2004 2022 Ericsson AB. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

SSH Release Notes

%VSN% notes.xml

## Ssh 4.13.2.1

### Fixed Bugs and Malfunctions

Binaries can be limited in logs with the parameter max_log_item_len. The default value is 500 bytes.

Own Id: OTP-18094

## Ssh 4.13.2

### Fixed Bugs and Malfunctions

Fix makefile dependency bugs.

Own Id: OTP-17847 Aux Id: PR-5574 GH-5548

Fixed faulty OpenSSH decoding of Ed25519/Ed448 keys in the OpenSSH format openssh_key_v1.

Own Id: OTP-17868 Aux Id: PR-5520

Correction of ssh_file typing, specially for the experimental openssh-key-v1 encoding.

Own Id: OTP-17912 Aux Id: GH-5680

Improper tag for private ED keys when encoding with ssh:encode/2.

The tuple had ed_priv as first element, but should have had ed_pri. This is now corrected.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-17928 Aux Id: PR-5679

### Improvements and New Features

Add support for Ed25519/Ed448 SSH host keys in the RFC 4716 format ("-----BEGIN EC PRIVATE KEY-----") generated by for example openssl or via Erlang functions (i.e. public_key:generate_key({namedCurve, ed25519})).

Ed25519 SSH host keys generated by ssh-keygen was, and are still, supported.

Own Id: OTP-17857 Aux Id: PR-5532

## Ssh 4.13.1

### Fixed Bugs and Malfunctions

The ssh sever parallel_login option was missing in OTP-24

Own Id: OTP-17850 Aux Id: ERIERL-764

## Ssh 4.13

### Fixed Bugs and Malfunctions

The value of the connect_timeout option is now used as default value for the negotiation timeout.

Own Id: OTP-17707 Aux Id: ERIERL-706

### Improvements and New Features

Add better error handling in connect/2,3,4. Detect incorrect arguments and return an informative error tuple instead of throwing a function_clause or similar.

Own Id: OTP-17515 Aux Id: ERIERL-648

Make ssh algorithm selection better handle dynamic changes changes in crypto fips mode.

Own Id: OTP-17795

## Ssh 4.12.5

### Fixed Bugs and Malfunctions

Fixed a race condition in the acceptor loop: if a client disconnected immediately after the tcp connect, the server could cease handling connection on that address:port.

Own Id: OTP-17764 Aux Id: ERIERL-726

## Ssh 4.12.4

### Fixed Bugs and Malfunctions

Fixed that a slow start (>30s) of a client subsystem could cause a log entry with the password.

Own Id: OTP-17390 Aux Id: ERIERL-648

Fixed an error when running as an sftp server and a client requests a directory contents listing.

The fix is to handle the error code {error, eacces} as {error, enoent} in the ssh_sftpd:get_attrs/5 internal function; that is, just skip it.

Own Id: OTP-17586 Aux Id: GH-5014

### Improvements and New Features

The "Key exchange failed" Info Report is now more informative.

Own Id: OTP-17450 Aux Id: ERIERL-655

## Ssh 4.12.3

### Fixed Bugs and Malfunctions

Filter out sensitive data (passwords etc) from progress reports and supervisor reports.

Own Id: OTP-17468 Aux Id: ERIERL-656

## Ssh 4.12.2

### Fixed Bugs and Malfunctions

Avoid an extra blank line in the ssh known_hosts file

Own Id: OTP-17427

## Ssh 4.12.1

### Improvements and New Features

Add missing known_hosts and authorized_keys file types to ssh_file:decode/2 and ssh_file:encode/2.

Own Id: OTP-17397

## Ssh 4.12

### Fixed Bugs and Malfunctions

Missing runtime dependencies has been added to this application.

Own Id: OTP-17243 Aux Id: PR-4557

The send window handling is changed to not initialize a too large window on some occasions.

Own Id: OTP-17353

### Improvements and New Features

Removed usage of erlang:is_port/1 from the SSH implementation.

Own Id: OTP-16750

Internal connection setup refactoring.

Own Id: OTP-17051

Refactor SSH fsm into a (hopefully) more comprehensible set of gen_statem callback-files.

Own Id: OTP-17140

The RSA SHA1 sign/verify variants are disabled by default. That is, ssh-rsa is disabled by default as well as the SHA1 sign/verify with RSA keys from id_rsa and ssh_host_rsa_key. All SHA2 sign/verify are enabled by default.

The reason is that SHA1 is now considered easy to break.

To enable RSA with SHA1, for example for a very old and unsafe peer, see Example 9 in the User's Guide chapter Configuring algorithms in SSH.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-17259 Aux Id: OTP-16511, ERIERL-619

Adapt ssh supervisors to the new 'significant' and 'auto_shutdown' flags in supervisor.

Own Id: OTP-17322 Aux Id: PR-4638, EEP-56, OTP-17334

The functions public_key:ssh_encode/2, public_key:ssh_decode/2, public_key:ssh_hostkey_fingerprint/1 and public_key:ssh_hostkey_fingerprint/2 are deprecated.

Replacement functions are available in SSH, see the Deprecations chapter in the Erlang/OTP documentation.

Own Id: OTP-17352

## Ssh 4.11.1.5

### Fixed Bugs and Malfunctions

Fixed problem with blocked server after multiple restarts. Applies to daemons with options {parallel_login,true} and also {max_sessions, int()>0}.

Own Id: OTP-17835 Aux Id: ERIERL-721

## Ssh 4.11.1.4

### Fixed Bugs and Malfunctions

The value of the connect_timeout option is now used as default value for the negotiation timeout.

Own Id: OTP-17707 Aux Id: ERIERL-706

## Ssh 4.11.1.3

### Fixed Bugs and Malfunctions

Filter out sensitive data (passwords etc) from progress reports and supervisor reports.

Own Id: OTP-17468 Aux Id: ERIERL-656

### Improvements and New Features

The "Key exchange failed" Info Report is now more informative.

Own Id: OTP-17450 Aux Id: ERIERL-655

## Ssh 4.11.1.2

### Fixed Bugs and Malfunctions

Avoid an extra blank line in the ssh known_hosts file

Own Id: OTP-17427

## Ssh 4.11.1.1

### Fixed Bugs and Malfunctions

Fixed that a slow start (>30s) of a client subsystem could cause a log entry with the password.

Own Id: OTP-17390 Aux Id: ERIERL-648

## Ssh 4.11.1

### Fixed Bugs and Malfunctions

The idle_time timer was not cancelled when a channel was opened within the timeout time on an empty connection that have had channels previously.

Own Id: OTP-17279

## Ssh 4.11

### Improvements and New Features

The long name field in SSH_FXP_NAME responses to display file information in sftp version 3 now contains the expanded format defined in the sftp draft. It is similar to what is returned by "ls -l" on Unix systems.

Own Id: OTP-17197 Aux Id: PR- 3049

## Ssh 4.10.8

### Fixed Bugs and Malfunctions

Don't timeout slow connection setups and tear-downs. A rare crash risk for the controller is also removed.

Own Id: OTP-17173 Aux Id: ERIERL-581

## Ssh 4.10.7

### Fixed Bugs and Malfunctions

The SSH daemon erroneously replaced LF with CRLF also when there was no pty requested from the server.

Own Id: OTP-17108 Aux Id: ERL-1442

## Ssh 4.10.6

### Fixed Bugs and Malfunctions

Fixed problems in the ssh cli/shell handling. Most important are:

1) the ssh:shell function did sometimes cause the input to be echoed twice,

2) the ssh:shell function didn't transfer the LANG and LC_ALL shell variables to the connected server which sometimes made Unicode handling erroneous,

3) Unicode was not always transferred correctly to and from the peer.

Own Id: OTP-16799

The SSH protocol message SSH_MSG_DISCONNECT was sometimes sent instead of SSH_MSG_CHANNEL_FAILURE

Own Id: OTP-16900

The ssh_cli module now always sends the exit-status to connected clients so they can use that to check for successful command execution.

