SFTPClient Component

Properties   Methods   Events   Config Settings   Errors  

The SFTPClient component provides client-side functionality for SFTP (Secure File Transfer Protocol).

Syntax

TsbxSFTPClient

Remarks

SFTP is a file transfer subsystem that runs on top of secure shell (SSH) connection. This means that SFTP uses the whole strength of security provided by the SSH protocol, at the same time providing strong file transfer capabilities.

Please do keep in mind that there exist two protocols that offer similar secure file transfer features. SFTP works on top of SSH and normally uses port 22. FTPS works on top of TLS (or SSL) and normally uses ports 21 and 990. The protocols are very different, so please make sure you are after the right component. This component works with SFTP. Use the FTPClient component to connect to FTPS servers.

Below are the typical steps that let you integrate SFTPClient to your project:

• Set up your Username and Password. SSH uses mandatory client-side authentication, so in most cases you need to provide your username, your password, or, sometimes, your private key. Use Key property to provide your key, if needed.
• Be ready to handle server authentication, which is also mandatory in SSH. SSH operates a concept of a trusted keys file, where keys of known servers are stored. You can assign a path to your own trusted keys file to the TrustedKeysFile property. When a client receives a server key, it reports it to your code via its KnownKeyReceived or UnknownKeyReceived event, depending on whether the key was found in the trusted list. If you leave TrustedKeysFile empty, SFTPClient will only be able to fire the UnknownKeyReceived event, since there will be no known keys to report.
• If needed, customize Proxy parameters and SSHSettings.
• Consider interacting more with SFTPClient by subscribing to AuthAttempt, AuthFailed, and AuthSucceeded events to be notified about the client authentication progress.
• When you are ready to connect, call Connect, passing the details of the server as parameters. During the initial handshake, the following events will fire: UnknownKeyReceived (or KnownKeyReceived), and then one or more AuthAttempt, AuthFailed and AuthSucceeded.
• Upon completion of the Connect method, the component is ready for file operations. Use DownloadFile, UploadFile, ListDir, DeleteFile and other file transfer methods to work with the server file system.
• When you are done with your work, call Disconnect to close the connection.

Some SFTP servers, primarily older ones, may expose various transfer issues. If you come across a weird issue that you believe should not be happening (such as repeated connection closures in the middle of the transfer), please try adjusting the following properties:

• AutoAdjustTransferBlock to false,
• PipelineLength to 1,
• UploadBlockSize to 16384,
• DownloadBlockSize to 16384.

These adjustments will put SFTPClient in very conservative transfer setup. While this setup may be quite sluggish with modern servers, it should make SFTPClient interoperable with most older servers.

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.

AuthAttempts Property (SFTPClient Component)

Specifies the number of SSH authentication attempts.

Syntax

property AuthAttempts: Integer read get_AuthAttempts write set_AuthAttempts;

Default Value

1

Remarks

Use this property to specify the number of authentication attempts to try. The AuthFailed event is fired for every failed attempt.

AutoAdjustTransferBlock Property (SFTPClient Component)

Specifies whether to adjust the send and receive buffer sizes automatically.

Syntax

property AutoAdjustTransferBlock: Boolean read get_AutoAdjustTransferBlock write set_AutoAdjustTransferBlock;

Default Value

true

Remarks

Automatic transfer block size adjustment may be beneficial for maximizing interoperability and achieving the best transfer speeds.

Use DownloadBlockSize, UploadBlockSize, and PipelineLength properties to adjust the transfer settings manually.

Connected Property (SFTPClient Component)

Indicates if the client is connected to the SFTP server.

Syntax

property Connected: Boolean read get_Connected;

Default Value

false

Remarks

Use this read-only property to check whether the client is connected to the server.

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

ConnectionInfo Property (SFTPClient Component)

Contains the secure connection info.

Syntax

property ConnectionInfo: TsbxSSHInfo read get_ConnectionInfo;

Remarks

This property contains various information about the secure connection.

This property is read-only.

Please refer to the SSHInfo type for a complete list of fields.

CurrentListEntry Property (SFTPClient Component)

Contains the current entry returned by ListDir .

Syntax

property CurrentListEntry: TsbxSFTPListEntry read get_CurrentListEntry;

Remarks

Use this property to access the current list entry as returned by ListDir call. Entries are passed back to the application one by one, with ListEntry thrown for each entry.

