mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-30 10:08:18 +00:00
35 lines
705 B
Python
35 lines
705 B
Python
|
import sys
|
||
|
|
|
||
|
|
seed = 0
|
||
|
|
|
||
|
|
|
||
|
|
def random_buffer(length: int) -> bytes:
|
||
|
|
length = length
|
||
|
|
if length % 4 != 0:
|
||
|
|
raise ValueError("Use only for whole words (multiples of 4 bytes)")
|
||
|
|
b = bytearray(length)
|
||
|
|
for i in range(length):
|
||
|
|
if i % 4 == 0:
|
||
|
|
rand = random32().to_bytes(4, sys.byteorder)
|
||
|
|
b[i] = rand[i % 4]
|
||
|
|
return bytes(b)
|
||
|
|
|
||
|
|
|
||
|
|
def random_reseed(reseed: int = 0):
|
||
|
|
global seed
|
||
|
|
seed = reseed
|
||
|
|
|
||
|
|
|
||
|
|
def random32():
|
||
|
|
global seed
|
||
|
|
seed = (1664525 * seed + 1013904223) & 0xFFFFFFFF
|
||
|
|
return seed
|
||
|
|
|
||
|
|
|
||
|
|
def random_uniform(n: int):
|
||
|
|
max = 0xFFFFFFFF - (0xFFFFFFFF % n)
|
||
|
|
while True:
|
||
|
|
x = random32()
|
||
|
|
if x < max:
|
||
|
|
return x // (max // n)
|