package wasi:random

/// WASI Random is a random data API.
///
/// It is intended to be portable at least between Unix-family platforms and
/// Windows.
interface random {
    /// Return `len` cryptographically-secure pseudo-random bytes.
    ///
    /// This function must produce data from an adequately seeded
    /// cryptographically-secure pseudo-random number generator (CSPRNG), so it
    /// must not block, from the perspective of the calling program, and the
    /// returned data is always unpredictable.
    ///
    /// This function must always return fresh pseudo-random data. Deterministic
    /// environments must omit this function, rather than implementing it with
    /// deterministic data.
    get-random-bytes: func(len: u64) -> list<u8>

    /// Return a cryptographically-secure pseudo-random `u64` value.
    ///
    /// This function returns the same type of pseudo-random data as
    /// `get-random-bytes`, represented as a `u64`.
    get-random-u64: func() -> u64
}