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

Please refer to the SFTPListEntry type for a complete list of fields.

DownloadBlockSize Property (SFTPClient Component)

The download block size in bytes.

Syntax

property DownloadBlockSize: Integer read get_DownloadBlockSize write set_DownloadBlockSize;

Default Value

65536

Remarks

Use this property to manually control the size of download blocks. Typically you will only need to adjust this property if the default transfer settings (AutoAdjustTransferBlock) don't work.

ExternalCrypto Property (SFTPClient Component)

Provides access to external signing and DC parameters.

Syntax

property ExternalCrypto: TsbxExternalCrypto read get_ExternalCrypto;

Remarks

Use this property to tune-up remote cryptography settings. SecureBlackbox supports two independent types of external cryptography: synchronous (based on the ExternalSign event) and asynchronous (based on the DC protocol and the DCAuth signing component).

This property is read-only.

Please refer to the ExternalCrypto type for a complete list of fields.

FIPSMode Property (SFTPClient Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

ForceCompression Property (SFTPClient Component)

Enforces compression for the SSH layer.

Syntax

property ForceCompression: Boolean read get_ForceCompression write set_ForceCompression;

Default Value

false

Remarks

Set this property before opening a connection to enforce compression of the SSH packets.

Key Property (SFTPClient Component)

Contains the client's SSH key.

Syntax

property Key: TsbxSSHKey read get_Key write set_Key;

Remarks

Use this property to provide the client's SSH key for authentication. Note that you may start with providing the public part of the key, and only complete it with the private part in response to PrivateKeyNeeded event.

Alternative, you may load the private key straightaway.

This property is not available at design time.

Please refer to the SSHKey type for a complete list of fields.

MaxSFTPVersion Property (SFTPClient Component)

Higher SFTP version to support.

Syntax

property MaxSFTPVersion: Integer read get_MaxSFTPVersion write set_MaxSFTPVersion;

Default Value

6

Remarks

MaxSFTPVersion and MinSFTPVersion properties control the range of SFTP protocol versions supported by this client.

MinSFTPVersion Property (SFTPClient Component)

Lower SFTP version to support.

Syntax

property MinSFTPVersion: Integer read get_MinSFTPVersion write set_MinSFTPVersion;

Default Value

0

Remarks

MaxSFTPVersion and MinSFTPVersion properties control the range of SFTP protocol versions to be supported by this client.

Password Property (SFTPClient Component)

Specifies user's authentication password.

Syntax

property Password: String read get_Password write set_Password;

Default Value

''

Remarks

Use this property to provide an authentication password. This property is only applicable for password-based and keyboard-interactive authentication types.

PipelineLength Property (SFTPClient Component)

The number of parallelized transfer requests.

Syntax

property PipelineLength: Integer read get_PipelineLength write set_PipelineLength;

Default Value

32

Remarks

This property controls the number of upload/download requests sent simultaneously. This speeds the transfer up, but may lead to issues with older/immature servers.

Typically you will only need to adjust this property if the default transfer settings (AutoAdjustTransferBlock) don't work.

Proxy Property (SFTPClient Component)

The proxy server settings.

Syntax

property Proxy: TsbxProxySettings read get_Proxy;

Remarks

Use this property to tune up the proxy server settings.

This property is read-only.

Please refer to the ProxySettings type for a complete list of fields.

ServerKey Property (SFTPClient Component)

Returns the server's public key.

Syntax

property ServerKey: TsbxSSHKey read get_ServerKey;

Remarks

Use this property to check the details of the server public key.

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

Please refer to the SSHKey type for a complete list of fields.

SocketSettings Property (SFTPClient Component)

Manages network connection settings.

Syntax

property SocketSettings: TsbxSocketSettings read get_SocketSettings;

Remarks

Use this property to tune up network connection parameters.

This property is read-only.

Please refer to the SocketSettings type for a complete list of fields.

SSHSettings Property (SFTPClient Component)

The SSH connection settings.

Syntax

property SSHSettings: TsbxSSHSettings read get_SSHSettings;

Remarks

Use this property to access and tune-up the SSH layer settings.

This property is read-only.

Please refer to the SSHSettings type for a complete list of fields.

TrustedKeysFile Property (SFTPClient Component)

A file containing the keys of authorized servers.

