package rand

Import Path
	crypto/rand (on go.dev)

Dependency Relation
	imports 12 packages, and imported by 7 packages


Involved Source Files

	
		Package rand implements a cryptographically secure
		random number generator.

	    rand_getrandom.go
	    rand_unix.go
	    util.go


Code Examples

	
		package main
		
		import (
			"bytes"
			"crypto/rand"
			"fmt"
		)
		
		func main() {
			c := 10
			b := make([]byte, c)
			_, err := rand.Read(b)
			if err != nil {
				fmt.Println("error:", err)
				return
			}
			// The slice should now contain random bytes instead of only zeroes.
			fmt.Println(bytes.Equal(b, make([]byte, c)))
		
		}




Package-Level Functions (total 3)


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


	
		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.


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




Package-Level Variables (only one)


	
		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, and /dev/urandom otherwise.
		  - On macOS and iOS, Reader uses arc4random_buf(3).
		  - On OpenBSD and NetBSD, Reader uses getentropy(2).
		  - On other Unix-like systems, Reader reads from /dev/urandom.
		  - On Windows, 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.