module Random::Formatter
Constants
- ALPHANUMERIC
Public Instance Methods
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.
p SecureRandom.alphanumeric #=> "2BuBuLf3WfSKyQbR" p SecureRandom.alphanumeric(10) #=> "i6K93NdqiH"
If a secure random number generator is not available,
NotImplementedError
is raised.
# File lib/securerandom.rb, line 289 def alphanumeric(n=nil) n = 16 if n.nil? choose(ALPHANUMERIC, n) 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.
# File lib/securerandom.rb, line 168 def base64(n=nil) [random_bytes(n)].pack("m0") 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.
# File lib/securerandom.rb, line 147 def hex(n=nil) random_bytes(n).unpack("H*")[0] end
static VALUE rand_random_number(int argc, VALUE *argv, VALUE obj) { rb_random_t *rnd = try_get_rnd(obj); VALUE v = rand_random(argc, argv, obj, rnd); if (NIL_P(v)) v = rand_random(0, 0, obj, rnd); else if (!v) invalid_argument(argv[0]); return v; }
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.
# File lib/securerandom.rb, line 127 def random_bytes(n=nil) n = n ? n.to_int : 16 gen_random(n) end
static VALUE rand_random_number(int argc, VALUE *argv, VALUE obj) { rb_random_t *rnd = try_get_rnd(obj); VALUE v = rand_random(argc, argv, obj, rnd); if (NIL_P(v)) v = rand_random(0, 0, obj, rnd); else if (!v) invalid_argument(argv[0]); return v; }
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.
# File lib/securerandom.rb, line 198 def urlsafe_base64(n=nil, padding=false) s = [random_bytes(n)].pack("m0") s.tr!("+/", "-_") s.delete!("=") unless padding s 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.
# File lib/securerandom.rb, line 218 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 Instance Methods
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 generated.
The result may contain whatever characters are in the source array.
p SecureRandom.choose([*'l'..'r'], 16) #=> "lmrqpoonmmlqlron" p SecureRandom.choose([*'0'..'9'], 5) #=> "27309"
If a secure random number generator is not available,
NotImplementedError
is raised.
# File lib/securerandom.rb, line 244 def choose(source, n) size = source.size m = 1 limit = size while limit * size <= 0x100000000 limit *= size m += 1 end result = ''.dup while m <= n rs = random_number(limit) is = rs.digits(size) (m-is.length).times { is << 0 } result << source.values_at(*is).join('') n -= m end if 0 < n rs = random_number(limit) is = rs.digits(size) if is.length < n (n-is.length).times { is << 0 } else is.pop while n < is.length end result.concat source.values_at(*is).join('') end result end
# File lib/securerandom.rb, line 225 def gen_random(n) self.bytes(n) end