For issues that might arise using the latest SSH Client versions, see Known issues.
Changes in Bitvise SSH Client 8.46: [ 16 January 2021 ]
Since version 8.45, the SSH Client now uses SFTP v6 file open block flags SSH_FXF_BLOCK_WRITE and SSH_FXF_BLOCK_ADVISORY if the server advertises support for them. This helps avoid corruption of files while they are being transferred. We have received a report of a server that advertises support for these flags, but fails an open request if the flags are used. The SSH Client will now repeat an open request that fails this way, without the flags.
When using Bitvise SSH Client command line clients sftpc, stermc, sexec, stnlc or spksc using a -keypairFile parameter that points to an encrypted keypair in non-Bitvise format, but without a -keypairPassphrase parameter that would provide a decryption passphrase, the SSH Client would display a cryptic error. The error is now less cryptic.
Changes in Bitvise SSH Client 8.45: [ 30 December 2020 ]
If the automatic update process encountered an error while downloading a new version installer from the primary download location, resulting in a partial executable being stored; and if download was then successful from the secondary download location; the resulting executable would be corrupted. Fixed.
Improved the automatic update locking mechanisms.
When displaying the host key received from the server, the SSH Client will now display the signature algorithm (e.g. RSA over SHA-256) rather than just the host key algorithm (e.g. RSA).
When the SSH Client was started hidden in the system notification area, it would cause a phantom Alt-Tab menu entry to appear. Fixed.
When uploading files using SFTP v6; and if the server advertises support for either the block flag SSH_FXF_BLOCK_WRITE or the combination SSH_FXF_BLOCK_WRITE | SSH_FXF_BLOCK_ADVISORY; then the SSH Client will request one of these block flags when opening the file. This is to prevent premature actions by other server-side processes or file transfer clients that can modify or corrupt the file before the upload is complete.
Uploading to a blind drop location that does not permit a directory listing could crash the SFTP window or the SSH Client process. Fixed.
For improved compatibility with blind drops, it is now possible to navigate the Local and Remote panes to any location, even one that results in an error or does not allow a directory listing. An error dialog will be displayed when attempting to list such a directory, but it is now possible to try transferring files to or from such locations regardless.
The log utility would output its own newlines as CRLF, but would record newlines from child processes as they were written by the process. If the child process used LF newlines (without CR), the output newline convention would be inconsistent. The log utility now consistently outputs newlines as CRLF.
Changes in Bitvise SSH Client 8.44: [ 4 October 2020 ]
Bitvise SSH Client and FlowSsh will now recognize servers with "Maverick_SSHD" and "GoAnywhere" in their SSH version strings as variants of "J2SSH_Maverick". This means Bitvise SSH Client and FlowSsh will no longer send SSH_MSG_EXT_INFO by default to such servers. See the previous compatibility change for J2SSH_Maverick, in version history for Bitvise SSH Client and FlowSsh versions 8.42.
If a client authentication key has been accepted by the server for authentication, the SSH Client will no longer prevent its use due to the server's server-sig-algs extension. In addition, the SSH Client will now log if a key is not used due to this extension.
A new or reset profile will no longer open a terminal and SFTP window automatically, by default. This improves behavior when connecting to servers that limit SSH sessions to a single concurrent channel. Automatic opening of these windows can still be enabled using the same settings on the Options tab.
The SSH Client's buttons would be hidden under Windows UI elements in Windows 10 Tablet mode. Fixed.
The SSH Client will now display clearer information when an update is available but cannot be started.
When using xterm and other non-bvterm protocols, the graphical SSH Client and stermc now support the sending of the following Alt + key combinations: Alt + Left Arrow, Right Arrow, Up Arrow, Down Arrow, Backspace, Page Up and Page Down. In addition, the graphical client also supports Alt + Enter. Alt + Enter is not supported in stermc because it is used by the Windows console to enter or exit full-screen mode.
When using xterm and other non-bvterm protocols, the speed of screen painting in the graphical SSH Client is now significantly improved.
The graphical SSH Client and stermc now support a terminal window resize initiated by an escape sequence from the server.
The graphical SSH Client and stermc will now accept xterm's 16-color and 256-color sequences even when regular xterm is in use (as opposed to xterm-16color or xterm-256color). This better supports programs such as byobu that send these sequences under plain xterm.
