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"
Methods
G
Class Public methods
gen_random(n)
# 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)
    ary = [now, @pid, pid]
    OpenSSL::Random.random_add(ary.join("").to_s, 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