def md5_encrypt(data, key):
	if len(data) % 16 != 0:
		data += (16 - (len(data) % 16)) * '\x00'

	hash_block = []

	output = ''
	last_hash = ''
	for c in data:
		md5_ctx = hashlib.md5()
		md5_ctx.update(c)
		md5_ctx.update(key)
		md5_ctx.update(last_hash)
		hash_block.append(md5_ctx.digest())
		last_hash = hash_block[-1]
		if len(hash_block) == 16:
			cur_block = ''
			for b in hash_block:
				cur_block += b

			md5_ctx = hashlib.md5()
			md5_ctx.update(cur_block)
			last_hash = md5_ctx.digest()
			output += cur_block + last_hash
			hash_block = []

	return output