From 5912d1e6241c59bfcf19828a4e65439aae9f963c Mon Sep 17 00:00:00 2001 From: s3lph Date: Fri, 20 Jul 2018 00:32:51 +0200 Subject: [PATCH 1/4] Use a libmagic wrapper to guess Content-Type headers. --- README.md | 1 + matemat/webserver/httpd.py | 18 ++++++++++-------- matemat/webserver/test/test_serve.py | 19 +++++++++++++++---- requirements.txt | 1 + 4 files changed, 27 insertions(+), 12 deletions(-) diff --git a/README.md b/README.md index 95aa201..49816f3 100644 --- a/README.md +++ b/README.md @@ -18,6 +18,7 @@ This project intends to provide a well-tested and maintainable alternative to - Python 3 (>=3.6) - Python dependencies: + - file-magic - jinja2 ## Usage diff --git a/matemat/webserver/httpd.py b/matemat/webserver/httpd.py index e962a8c..23045bc 100644 --- a/matemat/webserver/httpd.py +++ b/matemat/webserver/httpd.py @@ -4,7 +4,7 @@ from typing import Any, Callable, Dict, Tuple, Type, Union import logging import os import socket -import mimetypes +import magic from socketserver import TCPServer from http.server import HTTPServer, BaseHTTPRequestHandler from http.cookies import SimpleCookie @@ -308,7 +308,6 @@ class HttpHandler(BaseHTTPRequestHandler): if path in _PAGELET_PATHS: # Prepare some headers. Those can still be overwritten by the pagelet headers: Dict[str, str] = { - 'Content-Type': 'text/html', 'Cache-Control': 'no-cache' } # Call the pagelet function @@ -328,6 +327,10 @@ class HttpHandler(BaseHTTPRequestHandler): f'matemat_session_id={session_id}; expires={expires}') # Compute the body length and add the appropriate header headers['Content-Length'] = str(len(data)) + # If the pagelet did not set its own Content-Type header, use libmagic to guess an appropriate one + if 'Content-Type' not in headers: + filemagic: magic.FileMagic = magic.detect_from_content(data) + headers['Content-Type'] = f'{filemagic.mime_type}; charset={filemagic.encoding}' # Send all headers set by the pagelet for name, value in headers.items(): self.send_header(name, value) @@ -365,13 +368,12 @@ class HttpHandler(BaseHTTPRequestHandler): data = f.read() # File read successfully, send 'OK' header self.send_response(200) - # TODO: Guess the MIME type. Unfortunately this call solely relies on the file extension, not ideal? - mimetype, _ = mimetypes.guess_type(filepath) - # Fall back to octet-stream type, if unknown - if mimetype is None: - mimetype = 'application/octet-stream' + # Guess the MIME type and encoding using libmagic + filemagic: magic.FileMagic = magic.detect_from_filename(filepath) + mimetype: str = filemagic.mime_type + charset: str = filemagic.encoding # Send content type and length header - self.send_header('Content-Type', mimetype) + self.send_header('Content-Type', f'{mimetype}; charset={charset}') self.send_header('Content-Length', str(len(data))) self.send_header('Last-Modified', fileage.strftime('%a, %d %b %Y %H:%M:%S GMT')) self.send_header('Cache-Control', 'max-age=1') diff --git a/matemat/webserver/test/test_serve.py b/matemat/webserver/test/test_serve.py index c67e06e..2dd7e7e 100644 --- a/matemat/webserver/test/test_serve.py +++ b/matemat/webserver/test/test_serve.py @@ -17,7 +17,6 @@ def serve_test_pagelet_str(method: str, session_vars: Dict[str, Any], headers: Dict[str, str], pagelet_variables: Dict[str, str]) -> Union[bytes, str, PageletResponse]: - headers['Content-Type'] = 'text/plain' return 'serve test pagelet str' @@ -28,7 +27,7 @@ def serve_test_pagelet_bytes(method: str, session_vars: Dict[str, Any], headers: Dict[str, str], pagelet_variables: Dict[str, str]) -> Union[bytes, str, PageletResponse]: - headers['Content-Type'] = 'application/octet-stream' + headers['Content-Type'] = 'application/x-foo-bar' return b'serve\x80test\xffpagelet\xfebytes' @@ -49,7 +48,6 @@ def serve_test_pagelet_template(method: str, session_vars: Dict[str, Any], headers: Dict[str, str], pagelet_variables: Dict[str, str]) -> Union[bytes, str, PageletResponse]: - headers['Content-Type'] = 'text/plain' return TemplateResponse('test.txt', what='World') @@ -62,7 +60,6 @@ def serve_test_pagelet_fail(method: str, headers: Dict[str, str], pagelet_variables: Dict[str, str]) -> Union[bytes, str, PageletResponse]: session_vars['test'] = 'hello, world!' - headers['Content-Type'] = 'text/plain' raise HttpException(599, 'Error expected during unit testing') @@ -228,3 +225,17 @@ class TestServe(AbstractHttpdTest): self.assertIsNone(packet.pagelet) # Make sure a 405 Method Not Allowed header is served self.assertEqual(405, packet.statuscode) + + def test_serve_static_libmagic(self): + # The correct Content-Type header must be guessed, if a pagelet does not provide one + self.client_sock.set_request(b'GET /just/testing/serve_pagelet_str HTTP/1.1\r\n\r\n') + HttpHandler(self.client_sock, ('::1', 