When switching between normal and alternate screens, the SSH Client would fail to clear the alternate screen. Fixed.
When using xterm and other protocols except bvterm and ANSI, the SSH Client would previously start set to use "application" cursor keys. To start with "standard" cursor keys, the setting Alt. cursor keys had to be enabled, or in stermc the parameter -altCurs had to be used.
The SSH Client will now start by default using "standard" cursor keys. The relevant setting has been replaced with App. cursor keys, and stermc now supports the parameter -appCurs to start instead with "application" cursor keys.
Changed Unicode character widths for about 6% of assigned Unicode code points from 0 to 1, and for another ~8% of code points from 2 to 1. This aligns more closely with character widths used by servers and avoids unintended discrepancies in rendering.
On the Terminal tab, the SSH Client's Default colors dialog now provides both the "Old Windows" and "New Windows" palette options. To match use of colors in other terminals, the New Windows palette is now the default choice. Previously, it was xterm.
The command line terminal client, stermc, now also supports the new palette choices using the -palette parameter.
When using bvterm, the new Windows 10 console produces cursor artifacts when the cursor is moved outside the viewport. The SSH Client now takes steps to avoid this.
SSH Server Remote Control Panel:
When using the CSV export feature in the SSH Server Remote Control Panel for SSH Server versions 8.xx, the CSV export would fail if the data contained a reversibly encrypted password or secret key. Fixed.
Changes in Bitvise SSH Client 8.43: [ 22 May 2020 ]
The SSH Client adds its installation directory to the system PATH environment variable when installing, but did not remove it when uninstalling. The SSH Client installation directory is now removed from PATH when uninstalling. Reinstallations or upgrades from version 8.43 will briefly remove and then re-add the SSH Client installation directory to PATH.
Certain versions of the Pragma Fortress SSH server - including the most recent version when testing - can send a corrupted SSH authentication banner where an inexact, duplicate copy of the banner message is included before the language tag. SSH Client versions 7.xx and earlier could connect because they ignored the language tag, but SSH Client 8.xx versions would not because they check that the language tag does not exceed an unreasonable length.
The SSH Client now allows an exception for this server where the incorrect encoding is ignored. If the server cannot be identified as "Pragma FortressSSH", the language tag length check remains enforced.
Previously, an implied command such as the following:
sexec user@host dir /?
... would incorrectly cause command line clients including sftpc, stermc and sexec to display their own help text instead of invoking the remote command as specified. Fixed.
The graphical SSH Client now detects and warns about an insecure installation directory in an expanded, more thorough set of circumstances.
In version 8.42, the -sendExtInfo=... parameter was added to command line clients. An equivalent setting, Send EXT_INFO, is now also available in the graphical client, on the SSH tab.
Fixed an issue with auto-completion which could cause the SFTP graphical interface to dead-lock.
Changes in Bitvise SSH Client 8.42: [ 9 May 2020 ]
The SSH Client no longer supports installation on Windows 10 versions 1507 and 1511. These versions contain a flawed cryptographic implementation which prevents a number of SSH algorithms from working correctly. The lowest Windows 10 version supported is 1607.
During an initial, interactive installation; when installing into a non-default directory (e.g. outside of C:\Program Files (x86)\); the SSH Client installer will attempt to detect if any parent of the installation directory grants insecure permissions for non-administrative users. The installer will display a warning about installing into such insecure directories.
When updating an installation in such a directory, the update will succeed, but the graphical SSH Client will display a warning.
Some versions of Nvidia Surround modify Windows behavior in a way such that the window manager doesn't respect the SSH Client's fixed window width setting. The graphical SSH Client now works around this issue.
In the Host key manager interface, a host key could be incorrectly placed into the wrong recognized vs. unrecognized category if there were keys in both categories. Fixed.
The command-line clients sftpc, sexec, stermc, stnlc and spksc now support the command-line parameter -sendExtInfo=n so that the user can disable sending of the client-side SSH_MSG_EXT_INFO message to a server which advertises support, but does not actually support it.
Command-line clients will no longer display unnecessary warnings about failing to load update settings if the SSH Client was installed in an unattended manner and the graphical SSH Client has not yet been run.
In rare circumstances, an SSH session could terminate in such a way that the SSH Client would crash. Fixed.