Own Id: OTP-16908 Aux Id: PR-2753

### Improvements and New Features

A new option pk_check_user enables checking of the client's user name in the server when doing public key authentication.

Own Id: OTP-16889

## Ssh 4.10.5

### Fixed Bugs and Malfunctions

An ssh-client can take an accepted socket from a listening socket and do an ssh:connect/2 on it.

Multiple clients on sockets accepted from the same listening socket had stopped working. This is corrected now.

Own Id: OTP-17021 Aux Id: ERIERL-567

## Ssh 4.10.4.1

### Fixed Bugs and Malfunctions

Filter out sensitive data (passwords etc) from progress reports and supervisor reports.

Own Id: OTP-17468 Aux Id: ERIERL-656

## Ssh 4.10.4

### Fixed Bugs and Malfunctions

The inet option raw was not passed on from the ssh option list to inet.

Own Id: OTP-17016 Aux Id: ERIERL-562

## Ssh 4.10.3

### Fixed Bugs and Malfunctions

A supervisor sub-tree could be left if the connection handler process is brutally killed. This will make the max_sessions checking option to count the existing sessions erroneously and could finally block further sessions.

Own Id: OTP-17006 Aux Id: ERIERL-556

## Ssh 4.10.2

### Fixed Bugs and Malfunctions

Fix decoder bug.

Own Id: OTP-16904

## Ssh 4.10.1

### Fixed Bugs and Malfunctions

Fixed a bug when a message to ssh-agent was divided into separate packets.

Own Id: OTP-16761 Aux Id: PR-2679

Fix a bug that could crash the cli server if a too large cli-window was requested from the client.

Own Id: OTP-16791 Aux Id: ERIERL-520

### Improvements and New Features

Increased test coverage.

Own Id: OTP-14106

A chapter about hardening the OTP SSH is added to the User's Guide.

Own Id: OTP-16411

The internal Diffie-Hellman high level API for key generation was slow in old and by OpenSSL now unsupported cryptolib versions (1.0.1 and earlier).

If such a cryptolib is used anyhow, the low-level API is used internally in the crypto application.

Own Id: OTP-16774

A new timeout is defined for daemons: hello_timeout.

The timeout is supposed to be used as a simple DoS attack protection. It closes an incoming TCP-connection if no valid first SSH message is received from the client within the timeout limit after the TCP initial connection setup.

The initial value is 30s by compatibility reasons, but could be lowered if needed, for example in the code or in a config file.

Own Id: OTP-16803

## Ssh 4.10

### Fixed Bugs and Malfunctions

Fix error in ssh_sftpd typespec.

Own Id: OTP-16363

### Improvements and New Features

The plug-in file ssh_file.erl, that is responsible for default file handling, is re-factored, optimized and re-written.

Own Id: OTP-11688 Aux Id: OTP-12699

OpenSSH 6.5 introduced a new file representation of keys called openssh-key-v1.

OTP/SSH had an experimental implementation of this format. That implementation is now improved and supported with the exception of handling encrypted keys.

Own Id: OTP-15434

TCP/IP port forwarding, a.k.a tunneling a.k.a tcp-forward/direct-tcp is implemented. In the OpenSSH client, this corresponds to the options -L and -R.

The client or server listens to a specified socket, and when something connects to it with TCP/IP, that connection is forwarded in an encrypted tunnel to the peer. The peer then connects to a predefined IP/port pair and then acts as a proxy.

See the manual, ssh:tcpip_tunnel_to_server/6 and ssh:tcpip_tunnel_from_server/6.

The functionality is disabled per default but can be enabled when starting a daemon.

Own Id: OTP-15998 Aux Id: PR-2376, PR-2368

The client-side of the supervisor tree (under sshc_sup) was previously not complete; the channel handling processes were handled with links but had no supervisors.

This is now corrected with a client-side supervisor tree under sshc_sup, similar to the server-side supervisor tree under sshd_sup.

Own Id: OTP-16026 Aux Id: PR-2368, (OTP-15998)

The extension posix-rename@openssh.com is added to the ssh/sftp rename operation.

Own Id: OTP-16289 Aux Id: PR-2448

Calls of deprecated functions in the Old Crypto API are replaced by calls of their substitutions.

Own Id: OTP-16346

The default known_hosts file handling is improved to include ports.

The handling of the contents in that file is updated to support the full syntax, with exception of 1) the wildcard '?', 2) wildcards in canonical names and 3) the option '@cert-authority'

Own Id: OTP-16506

The MAC (Message Authorization Code) algorithms

hmac-sha1-etm@openssh.com hmac-sha2-256-etm@openssh.com hmac-sha2-512-etm@openssh.com

are implemented.

Own Id: OTP-16508

The key-exchange algorithms 'diffie-hellman-group14-sha1' and 'diffie-hellman-group-exchange-sha1' are disabled per default. The reason is that SHA1 now is considered insecure.

They can be enabled if needed, see SSH (App).

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-16509

The public key algorithm 'ssh-dss' is disabled per default. The reason is that it is now considered as insecure.

It can be enabled if needed, see SSH (App).

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-16510

The public key 'ssh-rsa' is now considered as insecure because of its usage of SHA1.

It is therefore deprecated and will no longer be enabled per default in OTP-24.0.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-16511

An option optimize (optimize_key_lookup) is introduced for the file interface ssh_file.erl

The option enables the user to select between the default handling which is fast but memory consuming vs memory efficient but not as fast. The effect might be observable only for large files.

See the manual for ssh_file:is_host_key/5 and ssh_file:is_auth_key/3.

Own Id: OTP-16512

The ssh agent is now implemented in the ssh_agent key callback module.

Enable with the the option {key_cb, {ssh_agent, []}} in for example ssh:connect/3.

See the ssh_agent manual for details.

Own Id: OTP-16513

Algorithm configuration could now be done in a .config file.

This is useful for example to enable an algorithm that is disabled by default. It could now be enabled in an .config-file without changing the code,

See the SSH User's Guide chapter "Configuration in SSH".

Own Id: OTP-16540

Documented which gen_tcp socket options can't be used in calls to ssh:connect and ssh:daemon.

Own Id: OTP-16589

Added kb_int_fun_4() to the authentication_daemon_options() to enable generating dynamic keyboard-interactive prompts from the user's state returned from the authentication fun pwdfun_4().

Own Id: OTP-16622 Aux Id: PR-2604

## Ssh 4.9.1.4

### Fixed Bugs and Malfunctions

The value of the connect_timeout option is now used as default value for the negotiation timeout.

Own Id: OTP-17707 Aux Id: ERIERL-706

## Ssh 4.9.1.3

### Fixed Bugs and Malfunctions

The idle_time timer was not cancelled when a channel was opened within the timeout time on an empty connection that have had channels previously.

Own Id: OTP-17279

## Ssh 4.9.1.2

### Fixed Bugs and Malfunctions

Fix decoder bug.

Own Id: OTP-16904

## Ssh 4.9.1.1

### Fixed Bugs and Malfunctions

Fix a bug that could crash the cli server if a too large cli-window was requested from the client.

Own Id: OTP-16791 Aux Id: ERIERL-520

### Improvements and New Features

A new timeout is defined for daemons: hello_timeout.

It closes an incoming TCP-connection if no valid 1st message is received from the client within the timeout limit.

Own Id: OTP-16803

## Ssh 4.9.1

### Fixed Bugs and Malfunctions

Potential hazard between re-keying decision and socket close.

Own Id: OTP-16462 Aux Id: ERIERL-464

## Ssh 4.9

### Fixed Bugs and Malfunctions

Unicode problems for ssh_sftp:write fixed.

Own Id: OTP-16377

### Improvements and New Features

Changes to the internal api of the experimental ssh_dbg tool.

Own Id: OTP-16353

The new functions ssh:set_sock_opts/2 and ssh:get_sock_opts/2 sets and reads option values for the underlying TCP stream.