Syntax

property TrustedKeysFile: String read get_TrustedKeysFile write set_TrustedKeysFile;

Default Value

''

Remarks

Use this property to provide a path to the 'authorized_keys' file to be used by the client.

UploadBlockSize Property (SFTPClient Component)

The upload block size in bytes.

Syntax

property UploadBlockSize: Integer read get_UploadBlockSize write set_UploadBlockSize;

Default Value

32256

Remarks

Use this property to manually control the size of upload blocks. Typically you will only need to adjust this property if the default transfer settings (AutoAdjustTransferBlock) don't work.

Username Property (SFTPClient Component)

The client's username to authenticate to the server.

Syntax

property Username: String read get_Username write set_Username;

Default Value

''

Remarks

Use this property to provide an authentication username (login). This property is only applicable for password-based and keyboard-interactive authentication types.

UseUTF8 Property (SFTPClient Component)

Enables UTF8 for all string content.

Syntax

property UseUTF8: Boolean read get_UseUTF8 write set_UseUTF8;

Default Value

false

Remarks

If UseUTF8 is true, the component expects all downloaded filenames to be encoded in UTF-8. Set UseUTF8 to false if you connect to a server that does not support UTF8 (e.g., OpenSSH). In this case the file names will be interpreted in the default character set.

Version Property (SFTPClient Component)

The SFTP version negotiated.

Syntax

property Version: Integer read get_Version;

Default Value

0

Remarks

Use this property to get the negotiated SFTP version.

This property is read-only.

AbsolutePath Method (SFTPClient Component)

Requests the absolute path for a relative path.

Syntax

function AbsolutePath(RemotePath: String): String;

Remarks

Use this method to ask the SFTP server to convert a relative path to an absolute.

ChangeDir Method (SFTPClient Component)

Changes current working directory on the server.

Syntax

procedure ChangeDir(RemoteDir: String);

Remarks

Changes current working directory on the server to RemoteDir.

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 an SFTP server.

Syntax

procedure Connect(Address: String; Port: Integer);

Remarks

Use this method to connect to the SFTP server identified via its Address and Port.

CreateLink Method (SFTPClient Component)

Creates a symbolic or hard link to a remote file.

Syntax

procedure CreateLink(LinkPath: String; TargetPath: String; HardLink: Boolean);

Remarks

Use this method to create a symbolic or hard link on the server. Provide the name of the new link object via the LinkPath parameter, and the destinating file or directory path via the TargetPath parameter. HardLink specifies whether the new link should be hard (true) or symbolic (false).

DeleteDir Method (SFTPClient Component)

Removes directory from the SFTP server.

Syntax

procedure DeleteDir(RemoteDir: String);

Remarks

Use RemoteDir to provide a path to the directory to be deleted.

DeleteFile Method (SFTPClient Component)

Deletes a file from the SFTP server.

Syntax

procedure DeleteFile(RemoteFile: String);

Remarks

Use the RemoteFile parameter to specify the name of the file to delete.

DeleteFiles Method (SFTPClient Component)

Deletes a group of files from the SFTP server.

Syntax

procedure DeleteFiles(RemotePath: String; Mask: String; CaseSensitive: Boolean; Recursive: Boolean);

Remarks

Use this method to delete a group of files from the SFTP server. Specify the files to be deleted via RemotePath and Mask parameters. Use CaseSensitive and Recursive parameters to tune up the operation.

This method is a more efficient way to delete a group of files than deleting them one by one.

DirExists Method (SFTPClient Component)

Checks if a directory exists on the SFTP server.

Syntax

function DirExists(RemoteDir: String): Boolean;

Remarks

RemoteDir specifies the name of the remote directory to check for existence.

Disconnect Method (SFTPClient Component)

Disconnects from the SFTP server.

Syntax

procedure Disconnect();

Remarks

Call this method to disconnect from the SFTP server.

DoAction Method (SFTPClient Component)

Performs an additional action.

Syntax

function DoAction(ActionID: String; ActionParams: String): String;

Remarks

DoAction is a generic method available in every component. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

DownloadBytes Method (SFTPClient Component)

Downloads a file from the server into an array of bytes.

Syntax

function DownloadBytes(RemoteFile: String): TBytes;

Remarks

Use this method to download RemoteFile into a byte array.

DownloadFile Method (SFTPClient Component)

Downloads a file from the SFTP server.

