diff options
Diffstat (limited to 'ruby_1_9_3/lib/securerandom.rb')
| -rw-r--r-- | ruby_1_9_3/lib/securerandom.rb | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/ruby_1_9_3/lib/securerandom.rb b/ruby_1_9_3/lib/securerandom.rb new file mode 100644 index 0000000000..d4ab947f54 --- /dev/null +++ b/ruby_1_9_3/lib/securerandom.rb @@ -0,0 +1,265 @@ +# = Secure random number generator interface. +# +# This library is an interface for secure random number generator which is +# suitable for generating session key in HTTP cookies, etc. +# +# It supports following secure random number generators. +# +# * openssl +# * /dev/urandom +# * Win32 +# +# == Example +# +# # random hexadecimal string. +# p SecureRandom.hex(10) #=> "52750b30ffbc7de3b362" +# p SecureRandom.hex(10) #=> "92b15d6c8dc4beb5f559" +# p SecureRandom.hex(11) #=> "6aca1b5c58e4863e6b81b8" +# p SecureRandom.hex(12) #=> "94b2fff3e7fd9b9c391a2306" +# p SecureRandom.hex(13) #=> "39b290146bea6ce975c37cfc23" +# ... +# +# # random base64 string. +# p SecureRandom.base64(10) #=> "EcmTPZwWRAozdA==" +# p SecureRandom.base64(10) #=> "9b0nsevdwNuM/w==" +# p SecureRandom.base64(10) #=> "KO1nIU+p9DKxGg==" +# p SecureRandom.base64(11) #=> "l7XEiFja+8EKEtY=" +# p SecureRandom.base64(12) #=> "7kJSM/MzBJI+75j8" +# p SecureRandom.base64(13) #=> "vKLJ0tXBHqQOuIcSIg==" +# ... +# +# # random binary string. +# p SecureRandom.random_bytes(10) #=> "\016\t{\370g\310pbr\301" +# p SecureRandom.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337" +# ... + +begin + require 'openssl' +rescue LoadError +end + +module SecureRandom + # SecureRandom.random_bytes generates a random binary string. + # + # The argument _n_ specifies the length of the result string. + # + # If _n_ is not specified, 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 secure random number generator is not available, + # NotImplementedError is raised. + def self.random_bytes(n=nil) + n = n ? n.to_int : 16 + + if defined? OpenSSL::Random + @pid = 0 if !defined?(@pid) + pid = $$ + if @pid != pid + now = Time.now + ary = [now.to_i, now.nsec, @pid, pid] + OpenSSL::Random.seed(ary.to_s) + @pid = pid + end + return OpenSSL::Random.random_bytes(n) + end + + if !defined?(@has_urandom) || @has_urandom + flags = File::RDONLY + flags |= File::NONBLOCK if defined? File::NONBLOCK + flags |= File::NOCTTY if defined? File::NOCTTY + 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: only #{ret.length} for #{n} bytes" + end + return ret + } + rescue Errno::ENOENT + @has_urandom = false + end + end + + if !defined?(@has_win32) + begin + require 'Win32API' + + crypt_acquire_context = Win32API.new("advapi32", "CryptAcquireContext", 'PPPII', 'L') + @crypt_gen_random = Win32API.new("advapi32", "CryptGenRandom", 'LIP', 'L') + + hProvStr = " " * 4 + prov_rsa_full = 1 + crypt_verifycontext = 0xF0000000 + + if crypt_acquire_context.call(hProvStr, nil, nil, prov_rsa_full, crypt_verifycontext) == 0 + raise SystemCallError, "CryptAcquireContext failed: #{lastWin32ErrorMessage}" + end + @hProv, = hProvStr.unpack('L') + + @has_win32 = true + rescue LoadError + @has_win32 = false + end + end + if @has_win32 + bytes = " ".force_encoding("ASCII-8BIT") * n + if @crypt_gen_random.call(@hProv, bytes.size, bytes) == 0 + raise SystemCallError, "CryptGenRandom failed: #{lastWin32ErrorMessage}" + end + return bytes + end + + raise NotImplementedError, "No random device" + end + + # SecureRandom.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 _n_ is not specified, 16 is assumed. + # It may be larger in future. + # + # The result may contain 0-9 and a-f. + # + # p SecureRandom.hex #=> "eb693ec8252cd630102fd0d0fb7c3485" + # p SecureRandom.hex #=> "91dc3bfb4de5b11d029d376634589b61" + # + # If secure random number generator is not available, + # NotImplementedError is raised. + def self.hex(n=nil) + random_bytes(n).unpack("H*")[0] + end + + # SecureRandom.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 _n_ is not specified, 16 is assumed. + # It may be larger in future. + # + # The result may contain A-Z, a-z, 0-9, "+", "/" and "=". + # + # p SecureRandom.base64 #=> "/2BuBuLf3+WfSKyQbRcc/A==" + # p SecureRandom.base64 #=> "6BbW0pxO0YENxn38HMUbcQ==" + # + # If secure random number generator is not available, + # NotImplementedError is raised. + # + # See RFC 3548 for the definition of base64. + def self.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 of the random length. + # The length of the result string is about 4/3 of _n_. + # + # If _n_ is not specified, 16 is assumed. + # It may be larger in 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 secure random number generator is not available, + # NotImplementedError is raised. + # + # See RFC 3548 for the definition of URL-safe base64. + def self.urlsafe_base64(n=nil, padding=false) + s = [random_bytes(n)].pack("m*") + s.delete!("\n") + s.tr!("+/", "-_") + s.delete!("=") if !padding + s + end + + # SecureRandom.random_number generates a random number. + # + # If a positive integer is given as _n_, + # SecureRandom.random_number returns an integer: + # 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: + # 0.0 <= SecureRandom.random_number() < 1.0. + # + # p SecureRandom.random_number #=> 0.596506046187744 + # p SecureRandom.random_number #=> 0.350621695741409 + # + 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 = SecureRandom.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 = SecureRandom.random_bytes(8).unpack("Q")[0] + Math.ldexp(i64 >> (64-Float::MANT_DIG), -Float::MANT_DIG) + end + end + + # SecureRandom.uuid generates a v4 random 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 address, time, etc. + # + # See RFC 4122 for details of UUID. + # + def self.uuid + ary = self.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 + + # Following code is based on David Garamond's GUID library for Ruby. + def self.lastWin32ErrorMessage # :nodoc: + get_last_error = Win32API.new("kernel32", "GetLastError", '', 'L') + format_message = Win32API.new("kernel32", "FormatMessageA", 'LPLLPLPPPPPPPP', 'L') + format_message_ignore_inserts = 0x00000200 + format_message_from_system = 0x00001000 + + code = get_last_error.call + msg = "\0" * 1024 + len = format_message.call(format_message_ignore_inserts + format_message_from_system, 0, code, 0, msg, 1024, nil, nil, nil, nil, nil, nil, nil, nil) + msg[0, len].tr("\r", '').chomp + end +end |