Initial working version

vendor/github.com/cloudfoundry/socks5-proxy/host_key.go

@@ -0,0 +1,49 @@
+package proxy
+
+import (
+	"net"
+
+	"golang.org/x/crypto/ssh"
+)
+
+type HostKey struct{}
+
+func NewHostKey() HostKey {
+	return HostKey{}
+}
+
+func (h HostKey) Get(username, privateKey, serverURL string) (ssh.PublicKey, error) {
+	publicKeyChannel := make(chan ssh.PublicKey, 1)
+	dialErrorChannel := make(chan error)
+
+	if username == "" {
+		username = "jumpbox"
+	}
+
+	signer, err := ssh.ParsePrivateKey([]byte(privateKey))
+	if err != nil {
+		return nil, err
+	}
+
+	clientConfig := NewSSHClientConfig(username, keyScanCallback(publicKeyChannel), ssh.PublicKeys(signer))
+
+	go func() {
+		conn, err := ssh.Dial("tcp", serverURL, clientConfig)
+		if err != nil {
+			publicKeyChannel <- nil
+			dialErrorChannel <- err
+			return
+		}
+		defer conn.Close()
+		dialErrorChannel <- nil
+	}()
+
+	return <-publicKeyChannel, <-dialErrorChannel
+}
+
+func keyScanCallback(publicKeyChannel chan ssh.PublicKey) ssh.HostKeyCallback {
+	return func(_ string, _ net.Addr, key ssh.PublicKey) error {
+		publicKeyChannel <- key
+		return nil
+	}
+}