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29 * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
33 * \brief ISAAC implementation
34 * \author Giovanni Bajo <rasky@develer.com>
38 #ifndef SEC_PRNG_ISAAC_H
39 #define SEC_PRNG_ISAAC_H
44 * Size of the internal ISAAC state (in 32-bit words).
46 * ISAAC is known to generate unbiased data as follows:
47 * * 3 words: 2^37 unbiased values
48 * * 4 words: 2^45 unbiased values
49 * * 5 words: 2^53 unbiased values
50 * * 6 words: 2^61 unbiased values
51 * * 7 words: 2^69 unbiased values
52 * * 8 words: 2^77 unbiased values
54 * The period of the generator is usually much longer, but it is
55 * obviously uninteresting for a CSPRNG.
57 #define CONFIG_ISAAC_RANDSIZL (3)
58 #define CONFIG_ISAAC_RANDSIZ (1<<(CONFIG_ISAAC_RANDSIZL))
60 typedef struct IsaacContext
64 uint32_t randrsl[CONFIG_ISAAC_RANDSIZ];
65 uint32_t randmem[CONFIG_ISAAC_RANDSIZ];
71 void isaac_init(IsaacContext *ctx);
73 #define isaac_stackinit(...) \
74 ({ IsaacContext *ctx = alloca(sizeof(IsaacContext)); isaac_init(ctx , ##__VA_ARGS__); &ctx->prng; })
77 #endif /* SEC_PRNG_ISAAC_H */