The CrushFTP server, and other servers based on the J2SSH Maverick implementation, may advertise support for SSH_MSG_EXT_INFO (RFC 8308), but have a bug where the server disconnects if the client sends this message. Bitvise SSH Client and FlowSsh now attempt to detect these servers based on their SSH version strings, and disable sending of the client-side SSH_MSG_EXT_INFO if detected.
OpenSSH 6.2 and 6.3 can be configured to enable AES GCM, but crash if it is used. Bitvise software versions 8.42 and higher will now disable AES GCM if the remote version string indicates an affected OpenSSH version.
The SFTP server which identifies itself as "SSH-2.0-SFTP Server" has a flawed SFTP v4+ text mode implementation. The default transfer mode with this server will now be Binary instead of AutoStd.
The dialog interface for the Mirror feature could require multiple clicks on the OK button. Fixed.
Remote Desktop forwarding:
The SSH Client now delays deletion of the Remote Desktop profile that mstsc is launched with. This is intended to improve compatibility with Windows on ARM64.
The SSH Client's graphical terminal window implementation for classical terminals (xterm and other non-bvterm terminals) now implements improved mouse wheel scrolling, properly accumulating mouse wheel deltas.
Some versions of Cmder have an issue which causes the Windows function ScrollConsoleScreenBuffer to fail unexpectedly. The bvterm client now works around this issue.
Changes in Bitvise SSH Client 8.38: [ 12 January 2020 ]
The SSH Client now supports machine-wide automatic update settings which can override user-specific settings. The SSH Client installer also supports command line parameters to configure automatic update settings.
Changes in Bitvise SSH Server's terminal subsystem in versions 8.xx have made the bvterm protocol unreasonably slow with certain console applications. Bitvise SSH Server and SSH Client versions 8.38 implement optimizations in both the server and client to address these issues.
sftpc: Pressing Esc on an empty line would incorrectly re-issue the last command. Fixed.
When public key or private key import fails, a more accurate error message will now be displayed in certain cases.
Changes in Bitvise SSH Client 8.37: [ 25 November 2019 ]
- When connecting through a proxy, if the setting Resolve DNS names locally was enabled, the SSH Client would often resolve DNS names remotely (via the proxy) anyway. Fixed.
Security Notification: [ 27 October 2019 ]
Authors of the Minerva attack have identified a small but significant timing information leak in the Crypto++ implementation of ECDSA over prime field curves. This attack may allow discovery of a private key through repeated observation of signature timing. If the leak can be utilized, an attacker could compromise a server host key or a client authentication key using a practical number of connections across a network.
The following is the impact on Bitvise SSH Server, SSH Client and FlowSsh versions before 8.36:
On all recent Windows versions (Vista and higher), there is no effect on users of Bitvise software versions 7.xx and 8.xx who use private keys of algorithms RSA, Ed25519, or ECDSA over the NIST curves nistp256, nistp384 or nistp521. On all recent versions of Windows, and using recent Bitvise software versions, these algorithms use Windows cryptography, which is unaffected by Minerva. In the case of Ed25519, we similarly use a non-Crypto++ implementation, which is unaffected.
On all versions of Windows, using all versions of Bitvise software, the Minerva issue may apply to users who generated, and are using, host keys or client keys of type ECDSA/secp256k1. Bitvise software versions 8.35 and earlier use Crypto++ to implement this algorithm on all platforms. We encourage such users to update to our latest software versions.
On Windows XP and Windows Server 2003, regardless of Bitvise software version; and for Bitvise software versions 5.xx and 6.xx, regardless of Windows version; the Minerva issue may apply to users of ECDSA private keys of any type. We encourage such users to update to our latest software versions, and/or to update to newer versions of Windows.
With Bitvise SSH Server, SSH Client and FlowSsh 8.36, we are releasing the following mitigations:
On all recent Windows versions (Vista and higher), where we previously used Crypto++ to support ECDSA/secp256k1, we are switching to alternatives. If the version of Windows is recent enough (for example, Windows 10, Windows Server 2016 and 2019), our default cryptographic provider (CiWinCng) now uses Windows cryptography to support ECDSA/secp256k1 as well as ECDH/secp256k1. Where Windows does not support secp256k1 (for example, Windows Vista to 8.1 and Windows Server 2008 to 2012 R2), we now support it using OpenSSL.
