Struct rand::EntropyRng
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pub struct EntropyRng { /* fields omitted */ }
A generator provided specifically for securely seeding algorithmic generators (PRNGs).
Where possible, EntropyRng
retrieves random data from the operating
system's interface for random numbers (OsRng
); if that fails it will
fall back to the JitterRng
entropy collector. In the latter case it will
still try to use OsRng
on the next usage.
If no secure source of entropy is available EntropyRng
will panic on use;
i.e. it should never output predictable data.
This is either a little slow (OsRng
requires a system call) or extremely
slow (JitterRng
must use significant CPU time to generate sufficient
jitter). It is recommended to only use EntropyRng
to seed a PRNG (as in
thread_rng
) or to generate a small key.
Methods
impl EntropyRng
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pub fn new() -> Self
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Create a new EntropyRng
.
This method will do no system calls or other initialization routines,
those are done on first use. This is done to make new
infallible,
and try_fill_bytes
the only place to report errors.
Trait Implementations
impl Debug for EntropyRng
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fn fmt(&self, __arg_0: &mut Formatter) -> Result
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Formats the value using the given formatter. Read more
impl RngCore for EntropyRng
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fn next_u32(&mut self) -> u32
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Return the next random u32
. Read more
fn next_u64(&mut self) -> u64
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Return the next random u64
. Read more
fn fill_bytes(&mut self, dest: &mut [u8])
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Fill dest
with random data. Read more
fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>
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Fill dest
entirely with random data. Read more