• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1"""
2PRNG management routines, thin wrappers.
3"""
4
5from OpenSSL._util import lib as _lib
6
7
8def add(buffer, entropy):
9    """
10    Mix bytes from *string* into the PRNG state.
11
12    The *entropy* argument is (the lower bound of) an estimate of how much
13    randomness is contained in *string*, measured in bytes.
14
15    For more information, see e.g. :rfc:`1750`.
16
17    This function is only relevant if you are forking Python processes and
18    need to reseed the CSPRNG after fork.
19
20    :param buffer: Buffer with random data.
21    :param entropy: The entropy (in bytes) measurement of the buffer.
22
23    :return: :obj:`None`
24    """
25    if not isinstance(buffer, bytes):
26        raise TypeError("buffer must be a byte string")
27
28    if not isinstance(entropy, int):
29        raise TypeError("entropy must be an integer")
30
31    _lib.RAND_add(buffer, len(buffer), entropy)
32
33
34def status():
35    """
36    Check whether the PRNG has been seeded with enough data.
37
38    :return: 1 if the PRNG is seeded enough, 0 otherwise.
39    """
40    return _lib.RAND_status()
41