def drbg_step
import bend-collections-laws-crypto@1.0.0.0/src/crypto/secp256k1/ecdsa.bend as Ecdsaimport Base
54# steps b-g: V = 0x01..., K = 0x00..., then two HMAC rounds over
55# V || 0x00 || int2octets(x) || bits2octets(h1) and V || 0x01 || ...
56def drbg_step(+k: List<&2, U32>, +v: List<&2, U32>, +tag: U32, +seed: List<&2, U32>) -> Drbg:
57 drbg_v(hmac(k, cat(v, tag <> seed)), v)