rand

Documentation

Overview

Package rand implements a cryptographically secure random number generator.

Index

• Variables
• func Int(rand io.Reader, max *big.Int) (n *big.Int, err error)
• func Prime(rand io.Reader, bits int) (*big.Int, error)
• func Read(b []byte) (n int, err error)

Variables

var Reader io.Reader

Reader is a global, shared instance of a cryptographically secure random number generator.

On Linux, FreeBSD, Dragonfly, NetBSD 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 ProcessPrng API. On JS/Wasm, Reader uses the Web Crypto API. On WASIP1/Wasm, Reader uses random_get from wasi_snapshot_preview1.

Functions

func Int

func Int(rand io.Reader, max *big.Int) (n *big.Int, err error)

Int returns a uniform random value in [0, max). It panics if max <= 0.

func Prime

func Prime(rand io.Reader, bits int) (*big.Int, 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 Read

func Read(b []byte) (n int, err error)

Read is a helper function that calls Reader.Read using io.ReadFull. On return, n == len(b) if and only if err == nil.