/
sshizzle-agent.go
89 lines (77 loc) · 2.22 KB
/
sshizzle-agent.go
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package main
import (
"crypto/rand"
"crypto/rsa"
"fmt"
"log"
"net"
"os"
"os/signal"
"strings"
"syscall"
"github.com/thalesgroup/sshizzle/internal/config"
"github.com/thalesgroup/sshizzle/internal/sshizzleagent"
"golang.org/x/crypto/ssh"
"golang.org/x/crypto/ssh/agent"
)
func main() {
// Ensure environment variables are set and config directory created
config, err := config.Check()
if err != nil {
log.Fatalln(err)
}
// Generate a new SSH public/private key pair
privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
if err != nil {
log.Fatalln(fmt.Errorf("error generating new private key: %s", err.Error()))
}
// Create a signer from the key
signer, err := ssh.NewSignerFromKey(privateKey)
if err != nil {
log.Fatalln(fmt.Errorf("error creating signer from private key: %s", err.Error()))
}
config.Signer = signer
if err = startAgent(config); err != nil {
log.Fatalln(fmt.Errorf("failed to start agent: %s", err.Error()))
}
}
func startAgent(c *config.SSHizzleConfig) error {
// Ensure the socket doesn't already exist
if _, err := os.Stat(c.Socket); err == nil {
log.Fatalln(fmt.Errorf("socket %s already exists", c.Socket))
}
// Create a new Unix socket and listen
syscall.Umask(0077)
listener, err := net.Listen("unix", c.Socket)
if err != nil {
log.Fatalln(fmt.Errorf("error listening on socket: %s", err.Error()))
}
defer listener.Close()
log.Println("Listening on", c.Socket)
// Create a new sshizzle agent
sshizzleAgent := sshizzleagent.NewSSHizzleAgent(c)
// Catch interrupt/kill signals to exit nicely
sigs := make(chan os.Signal)
signal.Notify(sigs, os.Interrupt, os.Kill)
go func() {
_ = <-sigs
err := listener.Close()
if err != nil {
log.Fatalln(err.Error())
}
}()
for {
conn, err := listener.Accept()
if err != nil {
// Catch SIGINT sent to Agent by user
if strings.Contains(err.Error(), "use of closed network connection") {
return nil
}
log.Fatalln(fmt.Errorf("listener error: %s", err.Error()))
}
// Don't return on EOF so socket stays open after serving each request
if err := agent.ServeAgent(sshizzleAgent, conn); err != nil && err.Error() != "EOF" {
log.Fatalln(fmt.Errorf("error serving agent on listener: %s", err.Error()))
}
}
}