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Right now, features are always enabled across all targets. This means that if _any_ Custom RNG is used _anywhere_ in a crate's dependancy graph on _any_ target. The "custom" feature will be active on all targets. This makes it impossible to have a bare metal target that uses "cpu" on x86_64 and a Custom RNG on aarch64. This solution also makes sure that any implementation `getrandom` itself provides cannot be overridden. Signed-off-by: Joe Richey <joerichey@google.com>
getrandom
A Rust library for retrieving random data from (operating) system source. It is
assumed that system always provides high-quality cryptographically secure random
data, ideally backed by hardware entropy sources. This crate derives its name
from Linux's getrandom function, but is cross platform, roughly supporting
the same set of platforms as Rust's std lib.
This is a low-level API. Most users should prefer using high-level random-number
library like rand.
Usage
Add this to your Cargo.toml:
[dependencies]
getrandom = "0.2"
Then invoke the getrandom function:
fn get_random_buf() -> Result<[u8; 32], getrandom::Error> {
let mut buf = [0u8; 32];
getrandom::getrandom(&mut buf)?;
Ok(buf)
}
Features
This library is no_std for every supported target. However, getting randomness
usually requires calling some external system API. This means most platforms
will require linking against system libraries (i.e. libc for Unix,
Advapi32.dll for Windows, Security framework on iOS, etc...).
For the wasm32-unknown-unknown target, one of the following features should be
enabled:
By default, compiling getrandom for an unsupported target will result in
a compilation error. If you want to build an application which uses getrandom
for such target, you can either:
- Use
[replace]or[patch]section in yourCargo.tomlto switch to a custom implementation with a support of your target.
Minimum Supported Rust Version
This crate requires Rust 1.33.0 or later.
License
The getrandom library is distributed under either of
at your option.