hgext/convert/transport.py

sslutil: add support for clients to set TLSv1.3 as the minimum protocol

AFAICT, all of the TLS versions are supported by the server without doing any
explicit work, and there's only a `devel` config to specify an exact version on
the server side.  Clients would also use TLSv1.3 if available, but this prevents
the server from negotiating down.  This also causes "tls1.3" to be listed in
`hg debuginstall`, even though it was previously supported (if the Python
intepreter supported it- IDK if there's a good way to proactively test for and
show future protocols without requiring manual updates like this).

The v1.3 tests are nested inside the v1.2 tests for simplicity.  The v1.2 blocks
already assume v1.0 and v1.1 support, so this seems reasonable for now.  If/when
the older protocols start getting dropped, this will have to be reworked anyway.

# -*- coding: utf-8 -*-

# Copyright (C) 2007 Daniel Holth <[e-mail]>
# This is a stripped-down version of the original bzr-svn transport.py,
# Copyright (C) 2006 Jelmer Vernooij <[e-mail]>

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.

from __future__ import annotations

# pytype: disable=import-error
import svn.client
import svn.core
import svn.ra

# pytype: enable=import-error

Pool = svn.core.Pool
SubversionException = svn.core.SubversionException

# Some older versions of the Python bindings need to be
# explicitly initialized. But what we want to do probably
# won't work worth a darn against those libraries anyway!
svn.ra.initialize()

svn_config = None


def _create_auth_baton(pool):
    """Create a Subversion authentication baton."""
    import svn.client  # pytype: disable=import-error

    # Give the client context baton a suite of authentication
    # providers.h
    providers = [
        svn.client.get_simple_provider(pool),
        svn.client.get_username_provider(pool),
        svn.client.get_ssl_client_cert_file_provider(pool),
        svn.client.get_ssl_client_cert_pw_file_provider(pool),
        svn.client.get_ssl_server_trust_file_provider(pool),
    ]
    # Platform-dependent authentication methods
    getprovider = getattr(
        svn.core, 'svn_auth_get_platform_specific_provider', None
    )
    if getprovider:
        # Available in svn >= 1.6
        for name in (b'gnome_keyring', b'keychain', b'kwallet', b'windows'):
            for type in (b'simple', b'ssl_client_cert_pw', b'ssl_server_trust'):
                p = getprovider(name, type, pool)
                if p:
                    providers.append(p)
    else:
        if hasattr(svn.client, 'get_windows_simple_provider'):
            providers.append(svn.client.get_windows_simple_provider(pool))

    return svn.core.svn_auth_open(providers, pool)


class NotBranchError(SubversionException):
    pass


class SvnRaTransport:
    """
    Open an ra connection to a Subversion repository.
    """

    def __init__(self, url=b"", ra=None):
        self.pool = Pool()
        self.svn_url = url
        self.username = b''
        self.password = b''

        # Only Subversion 1.4 has reparent()
        if ra is None or not hasattr(svn.ra, 'reparent'):
            self.client = svn.client.create_context(self.pool)
            ab = _create_auth_baton(self.pool)
            self.client.auth_baton = ab
            global svn_config
            if svn_config is None:
                svn_config = svn.core.svn_config_get_config(None)
            self.client.config = svn_config
            try:
                self.ra = svn.client.open_ra_session(
                    self.svn_url, self.client, self.pool
                )
            except SubversionException as xxx_todo_changeme:
                (inst, num) = xxx_todo_changeme.args
                if num in (
                    svn.core.SVN_ERR_RA_ILLEGAL_URL,
                    svn.core.SVN_ERR_RA_LOCAL_REPOS_OPEN_FAILED,
                    svn.core.SVN_ERR_BAD_URL,
                ):
                    raise NotBranchError(url)
                raise
        else:
            self.ra = ra
            svn.ra.reparent(self.ra, self.svn_url.encode('utf8'))

    class Reporter:
        def __init__(self, reporter_data):
            self._reporter, self._baton = reporter_data

        def set_path(self, path, revnum, start_empty, lock_token, pool=None):
            svn.ra.reporter2_invoke_set_path(
                self._reporter,
                self._baton,
                path,
                revnum,
                start_empty,
                lock_token,
                pool,
            )

        def delete_path(self, path, pool=None):
            svn.ra.reporter2_invoke_delete_path(
                self._reporter, self._baton, path, pool
            )

        def link_path(
            self, path, url, revision, start_empty, lock_token, pool=None
        ):
            svn.ra.reporter2_invoke_link_path(
                self._reporter,
                self._baton,
                path,
                url,
                revision,
                start_empty,
                lock_token,
                pool,
            )

        def finish_report(self, pool=None):
            svn.ra.reporter2_invoke_finish_report(
                self._reporter, self._baton, pool
            )

        def abort_report(self, pool=None):
            svn.ra.reporter2_invoke_abort_report(
                self._reporter, self._baton, pool
            )

    def do_update(self, revnum, path, *args, **kwargs):
        return self.Reporter(
            svn.ra.do_update(self.ra, revnum, path, *args, **kwargs)
        )