Opaque hmac256drbgabs_generate.

(* Specifications: *)
Lemma body_hmac_drbg_random_simple: semax_body HmacDrbgVarSpecs HmacDrbgFunSpecs
f_mbedtls_hmac_drbg_random hmac_drbg_random_spec_simple.
Lemma body_hmac_drbg_random_simple: semax_body HmacDrbgVarSpecs HmacDrbgFunSpecs
f_mbedtls_hmac_drbg_random hmac_drbg_random_spec_simple.