libgocryptfs/internal/stupidgcm/prefer.go

36 lines
1.0 KiB
Go

package stupidgcm
import (
"runtime"
"golang.org/x/sys/cpu"
)
// PreferOpenSSL tells us if OpenSSL is faster than Go GCM on this machine.
//
// Go GCM is only faster if the CPU either:
//
// 1) Is X86_64 && has AES instructions && Go is v1.6 or higher
// 2) Is ARM64 && has AES instructions && Go is v1.11 or higher
// (commit https://github.com/golang/go/commit/4f1f503373cda7160392be94e3849b0c9b9ebbda)
//
// See https://github.com/rfjakob/gocryptfs/wiki/CPU-Benchmarks
// for benchmarks.
func PreferOpenSSL() bool {
if BuiltWithoutOpenssl {
return false
}
// Safe to call on other architectures - will just read false.
if cpu.X86.HasAES || cpu.ARM64.HasAES {
// Go stdlib is probably faster
return false
}
// On the Apple M1, Go stdlib is faster than OpenSSL, despite cpu.ARM64.HasAES
// reading false: https://github.com/rfjakob/gocryptfs/issues/556#issuecomment-848079309
if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
return false
}
// OpenSSL is probably faster
return true
}