github.com/containers/podman/v4@v4.9.4/pkg/machine/keys.go (about)

     1  //go:build amd64 || arm64
     2  // +build amd64 arm64
     3  
     4  package machine
     5  
     6  import (
     7  	"errors"
     8  	"fmt"
     9  	"io"
    10  	"os"
    11  	"os/exec"
    12  	"path/filepath"
    13  	"strings"
    14  
    15  	"github.com/sirupsen/logrus"
    16  )
    17  
    18  var sshCommand = []string{"ssh-keygen", "-N", "", "-t", "ed25519", "-f"}
    19  
    20  // CreateSSHKeys makes a priv and pub ssh key for interacting
    21  // the a VM.
    22  func CreateSSHKeys(writeLocation string) (string, error) {
    23  	// If the SSH key already exists, hard fail
    24  	if _, err := os.Stat(writeLocation); err == nil {
    25  		return "", fmt.Errorf("SSH key already exists: %s", writeLocation)
    26  	}
    27  	if err := os.MkdirAll(filepath.Dir(writeLocation), 0700); err != nil {
    28  		return "", err
    29  	}
    30  	if err := generatekeys(writeLocation); err != nil {
    31  		return "", err
    32  	}
    33  	b, err := os.ReadFile(writeLocation + ".pub")
    34  	if err != nil {
    35  		return "", err
    36  	}
    37  	return strings.TrimSuffix(string(b), "\n"), nil
    38  }
    39  
    40  func CreateSSHKeysPrefix(identityPath string, passThru bool, skipExisting bool, prefix ...string) (string, error) {
    41  	_, e := os.Stat(identityPath)
    42  	if !skipExisting || errors.Is(e, os.ErrNotExist) {
    43  		if err := generatekeysPrefix(identityPath, passThru, prefix...); err != nil {
    44  			return "", err
    45  		}
    46  	} else {
    47  		fmt.Println("Keys already exist, reusing")
    48  	}
    49  	b, err := os.ReadFile(identityPath + ".pub")
    50  	if err != nil {
    51  		return "", err
    52  	}
    53  	return strings.TrimSuffix(string(b), "\n"), nil
    54  }
    55  
    56  // generatekeys creates an ed25519 set of keys
    57  func generatekeys(writeLocation string) error {
    58  	args := append(append([]string{}, sshCommand[1:]...), writeLocation)
    59  	cmd := exec.Command(sshCommand[0], args...)
    60  	stdErr, err := cmd.StderrPipe()
    61  	if err != nil {
    62  		return err
    63  	}
    64  	if err := cmd.Start(); err != nil {
    65  		return err
    66  	}
    67  	waitErr := cmd.Wait()
    68  	if waitErr == nil {
    69  		return nil
    70  	}
    71  	errMsg, err := io.ReadAll(stdErr)
    72  	if err != nil {
    73  		return fmt.Errorf("key generation failed, unable to read from stderr: %w", waitErr)
    74  	}
    75  	return fmt.Errorf("failed to generate keys: %s: %w", string(errMsg), waitErr)
    76  }
    77  
    78  // generatekeys creates an ed25519 set of keys
    79  func generatekeysPrefix(identityPath string, passThru bool, prefix ...string) error {
    80  	dir := filepath.Dir(identityPath)
    81  	file := filepath.Base(identityPath)
    82  
    83  	if err := os.MkdirAll(dir, 0700); err != nil {
    84  		return fmt.Errorf("could not create ssh directory: %w", err)
    85  	}
    86  
    87  	args := append([]string{}, prefix[1:]...)
    88  	args = append(args, sshCommand...)
    89  	args = append(args, file)
    90  
    91  	binary, err := exec.LookPath(prefix[0])
    92  	if err != nil {
    93  		return err
    94  	}
    95  	binary, err = filepath.Abs(binary)
    96  	if err != nil {
    97  		return err
    98  	}
    99  	cmd := exec.Command(binary, args...)
   100  	cmd.Dir = dir
   101  	if passThru {
   102  		cmd.Stdin = os.Stdin
   103  		cmd.Stdout = os.Stdout
   104  		cmd.Stderr = os.Stderr
   105  	}
   106  	logrus.Debugf("Running wsl cmd %v in dir: %s", args, dir)
   107  	return cmd.Run()
   108  }