# -*- coding: us-ascii -*-
# frozen_string_literal: true
# == 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:
# It supports the following secure random number generators:
# SecureRandom is extended by the Random::Formatter module which
# defines the following methods:
# These methods are usable as class methods of SecureRandom such as
# Generate random hexadecimal strings:
# SecureRandom.hex(10) #=> "52750b30ffbc7de3b362"
# SecureRandom.hex(10) #=> "92b15d6c8dc4beb5f559"
# SecureRandom.hex(13) #=> "39b290146bea6ce975c37cfc23"
# Generate random base64 strings:
# SecureRandom.base64(10) #=> "EcmTPZwWRAozdA=="
# SecureRandom.base64(10) #=> "KO1nIU+p9DKxGg=="
# SecureRandom.base64(12) #=> "7kJSM/MzBJI+75j8"
# Generate random binary strings:
# SecureRandom.random_bytes(10) #=> "\016\t{\370g\310pbr\301"
# SecureRandom.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337"
# Generate alphanumeric strings:
# SecureRandom.alphanumeric(10) #=> "S8baxMJnPl"
# SecureRandom.alphanumeric(10) #=> "aOxAg8BAJe"
# SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
# SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
@rng_chooser = Mutex.new # :nodoc:
raise NotImplementedError, "No random device"
@rng_chooser.synchronize do
remove_method :gen_random
alias gen_random gen_random_openssl
@rng_chooser.synchronize do
remove_method :gen_random
alias gen_random gen_random_urandom
def gen_random_openssl(n)
@pid = 0 unless defined?(@pid)
now = Process.clock_gettime(Process::CLOCK_REALTIME, :nanosecond)
OpenSSL::Random.random_add([now, @pid, pid].join(""), 0.0)
seed = Random.urandom(16)
OpenSSL::Random.random_add(seed, 16)
return OpenSSL::Random.random_bytes(n)
def gen_random_urandom(n)
raise NotImplementedError, "No random device"
raise NotImplementedError, "Unexpected partial read from random device: only #{ret.length} for #{n} bytes"
# 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".
# SecureRandom.random_bytes #=> "\xD8\\\xE0\xF4\r\xB2\xFC*WM\xFF\x83\x18\xF45\xB6"
# 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.
# 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.
# SecureRandom.hex #=> "eb693ec8252cd630102fd0d0fb7c3485"
# SecureRandom.hex #=> "91dc3bfb4de5b11d029d376634589b61"
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
random_bytes(n).unpack("H*")[0]
# 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 "=".
# SecureRandom.base64 #=> "/2BuBuLf3+WfSKyQbRcc/A=="
# SecureRandom.base64 #=> "6BbW0pxO0YENxn38HMUbcQ=="
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
# See RFC 3548 for the definition of base64.
[random_bytes(n)].pack("m0")
# 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.
# SecureRandom.urlsafe_base64 #=> "b4GOKm4pOYU_-BOXcrUGDg"
# SecureRandom.urlsafe_base64 #=> "UZLdOkzop70Ddx-IJR0ABg"
# SecureRandom.urlsafe_base64(nil, true) #=> "i0XQ-7gglIsHGV2_BNPrdQ=="
# 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("m0")
s.delete!("=") unless padding
# SecureRandom.uuid generates a random v4 UUID (Universally Unique IDentifier).
# SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
# SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
# 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.
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
private def gen_random(n)
# SecureRandom.choose generates a string that randomly draws from a
# source array of characters.
# The argument _source_ specifies the array of characters from which
# to generate the string.
# The argument _n_ specifies the length, in characters, of the string to be
# The result may contain whatever characters are in the source array.
# SecureRandom.choose([*'l'..'r'], 16) #=> "lmrqpoonmmlqlron"
# SecureRandom.choose([*'0'..'9'], 5) #=> "27309"
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
private def choose(source, n)
while limit * size <= 0x100000000
rs = random_number(limit)
(m-is.length).times { is << 0 }
result << source.values_at(*is).join('')
rs = random_number(limit)
(n-is.length).times { is << 0 }
is.pop while n < is.length
result.concat source.values_at(*is).join('')
ALPHANUMERIC = [*'A'..'Z', *'a'..'z', *'0'..'9']
# SecureRandom.alphanumeric generates a random alphanumeric string.
# The argument _n_ specifies the length, in characters, of the alphanumeric
# string to be generated.
# 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 and 0-9.
# SecureRandom.alphanumeric #=> "2BuBuLf3WfSKyQbR"
# SecureRandom.alphanumeric(10) #=> "i6K93NdqiH"
# If a secure random number generator is not available,
# +NotImplementedError+ is raised.
SecureRandom.extend(Random::Formatter)
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
