SFTP Component

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The SFTP component can be used to transfer files to and from SFTP servers using the SFTP Protocol.

Syntax

TibeSFTP

Remarks

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

The SFTP 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 is 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 (SFTP Component)

This shows whether the component is connected.

Syntax

property Connected: Boolean read get_Connected write set_Connected;

Default Value

false

Remarks

This property is used to determine whether or not the component is connected to the remote host.

Note: It is recommended to use the Connect or Disconnect method instead of setting this property.

This property is not available at design time.

DirList Property (SFTP Component)

Collection of entries resulting in the last directory listing.

Syntax

property DirList: TibeDirEntryList read get_DirList;

Remarks

This collection 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, 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 (SFTP Component)

The attributes of the RemoteFile .

Syntax

property FileAttributes: TibeSFTPFileAttributes 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 then call UpdateFileAttributes.

This property is not available at design time.

FileExists Property (SFTP Component)

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

Syntax

property FileExists: Boolean read get_FileExists;

Default Value

false

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 prior to calling this method.

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

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

Firewall Property (SFTP Component)

A set of properties related to firewall access.

Syntax

property Firewall: TibeFirewall 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 (SFTP Component)

The current status of the component.

Syntax

property Idle: Boolean read get_Idle;

Default Value

true

Remarks

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

This property is read-only.

LocalFile Property (SFTP Component)

The path to a local file for upload/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 only be overwritten 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 (SFTP 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

The LocalHost 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 multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

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 multi-homed 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 (SFTP 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 in the client side.

Overwrite Property (SFTP Component)

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 (SFTP Component)

The name of the remote file for uploading, downloading, etc.

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 (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 (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 (SFTP Component)

The current path in the SFTP server.

Syntax

property RemotePath: String read get_RemotePath write set_RemotePath;

Default Value

''

Remarks

The RemotePath shows the current working directory on the SFTP server. It can also be used to change the working directory by setting it to an absolute directory path, or a relative path with respect to the existing value of RemotePath.

If the first two bytes of the new path are '..', then a change to one level above in the directory tree is performed.

Setting RemotePath causes the component to send the appropriate command to the remote server only if connected.

Example (Changing Directory)

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

Note:It is recommended to use the ChangeRemotePath method instead of setting this property.

SSHAcceptServerHostKeyEncoded Property (SFTP Component)

This is the certificate (PEM/Base64 encoded).

Syntax

property SSHAcceptServerHostKeyEncoded: String read get_SSHAcceptServerHostKeyEncoded write set_SSHAcceptServerHostKeyEncoded;
property SSHAcceptServerHostKeyEncodedB: TBytes read get_SSHAcceptServerHostKeyEncodedB write set_SSHAcceptServerHostKeyEncodedB;

Default Value

''

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The Store and Subject properties also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

This property is not available at design time.

SSHAuthMode Property (SFTP Component)

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

Syntax

property SSHAuthMode: TibeTSSHAuthModes read get_SSHAuthMode write set_SSHAuthMode;

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

Default Value

amPassword

Remarks

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

SSHCertEncoded Property (SFTP Component)

This is the certificate (PEM/Base64 encoded).

Syntax

property SSHCertEncoded: String read get_SSHCertEncoded write set_SSHCertEncoded;
property SSHCertEncodedB: TBytes read get_SSHCertEncodedB write set_SSHCertEncodedB;

Default Value

''

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The Store and Subject properties also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

This property is not available at design time.

SSHCertStore Property (SFTP Component)

This is the name of the certificate store for the client certificate.

Syntax

property SSHCertStore: String read get_SSHCertStore write set_SSHCertStore;
property SSHCertStoreB: TBytes read get_SSHCertStoreB write set_SSHCertStoreB;

Default Value

'MY'

Remarks

This is the name of the certificate store for the client certificate.

The StoreType property denotes the type of the certificate store specified by Store. If the store is password protected, specify the password in StorePassword.

Store is used in conjunction with the Subject property to specify client certificates. If Store has a value, and Subject or Encoded is set, a search for a certificate is initiated. Please see the Subject property for details.

