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>

1 files changed, 0 insertions, 134 deletions

diff --git a/pkg/terminal/util.go b/pkg/terminal/util.go
deleted file mode 100644
index 0f0968c30..000000000
--- a/pkg/terminal/util.go
+++ /dev/null
@@ -1,134 +0,0 @@
-package terminal
-
-import (
-	"bufio"
-	"errors"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"sync"
-
-	"github.com/containers/storage/pkg/homedir"
-	"github.com/sirupsen/logrus"
-	"golang.org/x/crypto/ssh"
-	"golang.org/x/crypto/ssh/knownhosts"
-	"golang.org/x/term"
-)
-
-var (
-	passPhrase   []byte
-	phraseSync   sync.Once
-	password     []byte
-	passwordSync sync.Once
-)
-
-// ReadPassword prompts for a secret and returns value input by user from stdin
-// Unlike terminal.ReadPassword(), $(echo $SECRET | podman...) is supported.
-// Additionally, all input after `<secret>/n` is queued to podman command.
-func ReadPassword(prompt string) (pw []byte, err error) {
-	fd := int(os.Stdin.Fd())
-	if term.IsTerminal(fd) {
-		fmt.Fprint(os.Stderr, prompt)
-		pw, err = term.ReadPassword(fd)
-		fmt.Fprintln(os.Stderr)
-		return
-	}
-
-	var b [1]byte
-	for {
-		n, err := os.Stdin.Read(b[:])
-		// terminal.ReadPassword discards any '\r', so we do the same
-		if n > 0 && b[0] != '\r' {
-			if b[0] == '\n' {
-				return pw, nil
-			}
-			pw = append(pw, b[0])
-			// limit size, so that a wrong input won't fill up the memory
-			if len(pw) > 1024 {
-				err = errors.New("password too long, 1024 byte limit")
-			}
-		}
-		if err != nil {
-			// terminal.ReadPassword accepts EOF-terminated passwords
-			// if non-empty, so we do the same
-			if err == io.EOF && len(pw) > 0 {
-				err = nil
-			}
-			return pw, err
-		}
-	}
-}
-
-func PublicKey(path string, passphrase []byte) (ssh.Signer, error) {
-	key, err := ioutil.ReadFile(path)
-	if err != nil {
-		return nil, err
-	}
-
-	signer, err := ssh.ParsePrivateKey(key)
-	if err != nil {
-		if _, ok := err.(*ssh.PassphraseMissingError); !ok {
-			return nil, err
-		}
-		if len(passphrase) == 0 {
-			passphrase = ReadPassphrase()
-		}
-		return ssh.ParsePrivateKeyWithPassphrase(key, passphrase)
-	}
-	return signer, nil
-}
-
-func ReadPassphrase() []byte {
-	phraseSync.Do(func() {
-		secret, err := ReadPassword("Key Passphrase: ")
-		if err != nil {
-			secret = []byte{}
-		}
-		passPhrase = secret
-	})
-	return passPhrase
-}
-
-func ReadLogin() []byte {
-	passwordSync.Do(func() {
-		secret, err := ReadPassword("Login password: ")
-		if err != nil {
-			secret = []byte{}
-		}
-		password = secret
-	})
-	return password
-}
-
-func HostKey(host string) ssh.PublicKey {
-	// parse OpenSSH known_hosts file
-	// ssh or use ssh-keyscan to get initial key
-	knownHosts := filepath.Join(homedir.Get(), ".ssh", "known_hosts")
-	fd, err := os.Open(knownHosts)
-	if err != nil {
-		logrus.Error(err)
-		return nil
-	}
-
-	// support -H parameter for ssh-keyscan
-	hashhost := knownhosts.HashHostname(host)
-
-	scanner := bufio.NewScanner(fd)
-	for scanner.Scan() {
-		_, hosts, key, _, _, err := ssh.ParseKnownHosts(scanner.Bytes())
-		if err != nil {
-			logrus.Errorf("Failed to parse known_hosts: %s", scanner.Text())
-			continue
-		}
-
-		for _, h := range hosts {
-			if h == host || h == hashhost {
-				return key
-			}
-		}
-	}
-
-	return nil
-}