1 SSH Release Notes

1.1 Ssh 3.0.1

Fixed Bugs and Malfunctions

Fixes the problem that ssh_cli in some cases could delay the prompt if a tty was not requested by the client.

Own Id: OTP-10732
The variable NewCol is now correctly calculated allowing for tab-completion of function calls even when preceded with blank space (Thanks to Alexander Demidenko)

Own Id: OTP-11566
Fix incorrect dialyzer spec and types, also enhance documentation.

Thanks to Ayaz Tuncer.

Own Id: OTP-11627
Fixed a bug when ssh:exec executes a linux command on a linux ssh daemon. If the result is sent back from standard error, the length information was not stripped off correctly.

Own Id: OTP-11667
Fixed a bug with the ssh file 'known_hosts' which made the file grow with many equal entries.

Own Id: OTP-11671
Some local implementations of removing the last element from a list are replaced by lists:droplast/1. Note that this requires at least stdlib-2.0, which is the stdlib version delivered in OTP 17.0. (Thanks to Hans Svensson)

Own Id: OTP-11678
Bug fix for ssh:daemon/2,3 so that the failfun is called when it should.

Own Id: OTP-11680
Fixed bug which crashed ssh when SSH_MSG_KEX_DH_GEX_GROUP is received. This could cause a vm-crash for eheap_alloc during garbage collect.

Own Id: OTP-11696 Aux Id: 12547, 12532
Fixes a bug that breaks keyboard-interactive authentication. Thanks to Simon Cornish for reporting and suggesting a fix.

Own Id: OTP-11698
dialyzer specs are now correct for ssh:start/0, ssh:start/1, ssh:stop/0 and ssh_connection_handler:open_channel/5. (Thanks to Johannes Weißl )

Own Id: OTP-11705
Application upgrade (appup) files are corrected for the following applications:

asn1, common_test, compiler, crypto, debugger, dialyzer, edoc, eldap, erl_docgen, et, eunit, gs, hipe, inets, observer, odbc, os_mon, otp_mibs, parsetools, percept, public_key, reltool, runtime_tools, ssh, syntax_tools, test_server, tools, typer, webtool, wx, xmerl

A new test utility for testing appup files is added to test_server. This is now used by most applications in OTP.

(Thanks to Tobias Schlager)

Own Id: OTP-11744
Fixed dialyzer warning for ssh_connection:send.

Own Id: OTP-11821
ssh:daemon/2,3 : Added options negotiation_timeout and parallel_login to tune the authentication behaviour.

Own Id: OTP-11823

Improvements and New Features

Ssh now fully supports unicode filenames, filecontents, shell and cli. Please note that the underlying os and emulator must also give support for unicode. You may want to start the emulator with "erl +fnu" on Linux.

Own Id: OTP-10953

1.2 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

1.3 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

1.4 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

1.5 Ssh 2.1.6

Fixed Bugs and Malfunctions

Fixed timing rekeying bug.

Own Id: OTP-10940

1.6 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

1.7 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

1.8 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

1.9 Ssh 2.1.2.1

Improvements and New Features

Removed error report in ssh_connection_handler triggered by badmatch failure.

Own Id: OTP-11188

1.10 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]

1.11 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

1.12 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

1.13 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

1.14 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

1.15 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

1.16 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

1.17 Ssh 2.0.5

Improvements and New Features

Strengthened random number generation. (Thanks to Geoff Cant)

Own Id: OTP-9225

1.18 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

1.19 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

1.20 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

1.21 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

1.22 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:

1.23 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:

1.24 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:

1.25 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:

1.26 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:

1.27 Ssh 1.1.4

Fixed Bugs and Malfunctions

SSH sometimes caused a crash report at disconnect.

Own Id: OTP-8071 Aux Id: seq11319

1.28 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

1.29 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

1.30 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

1.31 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

1.32 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

1.33 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

1.34 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