I’ve been playing around with the Erlang SSH application lately and I’ve noticed some weird behaviours which I decided to report here for future reference.
The general impression that I got from the application - and from its coursins such as crypto, public_key and ssh - is that it does not reflect the usual OTP quality standards and that it should be used with care.
Misleading error message on ssh_sftp:start_channel/1 in case of missing shell
When starting a SFTP channel towards a system where user does not have
a shell (i.e. it has /bin/false or equilvalent assigned in the
/etc/passwd a misleading error message is returned to the user:
1> test:go().
** exception exit: {normal,{gen_server,call,
[<0.53.0>,
{{timeout,infinity},
wait_for_version_negotiation},
infinity]}}
in function gen_server:call/3 (gen_server.erl, line 188)
in call from ssh_channel:call/3 (ssh_channel.erl, line 88)
in call from ssh_sftp:start_channel/2 (ssh_sftp.erl, line 93)
in call from test:connect/1 (test.erl, line 14)Where:
-module(test).
-compile(export_all).
go() ->
ok = application:start(crypto),
ok = application:start(asn1),
ok = application:start(public_key),
ok = application:start(ssh),
connect("rabbitmq").
connect(Username) ->
{ok, SSHRef} = ssh:connect("localhost", 22, [{user, Username}]),
{ok, _SFTPChannelRef} = ssh_sftp:start_channel(SSHRef),
ok.This has been experienced in both R16B03 and R15B03.
Crash on SSH connect
On R16B03, when connecting via SSH on OS X Mavericks I get:
1> test:go().
** exception error: no match of right hand side value {error,"Internal error"}
in function test:connect/1 (test.erl, line 13)
3>
=ERROR REPORT==== 7-Feb-2014::13:38:06 ===
Erlang ssh connection handler failed with reason: function_clause
, Stacktace: [{ssh_connection_handler,userauth,
[{ssh_msg_userauth_pk_ok,<<>>, ...Internal Crash is not real when using the key_cb option
When using the key_cb option on ssh:connect/3 the user should
implement a series of callback functions. Not implementing them and
trying to connect results in an “internal error” which invites the
user to send a bug report. The undef callback function should be
catched and reported as a normal error, not an internal one.
please report this to erlang-bugs@erlang.org