Python中的CSRF攻击与验证码

<form action="/add_comment/" method="POST">
  {% csrf_token %}
  <input type="text" name="comment" />
  <input type="submit" value="提交" />
</form>

from io import BytesIO
from random import randint

from PIL import Image, ImageDraw, ImageFont


# 生成随机色彩
def random_color():
    return (randint(0, 255), randint(0, 255), randint(0, 255))


# 生成验证码
def generate_captcha():
    # 定义图片大小和背景色彩
    image_width, image_height = 120, 40
    background_color = (255, 255, 255)

    # 新建一个空白图片
    image = Image.new('RGB', (image_width, image_height), background_color)

    # 获得一个画笔对象
    draw = ImageDraw.Draw(image)

    # 设置字体
    font_size = 20
    font_path = 'arial.ttf'
    font = ImageFont.truetype(font_path, font_size)

    # 生成四个随机数字字符
    captcha = ''
    for i in range(4):
        char = chr(randint(48, 57))
        captcha += char
        color = random_color()
        # 将字符画到图片上
        draw.text((i * 30 + 10, 10), char, fill=color, font=font)

    # 加入干扰线
    for i in range(6):
        start_point = (randint(0, image_width), randint(0, image_height))
        end_point = (randint(0, image_width), randint(0, image_height))
        draw.line([start_point, end_point], fill=random_color(), width=2)

    # 加入干扰点
    for i in range(30):
        point = (randint(0, image_width), randint(0, image_height))
        draw.point(point, fill=random_color())

    # 内存中保存图片
    buffer = BytesIO()
    image.save(buffer, 'jpeg')
    buffer.seek(0)

    return captcha, buffer