make file submissions dis/allowable

securedrop/alembic/versions/523fff3f969c_add_versioned_instance_config.py

@@ -0,0 +1,41 @@
+"""add versioned instance config
+
+Revision ID: 523fff3f969c
+Revises: 3da3fcab826a
+Create Date: 2019-11-02 23:06:12.161868
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '523fff3f969c'
+down_revision = '3da3fcab826a'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('instance_config',
+    sa.Column('version', sa.Integer(), nullable=False),
+    sa.Column('valid_until', sa.DateTime(), nullable=True),
+    sa.Column('allow_document_uploads', sa.Boolean(), nullable=True),
+
+    sa.PrimaryKeyConstraint('version'),
+    sa.UniqueConstraint('valid_until'),
+    )
+    # ### end Alembic commands ###
+
+    # Data migration:  Since allow_document_uploads is the first
+    # instance_config setting (column), all we have to do is insert a
+    # row with its default value.
+    conn = op.get_bind()
+    conn.execute("""INSERT INTO instance_config (allow_document_uploads) VALUES (1)""")
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('instance_config')
+    # ### end Alembic commands ###

securedrop/journalist_app/__init__.py

@@ -20,7 +20,7 @@
 from journalist_app.utils import (get_source, logged_in,
                                   JournalistInterfaceSessionInterface,
                                   cleanup_expired_revoked_tokens)
-from models import Journalist
+from models import InstanceConfig, Journalist
 from store import Storage
 
 import typing
@@ -124,6 +124,10 @@ def _handle_http_exception(error):
     def expire_blacklisted_tokens():
         return cleanup_expired_revoked_tokens()
 
+    @app.before_request
+    def load_instance_config():
+        app.instance_config = InstanceConfig.get_current()
+
     @app.before_request
     def setup_g():
         # type: () -> Optional[Response]

securedrop/journalist_app/admin.py

@@ -9,11 +9,12 @@
 from sqlalchemy.orm.exc import NoResultFound
 
 from db import db
-from models import Journalist, InvalidUsernameException, FirstOrLastNameError, PasswordError
+from models import (InstanceConfig, Journalist, InvalidUsernameException,
+                    FirstOrLastNameError, PasswordError)
 from journalist_app.decorators import admin_required
 from journalist_app.utils import (make_password, commit_account_changes, set_diceware_password,
                                   validate_hotp_secret, revoke_token)
-from journalist_app.forms import LogoForm, NewUserForm
+from journalist_app.forms import LogoForm, NewUserForm, SubmissionPreferencesForm
 
 
 def make_blueprint(config):
@@ -28,9 +29,12 @@ def index():
     @view.route('/config', methods=('GET', 'POST'))
     @admin_required
     def manage_config():
-        form = LogoForm()
-        if form.validate_on_submit():
-            f = form.logo.data
+        # The UI prompt ("prevent") is the opposite of the setting ("allow"):
+        submission_preferences_form = SubmissionPreferencesForm(
+            prevent_document_uploads=not current_app.instance_config.allow_document_uploads)
+        logo_form = LogoForm()
+        if logo_form.validate_on_submit():
+            f = logo_form.logo.data
             custom_logo_filepath = os.path.join(current_app.static_folder, 'i',
                                                 'custom_logo.png')
             try:
@@ -42,10 +46,22 @@ def manage_config():
             finally:
                 return redirect(url_for("admin.manage_config"))
         else:
-            for field, errors in list(form.errors.items()):
+            for field, errors in list(logo_form.errors.items()):
                 for error in errors:
                     flash(error, "logo-error")
-            return render_template("config.html", form=form)
+            return render_template("config.html",
+                                   submission_preferences_form=submission_preferences_form,
+                                   logo_form=logo_form)
+
+    @view.route('/update-submission-preferences', methods=['POST'])
+    @admin_required
+    def update_submission_preferences():
+        form = SubmissionPreferencesForm()
+        if form.validate_on_submit():
+            # The UI prompt ("prevent") is the opposite of the setting ("allow"):
+            value = not bool(request.form.get('prevent_document_uploads'))
+            InstanceConfig.set('allow_document_uploads', value)
+            return redirect(url_for('admin.manage_config'))
 
     @view.route('/add', methods=('GET', 'POST'))
     @admin_required

securedrop/journalist_app/forms.py

@@ -64,6 +64,10 @@ class ReplyForm(FlaskForm):
     )
 
 
+class SubmissionPreferencesForm(FlaskForm):
+    prevent_document_uploads = BooleanField('prevent_document_uploads')
+
+
 class LogoForm(FlaskForm):
     logo = FileField(validators=[
         FileRequired(message=gettext('File required.')),

securedrop/journalist_templates/config.html

@@ -29,7 +29,7 @@ <h2>{{ gettext('Logo Image') }}</h2>
 <form method="post" enctype="multipart/form-data">
   <input name="csrf_token" type="hidden" value="{{ csrf_token() }}">
   <p>
-    {{ form.logo(id="logo-upload") }}
+    {{ logo_form.logo(id="logo-upload") }}
     <br>
   </p>
   <h5>
@@ -41,4 +41,19 @@ <h5>
   {% include 'logo_upload_flashed.html' %}
 </form>
 