On Windows XP and Windows Server 2003, we face the issue that maintained cryptographic libraries that continue to support these platforms are hard to switch to and harder to find, while the number of users is small and diminishing. In current versions, we continue to rely on Crypto++ on these platforms, but implement mitigations to make it harder or impossible to observe signature timing across the network.
On all versions of Windows, we continue to use Crypto++ to support non-standard DSA keys. These are DSA keys as used in SSH of size other than 1024 bits. Since versions 7.xx, we have discouraged the use of DSA keys of any size. Also, DSA is not within scope of the Minerva research, so the current attack does not apply directly. Nevertheless, because we use Crypto++ to support non-standard DSA keys on all platforms, we now activate mitigations for these keys to make it harder or impossible to observe signature timing remotely.
Changes in Bitvise SSH Client 8.36: [ 27 October 2019 ]
On Windows 10, Windows Server 2016 and 2019, the algorithms ECDSA/secp256k1 and ECDH/secp256k1 now use Windows cryptography. As a result, these algorithms are now also available when FIPS mode is enabled in Windows.
On Windows Vista to 8.1, and Windows Server 2008 to 2012 R2, the algorithms ECDSA/secp256k1 and ECDH/secp256k1 now use OpenSSL instead of Crypto++. As a side effect, use of these algorithms on Windows Vista now requires at least Service Pack 1 (OpenSSL will fail to initialize on Vista without service packs).
On Windows XP and Windows Server 2003, our software continues to use Crypto++ for all algorithms, but implements mitigations to make it harder or impossible to observe signature timing remotely. Continuing support for these Windows versions is increasingly impractical for multiple reasons including cryptography. Like Microsoft and other software vendors have done, we will need to stop supporting these platforms eventually, but we still support them right now.
When using single-click Remote Desktop forwarding, the SSH Client now runs mstsc.exe using its full system path. Previously, if the SSH Client was run by double-clicking a profile, and there was a copy of mstsc.exe or an impostor executable in the same directory, the potentially unintended executable would be run.
The SSH Client can now import OpenSSH private keys encrypted using CTR mode algorithms.
Changes in Bitvise SSH Client 8.35: [ 20 August 2019 ]
With version 8.17, the profile settings RDP > Authentication > Password and Store encrypted password in profile were changed to take effect the same way as similar settings under Login > Authentication, but their UI layout was not updated. Fixed.
Changes in Bitvise SSH Client 8.34: [ 17 June 2019 ]
When creating a new profile or when using the SSH Client's command line clients (sftpc, sexec, stermc, stnlc, spksc) without the -profile=... parameter, the SSH Client will now by default prefer Curve25519 and ECDH key exchange over traditional Diffie Hellman. Classic DH is significantly slower and more computationally expensive, while there continues to be no known reason to de-prefer Elliptic Curve cryptography. Existing profiles are unaffected and will keep their algorithm preference order.
In Windows 10 version 1903, when using the Open action or when double-clicking a file whose extension has no file association, Windows may no longer offer to select a program with which to open the file, but may instead fail the action. The SSH Client will now automatically use Open with if the Open action fails in this manner.
The SFTP GUI now supports mouse button 4 to trigger the Back action and mouse button 5 to trigger Forward, in a manner consistent with common browsers.
There exist interim, but deployed versions of SSH implementations including SmartFTP which implement the no-flow-control extension based on a previous, non-final draft where the extension value was empty. Bitvise SSH Server, SSH Client and FlowSsh will now no longer disconnect when receiving an unrecognized no-flow-control extension value, but will attempt to continue; and will now treat an empty value as if the remote party sent "p" (for "preferred").
Polished a few issues in BvSshUpdate, the SSH Client's command-line version update utility.
Changes in Bitvise SSH Client 8.32: [ 6 May 2019 ]
sftpc: Fixed an issue which prevented the -cmdFile=... parameter from working if the file contained only a single line without a line terminator.
Fixed an issue in how command line clients (sftpc, sexec, stermc, stnlc, spksc) were initializing the default key exchange algorithm list. This caused the following issues:
If the -gkx parameter (or its -sspi alias) was passed to enable GSSAPI (Kerberos) key exchange, the requisite GSS key exchange algorithms had to be additionally enabled via -profile=..., -kexAlgs=... or -kexMod=.... The -gkx and -sspi parameters will now again correctly enable GSS key exchange algorithms as intended.
