From 1aaacf8ef907d89e890e03d571e8fe9bb527e811 Mon Sep 17 00:00:00 2001 From: Ferry Boender Date: Mon, 30 Mar 2015 21:33:17 +0200 Subject: [PATCH] Allow scripts to write their own output using script_raw setting. User authentication and authorization. Rename 'vitaform' to 'scriptform'. Stream contents of uploaded files to temp files and pass their names to callbacks instead of the contents. --- src/scriptform.py | 286 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 198 insertions(+), 88 deletions(-) diff --git a/src/scriptform.py b/src/scriptform.py index a35c303..ff7b808 100755 --- a/src/scriptform.py +++ b/src/scriptform.py @@ -21,6 +21,8 @@ import cgi import re import datetime import subprocess +import base64 +import tempfile html_header = ''' @@ -89,38 +91,22 @@ html_footer = ''' ''' -def cmd(cmd, input=None, env=None): - """ - Run command `cmd` in a shell. `input` (string) is passed in the - process' STDIN. - - Returns a dictionary: `{'stdout': , 'stderr': , 'exitcode': - }`. - """ - p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, - stdout=subprocess.PIPE, stderr=subprocess.PIPE, - env=env) - stdout, stderr = p.communicate(input) - return { - 'stdout': stdout, - 'stderr': stderr, - 'exitcode': p.returncode - } - - class FormDefinition: """ FormDefinition holds information about a single form and provides methods for validation of the form values. """ def __init__(self, name, title, description, fields, script=None, - submit_title="Submit"): + script_raw=False, submit_title="Submit", + allowed_users=None): self.name = name self.title = title self.description = description self.fields = fields self.script = script + self.script_raw = script_raw self.submit_title = submit_title + self.allowed_users = allowed_users def get_field(self, field_name): for field in self.fields: @@ -133,7 +119,8 @@ class FormDefinition: """ values = {} for field_name in form_values: - if field_name == 'form_name': + if field_name == 'form_name' or \ + form_values[field_name].filename: continue v = self.validate_field(field_name, form_values.getfirst(field_name)) @@ -248,27 +235,32 @@ class WebAppHandler(BaseHTTPRequestHandler): def call(self, path, params): """ Find a method to call on self.app_class based on `path` and call it. + The method that's called is in the form 'h_'. If no path was + given, it will try to call the 'index' method. If no method could be + found but a `default` method exists, it is called. Otherwise 404 is + sent. + + Methods should take care of sending proper headers and content + themselves using self.send_response(), self.send_header(), + self.end_header() and by writing to self.wfile. """ - response_code = 200 - method_name = 'h_{}'.format(path) + method_name = 'h_{0}'.format(path) + method_cb = None try: if hasattr(self, method_name) and \ callable(getattr(self, method_name)): - out = getattr(self, method_name)(**params) + method_cb = getattr(self, method_name) elif path == '' and hasattr(self, 'index'): - out = self.index(**params) + method_cb = self.index elif hasattr(self, 'default'): - out = self.default(**params) + method_cb = self.default else: - response_code = 404 - out = 'Not Found' + self.send_error(404, "Not found") + return + method_cb(**params) except Exception, e: - self.wfile.write(e) + self.send_error(500, "Internal server error") raise - self.send_response(response_code) - self.send_header('Content-type', 'text/html') - self.end_headers() - self.wfile.write(out) class ScriptFormWebApp(WebAppHandler): @@ -278,9 +270,45 @@ class ScriptFormWebApp(WebAppHandler): def index(self): return self.h_list() + def auth(self): + """ + Verify that the user is authenticated. This is required if the form + definition contains a 'users' field. Returns True if the user is + validated. Otherwise, returns False and sends 401 HTTP back to the + client. + """ + self.username = None + + # If a 'users' element was present in the form configuration file, the + # user must be authenticated. + if self.scriptform.users: + authorized = False + auth_header = self.headers.getheader("Authorization") + if auth_header is not None: + auth_realm, auth_unpw = auth_header.split(' ', 1) + username, password = base64.decodestring(auth_unpw).split(":") + # Validate the username and password + if username in self.scriptform.users and \ + password == self.scriptform.users[username]: + self.username = username + authorized = True + + if not authorized: + # User is not authenticated. Send authentication request. + self.send_response(401) + self.send_header("WWW-Authenticate", 'Basic realm="Private Area"') + self.end_headers() + return False + return True def h_list(self): + if not self.auth(): + return + h_form_list = [] - for form_name, form_def in self.vitaform.forms.items(): + for form_name, form_def in self.scriptform.forms.items(): + if form_def.allowed_users is not None and \ + self.username not in form_def.allowed_users: + continue # User is not allowed to run this form h_form_list.append('''

  • {title}

    @@ -294,17 +322,25 @@ class ScriptFormWebApp(WebAppHandler): name=form_name) ) - return ''' + output = ''' {header}
    {form_list}
    {footer} - '''.format(header=html_header.format(title=self.vitaform.title), + '''.format(header=html_header.format(title=self.scriptform.title), footer=html_footer, form_list=''.join(h_form_list)) + self.send_response(200) + self.send_header('Content-type', 'text/html') + #self.send_header('Expires', 'Mon, 30 Mar 2015 16:00:00 GMT') + self.end_headers() + self.wfile.write(output) def h_form(self, form_name): + if not self.auth(): + return + field_tpl = { "string": '', "number": '', @@ -367,9 +403,12 @@ class ScriptFormWebApp(WebAppHandler): '''.format(title=field['title'], input=input)) - form = self.vitaform.get_form(form_name) + form_def = self.scriptform.get_form(form_name) + if form_def.allowed_users is not None and \ + self.username not in form_def.allowed_users: + raise Exception("Not authorized") - return ''' + output = ''' {header}

