisconnectedEvent = procedure (
  Sender: TObject;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnDisconnected: TDisconnectedEvent read FOnDisconnected write FOnDisconnected;

Remarks

If the connection is broken normally, StatusCode is 0 and Description is 'OK'.

If the connection is broken for any other reason, StatusCode has the error code returned by the Transmission Control Protocol (TCP/IP) subsystem. Description contains a description of this code. The value of StatusCode is equal to the value of the TCP/IP error.

Please refer to the Error Codes section for more information.

EndTransfer Event (SFTPClient Component)

Fired when a file completes downloading or uploading.

Syntax

type TEndTransferEvent = procedure (
  Sender: TObject;
  Direction: Integer;
  const LocalFile: String;
  const RemoteFile: String
) of Object;

property OnEndTransfer: TEndTransferEvent read FOnEndTransfer write FOnEndTransfer;

Remarks

The EndTransfer event fires when either an upload or a download operation completes. This occurs when the file finishes transferring or a directory listing is finished.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

LocalFile identifies the local file. RemoteFile is the remote file.

Error Event (SFTPClient Component)

Fired when errors occur during data delivery.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String;
  const LocalFile: String;
  const RemoteFile: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

LocalFile identifies the local file. RemoteFile is the remote file.

Log Event (SFTPClient Component)

Fired once for each log message.

Syntax

type TLogEvent = procedure (
  Sender: TObject;
  LogLevel: Integer;
  const Message: String;
  const LogType: String
) of Object;

property OnLog: TLogEvent read FOnLog write FOnLog;

Remarks

Fired once for each log message generated by the component. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the detail level of the message. Possible values are as follows:

Message is the log message.

LogType is reserved for future use.

SSHCustomAuth Event (SFTPClient Component)

Fired when the component is doing a custom authentication.

Syntax

type TSSHCustomAuthEvent = procedure (
  Sender: TObject;
  var Packet: String
) of Object;

property OnSSHCustomAuth: TSSHCustomAuthEvent read FOnSSHCustomAuth write FOnSSHCustomAuth;

Remarks

SSHCustomAuth is fired during the user authentication stage of the Secure Shell (SSH) logon process if SSHAuthMode is set to amCustom. Packet contains the last raw SSH packet sent by the server, in HEX-encoded format.

The client should create a new raw SSH packet to send to the server and set Packet to the HEX-encoded representation of the packet to send.

In all cases, Packet will start with the message type field.

To read the incoming packet, call DecodePacket and then use the GetSSHParam and GetSSHParamBytes methods. To create a packet, use the SetSSHParam method and then call EncodePacket to obtain a HEX-encoded value and assign this to the Packet parameter.

SSHKeyboardInteractive Event (SFTPClient Component)

Fired when the component receives a request for user input from the server.

Syntax

type TSSHKeyboardInteractiveEvent = procedure (
  Sender: TObject;
  const Name: String;
  const Instructions: String;
  const Prompt: String;
  var Response: String;
  EchoResponse: Boolean
) of Object;

property OnSSHKeyboardInteractive: TSSHKeyboardInteractiveEvent read FOnSSHKeyboardInteractive write FOnSSHKeyboardInteractive;

Remarks

SSHKeyboardInteractive is fired during the user authentication stage of the Secure Shell (SSH) logon process. During authentication, the component will request a list of available authentication methods for the SSHUser. For example, if the SSHHost responds with "keyboard-interactive", the component will fire this event to allow the client application to set the password.

During authentication, the SSH server may respond with a request for the user's authentication information. Name is a server-provided value associated with the authentication method such as "CRYPTOCard Authentication". Instructions will contain specific instructions, also supplied by the server, for how the user should respond.

Along with these values, the server will also send at least one input Prompt to be displayed to and filled out by the user. Response should be set to the user's input, and will be sent back in the user authentication information response. EchoResponse is a server recommendation for whether or not the user's response should be echoed back during input.

Note: The server may send several prompts in a single packet. The component will fire the SSHKeyboardInteractive event once for each prompt.

SSHServerAuthentication Event (SFTPClient Component)

Fired after the server presents its public key to the client.

Syntax

type TSSHServerAuthenticationEvent = procedure (
  Sender: TObject;
  const HostKey: String;
  const HostKeyB: TBytes;
  const Fingerprint: String;
  const KeyAlgorithm: String;
  const CertSubject: String;
  const CertIssuer: String;
  const Status: String;
  var Accept: Boolean
) of Object;

property OnSSHServerAuthentication: TSSHServerAuthenticationEvent read FOnSSHServerAuthentication write FOnSSHServerAuthentication;

Remarks

This event is fired when the client can decide whether or not to continue with the connection process. If the public key is known to be a valid key for the Secure Shell (SSH) server, Accept should be set to True within the event. Otherwise, the server will not be authenticated and the connection will be broken.

