mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/ConfirmEdit
synced 2024-12-11 15:56:23 +00:00
427 lines
13 KiB
Python
427 lines
13 KiB
Python
#!/usr/bin/python3
|
|
#
|
|
# Script to generate distorted text images for a captcha system.
|
|
#
|
|
# Copyright (C) 2005 Neil Harris
|
|
#
|
|
# 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.,
|
|
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
# http://www.gnu.org/copyleft/gpl.html
|
|
#
|
|
# Further tweaks by Brion Vibber <brion@pobox.com>:
|
|
# 2006-01-26: Add command-line options for the various parameters
|
|
# 2007-02-19: Add --dirs param for hash subdirectory splits
|
|
# Tweaks by Greg Sabino Mullane <greg@turnstep.com>:
|
|
# 2008-01-06: Add regex check to skip words containing other than a-z
|
|
|
|
import random
|
|
import math
|
|
import hashlib
|
|
from optparse import OptionParser
|
|
import os
|
|
import sys
|
|
import re
|
|
import multiprocessing
|
|
|
|
try:
|
|
from PIL import Image
|
|
from PIL import ImageFont
|
|
from PIL import ImageDraw
|
|
from PIL import ImageEnhance
|
|
from PIL import ImageOps
|
|
except ImportError:
|
|
sys.exit(
|
|
"This script requires the Python Imaging Library - http://www.pythonware.com/products/pil/"
|
|
)
|
|
|
|
# regex to test for suitability of words
|
|
nonalpha = re.compile("[^a-z]")
|
|
|
|
# when il beside each other, hard to read
|
|
confusedletters = re.compile(
|
|
"[ijtlr][ijtl]|r[nompqr]|[il]"
|
|
)
|
|
|
|
# Pillow 9.2 added getbbox to replace getsize, and getsize() was removed in Pillow 10
|
|
# https://pillow.readthedocs.io/en/stable/releasenotes/10.0.0.html#font-size-and-offset-methods
|
|
# We don't have a requirements.txt, and therefore don't declare any specific supported or min version...
|
|
IMAGEFONT_HAS_GETBBOX = hasattr(ImageFont.ImageFont, "getbbox")
|
|
|
|
|
|
# Does X-axis wobbly copy, sandwiched between two rotates
|
|
def wobbly_copy(src, wob, col, scale, ang):
|
|
x, y = src.size
|
|
f = random.uniform(4 * scale, 5 * scale)
|
|
p = random.uniform(0, math.pi * 2)
|
|
rr = ang + random.uniform(-30, 30) # vary, but not too much
|
|
int_d = Image.new("RGB", src.size, 0) # a black rectangle
|
|
rot = src.rotate(rr, Image.BILINEAR)
|
|
# Do a cheap bounding-box op here to try to limit work below
|
|
bbx = rot.getbbox()
|
|
if bbx is None:
|
|
return src
|
|
else:
|
|
l, t, r, b = bbx
|
|
# and only do lines with content on
|
|
for i in range(t, b + 1):
|
|
# Drop a scan line in
|
|
xoff = int(math.sin(p + (i * f / y)) * wob)
|
|
xoff += int(random.uniform(-wob * 0.5, wob * 0.5))
|
|
int_d.paste(rot.crop((0, i, x, i + 1)), (xoff, i))
|
|
# try to stop blurring from building up
|
|
int_d = int_d.rotate(-rr, Image.BILINEAR)
|
|
enh = ImageEnhance.Sharpness(int_d)
|
|
return enh.enhance(2)
|
|
|
|
|
|