Designations of certificate stores are platform dependent.

The following designations are the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

SSHCertStorePassword Property (SFTP Component)

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

property SSHCertStorePassword: String read get_SSHCertStorePassword write set_SSHCertStorePassword;

Default Value

''

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

SSHCertStoreType Property (SFTP Component)

This is the type of certificate store for this certificate.

Syntax

property SSHCertStoreType: TibeCertStoreTypes read get_SSHCertStoreType write set_SSHCertStoreType;

TibeCertStoreTypes = (
  cstUser,
  cstMachine,
  cstPFXFile,
  cstPFXBlob,
  cstJKSFile,
  cstJKSBlob,
  cstPEMKeyFile,
  cstPEMKeyBlob,
  cstPublicKeyFile,
  cstPublicKeyBlob,
  cstSSHPublicKeyBlob,
  cstP7BFile,
  cstP7BBlob,
  cstSSHPublicKeyFile,
  cstPPKFile,
  cstPPKBlob,
  cstXMLFile,
  cstXMLBlob,
  cstJWKFile,
  cstJWKBlob,
  cstSecurityKey,
  cstBCFKSFile,
  cstBCFKSBlob,
  cstPKCS11,
  cstAuto
);

Default Value

cstUser

Remarks

This is the type of certificate store for this certificate.

The component supports both public and private keys in a variety of formats. When the cstAuto value is used, the component will automatically determine the type. This property can take one of the following values:

SSHCertSubject Property (SFTP Component)

This is the subject of the certificate used for client authentication.

Syntax

property SSHCertSubject: String read get_SSHCertSubject write set_SSHCertSubject;

Default Value

''

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

If a field value contains a comma, it must be quoted.

SSHCompressionAlgorithms Property (SFTP Component)

A 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 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, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, 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 (SFTP Component)

A 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,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,arcfour256,arcfour128,arcfour,cast128-cbc,aes256-gcm@openssh.com,aes128-gcm@openssh.com,chacha20-poly1305@openssh.com'

Remarks

During the 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, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, 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 (SFTP Component)

The address of the 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 (SFTP Component)

The password for SSH password-based authentication.

Syntax

property SSHPassword: String read get_SSHPassword write set_SSHPassword;

Default Value

''

Remarks

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

SSHPort Property (SFTP Component)

The port on the 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 (SFTP Component)

The username for SSH authentication.

Syntax

property SSHUser: String read get_SSHUser write set_SSHUser;

Default Value

''

Remarks

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

Example (User/Password Auth): Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): 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 (SFTP 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 in order to only download a specific range of data from the current RemoteFile.

Timeout Property (SFTP Component)

A 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.

Please note that by default, all timeouts are inactivity timeouts, i.e. 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 (SFTP Component)

Append data from LocalFile to a remote file RemoteFile on an SFTP server.

Syntax

procedure Append();

Remarks

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 done by 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 doesn't already exist (similar to Upload).

If there is no SSH session in place, one is automatically created by the component first.

ChangeRemotePath Method (SFTP 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 and absolute path and must specify the entire path from the root of the server. For instance:

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 sub-folder of the current directory. The special value .. refers to the parent directory of the current path. For instance:

//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 (SFTP 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 prior to calling this method.

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

Config Method (SFTP 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 (SFTP Component)

Connects to the 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 where it is desirable to separate the connection and logon operations, for instance confirming a host is available by first creating the connection.

CreateFile Method (SFTP Component)

Creates a file on the 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 (SFTP Component)

Decodes a hex-encoded 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 only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

DeleteFile Method (SFTP Component)

Remove a file specified by FileName from an 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 there is no SSH session in place, one is automatically created by the component first.

Disconnect Method (SFTP Component)

This method 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 logoff and disconnect from the server. Call the Disconnect method in cases where it is desirable to immediately disconnect without first logging off.

DoEvents Method (SFTP Component)

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 (SFTP Component)

Download a RemoteFile from an 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 a path relative to RemotePath.