Own Id: OTP-16485

## Ssh 4.8.2

### Fixed Bugs and Malfunctions

Fixed that ssh_connection:send could allocate a large amount of memory if given an iolist() as input data.

Own Id: OTP-16373

Safe atom conversions.

Own Id: OTP-16375

Constant time comparisons added.

Own Id: OTP-16376

## Ssh 4.8.1

### Fixed Bugs and Malfunctions

The ssh cli (e.g shell) server behaved strangely when characters were inserted in a string such that the last characters tried to wrap the line.

Own Id: OTP-14849 Aux Id: ERL-545

If an OTP SSH server was serving an "exec" request and the executed code used Erlang standard_io for input/output, the I/O was erroneously handled by the *server's* group leader, so the I/O turned up in the the server's Erlang shell (if any). The user at the client side did therefor not see that I/O.

This is corrected now, so the client - for example the ssh OS shell command - handles the I/O. The user could send input to the server side exec handling code by writing on the terminal, and server side output from for example io:format is presented on the terminal - not only the functional result.

NOTE 1: Servers executing exec requests with the old, undocumented ways of specifying the custom exec handler is not changed. Changed are only the two cases where the server's 'exec' option either:
1) is not specified (i.e. using the default shell) or,
2) it has the {direct, fun(...) -> ... end} value format.

NOTE 2: Previously an end-of-line marker was appended on the result and error reports at the client side. They are removed now and the error reports are slightly enhanced.

TECHNICAL DETAILS: The server's device standard_input receives data events from the exec request's channel, and the device standard_output is sending its data by data events to the client on that channel. The result is that standard_io is now performed by the client's group leader.

Own Id: OTP-15417 Aux Id: OTP-16108

The functions ssh:shell/1,2,3 left the connection open when they returned. That leakage is fixed now.

Own Id: OTP-16047

Corrected that an Erlang SSH server could return the status code 4294967295 instead of 255 on some errors of an exec request.

Own Id: OTP-16123

### Improvements and New Features

Internal simplification of ssh_sftp/ssh_xfer

Own Id: OTP-15972

The documentation of One-Time Execution in the User's Guide is updated with more examples.

Own Id: OTP-16108 Aux Id: OTP-15417

The new value 'disabled' is introduced in the SSH daemon options 'exec' and 'shell'. Previously they lacked a clear way of disabling them.

Own Id: OTP-16113

The old algorithms 'aes192_cbc', 'aes256_cbc' and 'hmac-sha1-96' are added for compatibility with older peers.

The mac 'hmac-sha1-96' is nowadays not recommended and must therefore be explicitly enabled. Use for example the Option value {modify_algorithms, [{append, [{mac,['hmac-sha1-96']}]}]}

Own Id: OTP-16170

## Ssh 4.8

### Fixed Bugs and Malfunctions

Fixed wrong type definition for the daemon option subsystems.

Own Id: OTP-15820

Fixed a possible SSH logging crash if there was a problem in an early stage of session setup.

Own Id: OTP-15962 Aux Id: ERL-990

### Improvements and New Features

The documentation for the modules ssh_connection, ssh_sftp and ssh_sftpd are now generated from the -spec:s.

Own Id: OTP-15395

Internal cleanup including removal of the internal file ssh_userauth.hrl.

Own Id: OTP-15876 Aux Id: PR-2255, PR-2256

Removed unused definitions in ssh.hrl.

Own Id: OTP-15929 Aux Id: PR-2297

Removed unused fields in the internal #connection{} record.

Own Id: OTP-15984

To get information of a connection_ref() from for example ssh:connect/3, there was previously one function available namely ssh:connection_info/2. This ticket adds ssh:connection_info/1 which returns all information.

For daemons (servers) started with for example ssh:daemon/2 the function ssh:daemon_info/1 returning all information was available. This ticket adds ssh:daemon_info/2 which returns only the information specified in the second argument.

The info of connections and of daemons now also includes the item 'options'. Only those options that does not have their default values are returned.

For a connection also the items 'algorithms' and 'channels' are added.

Own Id: OTP-16040

## Ssh 4.7.7

### Improvements and New Features

SSH uses the new crypto API.

Own Id: OTP-15673

## Ssh 4.7.6.6

### Fixed Bugs and Malfunctions

The idle_time timer was not cancelled when a channel was opened within the timeout time on an empty connection that have had channels previously.

Own Id: OTP-17279

## Ssh 4.7.6.5

### Fixed Bugs and Malfunctions

Fix decoder bug.

Own Id: OTP-16904

## Ssh 4.7.6.4

### Fixed Bugs and Malfunctions

Potential hazard between re-keying decision and socket close.

Own Id: OTP-16462 Aux Id: ERIERL-464

## Ssh 4.7.6.3

### Fixed Bugs and Malfunctions

Fixed that ssh_connection:send could allocate a large amount of memory if given an iolist() as input data.

Own Id: OTP-16373

Safe atom conversions.

Own Id: OTP-16375

Constant time comparisons added.

Own Id: OTP-16376

## Ssh 4.7.6.2

### Fixed Bugs and Malfunctions

The ssh cli (e.g shell) server behaved strangely when characters were inserted in a string so that the last characters tried to wrap the line.

Own Id: OTP-14849 Aux Id: ERL-545

## Ssh 4.7.6.1

### Fixed Bugs and Malfunctions

Fixed a possible SSH logging crash if there was a problem in an early stage of session setup.

Own Id: OTP-15962 Aux Id: ERL-990

## Ssh 4.7.6

### Improvements and New Features

When an SSH server receives the very first message on a new TCP connection, and that message is not the expected one, the 64 first bytes of the received message are now dumped in the INFO REPORT that reports the Protocol Error.

This facilitates the debugging of who sends the bad message or of detecting a possible port scanning.

Own Id: OTP-15772

## Ssh 4.7.5

### Fixed Bugs and Malfunctions

The callback ssh_channel:init/1 was missing in OTP-21

Own Id: OTP-15762

If a client was connected to an server on an already open socket, the callback fun(PeerName,FingerPrint) in the accept_callback option passed the local name in the argument PeerName instead of the remote name.

Own Id: OTP-15763

## Ssh 4.7.4

### Fixed Bugs and Malfunctions

SSH sftp daemon now accepts an SSH_FXP_STAT message encoded according to the wrong sftp version. Some clients sends such messages.

Own Id: OTP-15498 Aux Id: ERL-822, PR-2077

## Ssh 4.7.3

### Fixed Bugs and Malfunctions

Fixed port leakage if a ssh:daemon call failed.

Own Id: OTP-15397 Aux Id: ERL-801

## Ssh 4.7.2

### Fixed Bugs and Malfunctions

Incompatibility with newer OpenSSH fixed. Previously versions 7.8 and later could cause Erlang SSH to exit.

Own Id: OTP-15413

The 'exec' option for ssh daemons had wrong format in the documentation.

Own Id: OTP-15416

### Improvements and New Features

Added public key methods ssh-ed25519 and ssh-ed448.

Requires OpenSSL 1.1.1 or higher as cryptolib under the OTP application crypto.

Own Id: OTP-15094 Aux Id: OTP-15419

The SSH property tests are now adapted to the PropEr testing tool.

Own Id: OTP-15312

The term "user" was not documented in the SSH app. A new chapter with terminology is added to the User's Manual where the term "user" is defined.

A reference manual page about the module ssh_file is also added. This is the default callback module for user's keys, host keys etc.

Own Id: OTP-15314

Host and user key checking is made more robust.

Own Id: OTP-15424

## Ssh 4.7.1

### Improvements and New Features

Extended the undocumented ssh_dbg debug module with an api for a circular trace buffer. This makes it easy to record the last low-level events before an error is detected. It is intended for solving difficult errors.

Own Id: OTP-15020

The key exchange methods 'curve25519-sha256@libssh.org', 'curve25519-sha256' and 'curve448-sha512' are implemented. The last two are defined in https://tools.ietf.org/html/draft-ietf-curdle-ssh-curves

They all depends on that OpenSSL 1.1.1 or higher is used as cryptolib.