Accept will be True only if either HostKey or Fingerprint is identical to the value of SSHAcceptServerHostKey.

Accept may be set to True manually to accept the server host key.

Note: SSH's security inherently relies on client verification of the host key. Ignoring the host key and always setting Accept to True is strongly discouraged, and could cause potentially serious security vulnerabilities in your application. It is recommended that clients maintain a list of known keys for each server and check HostKey against this list each time a connection is attempted.

Host Key contains the full binary text of the key, in the same format used internally by SSH.

Fingerprint holds the SHA-256 hash of HostKey in the hex-encoded form: 0a:1b:2c:3d. To configure the hash algorithm used to calculate this value, see SSHFingerprintHashAlgorithm.

KeyAlgorithm identifies the host key algorithm. The following values are supported:

• ssh-rsa
• ssh-dss
• rsa-sha2-256
• rsa-sha2-512
• x509v3-sign-rsa
• x509v3-sign-dss
• ecdsa-sha2-nistp256
• ecdsa-sha2-nistp384
• ecdsa-sha2-nistp521

CertSubject is the subject of the certificate. This is applicable only when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

CertIssuer is the issuer of the certificate. This is applicable only when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

Status is reserved for future use.

SSHStatus Event (SFTPClient Component)

Fired to track the progress of the secure connection.

Syntax

type TSSHStatusEvent = procedure (
  Sender: TObject;
  const Message: String
) of Object;

property OnSSHStatus: TSSHStatusEvent read FOnSSHStatus write FOnSSHStatus;

Remarks

The event is fired for informational and logging purposes only. Used to track the progress of the connection.

StartTransfer Event (SFTPClient Component)

Fired when a file starts downloading or uploading.

Syntax

type TStartTransferEvent = procedure (
  Sender: TObject;
  Direction: Integer;
  const LocalFile: String;
  const RemoteFile: String
) of Object;

property OnStartTransfer: TStartTransferEvent read FOnStartTransfer write FOnStartTransfer;

Remarks

The StartTransfer event fires when a data interface connection is created. This occurs when the file starts transferring or a directory listing is started.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

LocalFile identifies the local file. RemoteFile is the remote file.

Transfer Event (SFTPClient Component)

Fired during file download or upload.

Syntax

type TTransferEvent = procedure (
  Sender: TObject;
  Direction: Integer;
  const LocalFile: String;
  const RemoteFile: String;
  BytesTransferred: Int64;
  PercentDone: Integer;
  const Text: String;
  const TextB: TBytes;
  var Cancel: Boolean
) of Object;

property OnTransfer: TTransferEvent read FOnTransfer write FOnTransfer;

Remarks

One or more Transfer events are fired during file transfer. The BytesTransferred parameter shows the number of bytes transferred since the beginning of the transfer.

Text contains the portion of the file data being delivered.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

LocalFile identifies the local file. RemoteFile is the remote file.

The PercentDone parameter shows the progress of the transfer in the corresponding direction. If PercentDone can not be calculated the value will be -1.

To cancel the current transfer, set Cancel to True.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

>

constructor Create();

constructor Create(valEncoded: TBytes);

constructor Create(valStoreType: TipfCertStoreTypes; valStore: String; valStorePassword: String; valSubject: String);

constructor Create(valStoreType: TipfCertStoreTypes; valStore: TBytes; valStorePassword: String; valSubject: String);

DirEntry Type

This is a listing in a directory returned from the server.

Remarks

The DirEntry listings are filled out by the component when a directory listing is received as a response to a ListDirectory or ListDirectoryLong call. The server returns a listing for each directory and file at the current path that exists. This listing is parsed into a directory entry.

If ListDirectoryLong is called, all of the fields listed below are supplied by the server. When the ListDirectory method is called, however, the FileSize, FileTime, and IsDir fields all are left empty by the server. In this case, the only field it returns is the FileName.

The full line for the directory entry is provided by the Entry field.

Fields

Constructors

constructor Create();

Firewall Type

The firewall the component will connect through.

Remarks

When connecting through a firewall, this type is used to specify different properties of the firewall, such as the firewall Host and the FirewallType.

Fields

Constructors

constructor Create();

SFTPFileAttributes Type

Includes a set of attributes for a file existing on an secure file transfer protocol (SFTP) server.

Remarks

This type describes a file residing on an SFTP server.

Fields

Config Settings (SFTPClient Component)

SFTPClient Config Settings

SSHClient Config Settings

*SSH-1.99-*,*SSH-2.0-*,*SSH-2.99-*

TCPClient Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (SFTPClient Component)

SFTPClient Errors

SSHClient Errors

The component may also return one of the following error codes, which are inherited from other components.

TCPClient Errors

TCP/IP Errors