podman ssh work, using new c/common interface

implement new ssh interface into podman

this completely redesigns the entire functionality of podman image scp,
podman system connection add, and podman --remote. All references to golang.org/x/crypto/ssh
have been moved to common as have native ssh/scp execs and the new usage of the sftp package.

this PR adds a global flag, --ssh to podman which has two valid inputs `golang` and `native` where golang is the default.
Users should not notice any difference in their everyday workflows if they continue using the golang option. UNLESS they have been using an improperly verified ssh key, this will now fail. This is because podman was incorrectly using the
ssh callback method to IGNORE the ssh known hosts file which is very insecure and golang tells you not yo use this in production.

The native paths allows for immense flexibility, with a new containers.conf field `SSH_CONFIG` that specifies a specific ssh config file to be used in all operations. Else the users ~/.ssh/config file will be used.
podman --remote currently only uses the golang path, given its deep interconnection with dialing multiple clients and urls.

My goal after this PR is to go back and abstract the idea of podman --remote from golang's dialed clients, as it should not be so intrinsically connected. Overall, this is a v1 of a long process of offering native ssh, and one that covers some good ground with podman system connection add and podman image scp.

Signed-off-by: Charlie Doern <cdoern@redhat.com>

5 files changed, 46 insertions, 68 deletions

diff --git a/cmd/podman/common/completion.go b/cmd/podman/common/completion.go
index 02369c74a..71c62a7af 100644
--- a/cmd/podman/common/completion.go
+++ b/cmd/podman/common/completion.go
@@ -13,6 +13,7 @@ import (
 	libimageDefine "github.com/containers/common/libimage/define"
 	"github.com/containers/common/libnetwork/types"
 	"github.com/containers/common/pkg/config"
+	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/image/v5/pkg/sysregistriesv2"
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/containers/podman/v4/libpod/define"
@@ -1628,3 +1629,11 @@ func AutocompleteClone(cmd *cobra.Command, args []string, toComplete string) ([]
 	}
 	return nil, cobra.ShellCompDirectiveNoFileComp
 }
+
+// AutocompleteSSH - Autocomplete ssh modes
+func AutocompleteSSH(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	if !validCurrentCmdLine(cmd, args, toComplete) {
+		return nil, cobra.ShellCompDirectiveNoFileComp
+	}
+	return []string{string(ssh.GolangMode), string(ssh.NativeMode)}, cobra.ShellCompDirectiveNoFileComp
+}
diff --git a/cmd/podman/common/sign.go b/cmd/podman/common/sign.go
index e8a90ed57..dc0d3ff5d 100644
--- a/cmd/podman/common/sign.go
+++ b/cmd/podman/common/sign.go
@@ -3,9 +3,9 @@ package common
 import (
 	"fmt"
 
+	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/image/v5/pkg/cli"
 	"github.com/containers/podman/v4/pkg/domain/entities"
-	"github.com/containers/podman/v4/pkg/terminal"
 )
 
 // PrepareSigningPassphrase updates pushOpts.SignPassphrase and SignSigstorePrivateKeyPassphrase based on a --sign-passphrase-file value signPassphraseFile,
@@ -27,7 +27,7 @@ func PrepareSigningPassphrase(pushOpts *entities.ImagePushOptions, signPassphras
 		}
 		passphrase = p
 	} else if pushOpts.SignBySigstorePrivateKeyFile != "" {
-		p := terminal.ReadPassphrase()
+		p := ssh.ReadPassphrase()
 		passphrase = string(p)
 	} // pushOpts.SignBy triggers a GPG-agent passphrase prompt, possibly using a more secure channel, so we usually shouldn’t prompt ourselves if no passphrase was explicitly provided.
 	pushOpts.SignPassphrase = passphrase
diff --git a/cmd/podman/images/scp.go b/cmd/podman/images/scp.go
index a7aa43e61..18899d251 100644
--- a/cmd/podman/images/scp.go
+++ b/cmd/podman/images/scp.go
@@ -4,6 +4,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/podman/v4/cmd/podman/common"
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/spf13/cobra"
@@ -48,6 +49,11 @@ func scp(cmd *cobra.Command, args []string) (finalErr error) {
 	var (
 		err error
 	)
+
+	containerConfig := registry.PodmanConfig()
+
+	sshType := containerConfig.SSHMode
+
 	for i, val := range os.Args {
 		if val == "image" {
 			break
@@ -67,7 +73,8 @@ func scp(cmd *cobra.Command, args []string) (finalErr error) {
 		dst = args[1]
 	}
 
-	err = registry.ImageEngine().Scp(registry.Context(), src, dst, parentFlags, quiet)
+	sshEngine := ssh.DefineMode(sshType)
+	err = registry.ImageEngine().Scp(registry.Context(), src, dst, parentFlags, quiet, sshEngine)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/podman/root.go b/cmd/podman/root.go
index 48f8470be..3637b2674 100644
--- a/cmd/podman/root.go
+++ b/cmd/podman/root.go
@@ -12,6 +12,7 @@ import (
 
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/common/pkg/config"
+	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/podman/v4/cmd/podman/common"
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/containers/podman/v4/cmd/podman/validate"
@@ -338,6 +339,10 @@ func rootFlags(cmd *cobra.Command, opts *entities.PodmanConfig) {
 
 	lFlags := cmd.Flags()
 
