B10 creating a big.Int from a base 10 string.

ByteSub is a constant time algorithm for subtracting 1 from the array as if it were a big number.

Hash computes the HKDF over many values iteratively such that each value is hashed separately and based on preceding values The first value is computed as okm_0 = KDF(f || value) where f is a byte slice of 32 0xFF salt is zero-filled byte slice with length equal to the hash output length info is the protocol name okm is the 32 byte output The each subsequent iteration is computed by as okm_i = KDF(f_i || value || okm_{i-1}) where f_i = 2^b - 1 - i such that there are 0xFF bytes prior to the value.