If there is no SSH session 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()

EncodePacket Method (SFTP Component)

Hex encodes an 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 only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

GetSSHParam Method (SFTP Component)

Used to read a field from an 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 upon 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

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 only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

GetSSHParamBytes Method (SFTP Component)

Used to read a field from an SSH packet's payload.

Syntax

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

Remarks

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

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

Interrupt Method (SFTP Component)

Interrupt the current method.

Syntax

procedure Interrupt();

Remarks

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

ListDirectory Method (SFTP Component)

List the current directory specified by RemotePath on an 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 a path relative to RemotePath. The file listing is received through the DirList event.

If there is no SSH session in place, one is automatically created by the component first.

MakeDirectory Method (SFTP Component)

Create a directory on an SFTP server.

Syntax

procedure MakeDirectory(NewDir: String);

Remarks

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

If there is no SSH session in place, one is automatically created by the component first.

QueryFileAttributes Method (SFTP 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 (SFTP 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 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 set LocalFile, RemoteFile, and 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 in order 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 and 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 (SFTP Component)

Remove a directory specified by DirName from an SFTP server.

Syntax

procedure RemoveDirectory(DirName: String);

Remarks

A directory with 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 there is no SSH session in place, one is automatically created by the component first.

RenameFile Method (SFTP Component)

Change the name of RemoteFile to NewName .

Syntax

procedure RenameFile(NewName: String);

Remarks

The name of remote file or 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 there is no SSH session in place, one is automatically created by the component first.

Reset Method (SFTP Component)

Reset the component.

Syntax

procedure Reset();

Remarks

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

ResetQueue Method (SFTP 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 (SFTP 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 (SFTP Component)

Used to write 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 an 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 encoded in hexadecimal by prefixing "0x" to the beginning of the string, otherwise the value is assumed to be base-10.

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

SetUploadStream Method (SFTP 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 (SFTP Component)

Logoff from the SSH server.

Syntax

procedure SSHLogoff();

Remarks

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

SSHLogon Method (SFTP Component)

Logon to the SSHHost using the current SSHUser and SSHPassword .

Syntax

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

Remarks

Logon to the 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 (SFTP 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 (SFTP Component)

Upload a file specified by LocalFile to an 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 there is no SSH session 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()

Connected Event (SFTP Component)

This event is 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 (SFTP Component)

This event is 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

The ConnectionStatus 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 (SFTP 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 since this information is not returned in the directory listing. To inspect a symlink to determine if it is a link to a file or folder set RemoteFile and query the IsDir property.

Disconnected Event (SFTP Component)

This event is 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 (SFTP Component)

Fired when a file completes downloading/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 is when the file finishes transferring and/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 (SFTP Component)

Information about errors 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 (SFTP Component)

Fires 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

This event fires once for each log messages generated by the component. The verbosity is controlled by the LogLevel setting.

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

Message is the log message.

LogType is reserved for future use.

SSHCustomAuth Event (SFTP Component)

Fired when the component is doing 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 SSH logon process if SSHAuthMode is set to amCustom. Packet contains the raw last 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 (SFTP 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 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 (SFTP Component)

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

Syntax

type TSSHServerAuthenticationEvent = procedure (
  Sender: TObject;
  HostKey: String;
  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 where the client can decide whether to continue with the connection process or not. If the public key is known to be a valid key for the 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 that 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. Supported values are:

• 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 only applicable when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

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

Status is reserved for future use.

SSHStatus Event (SFTP Component)

Shows 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 (SFTP Component)

Fired when a file starts downloading/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 is when the file starts transferring and/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 (SFTP Component)

Fired during file download/upload.

Syntax

type TTransferEvent = procedure (
  Sender: TObject;
  Direction: Integer;
  const LocalFile: String;
  const RemoteFile: String;
  BytesTransferred: Int64;
  PercentDone: Integer;
  Text: String;
  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.

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

A set of attributes for a file existing on an SFTP server..

Remarks

This type describes a file residing on an SFTP server.

Fields

Config Settings (SFTP Component)

SFTP Config Settings

SSHClient Config Settings

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

Base Config Settings

Trappable Errors (SFTP Component)

SFTP 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