Own Id: OTP-15133 Aux Id: OTP-15240

The cipher 'chacha20-poly1305@openssh.com' is now supported if OpenSSL 1.1.1 or higher is used as cryptolib.

Own Id: OTP-15209 Aux Id: OTP-15164

## Ssh 4.7

### Fixed Bugs and Malfunctions

If the daemon port listener is restarted, it could potentially fail with eaddrinuse if the timing is unlucky. It will now retry and exponentially back off the listener restart a few times before failing.

Own Id: OTP-14955

A channel callback module always got the module name as reason in a call to terminate. Now it will get the proper Reason, usually 'normal'.

Own Id: OTP-15084

### Improvements and New Features

The option exec has new option values defined to make it much more easy to implement an own exec server.

An option called exec for daemons implementing the handling of 'exec' requests has existed a long time but has been undocumented. The old undocumented value - as well as its behavior - is kept for compatibility EXCEPT that error messages are changed and are sent as "stderror" text.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-14851

Updated ssh_connection:shell/2 documentation.

Own Id: OTP-14880

The experimental ssh_dbg module is completely re-written. Its purpose is to make tracing and debugging easier on deployed systems.

Own Id: OTP-14896

The SSH supervisor structure has been slightly changed. This makes stopping the ssh application considerably faster if there are open connections. This is important in for example restarts.

Own Id: OTP-14988

The type specifications in SSH are completly reworked and the following types are renamed:

ssh:ssh_connection_ref() is changed to ssh:connection_ref(),

ssh:ssh_daemon_ref() is changed to ssh:daemon_ref(),

ssh:ssh_channel_id() is changed to ssh:channel_id().

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-15002 Aux Id: OTP-15030

The internal timer handling in SSH is now based on the gen_statem timers.

Own Id: OTP-15019

Removed the undocumented and unused modules ssh_client_key.erl and ssh_server_key.erl.

Own Id: OTP-15028

The Reference Manual pages are partly updated.

The ssh page is now generated from specs and types, is restructured and is partly rephrased.

The ssh_channel, ssh_connection, ssh_client_key_api, ssh_server_key_api and ssh_sftp pages are updated with links, correct type names and some minor changes.

Own Id: OTP-15030 Aux Id: OTP-15002

The behaviors ssh_channel and ssh_daemon_channel are renamed to ssh_client_channel and ssh_server_channel respectively.

The old modules are kept for compatibility but should preferably be replaced when updating callback modules referring them.

Own Id: OTP-15041

New test suite for channels.

Own Id: OTP-15051

The rekey_limit option could now set the max time as well as the previously max data amount.

Own Id: OTP-15069 Aux Id: ERL-617

Changed process exit supervision from links to monitors.

Own Id: OTP-15082

Better handling of misbehaving channel callback modules.

Own Id: OTP-15083

A new moduli file is generated. This file is used for the recommended diffie-hellman-group-exchange-sha256 key exchange algorithm in SSH.

Own Id: OTP-15113

## Ssh 4.6.9.7

### Fixed Bugs and Malfunctions

Fixed possible hanging in ssh_sftp:stop_channel/1.

Own Id: OTP-16507 Aux Id: ERIERL-470

## Ssh 4.6.9.6

### Fixed Bugs and Malfunctions

Fixed that ssh_connection:send could allocate a large amount of memory if given an iolist() as input data.

Own Id: OTP-16373

Safe atom conversions.

Own Id: OTP-16375

Constant time comparisons added.

Own Id: OTP-16376

## Ssh 4.6.9.5

### Fixed Bugs and Malfunctions

The ssh cli (e.g shell) server behaved strangely when characters were inserted in a string so that the last characters tried to wrap the line.

Own Id: OTP-14849 Aux Id: ERL-545

## Ssh 4.6.9.4

### Fixed Bugs and Malfunctions

If a client was connected to an server on an already open socket, the callback fun(PeerName,FingerPrint) in the accept_callback option passed the local name in the argument PeerName instead of the remote name.

Own Id: OTP-15763

## Ssh 4.6.9.3

### Fixed Bugs and Malfunctions

Fixed port leakage if a ssh:daemon call failed.

Own Id: OTP-15397 Aux Id: ERL-801

## Ssh 4.6.9.2

### Fixed Bugs and Malfunctions

Incompatibility with newer OpenSSH fixed. Previously versions 7.8 and later could cause Erlang SSH to exit.

Own Id: OTP-15413

## Ssh 4.6.9.1

### Fixed Bugs and Malfunctions

SFTP clients reported the error reason "" if a non-OTP sftp server was killed during a long file transmission.

Now the signal name (for example "KILL") will be the error reason if the server's reason is empty.

The documentation also lacked type information about this class of errors.

Own Id: OTP-15148 Aux Id: ERIERL-194

Fix ssh_sftp decode error for sftp protocol version 4

Own Id: OTP-15149 Aux Id: ERIERL-199

## Ssh 4.6.9

### Fixed Bugs and Malfunctions

Host key hash erroneously calculated for clients following draft-00 of RFC 4419, for example PuTTY

Own Id: OTP-15064

Renegotiation could fail in some states

Own Id: OTP-15066

## Ssh 4.6.8

### Fixed Bugs and Malfunctions

An ssh_sftp server (running version 6) could fail if it is told to remove a file which in fact is a directory.

Own Id: OTP-15004

Fix rare spurios shutdowns of ssh servers when receiveing {'EXIT',_,normal} messages.

Own Id: OTP-15018

## Ssh 4.6.7

### Fixed Bugs and Malfunctions

Fix bad spec in ssh.hrl: double_algs().

Own Id: OTP-14990

## Ssh 4.6.6

### Fixed Bugs and Malfunctions

Remove a blocking risk when a channel is closed and an operation is tried on that channel after at least a second's time gap.

Own Id: OTP-14939

### Improvements and New Features

Added ssh_compat_SUITE.

This suite contains a number of interoperability tests mainly with OpenSSH. The tests start docker containers with different OpenSSH and OpenSSL/LibreSSLcryptolib versions and performs a number of tests of supported algorithms.

All login methods and all user's public key types are tested both for the client and the server.

All algorithms for kex, cipher, host key, mac and compressions are tested with a number of exec and sftp tests, both for the client and the server.

Own Id: OTP-14194 Aux Id: OTP-12487

Default exec is disabled when a user-defined shell is enabled.

Own Id: OTP-14881

## Ssh 4.6.5

### Fixed Bugs and Malfunctions

Adjusted supervisor timeouts

Own Id: OTP-14907

Remove ERROR messages for slow process exits

Own Id: OTP-14930

### Improvements and New Features

Add option save_accepted_host to ssh:connection. This option, if set to false, inhibits saving host keys to e.g the file known_hosts.

Own Id: OTP-14935

## Ssh 4.6.4

### Fixed Bugs and Malfunctions

Fix problem with OpenSSH 7.2 (and later) clients that has used sha1 instead of sha2 for rsa-sha-256/512 user's public keys.

Own Id: OTP-14827 Aux Id: ERL-531

## Ssh 4.6.3

### Fixed Bugs and Malfunctions

Passphrase option for ecdsa public keys was missing.

Own Id: OTP-14602

### Improvements and New Features

The host and user public key handling is hardened so that a faulty plugin can't deliver a key of wrong type.

Better checks in the server of the available hostkey's types at start and at each accept.

Better checks in the client of the available user public key types at connect.

Own Id: OTP-14676 Aux Id: ERIERL-52, OTP-14570

SSH can now fetch the host key from the private keys stored in an Engine. See the crypto application for details about Engines.

Own Id: OTP-14757

## Ssh 4.6.2

### Fixed Bugs and Malfunctions

Trailing white space was removed at end of the hello-string. This caused interoperability problems with some other ssh-implementations (e.g OpenSSH 7.3p1 on Solaris 11)

Own Id: OTP-14763 Aux Id: ERIERL-74

Fixes that tcp connections that was immediately closed (SYN, SYNACK, ACK, RST) by a client could be left in a zombie state.

