machineid provides support for reading the unique machine id of most host OS's (without admin privileges)
… because sometimes you just need to reliably identify your machines.
- Cross-Platform (tested on Win7 , Debian 8 , Ubuntu 14.04 , OS X 10.6 , FreeBSD 11 )
- No admin privileges required
- Hardware independent (no usage of MAC, BIOS or CPU — those are too unreliable, especially in a VM environment)
- IDs are unique1 to the installed OS
Get the library with
go get github.com/denisbrodbeck/machineid
You can also add the cli app directly to your $GOPATH/bin
with
go get github.com/denisbrodbeck/machineid/cmd/machineid
package main
import (
"fmt"
"log"
"github.com/denisbrodbeck/machineid"
)
func main() {
id, err := machineid.ID()
if err != nil {
log.Fatal(err)
}
fmt.Println(id)
}
Or even better, use securely hashed machine IDs:
package main
import (
"fmt"
"log"
"github.com/denisbrodbeck/machineid"
)
func main() {
id, err := machineid.ProtectedID("myAppName")
if err != nil {
log.Fatal(err)
}
fmt.Println(id)
}
Returns original machine id as a string
.
Returns hashed version of the machine ID as a string
. The hash is generated in a cryptographically secure way, using a fixed, application-specific key (calculates HMAC-SHA256 of the app ID, keyed by the machine ID).
This package returns the OS native machine UUID/GUID, which the OS uses for internal needs.
All machine IDs are usually generated during system installation and stay constant for all subsequent boots.
The following sources are used:
- BSD uses
/etc/hostid
andsmbios.system.uuid
as a fallback - Linux uses
/var/lib/dbus/machine-id
(man) - OS X uses
IOPlatformUUID
- Windows uses the
MachineGuid
fromHKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography
Do note, that machine-id
and MachineGuid
can be changed by root/admin, although that may not come without cost (broken system services and more).
Most IDs won't be regenerated by the OS, when you clone/image/restore a particular OS installation. This is a well known issue with cloned windows installs (not using the official sysprep tools).
Linux users can generate a new id with dbus-uuidgen
and put the id into /var/lib/dbus/machine-id
and /etc/machine-id
.
Windows users can use the sysprep
toolchain to create images, which produce valid images ready for distribution. Such images produce a new unique machine ID on each deployment.
A machine ID uniquely identifies the host. Therefore it should be considered "confidential", and must not be exposed in untrusted environments. If you need a stable unique identifier for your app, do not use the machine ID directly.
A reliable solution is to hash the machine ID in a cryptographically secure way, using a fixed, application-specific key.
That way the ID will be properly unique, and derived in a constant way from the machine ID but there will be no way to retrieve the original machine ID from the application-specific one.
Do something along these lines:
package main
import (
"crypto/hmac"
"crypto/sha256"
"fmt"
"github.com/denisbrodbeck/machineid"
)
const appKey = "WowSuchNiceApp"
func main() {
id, _ := machineid.ID()
fmt.Println(protect(appKey, id))
// Output: dbabdb7baa54845f9bec96e2e8a87be2d01794c66fdebac3df7edd857f3d9f97
}
func protect(appID, id string) string {
mac := hmac.New(sha256.New, []byte(id))
mac.Write([]byte(appID))
return fmt.Sprintf("%x", mac.Sum(nil))
}
Or simply use the convenience API call:
hashedID, err := machineid.ProtectedID("myAppName")
Don't want to download code, and just need a way to get the data by yourself?
BSD:
cat /etc/hostid
# or (might be empty)
kenv -q smbios.system.uuid
Linux:
cat /var/lib/dbus/machine-id
# or when not found (e.g. Fedora 20)
cat /etc/machine-id
OS X:
ioreg -rd1 -c IOPlatformExpertDevice | grep IOPlatformUUID
Windows:
reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography /v MachineGuid
or
- Open Windows Registry via
regedit
- Navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography
- Take value of key
MachineGuid
The Go gopher was created by Denis Brodbeck with gopherize.me, based on original artwork from Renee French.
The MIT License (MIT) — Denis Brodbeck. Please have a look at the LICENSE.md for more details.