+<hr class="no-line">
+
+<h2>{{ gettext('Submission Preferences') }}</h2>
+
+<form action="{{ url_for('admin.update_submission_preferences') }}" method="post">
+  <input name="csrf_token" type="hidden" value="{{ csrf_token() }}">
+  <p>
+    {{ submission_preferences_form.prevent_document_uploads() }}
+    <label for="prevent_document_uploads">{{ gettext('Prevent sources from uploading documents.  Sources will still be able to send messages.') }}</label>
+  </p>
+  <button type="submit" id="submit-submission-preferences">
+    <i class="fas fa-pencil-alt"></i> {{ gettext('UPDATE SUBMISSION PREFERENCES') }}
+  </button>
+</form>
+
 {% endblock %}

securedrop/models.py

@@ -739,3 +739,68 @@ class RevokedToken(db.Model):
     id = Column(Integer, primary_key=True)
     journalist_id = Column(Integer, ForeignKey('journalists.id'))
     token = db.Column(db.Text, nullable=False, unique=True)
+
+
+class InstanceConfig(db.Model):
+    '''Versioned key-value store of settings configurable from the journalist
+    interface.  The current version has valid_until=None.
+    '''
+
+    __tablename__ = 'instance_config'
+    version = Column(Integer, primary_key=True)
+    valid_until = Column(DateTime, default=None, unique=True)
+
+    allow_document_uploads = Column(Boolean, default=True)
+
+    # Columns not listed here will be included by InstanceConfig.copy() when
+    # updating the configuration.
+    metadata_cols = ['version', 'valid_until']
+
+    def __repr__(self):
+        return "<InstanceConfig(version=%s, valid_until=%s)>" % (self.version, self.valid_until)
+
+    def copy(self):
+        '''Make a copy of only the configuration columns of the given
+        InstanceConfig object: i.e., excluding metadata_cols.
+        '''
+
+        new = type(self)()
+        for col in self.__table__.columns:
+            if col.name in self.metadata_cols:
+                continue
+
+            setattr(new, col.name, getattr(self, col.name))
+
+        return new
+
+    @classmethod
+    def get_current(cls):
+        '''If the database was created via db.create_all(), data migrations
+        weren't run, and the "instance_config" table is empty.  In this case,
+        save and return a base configuration derived from each setting's
+        column-level default.
+        '''
+
+        try:
+            return cls.query.filter(cls.valid_until == None).one()  # noqa: E711
+        except NoResultFound:
+            current = cls()
+            db.session.add(current)
+            db.session.commit()
+            return current
+
+    @classmethod
+    def set(cls, name, value):
+        '''Invalidate the current configuration and append a new one with the
+        requested change.
+        '''
+
+        old = cls.get_current()
+        old.valid_until = datetime.datetime.utcnow()
+        db.session.add(old)
+
+        new = old.copy()
+        setattr(new, name, value)
+        db.session.add(new)
+
+        db.session.commit()

securedrop/sass/modules/_snippet.sass

@@ -43,3 +43,9 @@
 
         &:focus
           outline: none
+
+    .wide
+      width: 100%
+
+      textarea
+        width: 100%

securedrop/source_app/__init__.py

@@ -14,7 +14,7 @@
 
 from crypto_util import CryptoUtil
 from db import db
-from models import Source
+from models import InstanceConfig, Source
 from request_that_secures_file_uploads import RequestThatSecuresFileUploads
 from source_app import main, info, api
 from source_app.decorators import ignore_static
@@ -130,6 +130,11 @@ def check_tor2web():
                 .format(url=url_for('info.tor2web_warning'))),
                   "banner-warning")
 
+    @app.before_request
+    @ignore_static
+    def load_instance_config():
+        app.instance_config = InstanceConfig.get_current()
+
     @app.before_request
     @ignore_static
     def setup_g():

securedrop/source_app/api.py

@@ -1,7 +1,7 @@
 import json
 import platform
 
-from flask import Blueprint, make_response
+from flask import Blueprint, current_app, make_response
 
 import version
 
@@ -12,6 +12,7 @@ def make_blueprint(config):
     @view.route('/metadata')
     def metadata():
         meta = {
+            'allow_document_uploads': current_app.instance_config.allow_document_uploads,
             'gpg_fpr': config.JOURNALIST_KEY,
             'sd_version': version.__version__,
             'server_os': platform.linux_distribution()[1],

securedrop/source_app/main.py

@@ -121,6 +121,7 @@ def lookup():
 
         return render_template(
             'lookup.html',
+            allow_document_uploads=current_app.instance_config.allow_document_uploads,
             codename=g.codename,
             replies=replies,
             flagged=g.source.flagged,
@@ -131,16 +132,20 @@ def lookup():
     @view.route('/submit', methods=('POST',))
     @login_required
     def submit():
+        allow_document_uploads = current_app.instance_config.allow_document_uploads
         msg = request.form['msg']
         fh = None
-        if 'fh' in request.files:
+        if allow_document_uploads and 'fh' in request.files:
             fh = request.files['fh']
 
