# -*- coding: us-ascii -*-
# frozen_string_literal: true
begin
require 'openssl'
rescue LoadError
end
# == 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"
#
module SecureRandom
if defined?(OpenSSL::Random) && /mswin|mingw/ !~ RUBY_PLATFORM
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
else
def self.gen_random(n)
ret = Random.raw_seed(n)
unless ret
raise NotImplementedError, "No random device"
end
unless ret.length == n
raise NotImplementedError, "Unexpected partial read from random device: only #{ret.length} for #{n} bytes"
end
ret
end
end
end
module Random::Formatter
# SecureRandom.random_bytes generates a random binary string.
#
# The argument _n_ specifies the length of the result string.
#
# If _n_ is not specified or is nil, 16 is assumed.
# It may be larger in future.
#
# The result may contain any byte: "\x00" - "\xff".
#
# p SecureRandom.random_bytes #=> "\xD8\\\xE0\xF4\r\xB2\xFC*WM\xFF\x83\x18\xF45\xB6"
# p SecureRandom.random_bytes #=> "m\xDC\xFC/\a\x00Uf\xB2\xB2P\xBD\xFF6S\x97"
#
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
def random_bytes(n=nil)
n = n ? n.to_int : 16
gen_random(n)
end
# SecureRandom.hex generates a random hexadecimal string.
#
# The argument _n_ specifies the length, in bytes, of the random number to be generated.
# The length of the resulting hexadecimal string is twice of _n_.
#
# If _n_ is not specified or is nil, 16 is assumed.
# It may be larger in the future.
#
# The result may contain 0-9 and a-f.
#
# p SecureRandom.hex #=> "eb693ec8252cd630102fd0d0fb7c3485"
# p SecureRandom.hex #=> "91dc3bfb4de5b11d029d376634589b61"
#
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
def hex(n=nil)
random_bytes(n).unpack("H*")[0]
end
# SecureRandom.base64 generates a random base64 string.
#
# The argument _n_ specifies the length, in bytes, of the random number
# to be generated. The length of the result string is about 4/3 of _n_.
#
# If _n_ is not specified or is nil, 16 is assumed.
# It may be larger in the future.
#
# The result may contain A-Z, a-z, 0-9, "+", "/" and "=".
#
# p SecureRandom.base64 #=> "/2BuBuLf3+WfSKyQbRcc/A=="
# p SecureRandom.base64 #=> "6BbW0pxO0YENxn38HMUbcQ=="
#
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
#
# See RFC 3548 for the definition of base64.
def base64(n=nil)
[random_bytes(n)].pack("m*").delete("\n")
end
# SecureRandom.urlsafe_base64 generates a random URL-safe base64 string.
#
# The argument _n_ specifies the length, in bytes, of the random number
# to be generated. The length of the result string is about 4/3 of _n_.
#
# If _n_ is not specified or is nil, 16 is assumed.
# It may be larger in the future.
#
# The boolean argument _padding_ specifies the padding.
# If it is false or nil, padding is not generated.
# Otherwise padding is generated.
# By default, padding is not generated because "=" may be used as a URL delimiter.
#
# The result may contain A-Z, a-z, 0-9, "-" and "_".
# "=" is also used if _padding_ is true.
#
# p SecureRandom.urlsafe_base64 #=> "b4GOKm4pOYU_-BOXcrUGDg"
# p SecureRandom.urlsafe_base64 #=> "UZLdOkzop70Ddx-IJR0ABg"
#
# p SecureRandom.urlsafe_base64(nil, true) #=> "i0XQ-7gglIsHGV2_BNPrdQ=="
# p SecureRandom.urlsafe_base64(nil, true) #=> "-M8rLhr7JEpJlqFGUMmOxg=="
#
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
#
# See RFC 3548 for the definition of URL-safe base64.
def urlsafe_base64(n=nil, padding=false)
s = [random_bytes(n)].pack("m*")
s.delete!("\n")
s.tr!("+/", "-_")
s.delete!("=") unless padding
s
end
=begin
# SecureRandom.random_number generates a random number.
#
# If a positive integer is given as _n_,
# +SecureRandom.random_number+ returns an integer, such that:
# +0 <= SecureRandom.random_number(n) < n+.
#
# p SecureRandom.random_number(100) #=> 15
# p SecureRandom.random_number(100) #=> 88
#
# If 0 is given or an argument is not given,
# +SecureRandom.random_number+ returns a float, such that:
# +0.0 <= SecureRandom.random_number() < 1.0+.
#
# p SecureRandom.random_number #=> 0.596506046187744
# p SecureRandom.random_number #=> 0.350621695741409
#
def random_number(n=0)
if 0 < n
if defined? OpenSSL::BN
OpenSSL::BN.rand_range(n).to_i
else
hex = n.to_s(16)
hex = '0' + hex if (hex.length & 1) == 1
bin = [hex].pack("H*")
mask = bin[0].ord
mask |= mask >> 1
mask |= mask >> 2
mask |= mask >> 4
begin
rnd = random_bytes(bin.length)
rnd[0] = (rnd[0].ord & mask).chr
end until rnd < bin
rnd.unpack("H*")[0].hex
end
else
# assumption: Float::MANT_DIG <= 64
if defined? OpenSSL::BN
i64 = OpenSSL::BN.rand(64, -1).to_i
else
i64 = random_bytes(8).unpack("Q")[0]
end
Math.ldexp(i64 >> (64-Float::MANT_DIG), -Float::MANT_DIG)
end
end
=end
# SecureRandom.uuid generates a random v4 UUID (Universally Unique IDentifier).
#
# p SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
# p SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
# p SecureRandom.uuid #=> "62936e70-1815-439b-bf89-8492855a7e6b"
#
# The version 4 UUID is purely random (except the version).
# It doesn't contain meaningful information such as MAC addresses, timestamps, etc.
#
# The result contains 122 random bits (15.25 random bytes).
#
# See RFC 4122 for details of UUID.
#
def uuid
ary = random_bytes(16).unpack("NnnnnN")
ary[2] = (ary[2] & 0x0fff) | 0x4000
ary[3] = (ary[3] & 0x3fff) | 0x8000
"%08x-%04x-%04x-%04x-%04x%08x" % ary
end
private
def gen_random(n)
self.bytes(n)
end
end
SecureRandom.extend(Random::Formatter)
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