Articles and news

SFTPPlus Release 3.46.0

Mon 11 March 2019 | general release

We are announcing the latest release of SFTPPlus version 3.46.0.

New Features

  • The HTTP/HTTPS file transfer service now supports downloading multiple files at once as a Zip file. [server-side][web-api][http][https] [#5093]
  • It is now possible to set up password expiration for accounts and groups. [server-side][security] [#5146]
  • It is now possible to configure the preferred size of the group in the SSH Diffie-Hellman group key exchange method. [server-side][sftp][scp] [#5205]
  • The file dispatcher event handler now supports the copy action. This will copy the source file to one or more destinations, without removing the source file. [server-side][client-side] [#5210]
  • The file dispatcher event handler now supports the rename action. This will rename the source file (with an atomic move operation) without overwriting an existing file. [server-side][client-side] [#5220]

Defect Fixes

  • An event is now emitted when a file is closed after it was open for reading through the HTTP file transfer service. [server-side][http][https] [#5093]
  • The HTTP/HTTPS file transfer service now responds with 401 Unauthorized for requests made with 100 Continue when no credentials are provided in the request. [server-side][http][https] [#5223]

You can check the full release notes here.

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FTP client uploads with temporary names

Thu 21 February 2019 | ftp client-side blog

A drawer with file tabs.

When closely investigating managed file transfers, pushing a file to a remote FTP server turns out to be just a phase in a series of interlinked processes.

Once the file arrives on the FTPS server, it is read and further processed. The next step might involve downloading the file or copying it to another processing area.

When uploading a large file, copying or pulling it before completing the transfer can result in corrupted file data. For example, a pull operation might start before the file is fully uploaded, with only a fragment of the original file available for download.

Another common case in which data corruption may happen is when a partial upload occurs because of connection failures during transfer. A client starts sending a file to the server, but at some point connection is lost. Maybe the client VM was powered off unexpectedly or the network became temporarily unavailable for too long. This will result in a partial file being left on the server, which can be accidentally processed by the next stage in our process.

This is a serious issue with FTP and FTPS connections. FTP protocols do not mandate sending the total file size before an upload. Furthermore, they do not make use of an explicit end-of-file marker. An FTP client signals the completion of an upload by simply closing the data connection.

To mitigate this problem, a file locking mechanism can be implemented by uploading files using temporary names and then renaming them back to their initial names once all the data was pushed by the client.

Clients like WinSCP will use temporary names formed by appending a non-configurable .filepart extension to the initial file names.

In SFTPPlus you can configure a file transfer to use any suffix / extension during the upload, you are not restricted to the .filepart one. . For example, you can use the .tmp or .incomplete extensions.

Screenshot with transfer destination in SFTPPlus.

By using temporary names you can implement a process in which transferred files are locked while their contents are being uploaded. The chained process will ignore files with temporary names, only handling transferred files after the final rename operation.

On most file systems the rename operation is atomic and very fast.

The same technique can be used to lock a file while uploading through SFTP transfers.

The SCP protocol does not provide a rename operation, but the total file size is advertised in the SCP upload request, which happens before the client starts pushing the content of the file.

Read more about transferring files with temporary names in our documentation page.

Evaluating SFTPPlus MFT

The features listed in this article are just a selected few out of many integration and configuration options that are available today. Feel free to talk to the Support team about your requirements with file transfer software.

SFTPPlus MFT Server supports FTP, Explicit FTPS, Implicit FTPS, SFTP, SCP, HTTP and HTTPS.

SFTPPlus MFT is available as an on-premise solution supported on Windows, Linux, AIX, MacOS, Solaris, HP-UX, and FreeBSD.

It is also available on the cloud as Docker containers, AWS or Azure instances and many other cloud providers.

Request a trial using the form below.

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Restrict user with trusted IPs for SFTP and FTPS

Fri 15 February 2019 | security blog

Computer security illustration.

It is common practice to secure a file transfer server using firewall rules which only allow incoming connections from trusted partners.

Let's assume you have a US partner named "ACME Inc", connecting to your server from IP 1.1.1.1 using the user acme-inc, and another German partner called "AlleWerkzeuge AG", connecting to your server from IP 5.5.5.5 using the user alle-werkzeuge-ag.

You can configure your firewall to only allow connections from a list of trusted IPs like 1.1.1.1 and 5.5.5.5, but the firewall doesn't know about usernames. So it will allow the account acme-inc to connect even if the connection is initiated from 5.5.5.5, which is an IP outside of the ACME Inc network.

To complement firewall restrictions, SFTPPlus allows defining a fixed list of trusted IP rules from which it will allow connections for a specific user.

Such a configuration can be defined per user, but also per group, with multiple users inheriting their configuration from the group.

To restrict a specific user to connect through SFTP or FTPS to the file transfer server only from a certain IP (or IPs), you can use the source_ip_filter configuration option in SFTPPlus.