Syntax

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

Remarks

Use this method to download RemoteFile into the location specified by LocalFile.

DownloadFiles Method (SFTPClient Component)

Downloads multiple files from the SFTP server.

Syntax

procedure DownloadFiles(RemotePath: String; LocalDir: String);

Remarks

RemotePath contains a file mask or regular expression by which the files are selected for download.

LocalDir specifies the local folder where the files should be saved.

DownloadStream Method (SFTPClient Component)

Downloads a file from the SFTP server.

Syntax

procedure DownloadStream(RemoteFile: String; LocalStream: TStream);

Remarks

Use this method to download RemoteFile into a LocalStream object.

ExecuteSSHCommand Method (SFTPClient Component)

Sends an SSH command to the server in the middle of SFTP session.

Syntax

function ExecuteSSHCommand(Command: String): TBytes;

Remarks

Use this command to send an SSH command to the server in the middle of an SFTP session. The command is executed in a secondary channel, so the SFTP connection is not affected.

This method is suitable for simple commands that do not require interaction with the user. The call returns the command output.

ExtensionCmd Method (SFTPClient Component)

Sends an extension command to the server.

Syntax

function ExtensionCmd(Extn: String; DataBuffer: TBytes): TBytes;

Remarks

Use this method to send an extension command to the SFTP server. Provide the extension type via the Extn parameter, and the request body via the DataBuffer parameter.

Upon completion of the command, the method returns the response as received from the server.

FileExists Method (SFTPClient Component)

Checks whether a file exists on the server.

Syntax

function FileExists(RemoteFile: String): Boolean;

Remarks

Use this method to check if a RemoteFile exists on the server.

GetCurrentDir Method (SFTPClient Component)

Returns the current directory on the SFTP server.

Syntax

function GetCurrentDir(): String;

Remarks

Use this method to retrieve the current directory as stored by the component. This is a virtualized current directory, as SFTP protocol does not maintain a concept of the current directory.

GetFileSize Method (SFTPClient Component)

Checks the size of a remote file.

Syntax

function GetFileSize(RemoteFile: String): Int64;

Remarks

Returns the size of the RemoteFile.

ListDir Method (SFTPClient Component)

Lists the content of the current remote directory.

Syntax

function ListDir(IncludeFiles: Boolean; IncludeDirectories: Boolean): String;

Remarks

IncludeFiles specifies whether file names and symlinks should be included in the results. IncludeDirectories specifies whether directory names should be included in the result.

Upon receiving the listing, the component will report each entry in it via ListEntry event.

MakeDir Method (SFTPClient Component)

Creates a new directory on the server.

Syntax

procedure MakeDir(RemoteDir: String);

Remarks

RemoteDir specifies the name of the new directory.

RenameFile Method (SFTPClient Component)

Renames a file.

Syntax

procedure RenameFile(SourceFile: String; DestFile: String);

Remarks

Use this method to rename a remote file. Provide the old and the new name via SourceFile and DestFile parameters.

RequestAttributes Method (SFTPClient Component)

Requests attributes of the remote file.

Syntax

function RequestAttributes(RemotePath: String; FollowSymLinks: Boolean): String;

Remarks

Use this method to request attributes of a remote file. Pass the name of the file via the RemotePath parameter, and use FollowSymLinks to specify whether symbolic links should be resolved.

The method returns the list of attributes as a line of semicolon-separated entries: Size=78220;Owner=user@system;Group=none@system;Permissions=432;ATime=2020-04-28 08:21:00.295;MTime=2020-04-28 08:21:00.302;CTime=2020-04-28 08:21:00.295;AttribBits=24;LinkCount=1.

SetAttributes Method (SFTPClient Component)

Sets the attributes upon a remote file.

Syntax

procedure SetAttributes(RemotePath: String; Attributes: String);

Remarks

Use this method to set the attributes of a remote file.

UploadBytes Method (SFTPClient Component)

Uploads a byte array to the server.

Syntax

procedure UploadBytes(Bytes: TBytes; RemoteFile: String);

Remarks

Use this method to upload Bytes or its part to RemoteFile on the server.

UploadFile Method (SFTPClient Component)

Uploads a file to the server.

Syntax

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

Remarks

Use this method to upload LocalFile to the RemoteFile location on the server.

