Utilize ssh-keygen for checking of keys.

Removes the limitation to RSA and enables us to use all key types
SSH recognizes.
This commit is contained in:
W-Mark Kubacki 2014-07-20 18:02:59 +02:00
parent aed4271c8d
commit 887ad1ec8b

View File

@ -5,6 +5,11 @@
package user
import (
"errors"
"fmt"
"io/ioutil"
"os"
"strconv"
"strings"
"github.com/gogits/gogs/models"
@ -12,6 +17,7 @@ import (
"github.com/gogits/gogs/modules/base"
"github.com/gogits/gogs/modules/log"
"github.com/gogits/gogs/modules/middleware"
"github.com/gogits/gogs/modules/process"
)
const (
@ -23,6 +29,17 @@ const (
SECURITY base.TplName = "user/security"
)
var (
MinimumKeySize = map[string]int{
"(ED25519)": 256,
"(ECDSA)": 256,
"(NTRU)": 1087,
"(MCE)": 1702,
"(McE)": 1702,
"(RSA)": 2048,
}
)
func Setting(ctx *middleware.Context) {
ctx.Data["Title"] = "Setting"
ctx.Data["PageIsUserSetting"] = true
@ -142,6 +159,50 @@ func SettingPasswordPost(ctx *middleware.Context, form auth.UpdatePasswdForm) {
ctx.Redirect("/user/settings/password")
}
// Checks if the given public key string is recognized by SSH.
func CheckPublicKeyString(keyContent string) (ok bool, err error) {
if strings.ContainsAny(keyContent, "\n\r") {
return false, errors.New("Only a single line with a single key please")
}
// write the key to a file…
tmpFile, err := ioutil.TempFile(os.TempDir(), "keytest")
if err != nil {
return false, err
}
tmpPath := tmpFile.Name()
defer os.Remove(tmpPath)
tmpFile.WriteString(keyContent)
tmpFile.Close()
// … see if ssh-keygen recognizes its contents
stdout, stderr, err := process.Exec("CheckPublicKeyString", "ssh-keygen", "-l", "-f", tmpPath)
if err != nil {
return false, errors.New("ssh-keygen -l -f: " + stderr)
} else if len(stdout) < 2 {
return false, errors.New("ssh-keygen returned not enough output to evaluate the key")
}
sshKeygenOutput := strings.Split(stdout, " ")
if len(sshKeygenOutput) < 4 {
return false, errors.New("Not enough fields returned by ssh-keygen -l -f")
}
keySize, err := strconv.Atoi(sshKeygenOutput[0])
if err != nil {
return false, errors.New("Cannot get key size of the given key")
}
keyType := strings.TrimSpace(sshKeygenOutput[len(sshKeygenOutput)-1])
if minimumKeySize := MinimumKeySize[keyType]; minimumKeySize == 0 {
return false, errors.New("Sorry, unrecognized public key type")
} else {
if keySize < minimumKeySize {
return false, fmt.Errorf("The minimum accepted size of a public key %s is %d", keyType, minimumKeySize)
}
}
return true, nil
}
func SettingSSHKeys(ctx *middleware.Context, form auth.AddSSHKeyForm) {
ctx.Data["Title"] = "SSH Keys"
ctx.Data["PageIsUserSetting"] = true
@ -189,8 +250,8 @@ func SettingSSHKeys(ctx *middleware.Context, form auth.AddSSHKeyForm) {
return
}
if len(form.KeyContent) < 100 || !strings.HasPrefix(form.KeyContent, "ssh-rsa") {
ctx.Flash.Error("SSH key content is not valid.")
if ok, err := CheckPublicKeyString(form.KeyContent); !ok {
ctx.Flash.Error(err.Error())
ctx.Redirect("/user/settings/ssh")
return
}