diff options
| author | Jeff Epler <jepler@gmail.com> | 2021-02-17 16:50:49 -0600 |
|---|---|---|
| committer | Jeff Epler <jepler@gmail.com> | 2021-02-17 17:49:25 -0600 |
| commit | ab5eb86118f5b446d9cb1996b07cae56e3f45643 (patch) | |
| tree | 81719641005b2207e7a6b9018b22eab23860d575 /extmod | |
| parent | 261b077209bc668de843015e4f5c26e474214769 (diff) | |
raspberrypi: implement os.urandom
Since the datasheet cast some doubt on the strength of the "rosc_hw->randombit",
I use the SHA256 hash function to create a high quality random seed
from random values of uncertain entropy, as well as to generate a sequence
of random values from that seed using SHA256 as a cryptographically-secure
random number generator.
In practice, it produces over 100kB/s of random data which does not
have any gross problems according to _PractRand_.
Diffstat (limited to 'extmod')
| -rw-r--r-- | extmod/crypto-algorithms/sha256.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/extmod/crypto-algorithms/sha256.c b/extmod/crypto-algorithms/sha256.c index 276611cfd..9b5e45d23 100644 --- a/extmod/crypto-algorithms/sha256.c +++ b/extmod/crypto-algorithms/sha256.c @@ -14,6 +14,7 @@ /*************************** HEADER FILES ***************************/ #include <stdlib.h> +#include <string.h> #include "sha256.h" /****************************** MACROS ******************************/ |