    {title}

    @@ -384,63 +423,99 @@ class ScriptFormWebApp(WebAppHandler):
    {footer} '''.format( - header=html_header.format(title=self.vitaform.title), + header=html_header.format(title=self.scriptform.title), footer=html_footer, - title=form.title, - description=form.description, - name=form.name, - fields=''.join([render_field(f) for f in form.fields]), - submit_title=form.submit_title + title=form_def.title, + description=form_def.description, + name=form_def.name, + fields=''.join([render_field(f) for f in form_def.fields]), + submit_title=form_def.submit_title ) + self.send_response(200) + self.send_header('Content-type', 'text/html') + #self.send_header('Expires', 'Mon, 30 Mar 2015 16:00:00 GMT') + self.end_headers() + self.wfile.write(output) def h_submit(self, form_values): + if not self.auth(): + return + form_name = form_values.getfirst('form_name', None) + form_def = self.scriptform.get_form(form_name) + if form_def.allowed_users is not None and \ + self.username not in form_def.allowed_users: + raise Exception("Not authorized") + + # Write contents of all uploaded files to temp files. These temp + # filenames are passed to the callbacks instead of the actual contents. + file_fields = {} + for field_name in form_values: + field = form_values[field_name] + if field.filename: + tmpfile = tempfile.mktemp(prefix="scriptform_") + f = file(tmpfile, 'w') + while True: + buf = field.file.read(1024 * 16) + if not buf: + break + f.write(buf) + f.close() + field.file.close() + file_fields[field_name] = tmpfile # Validate the form values - form = self.vitaform.get_form(form_name) - values = form.validate(form_values) + form_values = form_def.validate(form_values) - # Call user's callback - if form.script: - # Run an external script - env = os.environ.copy() - env.update(values) - res = cmd(form.script, env=env) - if res['exitcode'] != 0: - result = '{}'.format(res['stderr']) - else: - result = '
    {}
    '.format(res['stdout']) - else: - # Run a python callback - callback = self.callbacks[form_name] - result = callback(values) - - return ''' - {header} -
    -

    {title}

    -

    Result

    -
    {result}
    - -
    - {footer} - '''.format( - header=html_header.format(title=self.vitaform.title), - footer=html_footer, - title=form.title, - form_name=form.name, - result=result, - ) + # Repopulate form values with uploaded tmp filenames + form_values.update(file_fields) + # Call user's callback. If a result is returned, we assume the callback + # was not a raw script, so we wrap its output in some nice HTML. + # Otherwise the callback should have written its own response to the + # self.wfile filehandle. + try: + result = self.scriptform.callback(form_name, form_values, self.wfile) + if result: + if result['exitcode'] != 0: + msg = '{0}'.format(result['stderr']) + else: + msg = '
    {0}
    '.format(result['stdout']) + output = ''' + {header} +
    +

    {title}

    +

    Result

    +
    {msg}
    + +
    + {footer} + '''.format( + header=html_header.format(title=self.scriptform.title), + footer=html_footer, + title=form_def.title, + form_name=form_def.name, + msg=msg, + ) + self.send_response(200) + self.send_header('Content-type', 'text/html') + #self.send_header('Expires', 'Mon, 30 Mar 2015 16:00:00 GMT') + self.end_headers() + self.wfile.write(output) + finally: + # Clean up uploaded files + # FIXME: Catch exceptions and such) + for file_name in file_fields.values(): + os.unlink(file_name) class ScriptForm: """ @@ -451,6 +526,7 @@ class ScriptForm: self.forms = {} self.callbacks = {} self.title = 'ScriptForm Actions' + self.users = None self.basepath = os.path.realpath(os.path.dirname(config_file)) self._load_config(config_file) @@ -470,6 +546,8 @@ class ScriptForm: config = json.load(file(path, 'r')) if 'title' in config: self.title = config['title'] + if 'users' in config: + self.users = config['users'] for form_name, form in config['forms'].items(): if 'script' in form: script = os.path.join(self.basepath, form['script']) @@ -481,13 +559,45 @@ class ScriptForm: form['description'], form['fields'], script, - submit_title=form.get('submit_title', None)) + script_raw=form.get('script_raw', False), + submit_title=form.get('submit_title', None), + allowed_users=form.get('allowed_users', None)) def get_form(self, form_name): return self.forms[form_name] + def callback(self, form_name, form_values, output_fh=None): + form = self.get_form(form_name) + if form.script: + return self.callback_script(form, form_values, output_fh) + else: + return self.callback_python(form, form_values, output_fh) + + def callback_script(self, form, form_values, output_fh=None): + env = os.environ.copy() + env.update(form_values) + + if form.script_raw: + p = subprocess.Popen(form.script, shell=True, stdout=output_fh, + stderr=output_fh, env=env) + stdout, stderr = p.communicate(input) + return None + else: + p = subprocess.Popen(form.script, shell=True, stdin=subprocess.PIPE, + stdout=subprocess.PIPE, stderr=subprocess.PIPE, + env=env) + stdout, stderr = p.communicate() + return { + 'stdout': stdout, + 'stderr': stderr, + 'exitcode': p.returncode + } + + def callback_python(self, form, form_values, output_fh=None): + pass + def run(self, listen_addr='0.0.0.0', listen_port=80): - ScriptFormWebApp.vitaform = self + ScriptFormWebApp.scriptform = self ScriptFormWebApp.callbacks = self.callbacks WebSrv(ScriptFormWebApp, listen_addr=listen_addr, listen_port=listen_port)