Own Id: OTP-14778 Aux Id: ERIERL-104

## Ssh 4.6.1

### Fixed Bugs and Malfunctions

Fixed broken printout

Own Id: OTP-14645

### Improvements and New Features

Disable aes_gcm ciphers if peer is OpenSSH 6.2 which is known to have trouble with them in some cases.

Own Id: OTP-14638

## Ssh 4.6

### Fixed Bugs and Malfunctions

Enables the ssh_io module to also accept binary values when reading standard_io instead of getting stuck in the receive clause.

Own Id: OTP-14506 Aux Id: PR1503

Previously, the file owner access permission in response to ssh_sftp:read_file_info/2 function was always read_write. With this fix, the actual value of file owner access permission is added to the returning record. That value is calculated from file mode value.

Own Id: OTP-14550 Aux Id: PR1533

### Improvements and New Features

A new option modify_algorithms is implemented. It enables specifying changes on the default algorithms list. See the reference manual and the SSH User's Guide chapter "Configuring algorithms in SSH".

Own Id: OTP-14568

## Ssh 4.5.1

### Fixed Bugs and Malfunctions

All unknown options are sent to the transport handler regardless of type.

Own Id: OTP-14541 Aux Id: EIRERL-63

## Ssh 4.5

### Improvements and New Features

The internal handling of SSH options is re-written.

Previously there were no checks if a client option was given to a daemon or vice versa. This is corrected now. If your code has e.g. a client-only option in a call to start a daemon, the call will fail.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-12872

Modernization of key exchange algorithms. See draft-ietf-curdle-ssh-kex-sha2 for a discussion.

Removed an outdated weak algorithm and added stronger replacements to keep interoperability with other modern ssh clients and servers. The default ordering of the algorithms is also adjusted.

Retired: The nowadays unsecure key-exchange diffie-hellman-group1-sha1 is not enabled by default, but can be enabled with the option preferred-algorithms.

Added: The new stronger key-exchange diffie-hellman-group16-sha512, diffie-hellman-group18-sha512 and diffie-hellman-group14-sha256 are added and enabled by default.

The questionable [RFC 6194] sha1-based algorithms diffie-hellman-group-exchange-sha1 and diffie-hellman-group14-sha1 are however still kept enabled by default for compatibility with ancient clients and servers that lack modern key-exchange alternatives. When the draft-ietf-curdle-ssh-kex-sha2 becomes an rfc, those sha1-based algorithms and diffie-hellman-group1-sha1 will be deprecated by IETF. They might then be removed from the default list in Erlang/OTP.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-14110

Modernized internal representation of sftp by use of maps.

Own Id: OTP-14117

The Extension Negotiation Mechanism and the extension server-sig-algs in draft-ietf-curdle-ssh-ext-info-05 are implemented.

The related draft-ietf-curdle-rsa-sha2-05 is implemented and introduces the signature algorithms rsa-sha2-256 and rsa-sha2-512.

Own Id: OTP-14193

The 'timeout' and 'connect_timeout' handling in ssh_sftp:start_channel documentation is clarified.

Own Id: OTP-14216

The functions ssh:connect, ssh:shell and ssh:start_channel now accept an IP-tuple as Host destination argument.

Own Id: OTP-14243

The function ssh:daemon_info/1 now returns Host and Profile as well as the Port info in the property list.

Own Id: OTP-14259

Removed the option public_key_alg which was deprecated in 18.2. Use pref_public_key_algs instead.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-14263

The SSH application is refactored regarding daemon starting. The resolution of contradicting Host argument and ip option were not described. There were also strange corner cases when the 'any' value was used in Host argument or ip option. This is (hopefully) resolved now, but it may cause incompatibilities for code using both Host and the ip option. The value 'loopback' has been added for a correct way of naming those addresses.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-14264

The supervisor code is refactored. The naming of listening IP-Port-Profile triples are slightly changed to improve consistency in strange corner cases as resolved by OTP-14264

Own Id: OTP-14267 Aux Id: OTP-14266

The idle_time option can now be used in daemons.

Own Id: OTP-14312

Added test cases for IETF-CURDLE Extension Negotiation (ext-info)

Own Id: OTP-14361

Testcases for IETF-CURDLE extension server-sig-algs including rsa-sha2-*

Own Id: OTP-14362 Aux Id: OTP-14361

The option auth_methods can now also be used in clients to select which authentication options that are used and in which order.

Own Id: OTP-14399

Checks that a ECDSA public key (ecdsa-sha2-nistp*) stored in a file has the correct size.

Own Id: OTP-14410

## Ssh 4.4.2.4

### Fixed Bugs and Malfunctions

Fix rare spurios shutdowns of ssh servers when receiveing {'EXIT',_,normal} messages.

Own Id: OTP-15018

Host key hash erroneously calculated for clients following draft-00 of RFC 4419, for example PuTTY

Own Id: OTP-15064

Renegotiation could fail in some states

Own Id: OTP-15066

## Ssh 4.4.2.3

### Fixed Bugs and Malfunctions

An ssh_sftp server (running version 6) could fail if it is told to remove a file which in fact is a directory.

Own Id: OTP-15004

## Ssh 4.4.2.2

### Improvements and New Features

Default exec is disabled when a user-defined shell is enabled.

Own Id: OTP-14881

## Ssh 4.4.2.1

### Fixed Bugs and Malfunctions

Trailing white space was removed at end of the hello-string. This caused interoperability problems with some other ssh-implementations (e.g OpenSSH 7.3p1 on Solaris 11)

Own Id: OTP-14763 Aux Id: ERIERL-74

## Ssh 4.4.2

### Fixed Bugs and Malfunctions

ssh:daemon_info/1 crashed if the listening IP was not 'any'

Own Id: OTP-14298 Aux Id: seq13294

## Ssh 4.4.1

### Fixed Bugs and Malfunctions

Fix bug when opening connections. If the tcp setup failed, that would in some cases not result in an error return value.

Own Id: OTP-14108

Reduce information leakage in case of decryption errors.

Own Id: OTP-14109

The key exchange algorithm diffie-hellman-group-exchange-sha* has a server-option {dh_gex_limits,{Min,Max}}. There was a hostkey signature validation error on the client side if the option was used and the Min or the Max differed from the corresponding values obtained from the client.

This bug is now corrected.

Own Id: OTP-14166

The sftpd server now correctly uses root_dir and cwd when resolving file paths if both are provided. The cwd handling is also corrected.

Thanks to kape1395!

Own Id: OTP-14225 Aux Id: PR-1331, PR-1335

Ssh_cli used a function that does not handle non-utf8 unicode correctly.

Own Id: OTP-14230 Aux Id: ERL-364

### Improvements and New Features

The implementation of the key exchange algorithms diffie-hellman-group-exchange-sha* are optimized, up to a factor of 11 for the slowest ( = biggest and safest) group size.

Own Id: OTP-14169 Aux Id: seq-13261

The ssh host key fingerprint generation now also takes a list of algorithms and returns a list of corresponding fingerprints. See public_key:ssh_hostkey_fingerprint/2 and the option silently_accept_hosts in ssh:connect.

Own Id: OTP-14223

## Ssh 4.4

### Fixed Bugs and Malfunctions

A file read with an sftp client could loose data if the packet_size is set to larger than 64k. This is corrected now in such a way that the packet_size is silently lowered if there is a risk for data loss.

Own Id: OTP-13857 Aux Id: ERL-238, OTP-13858

When user defined SSH shell REPL process exits with reason normal, the SSH channel callback module should report successful exit status to the SSH client. This provides simple way for SSH clients to check for successful completion of executed commands. (Thanks to isvilen)

Own Id: OTP-13905 Aux Id: PR-1173

### Improvements and New Features

Extended the option silently_accept_hosts for ssh:connect to make it possible for the client to check the SSH host key fingerprint string. Se the reference manual for SSH.

