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SSH
Release Notes
Version 3.0

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# 1 SSH Release Notes

### 1.1 Ssh 3.0

#### Fixed Bugs and Malfunctions

- The ssh cli is now faster at close and before new prompt.

  Own Id: OTP-11339 Aux Id: seq12423

- Ssh process structure was redesigned to better map to what is truly parallel this has solved a lot of strange timing issues that sometimes would occur, for instance a process leak could happen when a lot of connections where taken up and down in parallel in a short period of time. Also backwards compatible clauses to "original" but never supported features has been removed.

  Impact: Increases flow efficiency

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-11363

- Fix various typos in erts, kernel and ssh. Thanks to Martin Hässler.

  Own Id: OTP-11414

- Correct private_key type documentation in ssh_server_key_api. Thanks to Tristan Sloughter.

  Own Id: OTP-11449

- The functions in ssh_no_io.erl did not mimic the functions in ssh_io.erl correctly, the arity was incorrect for some functions which caused ssh to fail in the wrong way.

  Own Id: OTP-11490

#### Improvements and New Features

- Add option to disallow CLI

  Own Id: OTP-10976

- Add sockname and user to ssh:connection_info/2

  Own Id: OTP-11296

### 1.2 Ssh 2.1.8

#### Improvements and New Features

- Do not chmod ~/.ssh unnecessarily.

  Own Id: OTP-11189

- Make ssh_cli.erl handle CTRL+C. Thanks to Stefan Zegenhagen.

  Own Id: OTP-11199

- Clarified timeout options in documentation.

  Own Id: OTP-11249

- Add openssh_zlib compression type to ssh_transport. Thanks to Louis-Philippe Gauthier.

  Own Id: OTP-11256

### 1.3 Ssh 2.1.7

#### Fixed Bugs and Malfunctions

- ssh:daemon will get feeded with an argument even if it is not a valid expression.

  Own Id: OTP-10975

#### Improvements and New Features

- Properly ignore everything in lib/ssh/doc/html/. Thanks to Anthony Ramine.

  Own Id: OTP-10983

- Integrate elliptic curve contribution from Andreas Schultz

  In order to be able to support elliptic curve cipher suites in SSL/TLS, additions to handle elliptic curve infrastructure has been added to public_key and crypto.

  This also has resulted in a rewrite of the crypto API to gain consistency and remove unnecessary overhead. All OTP applications using crypto has been updated to use the new API.

  Impact: Elliptic curve cryptography (ECC) offers equivalent security with smaller key sizes than other public key algorithms. Smaller key sizes result in savings for power, memory, bandwidth, and computational cost that make ECC especially attractive for constrained environments.

  Own Id: OTP-11009

### 1.4 Ssh 2.1.6

#### Fixed Bugs and Malfunctions

- Fixed timing rekeying bug.

  Own Id: OTP-10940

### 1.5 Ssh 2.1.5

#### Fixed Bugs and Malfunctions

- Bug in rekeying for daemon fixed.

  Own Id: OTP-10911

#### Improvements and New Features

- Enhanced error message and added test for ssh clients trying to start non existing subsystems.

  Own Id: OTP-10714

### 1.6 Ssh 2.1.4

#### Improvements and New Features

- Better quality on the error messages for when key exchange failed.

  Own Id: OTP-10553 Aux Id: seq12152

- Fix link to documentation for ssh:connect/3,4. Thanks to Martin Hässler.

  Own Id: OTP-10862

### 1.7 Ssh 2.1.3

#### Fixed Bugs and Malfunctions

- It is now possible to send an empty binary using ssh_connection:send/3, this corner case previously caused ssh_connection:send to hang.

  Own Id: OTP-9478 Aux Id: kunagi-226 [137]

- Fix typo in keyboard-interactive string. Thanks to Daniel Goertzen

  Own Id: OTP-10456

- ssh_connectino:send/3 will not return until all data has been sent. Previously it could return too early, resulting in things such premature close of the connection. Also improved error handling of closed SSH channels.

