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| -rw-r--r-- | lib/secrand.rb | 128 |
1 files changed, 0 insertions, 128 deletions
diff --git a/lib/secrand.rb b/lib/secrand.rb deleted file mode 100644 index 5995500c7b..0000000000 --- a/lib/secrand.rb +++ /dev/null @@ -1,128 +0,0 @@ -# = Secure random number generator interface. -# -# This library is a interface for secure random number generator which is -# suitable for HTTP cookies, nonces, etc. -# -# It supports following secure random number generators. -# -# * openssl -# * /dev/urandom -# -# == Example -# -# # random hexadecimal string. -# p SecRand.hex(10) #=> "52750b30ffbc7de3b362" -# p SecRand.hex(10) #=> "92b15d6c8dc4beb5f559" -# p SecRand.hex(11) #=> "6aca1b5c58e4863e6b81b8" -# p SecRand.hex(12) #=> "94b2fff3e7fd9b9c391a2306" -# p SecRand.hex(13) #=> "39b290146bea6ce975c37cfc23" -# ... -# -# # random base64 string. -# p SecRand.base64(10) #=> "EcmTPZwWRAozdA==" -# p SecRand.base64(10) #=> "9b0nsevdwNuM/w==" -# p SecRand.base64(10) #=> "KO1nIU+p9DKxGg==" -# p SecRand.base64(11) #=> "l7XEiFja+8EKEtY=" -# p SecRand.base64(12) #=> "7kJSM/MzBJI+75j8" -# p SecRand.base64(13) #=> "vKLJ0tXBHqQOuIcSIg==" -# ... -# -# # random binary string. -# p SecRand.random_bytes(10) #=> "\016\t{\370g\310pbr\301" -# p SecRand.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337" -# ... - -begin - require 'openssl' -rescue LoadError -end - -module SecRand - # SecRand.random_bytes generates a random binary string. - # - # The argument n specifies the length of the result string. - # - # If secure random number generator is not available, - # NotImplementedError is raised. - def self.random_bytes(n=nil) - n ||= 16 - if defined? OpenSSL::Random - return OpenSSL::Random.random_bytes(n) - end - if !defined?(@has_urandom) || @has_urandom - @has_urandom = false - flags = File::RDONLY - flags |= File::NONBLOCK if defined? File::NONBLOCK - flags |= File::NOCTTY if defined? File::NOCTTY - flags |= File::NOFOLLOW if defined? File::NOFOLLOW - begin - File.open("/dev/urandom", flags) {|f| - unless f.stat.chardev? - raise Errno::ENOENT - end - @has_urandom = true - ret = f.readpartial(n) - if ret.length != n - raise NotImplementedError, "Unexpected partial read from random device" - end - return ret - } - rescue Errno::ENOENT - raise NotImplementedError, "No random device" - end - end - raise NotImplementedError, "No random device" - end - - # SecRand.hex generates a random hex string. - # - # The argument n specifies the length of the random length. - # The length of the result string is twice of n. - # - # If secure random number generator is not available, - # NotImplementedError is raised. - def self.hex(n=nil) - random_bytes(n).unpack("H*")[0] - end - - # SecRand.base64 generates a random base64 string. - # - # The argument n specifies the length of the random length. - # The length of the result string is about 4/3 of n. - # - # If secure random number generator is not available, - # NotImplementedError is raised. - def self.base64(n=nil) - [random_bytes(n)].pack("m*").delete("\n") - end - - # SecRand.random_number generates a random number. - # - # If an positive integer is given as n, - # SecRand.random_number returns an integer: - # 0 <= SecRand.random_number(n) < n. - # - # If 0 is given or an argument is not given, - # SecRand.random_number returns an float: - # 0.0 <= SecRand.random_number() < 1.0. - def self.random_number(n=0) - if 0 < n - 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 = SecRand.random_bytes(bin.length) - rnd[0] = (rnd[0].ord & mask).chr - end until rnd < bin - rnd.unpack("H*")[0].hex - else - # assumption: Float::MANT_DIG <= 64 - i64 = SecRand.random_bytes(8).unpack("Q")[0] - Math.ldexp(i64 >> (64-Float::MANT_DIG), -Float::MANT_DIG) - end - end -end |