random.wit

package wasi:random@0.2.1;
/// WASI Random is a random data API.
///
/// It is intended to be portable at least between Unix-family platforms and
/// Windows.
@since(version = 0.2.0)
interface random {
    /// Return `len` cryptographically-secure random or pseudo-random bytes.
    ///
    /// This function must produce data at least as cryptographically secure and
    /// fast as an adequately seeded cryptographically-secure pseudo-random
    /// number generator (CSPRNG). It must not block, from the perspective of
    /// the calling program, under any circumstances, including on the first
    /// request and on requests for numbers of bytes. The returned data must
    /// always be unpredictable.
    ///
    /// This function must always return fresh data. Deterministic environments
    /// must omit this function, rather than implementing it with deterministic
    /// data.
    @since(version = 0.2.0)
    get-random-bytes: func(len: u64) -> list<u8>;

    /// Return a cryptographically-secure random or pseudo-random `u64` value.
    ///
    /// This function returns the same type of data as `get-random-bytes`,
    /// represented as a `u64`.
    @since(version = 0.2.0)
    get-random-u64: func() -> u64;
}