# module SecureRandom

## Secure random number generator interface.¶ ↑

This library is an interface to secure random number generators which are suitable for generating session keys in HTTP cookies, etc.

You can use this library in your application by requiring it:

    require 'securerandom'

It supports the following secure random number generators:

- openssl

- /dev/urandom

- Win32

### Examples¶ ↑

Generate random hexadecimal strings:

    require 'securerandom'

    p SecureRandom.hex(10) #=> "52750b30ffbc7de3b362"
    p SecureRandom.hex(10) #=> "92b15d6c8dc4beb5f559"
    p SecureRandom.hex(13) #=> "39b290146bea6ce975c37cfc23"

Generate random base64 strings:

    p SecureRandom.base64(10) #=> "EcmTPZwWRAozdA=="
    p SecureRandom.base64(10) #=> "KO1nIU+p9DKxGg=="
    p SecureRandom.base64(12) #=> "7kJSM/MzBJI+75j8"

Generate random binary strings:

    p SecureRandom.random_bytes(10) #=> "\016\t{\370g\310pbr\301"
    p SecureRandom.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337"

Generate UUIDs:

    p SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
    p SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"

### Public Class Methods

bytes(n)
Alias for: gen_random
gen_random(n) click to toggle source

    # File lib/securerandom.rb, line 51
    def self.gen_random(n)
      @pid = 0 unless defined?(@pid)
      pid = $$
      unless @pid == pid
        now = Process.clock_gettime(Process::CLOCK_REALTIME, :nanosecond)
        OpenSSL::Random.random_add([now, @pid, pid].join(""), 0.0)
        seed = Random.raw_seed(16)
        if (seed)
          OpenSSL::Random.random_add(seed, 16)
        end
        @pid = pid
      end
      return OpenSSL::Random.random_bytes(n)
    end

Also aliased as: bytes