Own Id: OTP-13887 Aux Id: OTP-13888

## Ssh 4.3.6

### Fixed Bugs and Malfunctions

Re-negotiation problems with OpenSSH client solved.

Own Id: OTP-13972

## Ssh 4.3.5

### Fixed Bugs and Malfunctions

If a client illegaly sends an info-line and then immediatly closes the TCP-connection, a badmatch exception was raised.

Own Id: OTP-13966

## Ssh 4.3.4

### Fixed Bugs and Malfunctions

Intermittent ssh ERROR REPORT mentioning nonblocking_sender

Own Id: OTP-13953 Aux Id: seq13199

## Ssh 4.3.3

### Fixed Bugs and Malfunctions

Handle all possible exit values that should be interpreted as {error, closed}. Failing to do so could lead to unexpected crashes for users of the ssh application.

Own Id: OTP-13932 Aux Id: seq13189

## Ssh 4.3.2

### Fixed Bugs and Malfunctions

Upgrade of an established client connection could crash because the ssh client supervisors children had wrong type. This is fixed now.

Own Id: OTP-13782 Aux Id: seq13158

Partly checks the public key early in public key authorization

Own Id: OTP-13847 Aux Id: defensics-ssh3.1.0-190243,205277,219318

Corrected handling of SHA for ECDSA (Elliptic curve public keys)

Own Id: OTP-13850 Aux Id: defensics-ssh3.1.0-214168

Problems found by test suites as well as by Codenomicon/Defensics fixed: - reduce max random padding to 15 bytes (Codenomicon/Defensics) - inclomplete pdu handling (Codenomicon/Defensics) - badmatch in test suite - non-blocking send fixes deadlock in ssh_connection_SUITE:interrupted_send

Own Id: OTP-13854

Caller is now notified when a tcp close is received.

Own Id: OTP-13859 Aux Id: seq13177

### Improvements and New Features

Use application:ensure_all_started/2 instead of hard-coding deps

Own Id: OTP-13843 Aux Id: PR-1147

## Ssh 4.3.1

### Fixed Bugs and Malfunctions

SSH client does not any longer retry a bad password given as option to ssh:connect et al.

Own Id: OTP-13674 Aux Id: TR-HU92273

Removed possible hanging risk for a certain timing sequence when communicating client and server executes on the same node.

Own Id: OTP-13715

## Ssh 4.3

### Improvements and New Features

A socket created and connected by gen_tcp could now be used as input to ssh:connect, ssh:shell, ssh_sftp:start_channel and ssh:daemon.

Own Id: OTP-12860

Some time optimization mainly in message encoding.

Own Id: OTP-13131

Optimized the sftp client time by setting new packet and window sizes.

Own Id: OTP-13175

The ssh_connection_handler module in SSH is changed and now uses the new behaviour gen_statem.

The module can be used as an example of a gen_statem callback module but with a warning: This commit of ssh is just a straightforward port from gen_fsm to gen_statem with some code cleaning. Since the state machine and the state callbacks are almost unchanged the ssh module does not demonstrate the full potential of the new behaviour.

The "new" state machine uses compound states. The ssh server and client state machines are quite similar but differences exist. With gen_fsm there were flags in the user data which in fact implemented "substates". Now with gen_statem those are made explicit in the state names, eg. the state userauth and the binary role-flag becomes the two state names {userauth, server} and {userauth, client}.

Own Id: OTP-13267

The {error, Reason} tuples returned from ssh_sftp api functions are described.

Own Id: OTP-13347 Aux Id: ERL-86

Added -spec in ssh

Own Id: OTP-13479

It is now possible to call ssh:daemon/{1,2,3} with Port=0. This makes the daemon select a free listening tcp port before opening it. To find this port number after the call, use the new function ssh:daemon_info/1. See the reference manual for details.

Own Id: OTP-13527

## Ssh 4.2.2.6

### Fixed Bugs and Malfunctions

Fix rare spurios shutdowns of ssh servers when receiveing {'EXIT',_,normal} messages.

Own Id: OTP-15018

## Ssh 4.2.2.5

### Improvements and New Features

Default exec is disabled when a user-defined shell is enabled.

Own Id: OTP-14881

## Ssh 4.2.2.4

### Fixed Bugs and Malfunctions

Trailing white space was removed at end of the hello-string. This caused interoperability problems with some other ssh-implementations (e.g OpenSSH 7.3p1 on Solaris 11)

Own Id: OTP-14763 Aux Id: ERIERL-74

## Ssh 4.2.2.3

### Fixed Bugs and Malfunctions

The key exchange algorithm diffie-hellman-group-exchange-sha* has a server-option {dh_gex_limits,{Min,Max}}. There was a hostkey signature validation error on the client side if the option was used and the Min or the Max differed from the corresponding values obtained from the client.

This bug is now corrected.

Own Id: OTP-14166

### Improvements and New Features

Key exchange algorithms diffie-hellman-group-exchange-sha* optimized, up to a factor of 11 for the slowest ( = biggest and safest) one.

Own Id: OTP-14169 Aux Id: seq-13261

## Ssh 4.2.2.2

### Fixed Bugs and Malfunctions

Upgrade of an established client connection could crash because the ssh client supervisors children had wrong type. This is fixed now.

Own Id: OTP-13782 Aux Id: seq13158

## Ssh 4.2.2.1

### Fixed Bugs and Malfunctions

SSH client does not any longer retry a bad password given as option to ssh:connect et al.

Own Id: OTP-13674 Aux Id: TR-HU92273

## Ssh 4.2.2

### Fixed Bugs and Malfunctions

Documentation correction of ssh_sftp:position/4

Thanks to Rabbe Fogelholm.

Own Id: OTP-13305 Aux Id: ERL-87

## Ssh 4.2.1

### Fixed Bugs and Malfunctions

The authentication method 'keyboard-interactive' failed in the Erlang client when the server after successful authentication continued by asking for zero more passwords.

Own Id: OTP-13225

## Ssh 4.2

### Fixed Bugs and Malfunctions

Better error handling in ssh_file. There was some rare errors when a NFS-mounted file was opened by ssh_file and then remotely deleted during reading. That caused an endless loop.

That bug is now fixed.

Own Id: OTP-12699 Aux Id: OTP-11688

Fixed a bug in the compression algorithm zlib@openssh.com.

Own Id: OTP-12759

It is now possible to start more than one daemon with a file descriptor given in option fd. Each daemon must of course have a unique file descriptor.

Own Id: OTP-12966 Aux Id: seq12945

Fixed a bug that caused the option dh_gex_limit to be ignored.

Own Id: OTP-13029

A problem is fixed with the ssh:connect option pref_public_key_algs specifying user keys.

Own Id: OTP-13158

### Improvements and New Features

Document updates in the ssh reference manual: app doc file and ssh_connection.

Own Id: OTP-12003

The authorization phase is made stateful to prevent ssh acting on messages sent in wrong order.

Own Id: OTP-12787

Testcases for bad message lengths and for bad subfield lengths added.

Own Id: OTP-12792 Aux Id: Codenomicon #5214, 6166

The 'ecdsa-sha2-nistp256', 'ecdsa-sha2-nistp384' and 'ecdsa-sha2-nistp521' signature algorithms for ssh are implemented. See RFC 5656.

Own Id: OTP-12936

The crypto algorithms 'aes192-ctr' and 'aes256-ctr' are implemented. See RFC 4344.

Own Id: OTP-12939

The ciphers and macs AEAD_AES_128_GCM and AEAD_AES_256_GCM are implemented but not enabled per default. See the SSH App Reference Manual and RFC5647 for details.

The ciphers aes128-gcm@openssh.com and aes256-gcm@openssh.com are also implemented and available in the default configuration.

Own Id: OTP-13018

The ssh:daemon option dh_gex_groups is extended to read a user provided ssh moduli file with generator-modulus pairs. The file is in openssh format.

Own Id: OTP-13052 Aux Id: OTP-13054

There is now a file (public_key/priv/moduli) which lists size-generator-modulus triples. The purpose is to give servers the possibility to select the crypto primes randomly among a list of pregenerated triples. This reduces the risk for some attacks on diffie-hellman negotiation.

