Diogo Gomes / RNG

Changed to work with: http://redbearlab.com/blenano/

Dependents:   Garagem

Fork of RNG by Francois Berder

Random.cpp@1:0536a4ca8d35, 2013-09-17 (annotated)

Committer:
feb11
Date:
Tue Sep 17 12:35:12 2013 +0000
Revision:
1:0536a4ca8d35
Parent:
0:299f3795114b
Child:
2:2eb90943983b
improve randomness

Who changed what in which revision?

UserRevisionLine numberNew contents of line
feb11 0:299f3795114b 1 #include "Random.h"
feb11 0:299f3795114b 2 #include "Crypto.h"
feb11 0:299f3795114b 3
feb11 0:299f3795114b 4 Random::Random():
feb11 1:0536a4ca8d35 5 e(p19),
feb11 0:299f3795114b 6 f(p20)
feb11 0:299f3795114b 7 {
feb11 0:299f3795114b 8 AnalogIn a(p15), b(p16), c(p17), d(p18);
feb11 0:299f3795114b 9
feb11 0:299f3795114b 10 uint16_t tmp = a.read_u16();
feb11 0:299f3795114b 11 memcpy(pool, &tmp, 2);
feb11 0:299f3795114b 12 tmp = b.read_u16();
feb11 0:299f3795114b 13 memcpy(&pool[2], &tmp, 2);
feb11 0:299f3795114b 14 tmp = c.read_u16();
feb11 0:299f3795114b 15 memcpy(&pool[4], &tmp, 2);
feb11 0:299f3795114b 16 tmp = d.read_u16();
feb11 0:299f3795114b 17 memcpy(&pool[6], &tmp, 2);
feb11 0:299f3795114b 18 tmp = a.read_u16();
feb11 0:299f3795114b 19 memcpy(&pool[8], &tmp, 2);
feb11 0:299f3795114b 20 tmp = b.read_u16();
feb11 0:299f3795114b 21 memcpy(&pool[10], &tmp, 2);
feb11 0:299f3795114b 22 tmp = c.read_u16();
feb11 0:299f3795114b 23 memcpy(&pool[12], &tmp, 2);
feb11 0:299f3795114b 24 tmp = d.read_u16();
feb11 0:299f3795114b 25 memcpy(&pool[14], &tmp, 2);
feb11 0:299f3795114b 26 }
feb11 0:299f3795114b 27
feb11 0:299f3795114b 28 uint8_t Random::getByte()
feb11 0:299f3795114b 29 {
feb11 0:299f3795114b 30 uint8_t hash[16];
feb11 0:299f3795114b 31 MD5::computeHash(hash, pool, 16);
feb11 0:299f3795114b 32 uint8_t tmp = pool[hash[6]%16];
feb11 0:299f3795114b 33 memcpy(pool, hash, 16);
feb11 1:0536a4ca8d35 34 pool[0] ^= (e.read_u16() & 0xff);
feb11 0:299f3795114b 35 return tmp ^ (f.read_u16() & 0xff);
feb11 0:299f3795114b 36 }
feb11 0:299f3795114b 37
feb11 0:299f3795114b 38 void Random::getBytes(uint8_t *out, uint32_t length)
feb11 0:299f3795114b 39 {
feb11 0:299f3795114b 40 for(int i = 0; i < length; ++i)
feb11 0:299f3795114b 41 out[i] = getByte();
feb11 0:299f3795114b 42 }