The remote access is denied when the user connects from a source address which is not whitelisted.

Below is a screenshot from our web-based management console demonstrating such a configuration.

Screenshot of SFTPlus account configuration.

Read more about securing your SFTP/FTPS and HTTPS services with SFTPPlus in our documentation page.

Evaluating SFTPPlus MFT

The features listed in this article are just a selected few out of many integration and configuration options that are available today. Feel free to talk to the Support team about your requirements with file transfer software.

SFTPPlus MFT Server supports FTP, Explicit FTPS, Implicit FTPS, SFTP, SCP, HTTP and HTTPS.

SFTPPlus MFT is available as an on-premise solution supported on Windows, Linux, AIX, MacOS, Solaris, HP-UX, and FreeBSD.

It is also available on the cloud as Docker containers, AWS or Azure instances and many other cloud providers.

Request a trial using the form below.

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SFTPPlus Release 3.45.0

Thu 14 February 2019 | general release

We are announcing the latest release of SFTPPlus version 3.45.0.

New Features

  • It is now possible for SFTP/SCP clients to change their own password using the SSH command execution service. [server-side][sftp][scp] [#5129]
  • It is now possible to transfer files using temporary names, renaming to their initial names once successfully transferred. [client-side] [#5156]
  • Events emitted when a file is closed after a server-side SFTP or SCP transfer now include transferred size, duration, and average speed. [server-side][scp][sftp] [#5196]
  • You can now configure an account to allow authentication only from a specific list of source IP addresses. [server-side][security] [#5201]

Defect Fixes

  • The SFTP/SCP file transfer service no longer generates an internal server error when the SCP protocol is requested as an SSH subsystem. [server-side][scp] [#5129]
  • For move transfers, the removal of the source file is now retried when the operation fails. In previous versions, once the file was transferred, the source removal was attempted only once. [client-side] [#5156-1]
  • The transfer of a file is now retried when the operation to check the existence of the remote file fails. [client-side] [#5156]
  • For the SCP protocol, the event with ID 30042 is no longer emitted when the client is sending the whole file without an end of file marker. In previous versions, if the SCP client uploaded all the file data, but did not send the explicit confirmation for the end of file or stream, SFTPPlus was emitting the event 30042 to inform that the transfer was not complete. [server-side][scp] [#5196]

Deprecations and Removals

  • The events emitted for rename operations now have the destination path as the default path attribute. In previous versions the source path was used. The from attribute will contain the source path. The following event IDs are affected: 60043, 60044, 30025, 30026, 30027 [server-side][client-side] [#5156]
  • Support for FreeBSD 10.x on X86_64 was removed. [#5170]

You can check the full release notes here.

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Get email notifications from your FTP and SFTP servers

Thu 31 January 2019 | article

Introduction

Email notification article banner

SFTPlus can connect to any STMP servers and deliver emails based on the activity, actions and events triggered by a file transfer.

With SFTPPlus you can configure the list of recipients (with CC and BCC), email subject and email body.

The email notification can be use for FTPS or SFTP server monitoring and reporting, or just for critical failure/error conditions.

For example, you can trigger an email notification, whenever a SFTP file upload fails on your file transfer service. In this way, you can automatically monitor the server for new files and be notified when you got new files which failed to be fully uploaded.

Operation principles

An Email client resource is created inside the SFTPPlus configuration in order to define the STMP server address, port and credentials.

For each type / category of email notifications, create a separate Send as email event handlers.

Each event handler has a set of filters which determined the condition under which the emails are triggered. For example, you can trigger on all file upload to your site, or only on uploads from a certain user.

Multiple event handlers can use a single email client resource to deliver the emails.

Integration with Email Delivery Services

Using the standard STMP protocol, SFTPPlus can send email alerts using any of the cloud based email delivery services.

If your SFTP server is hosted with Azure, you might want to use the Sendgrid service. For FTP servers hosted with Amazon EC2 you might want to use the Amazon SES service.

Note that for Amazon EC2, port 25 is throttled. You should use port 587 instead.

Check our dedicated documentation page to see how to configure email alerts in SFTPPlus.

This resource is written as of SFTPPlus version 3.44.0.

Evaluating SFTPPlus MFT

The features listed in this article are just a selected few out of many integration and configuration options that are available today. Feel free to talk to the Support team about your requirements with file transfer software.

SFTPPlus MFT Server supports FTP, Explicit FTPS, Implicit FTPS, SFTP, SCP, HTTP and HTTPS.

SFTPPlus MFT is available as an on-premise solution supported on Windows, Linux, AIX, MacOS, Solaris, HP-UX, and FreeBSD.

It is also available on the cloud as Docker containers, AWS or Azure instances and many other cloud providers.

Request a trial using the form below.

Email Alerts Services That You Should Use image used in this article was created by Amit Agarwal and is licensed under CC BY 2.0 / Cropped from original.

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