tree aa118202970cc1fe2855c5f11738d7c6877be319
parent 86a20700712eb67ae35686e95a50eed8f315d9cb
author Nina Schoetterl-Glausch <nsg@linux.ibm.com> 1718893014 +0200
committer Andrew Jones <andrew.jones@linux.dev> 1723536372 +0200

lib: Add pseudo random functions

Add functions for generating pseudo random 32 and 64 bit values.
The implementation uses SHA-256 and so the randomness should have good
quality.
Implement the necessary subset of SHA-256.
The PRNG algorithm is equivalent to the following python snippet:

def prng32(seed):
    from hashlib import sha256
    state = seed.to_bytes(8, byteorder="big")
    while True:
        state = sha256(state).digest()
        for i in range(8):
            yield int.from_bytes(state[i*4:(i+1)*4], byteorder="big")

Acked-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Jones <andrew.jones@linux.dev>