root / captcha / src / captcha / captcha.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-
#
# Copyright (c) 2007 Tarek Ziadé
#
# Authors:
#   Tarek Ziadé <tarek@ziade.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
import os
import random
import base64

import Image
import ImageFont
import ImageDraw
import ImageFilter

dirname = os.path.dirname(__file__)
fontdir = os.path.join(dirname, 'fonts')
fonts = [os.path.realpath(os.path.join(fontdir, filename))
         for filename in os.listdir(fontdir)
         if filename.endswith('ttf')]

CHARS = "abcdefghijklmnopqrstuvwzyzABCDEFGHIJKLMNOPQRSTUVWZYZ0123456789"

def gen_random_word(wordLen=6):
    word = ""
    for i in range(0, wordLen):
        word = word + CHARS[random.randint(0, 0xffffff) % len(CHARS)]
    return word.strip()

def gen_captcha(text, fnt=random.choice(fonts), fnt_sz=35):
    """Generate a captcha image"""
    fgcolor = random.randint(0, 0xffff00)
    bgcolor = fgcolor ^ 0xffffff
    font = ImageFont.truetype(fnt,fnt_sz)
    dim = font.getsize(text)
    im = Image.new('RGB', (dim[0] + 10, dim[1] + 10), bgcolor)
    d = ImageDraw.Draw(im)
    x, y = im.size
    r = random.randint
    for num in range(100):
        d.rectangle((r(0,x),r(0,y),r(0,x),r(0,y)),fill=r(0,0xffffff))
    d.text((3,3), text, font=font, fill=fgcolor)
    return im.filter(ImageFilter.EDGE_ENHANCE_MORE)

def save_image(image, file_name, fmt):
    image.save(file_name, format=fmt)

def save_captcha(text=gen_random_word(), fnt=random.choice(fonts),
                 fnt_sz=35, file_name='test.jpg', fmt='JPEG'):
    save_image(gen_captcha(text, fnt, fnt_sz), file_name, fmt)

def get_captcha(text=gen_random_word(), fnt=random.choice(fonts), fnt_sz=35):
    captcha = gen_captcha(text, fnt, fnt_sz).tostring('jpeg', 'RGB')
    return captcha.encode('base64')

def get_html_captcha(text=gen_random_word(), fnt=random.choice(fonts), fnt_sz=35):
    pattern = """\
    <img src="data:image/jpg;base64,%s">
    <br/>
    <div>
      <input type="hidden" value="%s" name="word"/>
      bender ? <input type="text" name="guess"/>
    </div>
    """
    return pattern % (get_captcha(text, fnt, fnt_sz), text.encode('base64').strip())

def check_captcha(guess, b64word):
    return guess.strip().encode('base64') == b64word

if __name__ == '__main__':
    """Example: This grabs a random word from the dictionary 'words' (one
    word per line) and generates a jpeg image named 'test.jpg' using
    the truetype font 'porkys.ttf' with a font size of 25.
    """
    print get_html_captcha()