  Own Id: OTP-10467

- Fixed ssh_cli.erl crashes because #state.buf is yet 'undefined'.

  Fixed Client terminateing connections due to channel_request message response is sent to the wrong id.

  Affected SSH clients: - all clients based on SSH-2.0-TrileadSSH2Java_213 (problem #1) - SSH Term Pro (problem #2)

  Thanks to Stefan Zegenhagen

  Own Id: OTP-10475

- Fixed various syntax errors in SSH appup file

  Own Id: OTP-10657

#### Improvements and New Features

- SSH_FX_FILE_IS_A_DIRECTORY message for sftp implemented

  Own Id: OTP-6406 Aux Id: kunagi-218 [129]

- SSH Rekeying fixed

  Own Id: OTP-7785 Aux Id: kunagi-220 [131]

- Added User Guide for the SSH application

  Own Id: OTP-7786 Aux Id: kunagi-221 [132]

- Documentation regarding failfun, connectfun and disconnectfun provided

  Own Id: OTP-7792 Aux Id: kunagi-222 [133]

- SSH connection timer implementation

  New option, {idle_time, integer()}, sets a timeout on connection when no channels are active, defaults to infinity

  Own Id: OTP-10514 Aux Id: seq12020

- Some examples overflowing the width of PDF pages have been corrected.

  Own Id: OTP-10665

- Fixed internal error on when client and server can not agree o which authmethod to use.

  Own Id: OTP-10731 Aux Id: seq12237

### 1.8 Ssh 2.1.2.1

#### Improvements and New Features

- Removed error report in ssh_connection_handler triggered by badmatch failure.

  Own Id: OTP-11188

### 1.9 Ssh 2.1.2

#### Fixed Bugs and Malfunctions

- SSH quiet mode

  A new option to ssh:connect/3,4, quiet_mode. If true, the client will not print out anything on authorization.

  Own Id: OTP-10429 Aux Id: kunagi-273 [184]

- Restrict which key algorithms to use

  A new option to ssh:connect/3,4 is introduced, public_key_algs, where you can restrict which key algorithms to use and in which order to try them.

  Own Id: OTP-10498 Aux Id: kunagi-289 [200]

- Confidentiality of client password

  Unsets clients password after authentication.

  Own Id: OTP-10511 Aux Id: kunagi-292 [203]

- Fixed user interaction for SSH

  It's now available to accept hosts and input password

  Own Id: OTP-10513 Aux Id: kunagi-293 [204]

### 1.10 Ssh 2.1.1

#### Fixed Bugs and Malfunctions

- Ssh now only sends one channel close message under all circumstances, before it would sometimes incorrectly send two.

  Own Id: OTP-10060

- The options check mistreated the ip_v6_disable-option, and did not handle some, at the moment, undocumented options correctly.

  Own Id: OTP-10061

- The channel id in a channel failure message, sent to the peer, is now in all cases the remote channel id

  Own Id: OTP-10062

- Improved handling of multiple closes to avoid occasional crashes when a channel is closed more than once.

  Own Id: OTP-10112

- Fix lib/src/test/ssh_basic_SUITE.erl to fix IPv6 option typos

  Fixed incorrect option "ipv6_disable" to "ipv6_disabled" as documented in the ssh manual.

  Own Id: OTP-10219

- SSH: Make "auth_methods" server option re-usable

  The 'auth_methods' option is used by the server side of the SSH code to tell a connecting SSH client about the authentication methods that are supported by the server. The code still extracts and handles the 'auth_methods' option from Opts in appropriate places, but the Opts checking code in ssh.erl didn't allow that option to be specified.

  Own Id: OTP-10224

- Use the correct channel id when adjusting the channel window

  Own Id: OTP-10232

### 1.11 Ssh 2.1

#### Fixed Bugs and Malfunctions

- All keys in authorized_keys are considerd, wrongly only the first one was before.

