1 files changed, 44 insertions, 5 deletions

diff --git a/plumbing/transport/ssh/common.go b/plumbing/transport/ssh/common.go
index 46e7913..1531603 100644
--- a/plumbing/transport/ssh/common.go
+++ b/plumbing/transport/ssh/common.go
@@ -4,12 +4,14 @@ package ssh
 import (
 	"context"
 	"fmt"
+	"net"
 	"reflect"
 	"strconv"
 	"strings"
 
 	"github.com/go-git/go-git/v5/plumbing/transport"
 	"github.com/go-git/go-git/v5/plumbing/transport/internal/common"
+	"github.com/skeema/knownhosts"
 
 	"github.com/kevinburke/ssh_config"
 	"golang.org/x/crypto/ssh"
@@ -121,10 +123,24 @@ func (c *command) connect() error {
 	if err != nil {
 		return err
 	}
+	hostWithPort := c.getHostWithPort()
+	if config.HostKeyCallback == nil {
+		kh, err := newKnownHosts()
+		if err != nil {
+			return err
+		}
+		config.HostKeyCallback = kh.HostKeyCallback()
+		config.HostKeyAlgorithms = kh.HostKeyAlgorithms(hostWithPort)
+	} else if len(config.HostKeyAlgorithms) == 0 {
+		// Set the HostKeyAlgorithms based on HostKeyCallback.
+		// For background see https://github.com/go-git/go-git/issues/411 as well as
+		// https://github.com/golang/go/issues/29286 for root cause.
+		config.HostKeyAlgorithms = knownhosts.HostKeyAlgorithms(config.HostKeyCallback, hostWithPort)
+	}
 
 	overrideConfig(c.config, config)
 
-	c.client, err = dial("tcp", c.getHostWithPort(), config)
+	c.client, err = dial("tcp", hostWithPort, c.endpoint.Proxy, config)
 	if err != nil {
 		return err
 	}
@@ -139,7 +155,7 @@ func (c *command) connect() error {
 	return nil
 }
 
-func dial(network, addr string, config *ssh.ClientConfig) (*ssh.Client, error) {
+func dial(network, addr string, proxyOpts transport.ProxyOptions, config *ssh.ClientConfig) (*ssh.Client, error) {
 	var (
 		ctx    = context.Background()
 		cancel context.CancelFunc
@@ -151,10 +167,33 @@ func dial(network, addr string, config *ssh.ClientConfig) (*ssh.Client, error) {
 	}
 	defer cancel()
 
-	conn, err := proxy.Dial(ctx, network, addr)
+	var conn net.Conn
+	var err error
+
+	if proxyOpts.URL != "" {
+		proxyUrl, err := proxyOpts.FullURL()
+		if err != nil {
+			return nil, err
+		}
+		dialer, err := proxy.FromURL(proxyUrl, proxy.Direct)
+		if err != nil {
+			return nil, err
+		}
+
+		// Try to use a ContextDialer, but fall back to a Dialer if that goes south.
+		ctxDialer, ok := dialer.(proxy.ContextDialer)
+		if !ok {
+			return nil, fmt.Errorf("expected ssh proxy dialer to be of type %s; got %s",
+				reflect.TypeOf(ctxDialer), reflect.TypeOf(dialer))
+		}
+		conn, err = ctxDialer.DialContext(ctx, "tcp", addr)
+	} else {
+		conn, err = proxy.Dial(ctx, network, addr)
+	}
 	if err != nil {
 		return nil, err
 	}
+
 	c, chans, reqs, err := ssh.NewClientConn(conn, addr, config)
 	if err != nil {
 		return nil, err
@@ -173,7 +212,7 @@ func (c *command) getHostWithPort() string {
 		port = DefaultPort
 	}
 
-	return fmt.Sprintf("%s:%d", host, port)
+	return net.JoinHostPort(host, strconv.Itoa(port))
 }
 
 func (c *command) doGetHostWithPortFromSSHConfig() (addr string, found bool) {
@@ -201,7 +240,7 @@ func (c *command) doGetHostWithPortFromSSHConfig() (addr string, found bool) {
 		}
 	}
 
-	addr = fmt.Sprintf("%s:%d", host, port)
+	addr = net.JoinHostPort(host, strconv.Itoa(port))
 	return
 }