Mercurial > hg > mercurial-source
changeset 36716:83d67257ba90
tests: add low-level SSH protocol tests
We don't really have good low-level tests for the behavior of the SSH
wire protocol. This commit attempts to establish some.
The added tests consist of a mixture of starting a server
with `hg serve --stdio` and sending bytes to it and using
`hg debugpeer` to go through the official client code. Having
insight into what raw bytes are exchanged as well as what the peer
does is useful.
We also introduce a test extension for modifying the behavior of
the SSH server and peer. For example, we change the server to
not recognize the "hello" command, simulating behavior of <0.9.1
servers.
These tests are generally useful to have. But the impetus for creating
them now is they will be needed for verifying behavior of old clients
and servers when a new SSH protocol is introduced.
Differential Revision: https://phab.mercurial-scm.org/D2026
# no-check-commit because of serve_forever()
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 04 Feb 2018 14:02:41 -0800 |
parents | 5f029d03cf71 |
children | b202d360d2a4 |
files | tests/sshprotoext.py tests/test-ssh-proto.t |
diffstat | 2 files changed, 506 insertions(+), 0 deletions(-) [+] |
line wrap: on
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new file mode 100644 --- /dev/null +++ b/tests/sshprotoext.py @@ -0,0 +1,108 @@ +# sshprotoext.py - Extension to test behavior of SSH protocol +# +# Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com> +# +# This software may be used and distributed according to the terms of the +# GNU General Public License version 2 or any later version. + +# This extension replaces the SSH server started via `hg serve --stdio`. +# The server behaves differently depending on environment variables. + +from __future__ import absolute_import + +from mercurial import ( + error, + registrar, + sshpeer, + wireproto, + wireprotoserver, +) + +configtable = {} +configitem = registrar.configitem(configtable) + +configitem('sshpeer', 'mode', default=None) +configitem('sshpeer', 'handshake-mode', default=None) + +class bannerserver(wireprotoserver.sshserver): + """Server that sends a banner to stdout.""" + def serve_forever(self): + for i in range(10): + self._fout.write(b'banner: line %d\n' % i) + + super(bannerserver, self).serve_forever() + +class prehelloserver(wireprotoserver.sshserver): + """Tests behavior when connecting to <0.9.1 servers. + + The ``hello`` wire protocol command was introduced in Mercurial + 0.9.1. Modern clients send the ``hello`` command when connecting + to SSH servers. This mock server tests behavior of the handshake + when ``hello`` is not supported. + """ + def serve_forever(self): + l = self._fin.readline() + assert l == b'hello\n' + # Respond to unknown commands with an empty reply. + self._sendresponse(b'') + l = self._fin.readline() + assert l == b'between\n' + rsp = wireproto.dispatch(self._repo, self, b'between') + self._handlers[rsp.__class__](self, rsp) + + super(prehelloserver, self).serve_forever() + +class extrahandshakecommandspeer(sshpeer.sshpeer): + """An ssh peer that sends extra commands as part of initial handshake.""" + # There isn't a good hook point. So we wrap _callstream() and inject + # logic when the peer says "hello". + def _callstream(self, cmd, **args): + if cmd != b'hello': + return super(extrahandshakecommandspeer, self)._callstream(cmd, + **args) + + mode = self._ui.config(b'sshpeer', b'handshake-mode') + if mode == b'pre-no-args': + self._callstream(b'no-args') + return super(extrahandshakecommandspeer, self)._callstream( + cmd, **args) + elif mode == b'pre-multiple-no-args': + self._callstream(b'unknown1') + self._callstream(b'unknown2') + self._callstream(b'unknown3') + return super(extrahandshakecommandspeer, self)._callstream( + cmd, **args) + else: + raise error.ProgrammingError(b'unknown HANDSHAKECOMMANDMODE: %s' % + mode) + +def registercommands(): + def dummycommand(repo, proto): + raise error.ProgrammingError('this should never be