libgocryptfs/internal/prefer_openssl/prefer.go
2016-12-10 21:04:17 +01:00

32 lines
847 B
Go

// Package prefer_openssl tries to determine if we should prefer openssl
// on the platform we are running on.
package prefer_openssl
import (
"io/ioutil"
"regexp"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// filePreferOpenSSL tells us if OpenSSL is faster than Go GCM on this machine.
// Go GCM is faster when the CPU has AES instructions and Go is v1.6 or higher.
//
// See https://github.com/rfjakob/gocryptfs/issues/23#issuecomment-218286502
// for benchmarks.
//
// filePreferOpenSSL takes an explicit filename so it can be tested with saved
// cpuinfo files instead of /proc/cpuinfo.
func filePreferOpenSSL(file string) bool {
ci, err := ioutil.ReadFile(file)
if err != nil {
return true
}
haveAes, err := regexp.Match(`(?m)^flags.*\baes\b`, ci)
if err != nil {
tlog.Warn.Println(err)
return true
}
return !haveAes
}