// Reader is a global, shared instance of a cryptographically // secure random number generator. // // On Linux, FreeBSD, Dragonfly and Solaris, Reader uses getrandom(2) if // available, /dev/urandom otherwise. // On OpenBSD and macOS, Reader uses getentropy(2). // On other Unix-like systems, Reader reads from /dev/urandom. // On Windows systems, Reader uses the RtlGenRandom API. // On Wasm, Reader uses the Web Crypto API. var Reader io.Reader


// Int returns a uniform random value in [0, max). It panics if max <= 0. func Int(rand io.Reader, max *big.Int) (n *big.Int, err error)


// Prime returns a number of the given bit length that is prime with high probability. // Prime will return error for any error returned by rand.Read or if bits < 2. func Prime(rand io.Reader, bits int) (*big.Int, error)


// Read is a helper function that calls Reader.Read using io.ReadFull. // On return, n == len(b) if and only if err == nil. func Read(b []byte) (n int, err error)