UploadFiles Method (SFTPClient Component)

Uploads multiple files to the server.

Syntax

procedure UploadFiles(LocalPath: String; RemoteDir: String);

Remarks

Use this property to upload a batch of files to the server.

LocalPath specifies a wildcard or regular expression by which the local files are picked for uploading. RemoteDir specifies the location on the server where these files should be saved.

UploadStream Method (SFTPClient Component)

Uploads a file to the server.

Syntax

procedure UploadStream(LocalStream: TStream; RemoteFile: String);

Remarks

Use this method to upload the contents of LocalStream to the RemoteFile location on the server.

AuthAttempt Event (SFTPClient Component)

Fires when an authentication attempt is performed.

Syntax

type TAuthAttemptEvent = procedure (
  Sender: TObject;
  AuthType: Integer
) of Object;

property OnAuthAttempt: TAuthAttemptEvent read FOnAuthAttempt write FOnAuthAttempt;

Remarks

This event signals the start of an authentication attempt. The AuthType parameter specifies the authentication type. This event may be fired more than once if the client tries different authentication methods one after another.

Supported authentication types:

AuthFailed Event (SFTPClient Component)

Fires if an authentication attempt fails.

Syntax

type TAuthFailedEvent = procedure (
  Sender: TObject;
  AuthType: Integer
) of Object;

property OnAuthFailed: TAuthFailedEvent read FOnAuthFailed write FOnAuthFailed;

Remarks

This event fires if an authentication attempt fails (for example, if a bad password had been provided). AuthType parameter indicates the authentication type.

AuthFailed may be fired more than once, depending on the configured authentication parameters and the value assigned to the AuthAttempts property.

This event does not necessarily lead to connection abortion, as the client may still have a chance of authenticating with a different method.

Supported authentication types:

AuthSucceeded Event (SFTPClient Component)

Reports a successful authentication.

Syntax

type TAuthSucceededEvent = procedure (
  Sender: TObject
) of Object;

property OnAuthSucceeded: TAuthSucceededEvent read FOnAuthSucceeded write FOnAuthSucceeded;

Remarks

This event marks the completion of the authentication procedure, and signifies transition to the SSH connection subprotocol.

Banner Event (SFTPClient Component)

Reports the receipt of the Welcome message from the server.

Syntax

type TBannerEvent = procedure (
  Sender: TObject;
  Text: TBytes;
  Language: TBytes
) of Object;

property OnBanner: TBannerEvent read FOnBanner write FOnBanner;

Remarks

The component fires this event when it receives a welcome message from the server. Use the Text parameter to access the encoded message.

Disconnect Event (SFTPClient Component)

Reports SFTP connection closure.

Syntax

type TDisconnectEvent = procedure (
  Sender: TObject;
  CloseReason: Integer
) of Object;

property OnDisconnect: TDisconnectEvent read FOnDisconnect write FOnDisconnect;

Remarks

The component fires this event to report connection closure. No more SFTP activity could be done after the disconnect.

Error Event (SFTPClient Component)

Information about errors during SFTP connection.

Syntax

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

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The event is fired in case of exceptional conditions during data transfer.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of error codes please refer to SFTP.

ExternalSign Event (SFTPClient Component)

Handles remote or external signing initiated by the SignExternal method or other source.

Syntax

type TExternalSignEvent = procedure (
  Sender: TObject;
  const OperationId: String;
  const HashAlgorithm: String;
  const Pars: String;
  const Data: String;
  var SignedData: String
) of Object;

property OnExternalSign: TExternalSignEvent read FOnExternalSign write FOnExternalSign;

Remarks

Assign a handler to this event if you need to delegate a low-level signing operation to an external, remote, or custom signing engine. Depending on the settings, the handler will receive a hashed or unhashed value to be signed.

The event handler must pass the value of Data to the signer, obtain the signature, and pass it back to the component via the SignedData parameter.

OperationId provides a comment about the operation and its origin. It depends on the exact component being used, and may be empty. HashAlgorithm specifies the hash algorithm being used for the operation, and Pars contains algorithm-dependent parameters.

The component uses base16 (hex) encoding for the Data, SignedData, and Pars parameters. If your signing engine uses a different input and output encoding, you may need to decode and/or encode the data before and/or after the signing.

