tc_hmac_prng_init() function

HMAC-PRNG initialization procedure Initializes prng with personalization, disables tc_hmac_prng_generate

Syntax

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Summary

Declaration

Definition

from hmac_prng.h:115

int tc_hmac_prng_init(TCHmacPrng_t prng, const uint8_t *personalization, unsigned int plen);

Implemented in hmac_prng.c:112

Arguments

Argument

Description

prng

IN/OUT -- the PRNG state to initialize

personalization

IN -- personalization string

plen

IN -- personalization length in bytes

Return value

returns TC_CRYPTO_SUCCESS (1) returns TC_CRYPTO_FAIL (0) if: prng == NULL, personalization == NULL, plen > MAX_PLEN

Notes

Assumes: - personalization != NULL. The personalization is a platform unique string (e.g., the host name) and is the last line of defense against failure of the entropy source @warning NIST SP 800-90A specifies 3 items as seed material during initialization: entropy seed, personalization, and an optional nonce. TinyCrypts requires instead a non-null personalization (which is easily computed) and indirectly requires an entropy seed (since the reseed function is mandatorily called after init)