119  * This function fills a given buffer with random bytes. The entropy within
121  * a 64 bytes buffer has at least 64 * 8 / 2 = 256 bits of entropy.
122  * Within the function the entropy generation is done in junks of 64 bytes.
124  * The generation of the entropy is based on the assumption that every stckf()
125  * invocation produces 0.5 bits of entropy. To accumulate 256 bits of entropy
126  * at least 512 stckf() values are needed. The entropy relevant part of the
189 	__u64 entropy[4];  in prng_tdes_add_entropy()  local
194 			  (char *) entropy, (char *) entropy,  in prng_tdes_add_entropy()
195 			  sizeof(entropy));  in prng_tdes_add_entropy()
196 		memcpy(prng_data->prngws.parm_block, entropy, sizeof(entropy));  in prng_tdes_add_entropy()
210 	/* Add the entropy */  in prng_tdes_seed()
241 	/* initialize the PRNG, add 128 bits of entropy */  in prng_tdes_instantiate()
394 	/* generate initial seed, we need at least  256 + 128 bits entropy. */  in prng_sha512_instantiate()
398 		 * 32 bytes and produces 100% entropy. So we pull 64 bytes  in prng_sha512_instantiate()
399 		 * which gives us 512 bits entropy.  in prng_sha512_instantiate()
407 		 * 50% entropy. So we pull 2*64 bytes which gives us 512 bits  in prng_sha512_instantiate()
408 		 * of entropy.  in prng_sha512_instantiate()
454 	/* We need at least 256 bits of fresh entropy for reseeding */  in prng_sha512_reseed()
456 		/* trng produces 256 bits entropy in 32 bytes */  in prng_sha512_reseed()
460 		/* generate_entropy() produces 256 bits entropy in 64 bytes */  in prng_sha512_reseed()