Outdated key exchange algorithms, such as diffie-hellman-group1-sha1, were enabled by default when they should not be. With this change, backward compatibility may be broken for users connecting to servers that require outdated key exchange algorithms. If you are connecting to such a server using one of our command line clients, you will need to enable the outdated algorithm using either -profile=..., specifying a profile where the algorithm is enabled; or via -kexMod=..., as in the following examples:
sftpc -profile=C:\Path\Profile.tlp ... sftpc user@host -kexMod=diffie-hellman-group1-sha1 ...
Changes in Bitvise SSH Client 8.31: [ 15 April 2019 ]
This is not a new feature release, but a successor to 8.29 with continued maintenance updates.
We skip versions containing zeros to avoid misunderstandings. For example, 8.03 and 8.30 might both be called "8.3".
Fixed a memory safety issue which seems to be hard to trigger, but could have security ramifications.
Added error descriptions for Windows error codes related to checking for new versions and downloading updates.
Changes in Bitvise SSH Client 8.29: [ 23 March 2019 ]
Fixed an issue in previous 8.xx versions where, if the SSH Client had not been updated to a new version for longer than 42 days, trying to apply an update would fail due to a Windows registry Access denied error.
Users experiencing this problem can use one of the following workarounds:
Run the SSH Client elevated (right click > Run as administrator) before attempting to update.
Download the installer for the latest version from the SSH Client download page and run it manually.
Changes in Bitvise SSH Client 8.27: [ 4 March 2019 ]
In the graphical SFTP interface, the new directory auto-completion feature could cause the SSH Client to crash when entering a remote path. Fixed.
When using the GSSAPI key exchange method gssapi-keyex, the SSH Client could incorrectly log a warning about failing to save the server's host key. Fixed.
Changes in Bitvise SSH Client 8.26: [ 22 February 2019 ]
Fixed issue introduced in version 8.25 where the recent locations drop-down in the graphical SFTP interface would no longer function correctly.
Fixed issue introduced in version 8.24 where the SSH Server Remote Control Panel could no longer be launched when connected to SSH Server versions 7.xx and earlier.
Changes in Bitvise SSH Client 8.25: [ 18 February 2019 ]
- Regular files are no longer shown for auto completion of directory paths.
- Tab and Shift+Tab now behave consistently with auto-completion in other apps.
- File transfer events no longer cancel the auto-completion drop-down.
To improve UI responsiveness, directory listings are now performed in a background thread.
Changes in Bitvise SSH Client 8.24: [ 7 February 2019 ]
We have identified additional situations where loading a profile fails due to the ZoneId check which is new in 8.xx versions. The SSH Client will now ignore ZoneId-related errors returned by Windows offline files (ERROR_ONLY_IF_CONNECTED) and the Dokany virtual filesystem driver (ERROR_INVALID_PARAMETER).
The SSH Client now implements a Notes tab. This allows users to enter comments which will be saved with the profile and can be viewed later.
Version 8.22 introduced behavior to restore the main SSH Client window so it's not forgotten in the system notification area when a dependent window is closed. This version improves a couple of situations so that the main SSH Client window actually restores instead of flashing in the task bar.
Via a user report, we identified a type of Dropbear server which does not respond to SSH_MSG_GLOBAL_REQUEST. This may work properly in other Dropbear servers, but since the affected server cannot be distinguished from others by its SSH version string, the SSH Client will no longer send global requests to Dropbear servers.
Fixed an issue which caused initial terminal output, such as a welcome message received at the very start of the terminal session, to be cut off.
Automatic path completion is now supported for both local and remote path browsing.
The Filter feature now displays an X that can be clicked to cancel the filter instead of having to clear it via keyboard.
The LIST command can now also list an individual file path instead of only a directory.
A LIST command like LIST -al *.txt will now be interpreted as intended.
Directory listings returned by the LIST command will now have symbolic links resolved.
The OPTS UTF8 command is now supported.
When an update was launched at the same time as the default registry-based profile was opened with pending changes, the SSH Client would incorrectly ask whether to save the profile to a file. Fixed.