  Own Id: OTP-7235

- ssh daemon now properly handles ras host keys, in previous versions only dsa host keys sufficed to set up a connection.

  Own Id: OTP-7677

- ssh:shell/3 and ssh:connect/3 does not hang anymore if connection negotiation fails

  Own Id: OTP-8111

- Improve check so that we will not try to read ssh packet length indicator if not sure we have enough data.

  Own Id: OTP-8380

- Do not try to use user interaction when it is disabled.

  Own Id: OTP-9466 Aux Id: seq11886

- Improved error handling of internal errors i the ssh connection handling process

  Own Id: OTP-9905

- sftp daemon generates file handles correct

  Own Id: OTP-9948

#### Improvements and New Features

- Document supported algorithms

  Own Id: OTP-8109

- Graceful handling of premature close from an sftp client.

  Own Id: OTP-9391 Aux Id: seq11838

- Changed ssh implementation to use the public_key application for all public key handling. This is also a first step for enabling a callback API for supplying public keys and handling keys protected with password phrases.

  Additionally the test suites where improved so that they do not copy the users keys to test server directories as this is a security liability. Also ipv6 and file access issues found in the process has been fixed.

  This change also solves OTP-7677 and OTP-7235

  This changes also involves some updates to public_keys ssh-functions.

  Own Id: OTP-9911

- Added options for the ssh client to support user keys files that are password protected.

  Own Id: OTP-10036 Aux Id: OTP-6400, Seq10595

### 1.12 Ssh 2.0.9

#### Improvements and New Features

- Erlang/OTP can now be built using parallel make if you limit the number of jobs, for instance using 'make -j6' or 'make -j10'. 'make -j' does not work at the moment because of some missing dependencies.

  Own Id: OTP-9451

- Ssh behaviours now use the new directive "-callback". Parameters will be further specified in a later version of ssh.

  Own Id: OTP-9796

### 1.13 Ssh 2.0.8

#### Fixed Bugs and Malfunctions

- Calling ssh_sftp:stop_channel/1 resulted in that the trap_exit flag was set to true for the invoking process.

  Own Id: OTP-9386 Aux Id: seq11865

### 1.14 Ssh 2.0.7

#### Fixed Bugs and Malfunctions

- An unexpected message would crash the ssh_connection_handler and close the connection. Now an error message is generated instead.

  Own Id: OTP-9273

### 1.15 Ssh 2.0.6

#### Fixed Bugs and Malfunctions

- A memory leak has been fixed. I.e. per terminated connection the size of a pid and the length of a user name string was not cleared.

  Own Id: OTP-9232

### 1.16 Ssh 2.0.5

#### Improvements and New Features

- Strengthened random number generation. (Thanks to Geoff Cant)

  Own Id: OTP-9225

### 1.17 Ssh 2.0.4

#### Fixed Bugs and Malfunctions

- In some cases SSH returned {error, normal} when a channel was terminated unexpectedly. This has now been changed to {error, channel_closed}.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-8987 Aux Id: seq11748

- SSH did not handle the error reason enetunreach when trying to open a IPv6 connection.

  Own Id: OTP-9031

#### Improvements and New Features

- It is now possible to use SSH to sign and verify binary data.

  Own Id: OTP-8986

- SSH now ensures that the .ssh directory exists before trying to access files located in that directory.

  Own Id: OTP-9010

### 1.18 Ssh 2.0.3

#### Fixed Bugs and Malfunctions

- The fix regarding OTP-8849 was not included in the previous version as stated.

  Own Id: OTP-8918

### 1.19 Ssh 2.0.2

#### Fixed Bugs and Malfunctions

- The ssh_system_sup did not catch noproc and shutdown messages.

  Own Id: OTP-8863

- In some cases a crash report was generated when a connection was closing down. This was caused by a race condition between two processes.

  Own Id: OTP-8881 Aux Id: seq11656, seq11648

#### Improvements and New Features

- SSH no longer use deprecated public_key functions.

