Trait RNG 

pub trait RNG {
    // Required methods
    fn add_seed_keymaterial(
        &mut self,
        additional_seed: &dyn KeyMaterialTrait,
    ) -> Result<(), RNGError>;
    fn next_int(&mut self) -> Result<u32, RNGError>;
    fn next_bytes(&mut self, len: usize) -> Result<Vec<u8>, RNGError>;
    fn next_bytes_out(&mut self, out: &mut [u8]) -> Result<usize, RNGError>;
    fn fill_keymaterial_out(
        &mut self,
        out: &mut dyn KeyMaterialTrait,
    ) -> Result<usize, RNGError>;
    fn security_strength(&self) -> SecurityStrength;
}

An interface for random number generation. This interface is meant to be simpler and more ergonomic than the interfaces provided by the rng crate, but that one should be used by applications that intend to submit to FIPS certification as it more closely aligns with the requirements of SP 800-90A. Note: this interface produces bytes. If you want a KeyMaterialTrait, then use KeyMaterial::from_rng.

Implementors are expected to also implement Default (default-construction should produce a securely OS-seeded instance), but this is intentionally not a supertrait bound: requiring Default would make RNG not dyn-compatible, and &mut dyn RNG is needed so RNG instances can be handed around as trait objects.

Required Methods

fn add_seed_keymaterial( &mut self, additional_seed: &dyn KeyMaterialTrait, ) -> Result<(), RNGError>

Provide additional key material to be mixed in to the existing RNG instance. The exact behaviour will be implementation-specific, but this is intended for injecting additional entropy, not as the primary method of seeding the RNG.

fn next_int(&mut self) -> Result<u32, RNGError>

Returns the next random 32-bit integer.

fn next_bytes(&mut self, len: usize) -> Result<Vec<u8>, RNGError>

Returns the number of requested bytes.

fn next_bytes_out(&mut self, out: &mut [u8]) -> Result<usize, RNGError>

Returns the number of bytes written. The entire output buffer is zeroized before the random bytes are written.

fn fill_keymaterial_out( &mut self, out: &mut dyn KeyMaterialTrait, ) -> Result<usize, RNGError>

Fill the provided KeyMaterial with random bytes.

fn security_strength(&self) -> SecurityStrength

Returns the Security Strength of this RNG.

Implementors