A sample MD5 hash encoded in base16: a0dee2a0382afbb09120ffa7ccd8a152 - lower case base16 A0DEE2A0382AFBB09120FFA7CCD8A152 - upper case base16

A sample event handler that uses the .NET RSACryptoServiceProvider class may look like the following: signer.OnExternalSign += (s, e) => { var cert = new X509Certificate2("cert.pfx", "", X509KeyStorageFlags.Exportable); var key = (RSACryptoServiceProvider)cert.PrivateKey; var dataToSign = e.Data.FromBase16String(); var signedData = key.SignHash(dataToSign, "2.16.840.1.101.3.4.2.1"); e.SignedData = signedData.ToBase16String(); };

FileOperation Event (SFTPClient Component)

Signifies the start of a file transfer operation.

Syntax

type TFileOperationEvent = procedure (
  Sender: TObject;
  Operation: Integer;
  const RemotePath: String;
  const LocalPath: String;
  var Skip: Boolean;
  var Cancel: Boolean
) of Object;

property OnFileOperation: TFileOperationEvent read FOnFileOperation write FOnFileOperation;

Remarks

This event is fired each time the component starts an upload or download operation within a multi-file call. Operation defines the operation about to start, RemotePath specifies the name and path to the remote file, and LocalPath specifies the name and path to the local file.

If needed, set Skip to true to ignore the current file, or Cancel to abort the whole batch.

Supported operations:

FileOperationResult Event (SFTPClient Component)

Signifies the completion of a file transfer operation.

Syntax

type TFileOperationResultEvent = procedure (
  Sender: TObject;
  Operation: Integer;
  const RemotePath: String;
  const LocalPath: String;
  ErrorCode: Integer;
  const Comment: String;
  var Cancel: Boolean
) of Object;

property OnFileOperationResult: TFileOperationResultEvent read FOnFileOperationResult write FOnFileOperationResult;

Remarks

This event is fired each time the component completes a file transfer within a multi-file call. Operation defines the operation performed on the file, RemotePath specifies the name and path to the remote file, and LocalPath specifies the name and path to the local file.

ErrorCode and Comment return the code and textual description of the error, if it was encountered.

Set Cancel to True to cancel the multi-file operation.

Supported operations:

KnownKeyReceived Event (SFTPClient Component)

Signals that the server has introduced itself with a known key.

Syntax

type TKnownKeyReceivedEvent = procedure (
  Sender: TObject;
  const Algorithm: String;
  Bits: Integer;
  const FingerprintSHA256: String
) of Object;

property OnKnownKeyReceived: TKnownKeyReceivedEvent read FOnKnownKeyReceived write FOnKnownKeyReceived;

Remarks

The component fires this event to tell the application that the server has introduced itself with a known key from TrustedKeysFile.

The details of the key are provided: Algorithm and Bits specify the key algorithm and the number of bits. FingerprintSHA256 contains the key's fingerprint.

Use ServerKey to access more key details.

ListEntry Event (SFTPClient Component)

Reports a directory listing entry to the application.

Syntax

type TListEntryEvent = procedure (
  Sender: TObject;
  const Filename: String
) of Object;

property OnListEntry: TListEntryEvent read FOnListEntry write FOnListEntry;

Remarks

The component fires this event to report a directory listing entry to the application. FileName contains the entry name.

Use CurrentListEntry to access the details of the entry.

Notification Event (SFTPClient Component)

This event notifies the application about an underlying control flow event.

Syntax

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the component, the exact action it is performing, or the document being processed, one or both may be omitted.

PasswordChangeRequest Event (SFTPClient Component)

Signals that the server requests a password change.

Syntax

type TPasswordChangeRequestEvent = procedure (
  Sender: TObject;
  const Prompt: String;
  var NewPassword: String;
  var Cancel: Boolean
) of Object;

property OnPasswordChangeRequest: TPasswordChangeRequestEvent read FOnPasswordChangeRequest write FOnPasswordChangeRequest;

Remarks

The component fires this event to pass the password change request from the server to the application. This event is fired during the SSH handshake.

PrivateKeyNeeded Event (SFTPClient Component)

Asks the application for the client's private key.

Syntax

type TPrivateKeyNeededEvent = procedure (
  Sender: TObject;
  var Skip: Boolean
) of Object;

property OnPrivateKeyNeeded: TPrivateKeyNeededEvent read FOnPrivateKeyNeeded write FOnPrivateKeyNeeded;

Remarks

The component fires this event if the public key provided in Key was accepted by the server, but no private key is available for it.