         # Don't submit anything if it was an "empty" submission. #878
         if not (msg or fh):
-            flash(gettext(
-                "You must enter a message or choose a file to submit."),
-                  "error")
+            if allow_document_uploads:
+                flash(gettext(
+                    "You must enter a message or choose a file to submit."),
+                      "error")
+            else:
+                flash(gettext("You must enter a message."), "error")
             return redirect(url_for('main.lookup'))
 
         fnames = []

securedrop/source_templates/lookup.html

@@ -15,23 +15,34 @@
   {% endif %}
 </div>
 
+{% if allow_document_uploads %}
 <h2 class="headline">{{ gettext('Submit Files or Messages') }}</h2>
 <p class="explanation">{{ gettext('You can submit any kind of file, a message, or both.') }}</p>
+{% else %}
+<h2 class="headline">{{ gettext('Submit Messages') }}</h2>
+{% endif %}
 
-<p class="explanation extended-explanation">{{ gettext('If you are already familiar with GPG, you can optionally encrypt your files and messages with our <a href="{url}" class="text-link">public key</a> before submission. Files are encrypted as they are received by SecureDrop.').format(url=url_for('info.download_journalist_pubkey')) }}
+<p class="explanation extended-explanation">
+{% if allow_document_uploads %}
+{{ gettext('If you are already familiar with GPG, you can optionally encrypt your files and messages with our <a href="{url}" class="text-link">public key</a> before submission. Files are encrypted as they are received by SecureDrop.').format(url=url_for('info.download_journalist_pubkey')) }}
+{% else %}
+{{ gettext('If you are already familiar with GPG, you can optionally encrypt your messages with our <a href="{url}" class="text-link">public key</a> before submission.').format(url=url_for('info.download_journalist_pubkey')) }}
+{% endif %}
 {{ gettext('<a href="{url}" class="text-link">Learn more</a>.').format(url=url_for('info.why_download_journalist_pubkey')) }}</p>
 
 <hr class="no-line">
 
 <form id="upload" method="post" action="{{ url_for('main.submit') }}" enctype="multipart/form-data" autocomplete="off">
   <input name="csrf_token" type="hidden" value="{{ csrf_token() }}">
   <div class="snippet">
+{% if allow_document_uploads %}
     <div class="attachment grid-item center">
       <img class="center" id="upload-icon" src="{{ url_for('static', filename='i/arrow-upload-large.png') }}" width="56" height="56">
       <input type="file" name="fh" autocomplete="off">
       <p class="center" id="max-file-size">{{ gettext('Maximum upload size: 500 MB') }}</p>
     </div>
-    <div class="message grid-item">
+{% endif %}
+    <div class="message grid-item{% if not allow_document_uploads %} wide{% endif %}">
       <textarea name="msg" class="fill-parent" placeholder="{{ gettext('Write a message.') }}"></textarea>
     </div>
   </div>

securedrop/tests/migrations/migration_523fff3f969c.py

@@ -0,0 +1,40 @@
+from sqlalchemy import text
+from sqlalchemy.exc import OperationalError
+
+from db import db
+from journalist_app import create_app
+
+
+instance_config_sql = "SELECT * FROM instance_config"
+
+
+class UpgradeTester:
+    def __init__(self, config):
+        self.config = config
+        self.app = create_app(config)
+
+    def load_data(self):
+        pass
+
+    def check_upgrade(self):
+        with self.app.app_context():
+            db.engine.execute(text(instance_config_sql)).fetchall()
+
+
+class DowngradeTester:
+    def __init__(self, config):
+        self.config = config
+        self.app = create_app(config)
+
+    def load_data(self):
+        pass
+
+    def check_downgrade(self):
+        with self.app.app_context():
+            try:
+                db.engine.execute(text(instance_config_sql)).fetchall()
+
+            # The SQLite driver appears to return this rather than the
+            # expected NoSuchTableError.
+            except OperationalError:
+                pass

securedrop/tests/test_i18n.py

@@ -236,6 +236,8 @@ def __getattr__(self, name):
             return getattr(config, name)
     not_translated = 'code hello i18n'
     with source_app.create_app(Config()).test_client() as c:
+        with c.application.app_context():
+            db.create_all()
         c.get('/')
         assert not_translated == gettext(not_translated)