The SSH Server Remote Control Panel included with the SSH Client for SSH Server versions 8.15 and higher will now properly show available updates for the SSH Server.
Changes in Bitvise SSH Client 8.23: [ 27 December 2018 ]
Fixed an issue in previous 8.xx versions which would prevent Bitvise SSH Client and FlowSsh from connecting to a server that supports host key synchronization and employs a key type the client does not support. This affected connections from Windows XP and Windows Server 2003, where our cryptographic provider does not support Ed25519; and use under FIPS mode, where Ed25519 and ECDSA/secp256k1 are not supported.
Changes in Bitvise SSH Client 8.22: [ 21 December 2018 ]
A proportion of users are closing the main SSH Client window when connected so that it minimizes into the Windows notification area (the system tray). Users forget about that SSH Client instance and launch new instances for new sessions. Forgotten sessions stay online indefinitely and terminal window settings do not appear to save because the SSH Client is never closed.
To fix this, the SSH Client will now restore its main window if it's still hidden in the notification area after closing a related window such as terminal or SFTP. This behavior can be configured with a new setting found under Closing and minimization.
Since the changes related to password authentication in 8.17, the graphical client's command line parameter -password=... did not take effect if the SSH Client profile was configured to use password authentication but the checkbox Store encrypted password in profile was disabled. Fixed.
sftpc: Updated help text for get and put commands to clarify how the -r and -o parameters control when hash-based synchronization, heuristic resume or overwrite is used.
Changes in Bitvise SSH Client 8.21: [ 17 December 2018 ]
The graphical SSH Client's terminal window for xterm (and other non-bvterm terminals) implements a Select mode intended to behave like the Windows console's QuickEdit mode. A difference was catching users off-guard: canceling a mouse text selection with an arbitrary key press would not send the key to the server. For users who began a selection without noticing, it appeared as though the terminal window was eating a key press for no reason. Consistently with the Windows console, the SSH Client will now send key presses that cancel a selection to the server.
In previous versions, if the graphical SSH Client failed to load a profile specified on the command line, it would fall back to the last used profile and still act on the -loginOnStartup parameter if also provided. This would result in bewildering behavior. If a profile specified on the command line fails to load, the SSH Client now loads the default profile (stored in the Windows registry) and ignores -loginOnStartup.
In previous 8.xx versions, loading an SSH Client profile from a network share would fail when the ZoneId alternative data stream could not be opened. If the ZoneId ADS cannot be opened, a profile will now be loaded as if its origin is the local computer.
We have identified niche situations where one-click Remote Desktop forwarding might fail to start when an SSH Client DLL is not found. To resolve this, this version makes changes to how the Remote Desktop client is started.
There exist SSH clients which, in violation of RFC 4254, disconnect if a server sends a global request after successful authentication. A server might send a global request for purposes such as host key synchronization or disconnect detection. If the server supports RFC 8308, then to indicate it supports global requests, the SSH Client will include the extension global-requests-ok in its SSH_MSG_EXT_INFO.
In previous 8.xx versions, the SSH Client would not import RSA private and public keys larger than 8192 bits. This limit is once again 16384 bits.
The SSH Client installer will now offer to wait instead of exiting when another Bitvise installation is already in progress.
Slightly improved the user friendliness of the installer and uninstaller for command-line installations.
Changes in Bitvise SSH Client 8.19: [ 18 November 2018 ]
In previous 8.xx versions, the icons for the New terminal console, New SFTP window and New Remote Desktop actions were too similar. The SSH Client now sports updated icons that are easier to distinguish.
In previous 8.xx versions, when the SSH Client reconnected after losing a connection, it failed to continue ongoing transfers. Fixed.
SFTP interface: When connecting to SFTP servers that support synchronization using the SFTP v6 extensions check-file-name, check-file-handle and check-file-blocks, the resume and overwrite modes are now more clearly overridden by synchronize in the SFTP user interface.
sftpc: When connecting to SFTP servers that support synchronization, the -r and -o options for get and put commands now both act as aliases for synchronize. Previously, only -o acted as an alias for synchronize, and -r was unavailable.
