backups: Use selected SSH credential for remote

- Use javascript to disable or enable password fields.

- If SSH key auth is selected, then try the connection.

- If SSH password auth is selected, then copy the key.

Signed-off-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/backups/forms.py

@@ -251,15 +251,34 @@ class AddRemoteRepositoryForm(EncryptedBackupsMixin, forms.Form):
         help_text=_('Path of a new or existing repository. Example: '
                     '<i>user@host:~/path/to/repo/</i>'),
         validators=[repository_validator])
+    ssh_auth_type = forms.ChoiceField(
+        label=_('SSH Authentication Type'),
+        help_text=_('How to authenticate to the remote SSH server.<br />'
+                    'If Key-based Authentication is selected, then the '
+                    "FreedomBox service's SSH client public key must be added"
+                    " to the authorized keys list on the remote server.<br />"
+                    'If Password-based Authentication is selected, then '
+                    'FreedomBox will attempt to copy its SSH client public '
+                    'key to the remote server.'), widget=forms.RadioSelect(),
+        choices=[('key_auth', _('Key-based Authentication')),
+                 ('password_auth', _('Password-based Authentication'))])
     ssh_password = forms.CharField(
-        label=_('SSH server password'), strip=True,
-        help_text=_('Password of the SSH Server.<br />'
-                    'Either provide a password, or add the FreedomBox '
-                    "service's SSH client public key (listed above) to the "
-                    'authorized keys list on the remote machine.'),
-        widget=forms.PasswordInput(), required=False)
+        label=_('SSH server password'), widget=forms.PasswordInput(),
+        strip=True, help_text=_(
+            'Password of the SSH Server. Required only for Password-based '
+            'Authentication.'), required=False)
 
-    field_order = ['repository', 'ssh_password'] + encryption_fields
+    field_order = ['repository', 'ssh_auth_type', 'ssh_password'
+                   ] + encryption_fields
+
+    def clean(self):
+        super().clean()
+        ssh_password = self.cleaned_data.get('ssh_password')
+        if self.cleaned_data.get(
+                'ssh_auth_type') == 'password_auth' and not ssh_password:
+            raise forms.ValidationError(
+                _('SSH password is needed for password-based authentication.'))
+        return self.cleaned_data
 
     def clean_repository(self):
         """Validate repository form field."""

plinth/modules/backups/repository.py

@@ -335,6 +335,14 @@ class SshBorgRepository(BaseBorgRepository):
 
         return None
 
+    @property
+    def ssh_keyfile(self) -> str | None:
+        """Return path to SSH client key if stored, otherwise None."""
+        if 'ssh_keyfile' in self.credentials:
+            return self.credentials['ssh_keyfile']
+
+        return None
+
     @property
     def _mountpoint(self):
         """Return the local mount point where repository is to be mounted."""

plinth/modules/backups/static/backups_add_remote_repository.js

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+/**
+ * @licstart The following is the entire license notice for the JavaScript
+ * code in this page.
+ *
+ * This file is part of FreedomBox.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @licend The above is the entire license notice for the JavaScript code
+ * in this page.
+ */
+
+document.addEventListener('DOMContentLoaded', () => {
+    const keyAuth = document.getElementById('id_ssh_auth_type_0');
+    const passwordAuth = document.getElementById('id_ssh_auth_type_1');
+    const sshPasswordField = document.getElementById('id_ssh_password');
+    const encryptionType = document.getElementById('id_encryption');
+    const encryptionPassphraseField = document.getElementById('id_encryption_passphrase');
+    const encryptionConfirmPassphraseField = document.getElementById('id_confirm_encryption_passphrase');
+
+    function handleAuthTypeChange() {
+        if (keyAuth.checked) {
+            sshPasswordField.value = "";
+            sshPasswordField.disabled = true;
+        } else {
+            sshPasswordField.disabled = false;
+        }
+    }
+
+    function handleEncryptionTypeChange() {
+        if (encryptionType.value === "repokey") {
+            encryptionPassphraseField.disabled = false;
+            encryptionConfirmPassphraseField.disabled = false;
+        } else {
+            encryptionPassphraseField.value = "";
+            encryptionPassphraseField.disabled = true;
+            encryptionConfirmPassphraseField.value = "";
+            encryptionConfirmPassphraseField.disabled = true;
+        }
+    }
+
+    keyAuth.addEventListener('change', handleAuthTypeChange);
+    passwordAuth.addEventListener('change', handleAuthTypeChange);
+    encryptionType.addEventListener('change', handleEncryptionTypeChange);
+
+    handleAuthTypeChange();
+    handleEncryptionTypeChange();
+});

plinth/modules/backups/templates/backups_add_remote_repository.html

@@ -5,6 +5,12 @@
 
 {% load bootstrap %}
 {% load i18n %}
+{% load static %}
+
+{% block page_js %}
+  <script type="text/javascript" src="{% static 'backups/backups_add_remote_repository.js' %}"
+          defer></script>
+{% endblock %}
 
