/
ssh.go
153 lines (133 loc) · 3.7 KB
/
ssh.go
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/*
* Copyright (c) 2021 NetEase Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Project: CurveAdm
* Created Date: 2021-10-15
* Author: Jingli Chen (Wine93)
*/
// __SIGN_BY_WINE93__
package module
import (
"errors"
"net"
"time"
"github.com/melbahja/goph"
log "github.com/opencurve/curveadm/pkg/log/glg"
"golang.org/x/crypto/ssh"
)
type (
SSHConfig struct {
User string
Host string
Port uint
ForwardAgent bool // ForwardAgent > PrivateKeyPath > Password
BecomeMethod string
BecomeFlags string
BecomeUser string
PrivateKeyPath string
ConnectRetries int
ConnectTimeoutSec int
}
SSHClient struct {
client *goph.Client
config SSHConfig
}
)
func askIsHostTrusted(host string, key ssh.PublicKey) bool {
// format := "Unknown Host: %s \\nFingerprint: %s \\nWould you likt to add it?[y/N]: "
// prompt := fmt.Sprintf(format, host, ssh.FingerprintSHA256(key))
// return tui.ConfirmYes(prompt)
return true
}
func VerifyHost(host string, remote net.Addr, key ssh.PublicKey) error {
hostFound, err := goph.CheckKnownHost(host, remote, key, "")
/*
* Host in known hosts but key mismatch!
* Maybe because of MAN IN THE MIDDLE ATTACK!
*/
if hostFound && err != nil {
return err
} else if hostFound && err == nil { // handshake because public key already exists.
return nil
} else if askIsHostTrusted(host, key) == false { // Ask user to check if he trust the host public key.
// Make sure to return error on non trusted keys.
return errors.New("you typed no, aborted!")
}
// Add the new host to known hosts file.
return goph.AddKnownHost(host, remote, key, "")
}
func (client *SSHClient) Client() *goph.Client {
return client.client
}
func (client *SSHClient) Config() SSHConfig {
return client.config
}
func NewSSHClient(config SSHConfig) (*SSHClient, error) {
user := config.User
host := config.Host
port := config.Port
forwardAgent := config.ForwardAgent
privateKeyPath := config.PrivateKeyPath
connTimeoutSec := config.ConnectTimeoutSec
maxRetries := config.ConnectRetries
var auth goph.Auth
var err error
if forwardAgent {
auth, err = goph.UseAgent()
} else {
auth, err = goph.Key(privateKeyPath, "")
}
if err != nil {
log.Error("Create SSH auth",
log.Field("user", user),
log.Field("host", host),
log.Field("port", port),
log.Field("forwardAgent", forwardAgent),
log.Field("privateKeyPath", privateKeyPath),
log.Field("error", err))
return nil, err
}
tries := 0
connect:
tries++
client, err := goph.NewConn(&goph.Config{
User: user,
Addr: host,
Port: port,
Auth: auth,
Timeout: time.Duration(connTimeoutSec) * time.Second,
Callback: VerifyHost,
})
log.SwitchLevel(err)("Connect remote SSH",
log.Field("user", user),
log.Field("host", host),
log.Field("port", port),
log.Field("forwardAgent", forwardAgent),
log.Field("privateKeyPath", privateKeyPath),
log.Field("timeoutSec", connTimeoutSec),
log.Field("maxRetries", maxRetries),
log.Field("tries", tries),
log.Field("error", err))
if err != nil {
if tries < maxRetries {
goto connect
}
}
return &SSHClient{
client: client,
config: config,
}, err
}