  Own Id: OTP-8849

### 1.20 Ssh 2.0.1

#### Fixed Bugs and Malfunctions

- SSH in some cases terminated channels with reason normal when it should have been shutdown.

  Own Id: OTP-8714

- SSH in some cases generated a crash report when a channel was closed in a normal way.

  Own Id: OTP-8735 Aux Id: seq11615

- The processes ssh_subsystem_sup and one ssh_channel_sup was not terminated when a connection was closed.

  Own Id: OTP-8807

### 1.21 Ssh 2.0

#### Fixed Bugs and Malfunctions

- The function ssh:connect/4 was not exported.

  Own Id: OTP-8550 Aux Id:

- Aligned error message with used version (SSH_FX_FAILURE vs SSH_FX_NOT_A_DIRECTORY, the latter introduced in version 6).

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-8644 Aux Id: seq11574

- Resolved race condition when another connection is started before a channel is opened in the first connection.

  Own Id: OTP-8645 Aux Id: seq11577

#### Improvements and New Features

- The configuration parameter ip_v6_disabled is now available, which makes it possible for the user to alter the IP version SSH shall use.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-8535 Aux Id:

- The ssh_connection:send operation now accepts infinity as timeout.

  Own Id: OTP-8534 Aux Id:

- The connection handler now include stack traces when a channel message is not handled correctly.

  Own Id: OTP-8524 Aux Id:

- Removed deprecated modules (ssh_ssh, ssh_sshd and ssh_cm) and functions (ssh_sftp:connect and ssh_sftp:stop).

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-8596 Aux Id:

### 1.22 Ssh 1.1.8

#### Fixed Bugs and Malfunctions

- In some cases SSH ceased to collect more data from the transport layer.

  Own Id: OTP-8401 Aux Id: seq11479

#### Improvements and New Features

- Old release notes removed.

  Own Id: OTP-8356 Aux Id:

### 1.23 Ssh 1.1.7

#### Fixed Bugs and Malfunctions

- Now clear all processes when a connnection is terminated.

  Own Id: OTP-8121 Aux Id:

- In some rare cases the connection handler could enter an infinite loop.

  Own Id: OTP-8277 Aux Id: seq11428

- If an SFTP server did not respond with EOF, the function ssh_sftp:list_dir/2/3 would enter an infinite loop.

  Own Id: OTP-8278 Aux Id: seq11450

#### Improvements and New Features

- The documentation is now built with open source tools (xsltproc and fop) that exists on most platforms. One visible change is that the frames are removed.

  Own Id: OTP-8201 Aux Id:

### 1.24 Ssh 1.1.6

#### Fixed Bugs and Malfunctions

- ssh_sftp:start_channel did not handle all possible return values from ssh_channel:start correctly.

  Own Id: OTP-8176 Aux Id:

- SFTPD did not handle rename command (version 4) correctly.

  Own Id: OTP-8175 Aux Id: seq11373

- If a connection manager already had been terminated it could cause a channel to generate a crash report when it was about to stop.

  Own Id: OTP-8174 Aux Id: seq11377

- Requests could result in badarg or badmatch EXIT messages in the connection manager if the channel no longer existed.

  Own Id: OTP-8173 Aux Id: seq11379

- ssh_transport:unpack/3 could cause a badarg error.

  Own Id: OTP-8162 Aux Id:

#### Improvements and New Features

- The encryption algorithm aes128-cbc is now supported. Requires that crypto-1.6.1 is available.

  Own Id: OTP-8110 Aux Id:

### 1.25 Ssh 1.1.5

#### Fixed Bugs and Malfunctions

- ssh_sftp:start_channel/3 did not handle timout correctly.

  Own Id: OTP-8159 Aux Id: seq11386

- If a progress message was not recieved after invoking ssh:connect/3 the call could hang for ever. A timeout option has also been added.

