module SecureRandom

Overview

The SecureRandom module is an interface for creating secure random values in different formats. It uses the RNG (random number generator) of libcrypto (OpenSSL).

For example:

SecureRandom.base64 # => "LIa9s/zWzJx49m/9zDX+VQ=="
SecureRandom.hex    # => "c8353864ff9764a39ef74983ec0d4a38"
SecureRandom.uuid   # => "c7ee4add-207f-411a-97b7-0d22788566d6"

Defined in:

secure_random.cr

Class Method Summary

Class Method Detail

def self.base64(n = 16 : Int) : String #

Generates n random bytes that are encoded into Base64.

Check Base64#strict_encode for details.

SecureRandom.base64(4) # => "fK1eYg=="

[View source]
def self.hex(n = 16 : Int) : String #

Generates a hexadecimal string based on n random bytes.

The bytes are encoded into a string of a two-digit hexadecimal number (00-ff) per byte.

SecureRandom.hex    # => "05f100a1123f6bdbb427698ab664ff5f"
SecureRandom.hex(1) # => "1a"

[View source]
def self.random_bytes(n = 16 : Int) : Slice(UInt8) #

Generates a slice filled with n random bytes.

SecureRandom.random_bytes    # => [145, 255, 191, 133, 132, 139, 53, 136, 93, 238, 2, 37, 138, 244, 3, 216]
SecureRandom.random_bytes(4) # => [217, 118, 38, 196]

[View source]
def self.urlsafe_base64(n = 16 : Int, padding = false) : String #

URL-safe variant of #base64

Check Base64#urlsafe_encode for details.

SecureRandom.urlsafe_base64           # => "MAD2bw8QaBdvITCveBNCrw"
SecureRandom.urlsafe_base64(8, true)  # => "vvP1kcs841I="
SecureRandom.urlsafe_base64(16, true) # => "og2aJrELDZWSdJfVGkxNKw=="

[View source]
def self.uuid : String #

Generates a UUID (Universally Unique Identifier)

It generates a random v4 UUID. Check RFC 4122 Section 4.4 for the used algorithm and its implications.

SecureRandom.uuid # => "a4e319dd-a778-4a51-804e-66a07bc63358"

[View source]