called') + + wireproto.wireprotocommand(b'no-args', b'')(dummycommand) + wireproto.wireprotocommand(b'unknown1', b'')(dummycommand) + wireproto.wireprotocommand(b'unknown2', b'')(dummycommand) + wireproto.wireprotocommand(b'unknown3', b'')(dummycommand) + +def extsetup(ui): + # It's easier for tests to define the server behavior via environment + # variables than config options. This is because `hg serve --stdio` + # has to be invoked with a certain form for security reasons and + # `dummyssh` can't just add `--config` flags to the command line. + servermode = ui.environ.get(b'SSHSERVERMODE') + + if servermode == b'banner': + wireprotoserver.sshserver = bannerserver + elif servermode == b'no-hello': + wireprotoserver.sshserver = prehelloserver + elif servermode: + raise error.ProgrammingError(b'unknown server mode: %s' % servermode) + + peermode = ui.config(b'sshpeer', b'mode') + + if peermode == b'extra-handshake-commands': + sshpeer.sshpeer = extrahandshakecommandspeer + registercommands() + elif peermode: + raise error.ProgrammingError(b'unknown peer mode: %s' % peermode)
new file mode 100644 --- /dev/null +++ b/tests/test-ssh-proto.t @@ -0,0 +1,398 @@ + $ cat >> $HGRCPATH << EOF + > [ui] + > ssh = $PYTHON "$TESTDIR/dummyssh" + > [devel] + > debug.peer-request = true + > [extensions] + > sshprotoext = $TESTDIR/sshprotoext.py + > EOF + + $ hg init server + $ cd server + $ echo 0 > foo + $ hg -q add foo + $ hg commit -m initial + $ cd .. + +Test a normal behaving server, for sanity + + $ hg --debug debugpeer ssh://user@dummy/server + running * "*/tests/dummyssh" 'user@dummy' 'hg -R server serve --stdio' (glob) + devel-peer-request: hello + sending hello command + devel-peer-request: between + devel-peer-request: pairs: 81 bytes + sending between command + remote: 384 + remote: capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + remote: 1 + url: ssh://user@dummy/server + local: no + pushable: yes + +Server should answer the "hello" command in isolation + + $ hg -R server serve --stdio << EOF + > hello + > EOF + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + +>=0.9.1 clients send a "hello" + "between" for the null range as part of handshake. +Server should reply with capabilities and should send "1\n\n" as a successful +reply with empty response to the "between". + + $ hg -R server serve --stdio << EOF + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + +SSH banner is not printed by default, ignored by clients + + $ SSHSERVERMODE=banner hg debugpeer ssh://user@dummy/server + url: ssh://user@dummy/server + local: no + pushable: yes + +--debug will print the banner + + $ SSHSERVERMODE=banner hg --debug debugpeer ssh://user@dummy/server + running * "*/tests/dummyssh" 'user@dummy' 'hg -R server serve --stdio' (glob) + devel-peer-request: hello + sending hello command + devel-peer-request: between + devel-peer-request: pairs: 81 bytes + sending between command + remote: banner: line 0 + remote: banner: line 1 + remote: banner: line 2 + remote: banner: line 3 + remote: banner: line 4 + remote: banner: line 5 + remote: banner: line 6 + remote: banner: line 7 + remote: banner: line 8 + remote: banner: line 9 + remote: 384 + remote: capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + remote: 1 + url: ssh://user@dummy/server + local: no + pushable: yes + +And test the banner with the raw protocol + + $ SSHSERVERMODE=banner hg -R server serve --stdio << EOF + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + banner: line 0 + banner: line 1 + banner: line 2 + banner: line 3 + banner: line 4 + banner: line 5 + banner: line 6 + banner: line 7 + banner: line 8 + banner: line 9 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + +Connecting to a <0.9.1 server that doesn't support the hello command + + $ SSHSERVERMODE=no-hello hg --debug debugpeer ssh://user@dummy/server + running * "*/tests/dummyssh" 'user@dummy' 'hg -R server serve --stdio' (glob) + devel-peer-request: hello + sending hello command + devel-peer-request: between + devel-peer-request: pairs: 81 bytes + sending between command + remote: 0 + remote: 1 + url: ssh://user@dummy/server + local: no + pushable: yes + +The client should interpret