mirror of https://github.com/docker/cli.git
52 lines
1.2 KiB
Go
52 lines
1.2 KiB
Go
package sshutil
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import (
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"fmt"
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"net"
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"strconv"
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"strings"
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"golang.org/x/crypto/ssh"
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)
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const defaultPort = 22
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var errCallbackDone = fmt.Errorf("callback failed on purpose")
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// addDefaultPort appends a default port if hostport doesn't contain one
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func addDefaultPort(hostport string, defaultPort int) string {
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_, _, err := net.SplitHostPort(hostport)
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if err == nil {
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return hostport
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}
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hostport = net.JoinHostPort(hostport, strconv.Itoa(defaultPort))
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return hostport
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}
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// SshKeyScan scans a ssh server for the hostkey; server should be in the form hostname, or hostname:port
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func SSHKeyScan(server string) (string, error) {
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var key string
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KeyScanCallback := func(hostport string, remote net.Addr, pubKey ssh.PublicKey) error {
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hostname, _, err := net.SplitHostPort(hostport)
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if err != nil {
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return err
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}
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key = strings.TrimSpace(fmt.Sprintf("%s %s", hostname, string(ssh.MarshalAuthorizedKey(pubKey))))
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return errCallbackDone
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}
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config := &ssh.ClientConfig{
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HostKeyCallback: KeyScanCallback,
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}
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server = addDefaultPort(server, defaultPort)
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conn, err := ssh.Dial("tcp", server, config)
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if key != "" {
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// as long as we get the key, the function worked
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err = nil
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}
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if conn != nil {
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conn.Close()
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}
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return key, err
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}
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