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    Import std.crypto.random

    std.crypto.random

    Random bytes and numbers from the OS, for secrets, and comparing secrets in constant time.

    SecureRandom, bytes and numbers from the OS's randomness, through mbedTLS's generator, for keys, salts, nonces, and tokens; and ConstantTimeEquals, which compares secrets without telling where they differ.

    std/crypto/random.fb

    Types

    SecureRandom struct 

    Public Struct SecureRandom

    Random bytes and numbers from the OS's randomness, for keys, tokens, and other secrets.

    Examples

    Local token = SecureRandom.Bytes(16)
Expect(token.Count == 16)
Local roll = SecureRandom.Below(6)
Expect(roll >= 0 && roll < 6)

    std/crypto/random.fb, line 24

    • @PanicsAtCaller Public Static Method Bytes(count: Int): UInt8[] static method #

      count random bytes. Panics when count is negative.

    • @PanicsAtCaller Public Static Method Below(limit: Int64): Int64 static method #

      A random number from 0 up to limit, without limit, each as likely as another. Panics unless limit is above 0.

    Functions

    ConstantTimeEquals function 

    Public Function ConstantTimeEquals(a: UInt8[], b: UInt8[]): Bool

    Whether a and b have the same bytes, in a time that depends only on their counts, not on where they first differ, so comparing a secret, like a MAC, tells nothing about it.

    Examples

    Local secret = SecureRandom.Bytes(32)
Expect(ConstantTimeEquals(secret, secret.Clone()))
Expect(!ConstantTimeEquals(secret, SecureRandom.Bytes(32)))

    std/crypto/random.fb, line 68

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