pub struct RdRand(_);
Expand description
A cryptographically secure statistically uniform, non-periodic and non-deterministic random bit generator.
Note that this generator may be implemented using a deterministic algorithm that is reseeded routinely from a non-deterministic entropy source to achieve the desirable properties.
This generator is a viable replacement to any generator, however, since nobody has audited this hardware implementation yet, the usual disclaimers as to their suitability apply.
It is potentially faster than OsRng
, but is only supported by more recent architectures such
as Intel Ivy Bridge and AMD Zen.
Implementations
sourceimpl RdRand
impl RdRand
sourcepub fn new() -> Result<Self, ErrorCode>
pub fn new() -> Result<Self, ErrorCode>
Create a new instance of the random number generator.
This constructor checks whether the CPU the program is running on supports the instruction necessary for this generator to operate. If the instruction is not supported, an error is returned.
sourcepub fn try_next_u16(&self) -> Result<u16, ErrorCode>
pub fn try_next_u16(&self) -> Result<u16, ErrorCode>
Generate a single random u16
value.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
This method will retry calling the instruction a few times, however if all the
attempts fail, it will return None
.
In case Err
is returned, the caller should assume that a non-recoverable failure
has occured and use another random number genrator instead.
sourcepub fn try_next_u32(&self) -> Result<u32, ErrorCode>
pub fn try_next_u32(&self) -> Result<u32, ErrorCode>
Generate a single random u32
value.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
This method will retry calling the instruction a few times, however if all the
attempts fail, it will return None
.
In case Err
is returned, the caller should assume that a non-recoverable failure
has occured and use another random number genrator instead.
sourcepub fn try_next_u64(&self) -> Result<u64, ErrorCode>
pub fn try_next_u64(&self) -> Result<u64, ErrorCode>
Generate a single random u64
value.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
This method will retry calling the instruction a few times, however if all the
attempts fail, it will return None
.
In case Err
is returned, the caller should assume that a non-recoverable failure
has occured and use another random number genrator instead.
Note, that on 32-bit targets, there’s no underlying instruction to generate a 64-bit number, so it is emulated with the 32-bit version of the instruction.
sourcepub fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), ErrorCode>
pub fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), ErrorCode>
Fill a buffer dest
with random data.
This method will use the most appropriate variant of the instruction available on
the machine to achieve the greatest single-core throughput, however it has a
slightly higher setup cost than the plain next_u32
or next_u64
methods.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
This method will retry calling the instruction a few times, however if all the attempts fail, it will return an error.
If an error is returned, the caller should assume that an non-recoverable hardware failure has occured and use another random number genrator instead.
Trait Implementations
sourceimpl RngCore for RdRand
impl RngCore for RdRand
sourcefn next_u32(&mut self) -> u32
fn next_u32(&mut self) -> u32
Generate a single random u32
value.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
Panic
This method will retry calling the instruction a few times, however if all the
attempts fail, it will panic
.
In case panic
occurs, the caller should assume that an non-recoverable
hardware failure has occured and use another random number genrator instead.
sourcefn next_u64(&mut self) -> u64
fn next_u64(&mut self) -> u64
Generate a single random u64
value.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
Note, that on 32-bit targets, there’s no underlying instruction to generate a 64-bit number, so it is emulated with the 32-bit version of the instruction.
Panic
This method will retry calling the instruction a few times, however if all the
attempts fail, it will panic
.
In case panic
occurs, the caller should assume that an non-recoverable
hardware failure has occured and use another random number genrator instead.
sourcefn fill_bytes(&mut self, dest: &mut [u8])
fn fill_bytes(&mut self, dest: &mut [u8])
Fill a buffer dest
with random data.
See try_fill_bytes
for a more extensive documentation.
Panic
This method will panic any time try_fill_bytes
would return an error.
sourcefn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>
fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>
Fill a buffer dest
with random data.
This method will use the most appropriate variant of the instruction available on
the machine to achieve the greatest single-core throughput, however it has a
slightly higher setup cost than the plain next_u32
or next_u64
methods.
The underlying instruction may fail for variety reasons (such as actual hardware failure or exhausted entropy), however the exact reason for the failure is not usually exposed.
This method will retry calling the instruction a few times, however if all the attempts fail, it will return an error.
If an error is returned, the caller should assume that an non-recoverable hardware failure has occured and use another random number genrator instead.
impl Copy for RdRand
impl CryptoRng for RdRand
Auto Trait Implementations
impl RefUnwindSafe for RdRand
impl Send for RdRand
impl Sync for RdRand
impl Unpin for RdRand
impl UnwindSafe for RdRand
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
sourceimpl<T> CryptoRngCore for Twhere
T: CryptoRng + RngCore,
impl<T> CryptoRngCore for Twhere
T: CryptoRng + RngCore,
sourcefn as_rngcore(&mut self) -> &mut dyn RngCore
fn as_rngcore(&mut self) -> &mut dyn RngCore
RngCore
trait object.