Changes in Bitvise SSH Client 8.18: [ 7 November 2018 ]
In previous 8.xx versions, if the system clock was moved back after a check for updates (in UTC, not time zone specific), an automatic check would be repeated with high frequency. This could consume 80 kbps in bandwidth while the graphical SSH Client was running until the clock caught up. Fixed.
In previous 8.xx versions, an automatic check for updates would be performed if the graphical SSH Client was run with -noRegistry. An automatic check is no longer performed in this situation, but can be performed manually.
Changes in Bitvise SSH Client 8.17: [ 3 November 2018 ]
In version 8.15, loading a profile which was last saved by a previous version would cause the SSH Client to send an invalid elevation extension value to the server. This caused SSH Server versions 8.xx to disconnect. The SSH Client will now send a valid elevation extension value in this circumstance.
The Remote Desktop forwarding feature Use SSH login credentials would previously work only if the password authentication method was used for client authentication, but it did not work for password authentication over keyboard-interactive. This will now also work with password over keyboard-interactive.
In the graphical SSH Client, on the Login tab, setting Initial method to password could result in unintuitive behavior. Password change was not easily discoverable, and setting Initial method to password without entering a password caused the SSH Client to send an empty password at start of connection, incurring an authentication penalty.
This has been redesigned so that Initial method can be set to password without entering a password. In this case, a password dialog will dependably appear when connecting. As part of this change, it is no longer possible to enter a password on the Login tab without enabling Store encrypted password in profile.
In version 8.15, in command line clients, the -keypairFile parameter did not override a public key configured as an initial authentication method in a profile specified using -profile. The -keypairFile parameter will now once again override any public key configured in the profile.
Changes in Bitvise SSH Client 8.15: [ 25 October 2018 ]
The SSH Client now supports automatic updates. An administrator can configure the SSH Client to automatically apply all updates; only recommended updates; only strongly recommended updates; to apply updates only manually; or to never check for updates.
Currently, the SSH Client does not install an update service. It needs to be started from time to time by an administrative user in order to apply updates.
The graphical SSH Client and sftpc now support recursive directory mirroring. A directory and all of its subdirectories and files can be synchronized either in the upload or download direction. The SSH Client can synchronize updated files and detect and automatically remove files and directories from the target location that are not present in the source.
The graphical SSH Client and sftpc can now display hashes (cryptographic digests) of local and remote files if the server supports the SFTP v6 check-file extension.
Bitvise SSH Client and SSH Server now implement automatic host key rotation. The SSH Client will synchronize keys from the SSH Server and any other servers that support the OpenSSH mechanism "hostkey update and rotation". The SSH Server will announce to clients all configured host keys, including those not employed, to facilitate host key rotation. The SSH Client will automatically trust new keys announced by a trusted server and remove any keys the server has removed, as long as they were added automatically.
The SSH Client now supports high resolutions and will display crisp text on high-DPI displays such as retina or 4K. The SSH Client now comes with new, higher resolution icons.
SSH Client profiles downloaded from the internet will now be considered unsafe. If a profile is marked by a browser using which it was downloaded as originating from an unsafe zone, the SSH Client will now load safe parts only. When loading a profile interactively in the graphical SSH Client, a prompt will be displayed, allowing the user to mark the profile as safe. If the user confirms, the profile can be fully loaded.
Bitvise SSH Server, SSH Client and FlowSsh once again support non-standard DSA keys larger than 1024 bits. We do not recommend using these keys, and new keys of this type cannot be generated. Also, these keys cannot be used when FIPS mode cryptography is enabled in Windows. Re-adding support for these keys is intended to resolve an obstacle that may still be preventing some users of 6.xx versions from upgrading.
When using Windows cryptography, Bitvise SSH Server, SSH Client and FlowSsh now implement a backup strategy for DH and ECDH key exchange. Windows implements key exchange, but it does not expose the agreed value in a form suitable for SSH. Bitvise software must retrieve the value by carefully traversing undocumented Windows structures. In versions 7.xx, this required our software to be upgraded to continue working after the Windows 10 1803 update. Our software will now log a warning and fall back to Crypto++ if it cannot perform key exchange because Windows internal structures have changed. However: if FIPS mode is enabled in Windows, this backup strategy is not used, and the software must be updated.
When importing keys, such as from files, the stage at which an import failed is now described in more detail.