See the reference manual for public_key:dh_gex_group/4 where the handling of this is described.

The ssh server (ssh:daemon) uses this.

Own Id: OTP-13054 Aux Id: OTP-13052

The ssh:daemon option pwdfun now also takes a fun/4. This enables the user to 1) check userid-password in another way than the builtin algorithm, 2) implement rate limiting per user or source IP or IP+Port, and 3) implement blocking of missbehaving peers.

The old fun/2 still works as previously.

Own Id: OTP-13055 Aux Id: OTP-13053

There is now a new option to make the server limit the size range of moduli available for the diffie-hellman group exchange negotiation. See option {dh_gex_limits,{Min,Max}} in ssh:daemon/3.

Own Id: OTP-13066

Ecdh key exchange now validates compressed and uncompressed keys as defined in rfc5656

Own Id: OTP-13067

Search order for the .ssh directory are changed so $HOME is tried before init:get_argument(home).

Own Id: OTP-13109

The sftp receive window handling is optimized so it will not update the remote end too often. This makes "sftp mget" considerable faster.

Own Id: OTP-13130

The option key_cb is extended to take an optional list that is passed to the callback module as an option. With this it is possible to have different keys depending on which host that is connected. Another possibility is to write a callback module that fetches keys etc from a database.

Thanks to Vipin Nair.

Own Id: OTP-13156

## Ssh 4.1.3

### Known Bugs and Problems

SSH_MSG_KEX_DH_GEX_REQUEST_OLD implemented to make PuTTY work with erl server.

Own Id: OTP-13140

## Ssh 4.1.2

### Fixed Bugs and Malfunctions

Add a 1024 group to the list of key group-exchange groups

Own Id: OTP-13046

## Ssh 4.1.1

### Improvements and New Features

A new option max_channels limits the number of channels with active server-side subsystems that are accepted.

Own Id: OTP-13036

## Ssh 4.1

### Fixed Bugs and Malfunctions

Send an understandable disconnect message when the key exchange phase can't find a common algorithm. There are also some test cases added.

Own Id: OTP-11531

The third parameter in ssh_sftp:write_file is now accepting iolists again. Unicode handling adjusted.

Own Id: OTP-12853 Aux Id: seq12891

### Improvements and New Features

First part of ssh test suite re-organization and extension.

Own Id: OTP-12230

The key exchange algorithms 'ecdh-sha2-nistp256', 'ecdh-sha2-nistp384' and 'ecdh-sha2-nistp521' are implemented. See RFC 5656.

This raises the security level considerably.

Own Id: OTP-12622 Aux Id: OTP-12671, OTP-12672

The key exchange algorithm 'diffie-hellman-group14-sha1' is implemented. See RFC 4253.

This raises the security level.

Own Id: OTP-12671 Aux Id: OTP-12672, OTP-12622

The key exchange algorithms 'diffie-hellman-group-exchange-sha1' and 'diffie-hellman-group-exchange-sha256' are implemented. See RFC 4419.

This raises the security level.

Own Id: OTP-12672 Aux Id: OTP-12671, OTP-12622

Adding random length extra padding as recommended in RFC 4253 section 6.

Own Id: OTP-12831

New test library for low-level protocol testing. There is also a test suite using it for some preliminary tests. The intention is to build on that for more testing of individual ssh messages. See lib/ssh/test/ssh_trpt_test_lib.erl and ssh_protocol_SUITE.erl in the same directory.

Own Id: OTP-12858

Increased default values for diffie-hellman-group-exchange-sha* to Min = 1024, N = 6144, Max = 8192.

Added 6144 and 8192 bit default gex groups.

Own Id: OTP-12937

The mac algorithm 'hmac-sha2-512' is implemented. See RFC 6668.

Own Id: OTP-12938

## Ssh 4.0

### Fixed Bugs and Malfunctions

Ssh crashed if a message was sent on a channel with packet_size = 0.

A new option for ssh:daemon is also introduced: minimal_remote_max_packet_size. This option sets the least max packet size declaration that the daemon will accept from a client. The default value is 0 to maintain compatibility with OpenSSH and the rfc:s.

Own Id: OTP-12645 Aux Id: seq12816

Included test of the 'e' and 'f' parameters in diffie-hellman key exchange as specified in rfc 4253 section 8.

Own Id: OTP-12649

Fixes the bug that once the rekey_limit bytes (by default, 1GB) had been transmitted the connection was rekeyed every minute, not after the next transferred 'rekey_limit' chunk.

Thanks to Simon Cornish for the report and the fix!

Own Id: OTP-12692

Fixes a bug that causes an SFTP connection to always fail when {timeout, Timeout} option is used with ssh_sftp:start_channel.

Thanks to Simon Cornish

Own Id: OTP-12708

Fix various ssh key exchange problems.

Thanks to Simon Cornish

Own Id: OTP-12760 Aux Id: pull req 715

The options system_dir and user_dir assumes that the value is a path to a directory which is readable. This is now checked early, so ssh:daemon and ssh:connect will fail with an error message immediately.

Own Id: OTP-12788

A daemon now checks that a client doesn't try to authorize with methods not in the option auth_methods.

Own Id: OTP-12790

Disconnectfun now should trigger on all disconnects.

Own Id: OTP-12811

### Improvements and New Features

Better usage of binary matching in ssh_auth.erl and ssh_message.erl

Own Id: OTP-11697

A new option 'preferred_algorithms' is available for ssh:daemon and ssh:connect.

This option defines the algorithms presented to the peer in the algorithm negotiation phase of the ssh protocol.

The default list can be obtained from the new function ssh:default_algorithms/0.

*** INCOMPATIBILITY with removed undocumented options 'role' and 'compression' ***

Own Id: OTP-12029

The internal group to user_drv protocol has been changed to be synchronous in order to guarantee that output sent to a process implementing the user_drv protocol is printed before replying. This protocol is used by the standard_output device and the ssh application when acting as a client.

This change changes the previous unlimited buffer when printing to standard_io and other devices that end up in user_drv to 1KB.

*** POTENTIAL INCOMPATIBILITY ***

Own Id: OTP-12240

If ssh_connection:subsystem/4 fails we do not want to crash but rather terminate gracefully.

Own Id: OTP-12648 Aux Id: seq12834

New option id_string for ssh:daemon and ssh:connect for limiting banner grabbing attempts.

The possible values are: {id_string,string()} and {id_string,random}. The latter will make ssh generate a random nonsence id-string for each new connection.

Own Id: OTP-12659

To enable the ssh daemon to run in a virtualized environment, where there can be more that one server that has the same ip-address and port, we add a new option profile.

Own Id: OTP-12675

Upgrade test suite added.

Own Id: OTP-12676

A new option for handling the SSH_MSG_DEBUG message's printouts. A fun could be given in the options that will be called whenever the SSH_MSG_DEBUG message arrives. This enables the user to format the printout or just discard it.

Own Id: OTP-12738 Aux Id: seq12860

Testcase improvements and corrections:

* Add testcases for the disconnectfun option on both server and client sides

* Timeout testcases adjusted for slow machines where they sometimes failed

Own Id: OTP-12786

The option disconnectfun can now be used both on the client and server side.

Own Id: OTP-12789

A new option unknown_msgfun/2 for ssh:connect and ssh:daemon for handling unknown messages. With the option it is possible to intercept before an INFO log message is generated.

One usage is to filter out messages that are not wanted in the error logger as info reports. An example of such a message is the 'etimedout' tcp error message that will be received if a connection has keep_alive and the peer is restarted.

Own Id: OTP-12813 Aux Id: seq12881

## Ssh 3.2.4

### Fixed Bugs and Malfunctions

Gracefully terminate if sockets is unexpectedly closed.