+	sshFlagName := "ssh"
+	lFlags.StringVar(&opts.SSHMode, sshFlagName, string(ssh.GolangMode), "define the ssh mode")
+	_ = cmd.RegisterFlagCompletionFunc(sshFlagName, common.AutocompleteSSH)
+
 	connectionFlagName := "connection"
 	lFlags.StringVarP(&opts.Engine.ActiveService, connectionFlagName, "c", srv, "Connection to use for remote Podman service")
 	_ = cmd.RegisterFlagCompletionFunc(connectionFlagName, common.AutocompleteSystemConnections)
diff --git a/cmd/podman/system/connection/add.go b/cmd/podman/system/connection/add.go
index 191603718..f3b61b254 100644
--- a/cmd/podman/system/connection/add.go
+++ b/cmd/podman/system/connection/add.go
@@ -1,23 +1,19 @@
 package connection
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
-	"net"
 	"net/url"
 	"os"
 	"regexp"
 
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/common/pkg/config"
+	"github.com/containers/common/pkg/ssh"
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/containers/podman/v4/cmd/podman/system"
-	"github.com/containers/podman/v4/libpod/define"
-	"github.com/containers/podman/v4/pkg/domain/utils"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
-	"golang.org/x/crypto/ssh"
 )
 
 var (
@@ -74,6 +70,15 @@ func init() {
 
 func add(cmd *cobra.Command, args []string) error {
 	// Default to ssh schema if none given
+
+	entities := &ssh.ConnectionCreateOptions{
+		Port:     cOpts.Port,
+		Path:     args[1],
+		Identity: cOpts.Identity,
+		Name:     args[0],
+		Socket:   cOpts.UDSPath,
+		Default:  cOpts.Default,
+	}
 	dest := args[1]
 	if match, err := regexp.Match("^[A-Za-z][A-Za-z0-9+.-]*://", []byte(dest)); err != nil {
 		return fmt.Errorf("invalid destination: %w", err)
@@ -89,30 +94,20 @@ func add(cmd *cobra.Command, args []string) error {
 		uri.Path = cmd.Flag("socket-path").Value.String()
 	}
 
-	switch uri.Scheme {
-	case "ssh":
-		if uri.User.Username() == "" {
-			if uri.User, err = utils.GetUserInfo(uri); err != nil {
-				return err
-			}
-		}
+	var sshMode ssh.EngineMode
+	containerConfig := registry.PodmanConfig()
 
-		if cmd.Flags().Changed("port") {
-			uri.Host = net.JoinHostPort(uri.Hostname(), cmd.Flag("port").Value.String())
-		}
+	flag := containerConfig.SSHMode
 
-		if uri.Port() == "" {
-			uri.Host = net.JoinHostPort(uri.Hostname(), cmd.Flag("port").DefValue)
-		}
-		iden := ""
-		if cmd.Flags().Changed("identity") {
-			iden = cOpts.Identity
-		}
-		if uri.Path == "" || uri.Path == "/" {
-			if uri.Path, err = getUDS(uri, iden); err != nil {
-				return err
-			}
-		}
+	sshMode = ssh.DefineMode(flag)
+
+	if sshMode == ssh.InvalidMode {
+		return fmt.Errorf("invalid ssh mode")
+	}
+
+	switch uri.Scheme {
+	case "ssh":
+		return ssh.Create(entities, sshMode)
 	case "unix":
 		if cmd.Flags().Changed("identity") {
 			return errors.New("--identity option not supported for unix scheme")
@@ -176,41 +171,3 @@ func add(cmd *cobra.Command, args []string) error {
 	}
 	return cfg.Write()
 }
-
-func getUDS(uri *url.URL, iden string) (string, error) {
-	cfg, err := utils.ValidateAndConfigure(uri, iden)
-	if err != nil {
-		return "", fmt.Errorf("failed to validate: %w", err)
-	}
-	dial, err := ssh.Dial("tcp", uri.Host, cfg)
-	if err != nil {
-		return "", fmt.Errorf("failed to connect: %w", err)
-	}
-	defer dial.Close()
-
-	session, err := dial.NewSession()
-	if err != nil {
-		return "", fmt.Errorf("failed to create new ssh session on %q: %w", uri.Host, err)
-	}
-	defer session.Close()
-
-	// Override podman binary for testing etc
-	podman := "podman"
-	if v, found := os.LookupEnv("PODMAN_BINARY"); found {
-		podman = v
-	}
-	infoJSON, err := utils.ExecRemoteCommand(dial, podman+" info --format=json")
-	if err != nil {
-		return "", err
-	}
-
-	var info define.Info
-	if err := json.Unmarshal(infoJSON, &info); err != nil {
-		return "", fmt.Errorf("failed to parse 'podman info' results: %w", err)
-	}
-
-	if info.Host.RemoteSocket == nil || len(info.Host.RemoteSocket.Path) == 0 {
-		return "", fmt.Errorf("remote podman %q failed to report its UDS socket", uri.Host)
-	}
-	return info.Host.RemoteSocket.Path, nil
-}