45678), self.server) + packet = self.client_sock.get_response() + self.assertEqual('text/plain; charset=us-ascii', packet.headers['Content-Type']) + + def test_serve_static_libmagic_skipped(self): + # The Content-Type set by a pagelet should not be overwritten + self.client_sock.set_request(b'GET /just/testing/serve_pagelet_bytes HTTP/1.1\r\n\r\n') + HttpHandler(self.client_sock, ('::1', 45678), self.server) + packet = self.client_sock.get_response() + self.assertEqual('application/x-foo-bar', packet.headers['Content-Type']) diff --git a/requirements.txt b/requirements.txt index 7f7afbf..4913234 100644 --- a/requirements.txt +++ b/requirements.txt @@ -1 +1,2 @@ +file-magic jinja2 From e2f2ab7727b825117f2858a0e9197da5c3d9f624 Mon Sep 17 00:00:00 2001 From: s3lph Date: Fri, 20 Jul 2018 00:45:15 +0200 Subject: [PATCH 2/4] Added libmagic to testing and staging Dockerfiles. --- .gitlab-ci.yml | 2 +- Dockerfile | 1 + testing/Dockerfile | 2 +- 3 files changed, 3 insertions(+), 2 deletions(-) diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml index 72bd21c..5bfad1b 100644 --- a/.gitlab-ci.yml +++ b/.gitlab-ci.yml @@ -1,5 +1,5 @@ --- -image: s3lph/matemat-ci:20180711-02 +image: s3lph/matemat-ci:20180720-01 stages: - test diff --git a/Dockerfile b/Dockerfile index 83514a4..d084dfb 100644 --- a/Dockerfile +++ b/Dockerfile @@ -2,6 +2,7 @@ FROM python:3.6-alpine RUN mkdir -p /var/matemat/db /var/matemat/upload +RUN apk add libmagic=5.33-r0 ADD . / RUN pip3 install -r /requirements.txt diff --git a/testing/Dockerfile b/testing/Dockerfile index c51e01b..94644e6 100644 --- a/testing/Dockerfile +++ b/testing/Dockerfile @@ -5,7 +5,7 @@ RUN useradd -d /home/matemat -m matemat RUN mkdir -p /var/matemat/db && chown matemat:matemat -R /var/matemat/db RUN mkdir -p /var/matemat/upload && chown matemat:matemat -R /var/matemat/upload RUN apt-get update -qy -RUN apt-get install -y --no-install-recommends sudo openssh-client git docker.io python3-dev python3-pip python3-coverage python3-setuptools build-essential +RUN apt-get install -y --no-install-recommends file sudo openssh-client git docker.io python3-dev python3-pip python3-coverage python3-setuptools build-essential RUN pip3 install wheel pycodestyle mypy WORKDIR /home/matemat From 8598daf3b08752066096b3db4dab20c9a98722d1 Mon Sep 17 00:00:00 2001 From: s3lph Date: Fri, 20 Jul 2018 00:49:29 +0200 Subject: [PATCH 3/4] Catch potential file-magic exception. --- matemat/webserver/httpd.py | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/matemat/webserver/httpd.py b/matemat/webserver/httpd.py index 23045bc..795e0df 100644 --- a/matemat/webserver/httpd.py +++ b/matemat/webserver/httpd.py @@ -329,8 +329,14 @@ class HttpHandler(BaseHTTPRequestHandler): headers['Content-Length'] = str(len(data)) # If the pagelet did not set its own Content-Type header, use libmagic to guess an appropriate one if 'Content-Type' not in headers: - filemagic: magic.FileMagic = magic.detect_from_content(data) - headers['Content-Type'] = f'{filemagic.mime_type}; charset={filemagic.encoding}' + try: + filemagic: magic.FileMagic = magic.detect_from_content(data) + mimetype: str = filemagic.mime_type + charset: str = filemagic.encoding + except ValueError: + mimetype = 'application/octet-stream' + charset = 'binary' + headers['Content-Type'] = f'{mimetype}; charset={charset}' # Send all headers set by the pagelet for name, value in headers.items(): self.send_header(name, value) @@ -369,9 +375,13 @@ class HttpHandler(BaseHTTPRequestHandler): # File read successfully, send 'OK' header self.send_response(200) # Guess the MIME type and encoding using libmagic - filemagic: magic.FileMagic = magic.detect_from_filename(filepath) - mimetype: str = filemagic.mime_type - charset: str = filemagic.encoding + try: + filemagic: magic.FileMagic = magic.detect_from_filename(filepath) + mimetype: str = filemagic.mime_type + charset: str = filemagic.encoding + except ValueError: + mimetype = 'application/octet-stream' + charset = 'binary' # Send content type and length header self.send_header('Content-Type', f'{mimetype}; charset={charset}') self.send_header('Content-Length', str(len(data))) From e6d5aef2b223bce1d4b16d92f251a93d5c8c4f79 Mon Sep 17 00:00:00 2001 From: s3lph Date: Fri, 20 Jul 2018 00:57:30 +0200 Subject: [PATCH 4/4] Removed libmagic dependency from staging Dockerfile; already present in the python:3.6-alpine base image. --- Dockerfile | 1 - 1 file changed, 1 deletion(-) diff --git a/Dockerfile b/Dockerfile index d084dfb..83514a4 100644 --- a/Dockerfile +++ b/Dockerfile @@ -2,7 +2,6 @@ FROM python:3.6-alpine RUN mkdir -p /var/matemat/db /var/matemat/upload -RUN apk add libmagic=5.33-r0 ADD . / RUN pip3 install -r /requirements.txt