Own Id: OTP-12782

Made Codenomicon Defensics test suite pass:

limit number of algorithms in kexinit message check 'e' and 'f' parameters in kexdh implement 'keyboard-interactive' user authentication on server side return plain text message to bad version exchange message

Own Id: OTP-12784

## Ssh 3.2.3

### Fixed Bugs and Malfunctions

A new option for handling the SSH_MSG_DEBUG message's printouts. A fun could be given in the options that will be called whenever the SSH_MSG_DEBUG message arrives. This enables the user to format the printout or just discard it.

Own Id: OTP-12738 Aux Id: seq12860

## Ssh 3.2.2

### Improvements and New Features

New option id_string for ssh:daemon and ssh:connect for limiting banner grabbing attempts.

The possible values are: {id_string,string()} and {id_string,random}. The latter will make ssh generate a random nonsence id-string for each new connection.

Own Id: OTP-12659

## Ssh 3.2.1

### Fixed Bugs and Malfunctions

Ssh crashed if a message was sent on a channel with packet_size = 0.

A new option for ssh:daemon is also introduced: minimal_remote_max_packet_size. This option sets the least max packet size declaration that the daemon will accept from a client. The default value is 0 to maintain compatibility with OpenSSH and the rfc:s.

Own Id: OTP-12645 Aux Id: seq12816

## Ssh 3.2

### Fixed Bugs and Malfunctions

If a channel is closed by the peer while using a function with call semantics in ssh_connection.erl return {error, closed}. Document that the functions can return {error, timeout | closed} and not only ssh_request_status()

Own Id: OTP-12004

Bug that causes ssh:connect to return {error,int()} instead of {error,timeout} when ssh handshake takes too long time.

Own Id: OTP-12369

Documentation corrections. (Thanks to Rabbe Fogelholm)

Own Id: OTP-12399

### Improvements and New Features

Example of ssh_connection:exec added.

Own Id: OTP-12558

## Ssh 3.1

### Fixed Bugs and Malfunctions

Make sure the clean rule for ssh, ssl, eunit and otp_mibs actually removes generated files.

Own Id: OTP-12200

Improved Property Tests (Thanks to Thomas, John and Tobias at QuviQ)

Own Id: OTP-12256

Correct typo of renegotiate that could cause rekeying to fail

Own Id: OTP-12277 Aux Id: seq12736

The {timeout, Timeout} option passed to ssh_sftp:start_channel was not applied to the early phases of the SSH protocol. This patch passes the Timeout through to ssh:connect. In case the timeout occurs during these phases, {error, timeout} is returned. (Thanks to Simon Cornish)

Own Id: OTP-12306

### Improvements and New Features

Added API functions ptty_alloc/3 and ptty_alloc/4, to allocate a pseudo tty.

Own Id: OTP-11542 Aux Id: seq12493, OTP-11631

Supports tar file creation on other media than file systems mounted on the local machine.

The erl_tar api is extended with erl_tar:init/3 that enables usage of user provided media storage routines. A ssh-specific set of such routines is hidden in the new function ssh_sftp:open_tar/3 to simplify creating a tar archive on a remote ssh server.

A chunked file reading option is added to erl_tar:add/3,4 to save memory on e.g small embedded systems. The size of the slices read from a file in that case can be specified.

Own Id: OTP-12180 Aux Id: seq12715

Always send SSH_DISCONNECT protocol messages when peer sends corrupt messages.

Own Id: OTP-12185

Hooks for funs that can change binaries sent to remote sites from erl_tar for renote tar file creation are added. See ssh_sftp:open_tar/3,4 for details. The hooks could also be used to read remote tar files that need transformation before file extraction.

Those hooks are intended for encryption and decryption of tar files. Effort is put into memory, disk and network resource economy.

Own Id: OTP-12312 Aux Id: OTP-12180

## Ssh 3.0.8

### Fixed Bugs and Malfunctions

Fixes of login blocking after port scanning.

Own Id: OTP-12247 Aux Id: seq12726

## Ssh 3.0.7

### Fixed Bugs and Malfunctions

Add option sftp_vsn to SFTP

Own Id: OTP-12227

### Improvements and New Features

Fix option user_interaction to work as expected. When password authentication is implemented with ssh keyboard-interactive method and the password is already supplied, so that we do not need to query user, then connections should succeed even though user_interaction option is set to false.

Own Id: OTP-11329 Aux Id: seq12420, seq12335

## Ssh 3.0.6

### Fixed Bugs and Malfunctions

Gracefully handle bad data from the client when expecting ssh version exchange.

Own Id: OTP-12157 Aux Id: seq12706

When restarting an ssh daemon, that was stopped with ssh:stop_listner/ [1,2] new options given shall replace old ones.

Own Id: OTP-12168 Aux Id: seq12711

### Improvements and New Features

ssh now has a format_status function to avoid printing sensitive information in error loggs.

Own Id: OTP-12030

### Known Bugs and Problems

The option parallel_login didn't work with the value true. All logins were serial.

Own Id: OTP-12194

## Ssh 3.0.5

### Fixed Bugs and Malfunctions

When starting an ssh-daemon giving the option {parallel_login, true}, the timeout for authentication negotiation ({negotiation_timeout, integer()}) was never removed.

This caused the session to always be terminated after the timeout if parallel_login was set.

Own Id: OTP-12057 Aux Id: seq12663

### Improvements and New Features

Warning: this is experimental and may disappear or change without previous warning.

Experimental support for running Quickcheck and PropEr tests from common_test suites is added to common_test. See the reference manual for the new module ct_property_testing.

Experimental property tests are added under lib/{inet,ssh}/test/property_test. They can be run directly or from the commont_test suites inet/ftp_property_test_SUITE.erl and ssh/test/ssh_property_test_SUITE.erl.

See the code in the test directories and the man page for details.

(Thanks to Tuncer Ayaz for a patch adding Triq)

Own Id: OTP-12119

## Ssh 3.0.4

### Fixed Bugs and Malfunctions

When starting an ssh-daemon giving the option {parallel_login, true}, the timeout for authentication negotiation ({negotiation_timeout, integer()}) was never removed.

This caused the session to always be terminated after the timeout if parallel_login was set.

Own Id: OTP-12057 Aux Id: seq12663

## Ssh 3.0.3

### Fixed Bugs and Malfunctions

Removed mail address from error reports and corrected spelling error (Stacktace -> stacktrace)

Own Id: OTP-11883 Aux Id: seq12586

Decode/encode fixes in SSH_MSG_IGNORE and SSH_MSG_UNIMPLEMENTED.

Own Id: OTP-11983

### Improvements and New Features

Accepts that some older OpenSSH clients sends incorrect disconnect messages.

Own Id: OTP-11972

Handle inet and inet6 option correctly

Own Id: OTP-11976

## Ssh 3.0.2

### Fixed Bugs and Malfunctions

Fixed timeout bug in ssh:connect.

Own Id: OTP-11908

### Improvements and New Features

Option max_sessions added to ssh:daemon/{2,3}. This option, if set, limits the number of simultaneous connections accepted by the daemon.

Own Id: OTP-11885

## 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

## 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

## 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

## 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

## Ssh 2.1.6

### Fixed Bugs and Malfunctions

Fixed timing rekeying bug.

Own Id: OTP-10940

## 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

## 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

## 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 cannot agree o which authmethod to use.

Own Id: OTP-10731 Aux Id: seq12237

## Ssh 2.1.2.1

### Improvements and New Features

Removed error report in ssh_connection_handler triggered by badmatch failure.

Own Id: OTP-11188

## 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]

## 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

## 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

## 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

## 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

## 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

## 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

## Ssh 2.0.5

### Improvements and New Features

Strengthened random number generation. (Thanks to Geoff Cant)

Own Id: OTP-9225

## 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

## 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

## 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

## 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

## 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:

## 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:

## 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:

## 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:

## 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:

## Ssh 1.1.4

### Fixed Bugs and Malfunctions

SSH sometimes caused a crash report at disconnect.

Own Id: OTP-8071 Aux Id: seq11319

## 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

## 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

## 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

## 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

## 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

## 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

## 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