Conversion to and from Cstruct.t
of_cstruct_be ~bits cs interprets the bit pattern of cs as a t in big-endian.
If ~bits is not given, the operation considers the entire cs, otherwise the initial min ~bits (bit-length cs) bits of cs.
Assuming n is the number of bits to extract, the n-bit in cs is always the least significant bit of the result. Therefore:
- if the bit size
koftis larger thann,k - nmost significant bits in the result are0; and - if
kis smaller thann, the result containsklast of thenfirst bits ofcs.
to_cstruct_be ~size t is the big-endian representation of t.
If ~size is not given, it defaults to the minimal number of bytes needed to represent t, which is bits t / 8 rounded up.
The least-significant bit of t is always the last bit in the result. If the size is larger than needed, the output is padded with zero bits. If it is smaller, the high bits in t are dropped.
into_cstruct_be t cs writes the big-endian representation of t into cs. It behaves like to_cstruct_be, with ~size spanning the entire cs.
Random generation
val gen : ?g:Mirage_crypto_rng.g -> Z.t -> Z.tgen ~g n picks a value in the interval [0, n - 1] uniformly at random.
val gen_r : ?g:Mirage_crypto_rng.g -> Z.t -> Z.t -> Z.tgen_r ~g low high picks a value from the interval [low, high - 1] uniformly at random.