def gen_captcha(text, fontname, fontsize, file_name):
|
|
"""Generate a captcha image"""
|
|
# white text on a black background
|
|
bgcolor = 0x0
|
|
fgcolor = 0xFFFFFF
|
|
# create a font object
|
|
font = ImageFont.truetype(fontname, fontsize)
|
|
|
|
# determine dimensions of the text
|
|
if IMAGEFONT_HAS_GETBBOX:
|
|
dim = font.getbbox(text)[2:]
|
|
else:
|
|
dim = font.getsize(text)
|
|
|
|
# create a new image significantly larger that the text
|
|
edge = max(dim[0], dim[1]) + 2 * min(dim[0], dim[1])
|
|
im = Image.new("RGB", (edge, edge), bgcolor)
|
|
d = ImageDraw.Draw(im)
|
|
x, y = im.size
|
|
# add the text to the image
|
|
# Using between 5-6 pixels of negative kerning seemed
|
|
# enough to confuse tesseract but still be very readable
|
|
offset = 0
|
|
for c in text:
|
|
d.text(
|
|
(x / 2 - dim[0] / 2 + offset, y / 2 - dim[1] / 2 + random.uniform(-3, 7)),
|
|
c,
|
|
font=font,
|
|
fill=fgcolor,
|
|
)
|
|
if IMAGEFONT_HAS_GETBBOX:
|
|
offset += font.getbbox(c)[2:][0]
|
|
else:
|
|
offset += font.getsize(c)[0]
|
|
|
|
offset -= random.uniform(5, 6)
|
|
|
|
for i in range(10):
|
|
d.arc(
|
|
(
|
|
int(
|
|
offset * ((i / 2) - 1) / 5
|
|
+ x / 2
|
|
- dim[0] / 2
|
|
+ random.uniform(0, 10)
|
|
),
|
|
int(y / 2 - dim[1] + 30 + random.uniform(-10, 15)),
|
|
int(offset * i / 7 + x / 2 - dim[0] / 2 + random.uniform(-5, 5)),
|
|
int(y / 2 - dim[1] + 30 + random.uniform(-10, 30)),
|
|
),
|
|
int(random.uniform(-30, 30)),
|
|
int(random.uniform(160, 300)),
|
|
fill=fgcolor,
|
|
)
|
|
|
|
# now get the bounding box of the nonzero parts of the image
|
|
bbox = im.getbbox()
|
|
bord = min(dim[0], dim[1]) / 4 # a bit of a border
|
|
im = im.crop((bbox[0] - bord, bbox[1] - bord, bbox[2] + bord, bbox[3] + bord))
|
|
|
|
# and turn into black on white
|
|
im = ImageOps.invert(im)
|
|
|
|
# save the image, in format determined from filename
|
|
im.save(file_name)
|
|
|
|
|
|
def gen_subdir(basedir, md5hash, levels):
|
|
"""Generate a subdirectory path out of the first _levels_
|
|
characters of _hash_, and ensure the directories exist
|
|
under _basedir_."""
|
|
subdir = None
|
|
for i in range(0, levels):
|
|
char = md5hash[i]
|
|
if subdir:
|
|
subdir = os.path.join(subdir, char)
|
|
else:
|
|
subdir = char
|
|
fulldir = os.path.join(basedir, subdir)
|
|
if not os.path.exists(fulldir):
|
|
os.mkdir(fulldir)
|
|
return subdir
|
|
|
|
|
|
def try_pick_word(words, badwordlist, verbose, nwords, min_length, max_length):
|
|
if words is not None:
|
|
word = words[random.randint(0, len(words) - 1)]
|
|
while nwords > 1:
|
|
word2 = words[random.randint(0, len(words) - 1)]
|
|
word = word + word2
|
|
nwords = nwords - 1
|
|
else:
|
|
word = ""
|
|
max_length = max_length if max_length > 0 else 10
|
|
for i in range(0, random.randint(min_length, max_length)):
|
|
