# File tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 290
def alphanumeric(n=nil)
n = 16 if n.nil?
choose(ALPHANUMERIC, n)
end
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 tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 169
def base64(n=nil)
[random_bytes(n)].pack("m0")
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 tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 245
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
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 tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 226
def gen_random(n)
self.bytes(n)
end
# File tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 148
def hex(n=nil)
random_bytes(n).unpack("H*")[0]
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 tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 128
def random_bytes(n=nil)
n = n ? n.to_int : 16
gen_random(n)
end
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.
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;
}
# File tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 199
def urlsafe_base64(n=nil, padding=false)
s = [random_bytes(n)].pack("m0")
s.tr!("+/", "-_")
s.delete!("=") unless padding
s
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.
# File tmp/rubies/ruby-2.5.9/lib/securerandom.rb, line 219
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
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.