flakes/paste/paste/paste.py

   1 import os
   2 import secrets
   3 from flask import Flask, abort, request, Response, url_for
   4 from pygments.formatters.html import HtmlFormatter
   5 from pygments import highlight
   6 import pygments.lexers as lexers
   7 import base64
   8 import magic
   9 import mimetypes
  10
  11 magic = magic.Magic(mime=True)
  12
  13 mit_license = """
  14 Copyright (c) 2022 Immae
  15
  16 Permission is hereby granted, free of charge, to any person obtaining a copy
  17 of this software and associated documentation files (the "Software"), to deal
  18 in the Software without restriction, including without limitation the rights
  19 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  20 copies of the Software, and to permit persons to whom the Software is
  21 furnished to do so, subject to the following conditions:
  22
  23 The above copyright notice and this permission notice shall be included in all
  24 copies or substantial portions of the Software.
  25
  26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  28 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  29 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  30 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  31 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32 SOFTWARE.
  33 """
  34
  35 config = {
  36         "directory": os.environ["PASTE_DIRECTORY"],
  37         "self_paste_id": "abcd123",
  38         "license_paste_id": "license",
  39         "max_content_length": 16 * 1000 * 1000
  40         }
  41
  42 app = Flask(__name__)
  43 app.config['MAX_CONTENT_LENGTH'] = config["max_content_length"]
  44
  45 def file_location(paste_id):
  46     if paste_id == config["self_paste_id"]:
  47         return os.path.realpath(__file__)
  48     else:
  49         return os.path.join(config['directory'], paste_id + ".dat")
  50
  51 def read_paste(paste_id):
  52     file = file_location(paste_id)
  53     if os.path.isfile(file):
  54         content = open(file, "rb").read()
  55         mime = magic.from_buffer(content)
  56         if mime.startswith("text/x-script."):
  57             mime="text/plain"
  58         return (content, mime)
  59     elif paste_id == config["license_paste_id"]:
  60         return (mit_license, "text/plain")
  61     else:
  62         abort(404)
  63
  64 def generate_paste_id(n=3, attempts=0):
  65     path = secrets.token_hex(n)[:n]
  66     file = file_location(path)
  67     if os.path.isfile(file):
  68         attempts = attempts + 1
  69         if attempts > 5:
  70             n = n + 1
  71         return generate_paste_id(n, attempts)
  72     return path
  73
  74 @app.route('/', methods=["GET"])
  75 def index():
  76     return Response('''<pre>
  77 $ curl -X POST --data-binary @{self} {host}
  78 {paste}
  79
  80 -> GET {paste}
  81    guesses mimetype
  82 -> GET {paste}/raw
  83    text/plain
  84 -> GET {paste}/bin
  85    application/octet-stream
  86 -> GET {paste}/b64
  87    base64 encoded
  88 -> GET {paste}/ub64
  89    tries to decode base64
  90 -> GET {paste}/python
  91    pretty-print python (replace with anything known by pygments)
  92 -> GET {paste}/guess
  93    pretty-print (language guessed by pygments)
  94 -> GET {paste}/download
  95    force download of file
  96 </pre>
  97 <a href="{paste}/py">Get the source</a><br />
  98 Software licensed under the terms of the <a href="{host}/license">MIT license</a>
  99 '''.format(host=url_for('post_paste', _external=True, _scheme="https"),
 100                  paste=url_for('get_paste', _external=True, _scheme="https", paste_id=config["self_paste_id"]),
 101                  license=url_for('get_paste', _external=True, _scheme="https", paste_id=config["license_paste_id"]),
 102                  self=os.path.basename(__file__)
 103                  ), mimetype="text/html")
 104
 105 @app.route('/', methods=["POST"])
 106 def post_paste():
 107     content = request.get_data()
 108     paste_id = generate_paste_id()
 109     with open(file_location(paste_id), "wb") as f:
 110         f.write(content)
 111     return url_for('get_paste', _external=True, _scheme="https", paste_id=paste_id) + "\n"
 112
 113
 114 @app.route('/<paste_id>', methods=["GET"])
 115 def get_paste(paste_id):
 116     content, mime = read_paste(paste_id)
 117     return Response(content, mimetype=mime)
 118
 119 @app.route('/<paste_id>/<lang>', methods=["GET"])
 120 def get_paste_with(paste_id, lang):
 121     content, mime = read_paste(paste_id)
 122     if lang == "raw":
 123         return Response(content, mimetype="text/plain")
 124     elif lang == "bin":
 125         return Response(content, mimetype="application/octet-stream")
 126     elif lang == "b64":
 127         return Response(base64.encodebytes(content), mimetype="text/plain")
 128     elif lang == "download":
 129         extension = mimetypes.guess_extension(mime, strict=False)
 130         if extension is None:
 131             cd = "attachment"
 132         else:
 133             cd = 'attachment; filename="{}{}"'.format(paste_id, extension)
 134         return Response(content, mimetype=mime,
 135                 headers={"Content-Disposition": cd})
 136     elif lang == "ub64":
 137         try:
 138             return base64.b64decode(content)
 139         except:
 140             abort(400)
 141     try:
 142         if lang == "guess":
 143             lexer = lexers.guess_lexer(content)
 144         else:
 145             lexer = lexers.find_lexer_class_by_name(lang)()
 146     except:
 147         abort(400)
 148     fmter = HtmlFormatter(
 149         noclasses=True, full=True, style="colorful", linenos="table")
 150
 151     return Response(highlight(content, lexer, fmter), mimetype="text/html")