Bitvise SSH Server and Client now support the elevation extension. In previous versions, if a Windows account with administrative rights connected to the SSH Server, the server would always elevate the session if possible. Otherwise, the user would not be able to get an elevated session because there was no way to convey the user's preference. With the elevation extension, the user can request a non-administrative security context by requesting no elevation (elevation is still applied by default). In command line clients including stermc, sexec and sftpc, this is controlled using the switch -elevation=n.
Bitvise SSH Server and Client now support the no-flow-control extension. This disables SSH flow control for clients that only support opening one channel. No flow control is now preferred by sftpc, stermc, sexec and spksc, which only need to open one channel in the SSH session. The graphical SSH Client does not support no-flow-control because it requires multiple channels.
Bitvise SSH Server and Client now support the ext-auth-info extension. This allows the server to respond to user authentication failures with more detailed information in situations where this is safe. For example, if the client attempts to perform a password change but the new password does not meet complexity requirements, the server can communicate this instead of making the user guess.
Bitvise SSH Server and Client now support the delay-compression extension. Delayed compression reduces attack surface for unauthenticated clients by delaying availability of compression until after a user is authenticated. The delay-compression extension is an improvement over previously supported alternatives: the firstname.lastname@example.org method contains a by-design race condition, while the approach of invoking a second key exchange doubles the overhead of establishing an SSH session.
Settings for the graphical xterm/vt100 terminal console window (totermw) are now stored in the SSH Client profile instead of in the Windows registry.
In the graphical SFTP interface, the Open and Edit commands will now be much more responsive if a transfer is already in progress. The in-progress transfer will be paused and the file associated with the Open or Edit command will be transferred as a priority.
Both the graphical SFTP interface and sftpc can now work with local paths longer than 259 characters, as well as unsafe paths not permitted by Windows in some contexts (e.g. "C:\Com1\file").
A new file transfer mode, TextLf, is now supported. This works the same as AutoLf, but forces newline conversions without relying on file type detection.
The SSH Client now displays the country (if available) of remote IP addresses. The SSH Client uses the MaxMind GeoLite2 Country database (under license). The country database comes with the SSH Client installation and is not automatically updated, other than by updating the SSH Client itself.
Command line clients:
It is now easier to connect to SSH servers that accept connections on non-default ports. If no port is specified on the command line, but the SSH Client knows a host key for the destination server, the SSH Client will automatically connect to the port associated with the server in the host key database. If there are multiple port associations, however, the port still needs to be specified, unless one of them is 22.
It is now easier to enable and disable individual algorithms with our command-line clients. Previously, to use non-default algorithms, either a -profile needed to be used, or a complete algorithm list had to be supplied using -hkey, -kex, -encr or -mac. It is now still possible to pass a whole list using the same parameters, or using their new aliases -hkeyAlgs, -kexAlgs, -encrAlgs or -macAlgs. In addition, it is possible to modify the default algorithm lists using -hkeyMod, -kexMod, -encrMod or -macMod. When using the "Mod" versions, provide a comma-separated list of algorithm names with optional prefixes. Names prefixed with "+" are added to the front of the list; names without a prefix are appended to the end; and names prefixed with "!" are removed. Example: -encrMod=+aes256-gcm,!3des-ctr
The log utility now supports filesystem paths in Unicode.
To use an OpenSSH authentication agent, you must use a third-party distribution of OpenSSH, for example the version that comes with Cygwin. The version of the OpenSSH agent that comes with Windows runs under the Windows Subsystem for Linux and uses Unix sockets in a way that's currently inaccessible to native Windows applications.
LastPass for Applications achieves some of its functions by injecting a DLL with foreign code into other applications. As of February 2018, the DLL injected by LastPass has been observed to cause a crash in Bitvise SSH Client when connecting to a server.
Windows XP: All versions of our software that we recommend using are built using Visual Studio 2015. The C++ run-time library used by this Visual Studio version has a known issue where 1-2 kB of memory are leaked each time a new thread is created. This issue does not occur on later Windows versions; it does not occur e.g. on Windows Server 2003. Microsoft has stated they do not intend to fix this issue. Bitvise's view is that the impacts on our SSH Client and FlowSsh are manageable; whereas our SSH Server is rarely used on Windows XP. We therefore do not plan to work around this; but we warn that this can be a potential denial of service vector on Windows XP.