this as no capabilities + + $ SSHSERVERMODE=no-hello hg debugcapabilities ssh://user@dummy/server + Main capabilities: + +Sending an unknown command to the server results in an empty response to that command + + $ hg -R server serve --stdio << EOF + > pre-hello + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + + $ hg --config sshpeer.mode=extra-handshake-commands --config sshpeer.handshake-mode=pre-no-args --debug debugpeer ssh://user@dummy/server + running * "*/tests/dummyssh" 'user@dummy' 'hg -R server serve --stdio' (glob) + devel-peer-request: no-args + sending no-args command + devel-peer-request: hello + sending hello command + devel-peer-request: between + devel-peer-request: pairs: 81 bytes + sending between command + remote: 0 + remote: 384 + remote: capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + remote: 1 + url: ssh://user@dummy/server + local: no + pushable: yes + +Send multiple unknown commands before hello + + $ hg -R server serve --stdio << EOF + > unknown1 + > unknown2 + > unknown3 + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + + $ hg --config sshpeer.mode=extra-handshake-commands --config sshpeer.handshake-mode=pre-multiple-no-args --debug debugpeer ssh://user@dummy/server + running * "*/tests/dummyssh" 'user@dummy' 'hg -R server serve --stdio' (glob) + devel-peer-request: unknown1 + sending unknown1 command + devel-peer-request: unknown2 + sending unknown2 command + devel-peer-request: unknown3 + sending unknown3 command + devel-peer-request: hello + sending hello command + devel-peer-request: between + devel-peer-request: pairs: 81 bytes + sending between command + remote: 0 + remote: 0 + remote: 0 + remote: 384 + remote: capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + remote: 1 + url: ssh://user@dummy/server + local: no + pushable: yes + +Send an unknown command before hello that has arguments + + $ hg -R server serve --stdio << EOF + > with-args + > foo 13 + > value for foo + > bar 13 + > value for bar + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 0 + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + +Send an unknown command having an argument that looks numeric + + $ hg -R server serve --stdio << EOF + > unknown + > foo 1 + > 0 + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + + $ hg -R server serve --stdio << EOF + > unknown + > foo 1 + > 1 + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + +When sending a dict argument value, it is serialized to +"<arg> <item count>" followed by "<key> <len>\n<value>" for each item +in the dict. + +Dictionary value for unknown command + + $ hg -R server serve --stdio << EOF + > unknown + > dict 3 + > key1 3 + > foo + > key2 3 + > bar + > key3 3 + > baz + > hello + > EOF + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + +Incomplete dictionary send + + $ hg -R server serve --stdio << EOF + > unknown + > dict 3 + > key1 3 + > foo + > EOF + 0 + 0 + 0 + 0 + +Incomplete value send + + $ hg -R server serve --stdio << EOF + > unknown + > dict 3 + > key1 3 + > fo + > EOF + 0 + 0 + 0 + 0 + +Send a command line with spaces + + $ hg -R server serve --stdio << EOF + > unknown withspace + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + + $ hg -R server serve --stdio << EOF + > unknown with multiple spaces + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + + $ hg -R server serve --stdio << EOF + > unknown with spaces + > key 10 + > some value + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000 + > EOF + 0 + 0 + 0 + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + +Send an unknown command after the "between" + + $ hg -R server serve --stdio << EOF + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000unknown + > EOF + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + 0 + +And one with arguments + + $ hg -R server serve --stdio << EOF + > hello + > between + > pairs 81 + > 0000000000000000000000000000000000000000-0000000000000000000000000000000000000000unknown + > foo 5 + > value + > bar 3 + > baz + > EOF + 384 + capabilities: lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN + 1 + + 0 + 0 + 0 + 0 + 0