TCryptoRandom · BlitzMax

Generate unpredictable data, suitable for creating secret keys.

If this is used in an application inside a VM, and the VM is snapshotted and restored, then the above functions will produce the same output.

Functions

`Function Random:UInt()`

Returns an unpredictable value between 0 and $ffffffff (inclusive).

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

For Local i:Int = 0 Until 10
    Print TCryptoRandom.Random()
Next

`Function Uniform:UInt(upperBound:UInt)`

Returns an unpredictable value between 0 and upperBound (excluded).

Unlike Random() Mod upperBound, it does its best to guarantee a uniform distribution of the possible output values even when upperBound is not a power of 2.

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

For Local i:Int = 0 Until 10
    Print TCryptoRandom.Uniform(1000)
Next

`Function FillBuffer(buf:Byte Ptr, size:Size_T)`

Fills size bytes starting at buf with an unpredictable sequence of bytes, derived from a secret seed.

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

Local buf:Byte[32]

TCryptoRandom.FillBuffer(buf)

For Local i:Int = 0 Until buf.length
    Print buf[i]
Next

`Function FillBuffer(buf:Byte[])`

Fills an array of bytes with an unpredictable sequence of bytes, derived from a secret seed.

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

Local buf:Byte[32]

TCryptoRandom.FillBuffer(buf)

For Local i:Int = 0 Until buf.length
    Print buf[i]
Next

`Function FillKey(key:TCryptoKey Var, bytes:Size_T = 32)`

Fills a key with an unpredictable sequence of bytes in length, derived from a secret seed.

`Function Ratchet()`

Erases part of the state and replaces the secret key, making it impossible to recover the previous states in case the current one ever gets exposed due to a vulnerability.

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

For Local i:Int = 0 Until 10
    Print TCryptoRandom.Random()
Next

TCryptoRandom.Ratchet()

`Function Reseed()`

Reseeds the random number generator.

Must be called after a fork() call.

Example

SuperStrict

Framework brl.standardio
Import brl.crypto

For Local i:Int = 0 Until 10
    Print TCryptoRandom.Random()
Next

TCryptoRandom.Reseed()