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import os, sys, array, math
from io import BytesIO
from wptserve.utils import isomorphic_decode
import importlib
subresource = importlib.import_module("common.security-features.subresource.subresource")
class Image:
"""This class partially implements the interface of the PIL.Image.Image.
One day in the future WPT might support the PIL module or another imaging
library, so this hacky BMP implementation will no longer be required.
"""
def __init__(self, width, height):
self.width = width
self.height = height
self.img = bytearray([0 for i in range(3 * width * height)])
@staticmethod
def new(mode, size, color=0):
return Image(size[0], size[1])
def _int_to_bytes(self, number):
packed_bytes = [0, 0, 0, 0]
for i in range(4):
packed_bytes[i] = number & 0xFF
number >>= 8
return packed_bytes
def putdata(self, color_data):
for y in range(self.height):
for x in range(self.width):
i = x + y * self.width
if i > len(color_data) - 1:
return
self.img[i * 3: i * 3 + 3] = color_data[i][::-1]
def save(self, f, type):
assert type == "BMP"
# 54 bytes of preambule + image color data.
filesize = 54 + 3 * self.width * self.height
# 14 bytes of header.
bmpfileheader = bytearray([ord('B'), ord('M')] + self._int_to_bytes(filesize) +
[0, 0, 0, 0, 54, 0, 0, 0])
# 40 bytes of info.
bmpinfoheader = bytearray([40, 0, 0, 0] +
self._int_to_bytes(self.width) +
self._int_to_bytes(self.height) +
[1, 0, 24] + (25 * [0]))
padlength = (4 - (self.width * 3) % 4) % 4
bmppad = bytearray([0, 0, 0])
padding = bmppad[0 : padlength]
f.write(bmpfileheader)
f.write(bmpinfoheader)
for i in range(self.height):
offset = self.width * (self.height - i - 1) * 3
f.write(self.img[offset : offset + 3 * self.width])
f.write(padding)
def encode_string_as_bmp_image(string_data):
data_bytes = array.array("B", string_data.encode("utf-8"))
num_bytes = len(data_bytes)
# Encode data bytes to color data (RGB), one bit per channel.
# This is to avoid errors due to different color spaces used in decoding.
color_data = []
for byte in data_bytes:
p = [int(x) * 255 for x in '{0:08b}'.format(byte)]
color_data.append((p[0], p[1], p[2]))
color_data.append((p[3], p[4], p[5]))
color_data.append((p[6], p[7], 0))
# Render image.
num_pixels = len(color_data)
sqrt = int(math.ceil(math.sqrt(num_pixels)))
img = Image.new("RGB", (sqrt, sqrt), "black")
img.putdata(color_data)
# Flush image to string.
f = BytesIO()
img.save(f, "BMP")
f.seek(0)
return f.read()
def generate_payload(request, server_data):
data = (u'{"headers": %(headers)s}') % server_data
if b"id" in request.GET:
request.server.stash.put(request.GET[b"id"], data)
data = encode_string_as_bmp_image(data)
return data
def generate_report_headers_payload(request, server_data):
stashed_data = request.server.stash.take(request.GET[b"id"])
return stashed_data
def main(request, response):
handler = lambda data: generate_payload(request, data)
content_type = b'image/bmp'
if b"report-headers" in request.GET:
handler = lambda data: generate_report_headers_payload(request, data)
content_type = b'application/json'
subresource.respond(request,
response,
payload_generator = handler,
content_type = content_type,
access_control_allow_origin = b"*")