mirror of
https://github.com/tinygo-org/tinygo.git
synced 2026-08-07 04:23:41 +00:00
Ayke van Laethem
d05103668f
This doesn't have the potential blocking issue of the getentropy call (which calls WASI random_get when using wasi-libc) and should therefore be a lot faster. For context, this is what the random_get documentation says: > Write high-quality random data into a buffer. This function blocks > when the implementation is unable to immediately provide sufficient > high-quality random data. This function may execute slowly, so when > large mounts of random data are required, it's advisable to use this > function to seed a pseudo-random number generator, rather than to > provide the random data directly.
31 lines
734 B
Go
31 lines
734 B
Go
// +build darwin freebsd tinygo.wasm
|
|
|
|
// This implementation of crypto/rand uses the arc4random_buf function
|
|
// (available on both MacOS and WASI) to generate random numbers.
|
|
//
|
|
// Note: arc4random_buf (unlike what the name suggets) does not use the insecure
|
|
// RC4 cipher. Instead, it uses a high-quality cipher, varying by the libc
|
|
// implementation.
|
|
|
|
package rand
|
|
|
|
import "unsafe"
|
|
|
|
func init() {
|
|
Reader = &reader{}
|
|
}
|
|
|
|
type reader struct {
|
|
}
|
|
|
|
func (r *reader) Read(b []byte) (n int, err error) {
|
|
if len(b) != 0 {
|
|
libc_arc4random_buf(unsafe.Pointer(&b[0]), uint(len(b)))
|
|
}
|
|
return len(b), nil
|
|
}
|
|
|
|
// void arc4random_buf(void *buf, size_t buflen);
|
|
//export arc4random_buf
|
|
func libc_arc4random_buf(buf unsafe.Pointer, buflen uint)
|