96 lines
2.4 KiB
Go
96 lines
2.4 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"flag"
|
||
|
|
"io/ioutil"
|
||
|
|
"log"
|
||
|
|
"os"
|
||
|
|
"os/user"
|
||
|
|
"path/filepath"
|
||
|
|
|
||
|
|
"github.com/hashicorp/packer/helper/communicator/sshkey"
|
||
|
|
)
|
||
|
|
|
||
|
|
type options struct {
|
||
|
|
Type string
|
||
|
|
Bits int
|
||
|
|
Filename string
|
||
|
|
}
|
||
|
|
|
||
|
|
func (o *options) AddFlagSets(fs *flag.FlagSet) {
|
||
|
|
fs.StringVar(&o.Type, "type", "rsa", `dsa | ecdsa | ed25519 | rsa
|
||
|
|
Specifies the type of key to create. The possible values are 'dsa', 'ecdsa',
|
||
|
|
'ed25519', or 'rsa'.
|
||
|
|
`)
|
||
|
|
fs.IntVar(&o.Bits, "bits", 0, `Specifies the number of bits in the key to create. By default maximum
|
||
|
|
number will be picked. For RSA keys, the minimum size is 1024 bits and the
|
||
|
|
default is 3072 bits. Generally, 3072 bits is considered sufficient. DSA
|
||
|
|
keys must be exactly 1024 bits as specified by FIPS 186-2. For ECDSA keys,
|
||
|
|
the bits flag determines the key length by selecting from one of three
|
||
|
|
elliptic curve sizes: 256, 384 or 521 bits. Attempting to use bit lengths
|
||
|
|
other than these three values for ECDSA keys will fail. Ed25519 keys have a
|
||
|
|
fixed length and the bits flag will be ignored.
|
||
|
|
`)
|
||
|
|
|
||
|
|
defaultPath := ""
|
||
|
|
user, err := user.Current()
|
||
|
|
if err == nil {
|
||
|
|
defaultPath = filepath.Join(user.HomeDir, ".ssh", "tests")
|
||
|
|
}
|
||
|
|
|
||
|
|
fs.StringVar(&o.Filename, "filename", defaultPath, `Specifies the filename of the key file.
|
||
|
|
`)
|
||
|
|
}
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
log.SetFlags(0)
|
||
|
|
log.SetPrefix("ssh-keygen: ")
|
||
|
|
fs := flag.NewFlagSet("ssh-keygen", flag.ContinueOnError)
|
||
|
|
cla := options{}
|
||
|
|
cla.AddFlagSets(fs)
|
||
|
|
if err := fs.Parse(os.Args[1:]); err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
|
||
|
|
algo, err := sshkey.AlgorithmString(cla.Type)
|
||
|
|
if err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
|
||
|
|
log.Printf("Generating public/private %s key pair.", algo)
|
||
|
|
|
||
|
|
keypair, err := sshkey.GeneratePair(algo, nil, cla.Bits)
|
||
|
|
if err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
|
||
|
|
if isDir(cla.Filename) {
|
||
|
|
cla.Filename = filepath.Join(cla.Filename, "id_"+algo.String())
|
||
|
|
}
|
||
|
|
if fileExists(cla.Filename) {
|
||
|
|
log.Fatalf("%s already exists.", cla.Filename)
|
||
|
|
}
|
||
|
|
log.Printf("Saving private key to %s", cla.Filename)
|
||
|
|
if err := ioutil.WriteFile(cla.Filename, keypair.Private, 0600); err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
publicFilename := cla.Filename + ".pub"
|
||
|
|
log.Printf("Saving public key to %s", publicFilename)
|
||
|
|
if err := ioutil.WriteFile(publicFilename, keypair.Public, 0644); err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func isDir(filename string) bool {
|
||
|
|
info, err := os.Stat(filename)
|
||
|
|
if err != nil {
|
||
|
|
log.Fatal(err)
|
||
|
|
}
|
||
|
|
return info.IsDir()
|
||
|
|
}
|
||
|
|
|
||
|
|
func fileExists(filename string) bool {
|
||
|
|
_, err := os.Stat(filename)
|
||
|
|
return err == nil
|
||
|
|
}
|