  Own Id: OTP-8160 Aux Id: seq11386

- A comma has been missing in the ssh.appup file since SSH-1.0.2.

  Own Id: OTP-8161 Aux Id:

### 1.26 Ssh 1.1.4

#### Fixed Bugs and Malfunctions

- SSH sometimes caused a crash report at disconnect.

  Own Id: OTP-8071 Aux Id: seq11319

### 1.27 Ssh 1.1.3

#### Fixed Bugs and Malfunctions

- The operation ssh_sftp:stop_channel/1 returned an exception if the connection already had been closed.

  Own Id: OTP-7996 Aux Id: seq11281

- SSH did not handle if supervisor:start_child/2 returned {error, already_present}.

  Own Id: OTP-8034 Aux Id: seq11307

- SSH no longer cause supervisor reports when a connection is terminated in a controlled manner.

  Own Id: OTP-8035 Aux Id: seq11308

### 1.28 Ssh 1.1.2

#### Fixed Bugs and Malfunctions

- Ssh confused local and remote channel id's, which in some cases resulted in that messages were discarded.

  Own Id: OTP-7914 Aux Id: seq11234

- Ssh could not handle echo values other than 0 and 1.

  Own Id: OTP-7917 Aux Id: seq11238

- A crash occurred if a non-valid channel reference was received.

  Own Id: OTP-7918 Aux Id: seq11238

- Sftpd connections was not closed after receiving eof from a client.

  Own Id: OTP-7921 Aux Id: seq11222

- It was not possible to start a SFTP subsystem on certain platforms, i.e. those who do not support symbolic links.

  Own Id: OTP-7930 Aux Id:

- In some cases the message {ssh_cm, ssh_connection_ref(), {closed, ssh_channel_id()}} was not passed to the registered callback module.

  Own Id: OTP-7957 Aux Id:

#### Improvements and New Features

- By using the sftpd option {max_files, Integer}, the message size for READDIR commands can be reduced.

  Own Id: OTP-7919 Aux Id: seq11230

### 1.29 Ssh 1.1.1

#### Fixed Bugs and Malfunctions

- The erlang ssh server has presented itself incorrectly, using the special version ssh-1.99, although it never has supported versions below 2.0. Since ssh-1.1 client versions below 2.0 are correctly rejected instead of letting the server crash later on. Alas the problem with the presentation string was not discovered until after ssh.1.1 was released. Now the server will present itself as ssh-2.0.

  Own Id: OTP-7795

- An internal function call used an incorrect parameter, which caused problem when the old listen API was used. This was introduced in Ssh-1.1.

  Own Id: OTP-7920 Aux Id: seq11211

#### Improvements and New Features

- Ssh timeouts will now behave as expected i.e. defaults to infinity only the user of the ssh application can know of a reasonable timeout value for their application.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-7807

- The implementation of timeouts added as a patch in ssh-1.0.1 was slightly changed and is now documented.

  Own Id: OTP-7808

- To honor the multiplexing of channels over one ssh connection concept ssh_sftp:connect/ [1,2,3] is deprecated and replaced by ssh_sftp:start_channel/[1,2,3] and ssh_sftp:stop/1 is deprecated and replaced by ssh_sftp:stop_channel/1 and to stop the ssh connection ssh:close/ 1 should be called.

  Own Id: OTP-7809

- Added the message {ssh_channel_up, ChannelId, ConnectionManager} that shall be handled by the channel callback handle_msg/2. This makes the function handle_msg/2 a mandatory function for ssh channels implementations which it was not in ssh-1.1.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-7828

### 1.30 Ssh 1.1

#### Fixed Bugs and Malfunctions

- A flaw in the implementation of the supervision tree caused the ssh daemon to close the connections to all currently logged in users if one user logged out. Another problem related to the supervision tree caused the closing down of clients to leak processes i.e. all processes was not shutdown correctly.

  Own Id: OTP-7676

- Tabs could cause ssh_cli to print things in a surprising way.

