Package rand
Package rand implements a cryptographically secure
pseudorandom number generator.
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Variables
Reader is a global, shared instance of a cryptographically
strong pseudo-random generator.
On Linux, Reader uses getrandom(2) if available, /dev/urandom otherwise.
On OpenBSD, Reader uses getentropy(2).
On other Unix-like systems, Reader reads from /dev/urandom.
On Windows systems, Reader uses the CryptGenRandom API.
var Reader io.Reader
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(rand io.Reader, bits int) (p *big.Int, err error)
Prime returns a number, p, of the given size, such that p is prime
with high probability.
Prime will return error for any error returned by rand.Read or if bits < 2.
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.
▾ Example
This example reads 10 cryptographically secure pseudorandom numbers from
rand.Reader and writes them to a byte slice.
Code:
c := 10
b := make([]byte, c)
_, err := rand.Read(b)
if err != nil {
fmt.Println("error:", err)
return
}
fmt.Println(bytes.Equal(b, make([]byte, c)))
Output:
false