libgocryptfs/internal/prefer_openssl/prefer.go
Jakob Unterwurzacher 49b597f07c prefer_openssl: autodetect whether to use OpenSSL or Go GCM
Go GCM is faster than OpenSSL if the CPU has AES instructions
and you are running Go 1.6+.

The "-openssl" option now defaults to "auto".

"gocryptfs -debug -version" displays the result of the autodetection.

See https://github.com/rfjakob/gocryptfs/issues/23 for details and
benchmarks.
2016-05-12 00:42:42 +02:00

30 lines
710 B
Go

package prefer_openssl
import (
"fmt"
"io/ioutil"
"regexp"
)
// filePreferOpenSSL tells us if OpenSSL is faster than Go GCM on this machine.
// Go GCM is fastern 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 {
fmt.Println(err)
return true
}
haveAes, err := regexp.Match(`(?m)^flags.*\baes\b`, ci)
if err != nil {
fmt.Println(err)
return true
}
return !haveAes
}