word = word + chr(97 + random.randint(0, 25))
|
|
|
|
if verbose:
|
|
print("word is %s" % word)
|
|
|
|
if len(word) < min_length:
|
|
if verbose:
|
|
print(
|
|
"skipping word pair '%s' because it has fewer than %d characters"
|
|
% (word, min_length)
|
|
)
|
|
return None
|
|
|
|
if max_length > 0 and len(word) > max_length:
|
|
if verbose:
|
|
print(
|
|
"skipping word pair '%s' because it has more than %d characters"
|
|
% (word, max_length)
|
|
)
|
|
return None
|
|
|
|
if nonalpha.search(word):
|
|
if verbose:
|
|
print(
|
|
"skipping word pair '%s' because it contains non-alphabetic characters"
|
|
% word
|
|
)
|
|
return None
|
|
if confusedletters.search(word):
|
|
if verbose:
|
|
print(
|
|
"skipping word pair '%s' because it contains confusing letters beside each other"
|
|
% word
|
|
)
|
|
return None
|
|
|
|
for naughty in badwordlist:
|
|
if naughty in word:
|
|
if verbose:
|
|
print(
|
|
"skipping word pair '%s' because it contains word '%s'"
|
|
% (word, naughty)
|
|
)
|
|
return None
|
|
return word
|
|
|
|
|
|
def pick_word(words, badwordlist, verbose, nwords, min_length, max_length):
|
|
for x in range(
|
|
1000
|
|
): # If we can't find a valid combination in 1000 tries, just give up
|
|
word = try_pick_word(
|
|
words, badwordlist, verbose, nwords, min_length, max_length
|
|
)
|
|
if word:
|
|
return word
|
|
sys.exit("Unable to find valid word combinations")
|
|
|
|
|
|
def read_wordlist(filename):
|
|
if not os.path.isfile(filename):
|
|
return []
|
|
f = open(filename)
|
|
words = [x.strip().lower() for x in f.readlines()]
|
|
f.close()
|
|
return words
|
|
|
|
|
|
def run_in_thread(object):
|
|
count = object[0]
|
|
words = object[1]
|
|
badwordlist = object[2]
|
|
opts = object[3]
|
|
font = object[4]
|
|
fontsize = object[5]
|
|
|
|
for i in range(count):
|
|
word = pick_word(
|
|
words,
|
|
badwordlist,
|
|
opts.verbose,
|
|
opts.number_words,
|
|
opts.min_length,
|
|
opts.max_length,
|
|
)
|
|
salt = "%08x" % random.randrange(2**32)
|
|
# 64 bits of hash is plenty for this purpose
|
|
md5hash = hashlib.md5(
|
|
(opts.key + salt + word + opts.key + salt).encode("utf-8")
|
|
).hexdigest()[:16]
|
|
filename = "image_%s_%s.png" % (salt, md5hash)
|
|
if opts.dirs:
|
|
subdir = gen_subdir(opts.output, md5hash, opts.dirs)
|
|
filename = os.path.join(subdir, filename)
|
|
if opts.verbose:
|
|
print(filename)
|
|
gen_captcha(word, font, fontsize, os.path.join(opts.output, filename))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
"""This grabs random words from the dictionary 'words' (one
|
|
word per line) and generates a captcha image for each one,
|
|
with a keyed salted hash of the correct answer in the filename.
|
|
|
|
To check a reply, hash it in the same way with the same salt and
|
|
secret key, then compare with the hash value given.