 {% block content %}
 

plinth/modules/backups/views.py

@@ -385,10 +385,13 @@ class AddRemoteRepositoryView(FormView):
         if form.cleaned_data.get('encryption') == 'none':
             encryption_passphrase = None
 
-        credentials = {
-            'ssh_password': form.cleaned_data.get('ssh_password'),
-            'encryption_passphrase': encryption_passphrase
-        }
+        credentials = {'encryption_passphrase': encryption_passphrase}
+        if form.cleaned_data.get('ssh_auth_type') == 'password_auth':
+            credentials['ssh_password'] = form.cleaned_data.get('ssh_password')
+        else:
+            _pubkey_path, key_path = get_ssh_client_auth_key_paths()
+            credentials['ssh_keyfile'] = str(key_path)
+
         with handle_common_errors(self.request):
             repository = SshBorgRepository(path, credentials)
             repository.verfied = False
@@ -437,42 +440,70 @@ class VerifySshHostkeyView(FormView):
         with known_hosts_path.open('a', encoding='utf-8') as known_hosts_file:
             known_hosts_file.write(ssh_public_key + '\n')
 
+    def _check_save_repository(self):
+        """Save the repository and redirect according to the result."""
+        if _save_repository(self.request, self._get_repository()):
+            return redirect(reverse_lazy('backups:index'))
+
+        return redirect(reverse_lazy('backups:add-remote-repository'))
+
     def _check_copy_ssh_client_public_key(self):
-        """ Try to copy FreedomBox's SSH client public key to the host."""
+        """Try to copy FreedomBox's SSH client public key to the host."""
         repo = self._get_repository()
-        result, message = copy_ssh_client_public_key(repo.hostname,
-                                                     repo.username,
-                                                     repo.ssh_password)
-        if result:
-            logger.info(
-                "Copied SSH client public key to remote host's authorized "
-                "keys.")
-            _pubkey_path, key_path = get_ssh_client_auth_key_paths()
-            repo.replace_ssh_password_with_keyfile(str(key_path))
-            if _save_repository(self.request, repo):
-                return redirect(reverse_lazy('backups:index'))
-        else:
+        ssh_password = repo.ssh_password
+        if ssh_password:
+            result, message = copy_ssh_client_public_key(
+                repo.hostname, repo.username, repo.ssh_password)
+            if result:
+                logger.info("Copied SSH client public key to remote host's "
+                            "authorized keys.")
+                _pubkey_path, key_path = get_ssh_client_auth_key_paths()
+                repo.replace_ssh_password_with_keyfile(str(key_path))
+                return self._check_save_repository()
+
             logger.warning('Failed to copy SSH client public key: %s', message)
             messages.error(
                 self.request,
                 _('Failed to copy SSH client public key: %s') % message)
-            # Remove the repository so that the user can have another go at
-            # creating it.
-            try:
-                repo.remove()
-                messages.error(self.request, _('Repository removed.'))
-            except KeyError:
-                pass
+
+        else:
+            logger.error(
+                'SSH password is required to copy SSH client public key.')
+            messages.error(
+                self.request,
+                _('SSH password is required to copy SSH public key.'))
+
+        # Remove the repository so that the user can have another go at
+        # creating it.
+        try:
+            repo.remove()
+            messages.error(self.request, _('Repository removed.'))
+        except KeyError:
+            pass
 
         return redirect(reverse_lazy('backups:add-remote-repository'))
 
+    def _check_next_step(self):
+        """Check whether we need to copy the SSH client public key.
+
+        Otherwise, save the repository and redirect.
+        """
+        if self._get_repository().ssh_keyfile:
+            # SSH keyfile credential is stored. Assume it is already copied to
+            # the remote host. Check the connection.
+            logger.info('Check connection using SSH keyfile...')
+            return self._check_save_repository()
+
+        logger.info('Copy SSH client public key to remote host...')
+        return self._check_copy_ssh_client_public_key()
+
     def get(self, *args, **kwargs):
         """Skip this view if host is already verified."""
         if not is_ssh_hostkey_verified(self._get_repository().hostname):
             return super().get(*args, **kwargs)
 
         messages.success(self.request, _('SSH host already verified.'))
-        return self._check_copy_ssh_client_public_key()
+        return self._check_next_step()
 
     def form_valid(self, form):
         """Create and store the repository."""
@@ -480,7 +511,8 @@ class VerifySshHostkeyView(FormView):
         with handle_common_errors(self.request):
             self._add_ssh_hostkey(ssh_public_key)
             messages.success(self.request, _('SSH host verified.'))
-            return self._check_copy_ssh_client_public_key()
+
+        return self._check_next_step()
 
 
 def _save_repository(request, repository):