  Own Id: OTP-7683 Aux Id: seq11102

- [sftp, sftpd] - Added patch to make sftp timestamps more correct, in the long run it would be nice to have better support in file to be able to make it always behave correctly now it will be correct 99 % of time instead of almost never correct, at least on unix-based platforms.

  Own Id: OTP-7685 Aux Id: seq11082

- [sftpd] - Added patch to further improve handling of symbolic links in the sftp-server.

  Own Id: OTP-7766 Aux Id: seq11101

- Ssh incorrectly sent the local id instead of the remote id of a channel to the peer. For simpler cases these ids often happen to have the same value. One case when they do not is when the client sends an exec command two times in a raw on the same ssh connection (different channels of course as the channel will be closed when the exec command has been evaluated) .

  Own Id: OTP-7767

- Packet data could be lost under high load due to the fact that buffered data was sometimes wrongly discarded before it had been sent.

  Own Id: OTP-7768

- Improved ipv6-handling as some assumptions about inet functions where incorrect.

  Own Id: OTP-7770

#### Improvements and New Features

- Added new API function ssh:connection_info/2.

  Own Id: OTP-7456

- Now starts ssh channel processes later avoiding synchronization problems between processes.

  Own Id: OTP-7516

- Ssh now rejects old versions of the ssh protocol for security reasons. (Even if they where not correctly rejected before the connection would probably have failed anyway due to other reasons.)

  Own Id: OTP-7645 Aux Id: seq11094

- New API module ssh_channel has been added. This is a behaviour to facilitate the implementation of ssh clients and plug in subsystems to the ssh daemon. Note that this slightly changes the options to the API function ssh:daemon/[1,2,3] deprecating all no longer documented options. Note that the new API enforces the "logical way" of using the old API i.e. making the subsystem process part of the ssh applications supervisor tree, so missuses of the old API are not compatible with the new API.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-7769

#### Known Bugs and Problems

- Public keys protected by a password are currently not handled by the erlang ssh application.

  Own Id: OTP-6400 Aux Id: 10595

### 1.31 Ssh 1.0.2

#### Fixed Bugs and Malfunctions

- [sftpd] - Listing of symbolic link directories should now work as expected.

  Own Id: OTP-7141 Aux Id: seq10856

### 1.32 Ssh 1.0.1

#### Fixed Bugs and Malfunctions

- [sftp] - When listing a directory with more than 100 files only the first 100 where listed. This has now been fixed.

  Own Id: OTP-7318 Aux Id: seq10953

- When restarting an ssh-system the expected return value from ssh_system_sup:restart_acceptor/2 was incorrect, this is no longer the case.

  Own Id: OTP-7564 Aux Id: seq11055

- A few minor bugs where fixed in ssh_userreg.erl and ssh_connection_manager and a a ssh_cli option was added to restore backwards compatibility with the old ssh_cm - API.

  Own Id: OTP-7565

- Fixed bug in ipv6 support and added option to disable ipv6 as a workaround for badly configured computers.

  Own Id: OTP-7566

#### Improvements and New Features

- [sftp] - Option added to set timeout value in sftp.

  Own Id: OTP-7305 Aux Id: seq10945

### 1.33 Ssh 1.0

#### Fixed Bugs and Malfunctions

- Removed some special handling of prompts that made ssh behave differently than openssh.

  Own Id: OTP-7485 Aux Id: seq11025

- Bug in encoding of pty opts has been fixed.

  Own Id: OTP-7504

#### Improvements and New Features

- The architecture of the ssh processes has been reconstructed to fit in a supervision tree as to become a real OTP application and benefit from this when starting and stopping.

  Own Id: OTP-7356 Aux Id: seq10899

- Support for pty option echo off added. Requires kernel from R12B-4.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-7502 Aux Id: seq10959

- The ssh API has been enhanced a lot of old API functions has become deprecated.

  Own Id: OTP-7503