|
|
"""
|
|
script_dir = os.path.dirname(os.path.realpath(__file__))
|
|
parser = OptionParser()
|
|
parser.add_option(
|
|
"--wordlist", help="A list of words (required)", metavar="WORDS.txt"
|
|
)
|
|
parser.add_option(
|
|
"--random",
|
|
help="Use random characters instead of a wordlist",
|
|
action="store_true",
|
|
)
|
|
parser.add_option(
|
|
"--key", help="The passphrase set as $wgCaptchaSecret (required)", metavar="KEY"
|
|
)
|
|
parser.add_option(
|
|
"--output",
|
|
help="The directory to put the images in - $wgCaptchaDirectory (required)",
|
|
metavar="DIR",
|
|
)
|
|
parser.add_option("--font", help="The font to use (required)", metavar="FONT.ttf")
|
|
parser.add_option(
|
|
"--font-size",
|
|
help="The font size (default 40)",
|
|
metavar="N",
|
|
type="int",
|
|
default=40,
|
|
)
|
|
parser.add_option(
|
|
"--count",
|
|
help="The maximum number of images to make (default 20)",
|
|
metavar="N",
|
|
type="int",
|
|
default=20,
|
|
)
|
|
parser.add_option(
|
|
"--badwordlist",
|
|
help="A list of words that should not be used",
|
|
metavar="FILE",
|
|
default=os.path.join(script_dir, "badwordlist"),
|
|
)
|
|
parser.add_option(
|
|
"--fill",
|
|
help="Fill the output directory to contain N files, overrides count, cannot be used with --dirs",
|
|
metavar="N",
|
|
type="int",
|
|
)
|
|
parser.add_option(
|
|
"--dirs",
|
|
help="Put the images into subdirectories N levels deep - $wgCaptchaDirectoryLevels",
|
|
metavar="N",
|
|
type="int",
|
|
)
|
|
parser.add_option(
|
|
"--verbose", "-v", help="Show debugging information", action="store_true"
|
|
)
|
|
parser.add_option(
|
|
"--number-words",
|
|
help="Number of words from the wordlist which make a captcha challenge (default 2)",
|
|
type="int",
|
|
default=2,
|
|
)
|
|
parser.add_option(
|
|
"--min-length",
|
|
help="Minimum length for a captcha challenge",
|
|
type="int",
|
|
default=1,
|
|
)
|
|
parser.add_option(
|
|
"--max-length",
|
|
help="Maximum length for a captcha challenge",
|
|
type="int",
|
|
default=-1,
|
|
)
|
|
parser.add_option(
|
|
"--threads",
|
|
help="Maximum number of threads to be used to generate captchas.",
|
|
type="int",
|
|
default=1,
|
|
)
|
|
|
|
opts, args = parser.parse_args()
|
|
|
|
if opts.wordlist:
|
|
wordlist = opts.wordlist
|
|
elif opts.random:
|
|
wordlist = None
|
|
else:
|
|
sys.exit("Need to specify a wordlist")
|
|
if opts.key:
|
|
key = opts.key
|
|
else:
|
|
sys.exit("Need to specify a key")
|
|
if opts.output:
|
|
output = opts.output
|
|
else:
|
|
sys.exit("Need to specify an output directory")
|
|
if opts.font and os.path.exists(opts.font):
|
|
font = opts.font
|
|
else:
|
|
sys.exit("Need to specify the location of a font")
|
|
|
|
badwordlist = read_wordlist(opts.badwordlist)
|
|
count = opts.count
|
|
fill = opts.fill
|
|
fontsize = opts.font_size
|
|
threads = opts.threads
|
|
|
|
if fill:
|
|
count = max(0, fill - len(os.listdir(output)))
|
|
|
|
words = None
|
|
if wordlist:
|
|
words = read_wordlist(wordlist)
|
|
words = [
|
|
x
|
|
for x in words
|
|
if len(x) in (4, 5) and x[0] != "f" and x[0] != x[1] and x[-1] != x[-2]
|
|
]
|
|
|
|
if count == 0:
|
|
sys.exit("No need to generate CAPTCHA images.")
|
|
|
|
if count < threads:
|
|
chunks = 1
|
|
threads = 1
|
|
else:
|
|
chunks = count // threads
|
|
|
|
p = multiprocessing.Pool(threads)
|
|
data = []
|
|
print(
|
|
"Generating %s CAPTCHA images separated in %s image(s) per chunk run by %s threads..."
|
|
% (count, chunks, threads)
|
|
)
|
|
for i in range(0, threads):
|
|
data.append([chunks, words, badwordlist, opts, font, fontsize])
|
|
|
|
p.map(run_in_thread, data)
|