Use this event handler to attach the private key to your Key. The component will pick the key up and continue the authentication.

Progress Event (SFTPClient Component)

Fires periodically during the data transfer.

Syntax

type TProgressEvent = procedure (
  Sender: TObject;
  Total: Int64;
  Current: Int64;
  var Cancel: Boolean
) of Object;

property OnProgress: TProgressEvent read FOnProgress write FOnProgress;

Remarks

Use this event to check the progress of an upload or download operation. Total indicates the total number of bytes to be transferred; Current specifies how much data has been transferred so far, and Cancel gives you a chance to cancel the operation.

UnknownKeyReceived Event (SFTPClient Component)

Signals that the server has introduced itself with an unknown key.

Syntax

type TUnknownKeyReceivedEvent = procedure (
  Sender: TObject;
  const Algorithm: String;
  Bits: Integer;
  const FingerprintSHA256: String;
  var Action: Integer
) of Object;

property OnUnknownKeyReceived: TUnknownKeyReceivedEvent read FOnUnknownKeyReceived write FOnUnknownKeyReceived;

Remarks

The component fires this event to tell the application that the server has introduced itself with a key not present in TrustedKeysFile.

The details of the key are provided: Algorithm and Bits specify the key algorithm and the number of bits. FingerprintSHA256 contains the key's fingerprint.

In this event handler, you need to make a decision whether to proceed with the connection. Use Action to tell the component what it should do with the key:

Note that accepting an unknown and unchecked key may be risky.

ExternalCrypto Type

Specifies the parameters of external cryptographic calls.

Remarks

External cryptocalls are used in a Distributed Cryptography (DC) subsystem, which allows the delegation of security operations to the remote agent. For instance, it can be used to compute the signature value on the server, while retaining the client's private key locally.

Fields

Constructors

>

constructor Create();

Creates a new ExternalCrypto object with default field values.

ProxySettings Type

A container for proxy server settings.

Remarks

This type exposes a collection of properties for tuning up the proxy server configuration.

Fields

Constructors

>

constructor Create();

Creates a new ProxySettings object.

SFTPListEntry Type

A container for filesystem element's attributes.

Remarks

This type contains attributes of a single entry returned by a ListDir command.

The contents of this container may differ for different servers (not all servers support all attributes).

Fields

Constructors

>

constructor Create();

Creates a new SFTPListEntry object.

SocketSettings Type

A container for the socket settings.

Remarks

This type is a container for socket-layer parameters.

Fields

Constructors

>

constructor Create();

Creates a new SocketSettings object.

SSHInfo Type

Contains information about SSH connection.

Remarks

SSHInfo object contains information about one SSH connection.

Fields

Constructors

>

constructor Create();

Creates an empty object representing a SSH connection info.

SSHKey Type

SSHKey is used to store information about single compound public-key algorithm (such as RSA or DSA) key.

Remarks

SSH keys are used to secure the SSH protocol flow. They support different algorithms and key lengths, a very typical example being RSA-2048 bits.

Fields

Constructors

>

constructor Create();

Creates a new key.

SSHSettings Type

A container for various SSH protocol settings.

Remarks

SSHSettings stores various settings of SSH client or server.

Fields

Constructors

>

constructor Create();

Creates a new object with default settings.

Config Settings (SFTPClient Component)

The component accepts one or more of the following configuration settings. Configuration 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.

SFTPClient Config Settings

Base Config Settings

Trappable Errors (SFTPClient Component)

SFTPClient Errors

	1048577   Invalid parameter value (SB_ERROR_INVALID_PARAMETER)
	1048578   Component is configured incorrectly (SB_ERROR_INVALID_SETUP)
	1048579   Operation cannot be executed in the current state (SB_ERROR_INVALID_STATE)
	1048580   Attempt to set an invalid value to a property (SB_ERROR_INVALID_VALUE)
	1048581   Certificate does not have its private key loaded (SB_ERROR_NO_PRIVATE_KEY)
	1048581   Cancelled by the user (SB_ERROR_CANCELLED_BY_USER) 
	31457281   Unsupported file operation (SB_ERROR_SFTP_UNSUPPORTED_FILEOPERATION)