SSH server entry point - take 2 #99
34
cmd/ssh/README.md
Normal file
34
cmd/ssh/README.md
Normal file
@ -0,0 +1,34 @@
|
||||
# URDT-USSD SSH server
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||||
|
||||
An SSH server entry point for the vise engine.
|
||||
|
||||
|
||||
## Adding public keys for access
|
||||
|
||||
Map your (client) public key to a session identifier (e.g. phone number)
|
||||
|
||||
```
|
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go run -v -tags logtrace ./cmd/ssh/sshkey/main.go -i <session_id> [--dbdir <dbpath>] <client_publickey_filepath>
|
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```
|
||||
|
||||
|
||||
## Create a private key for the server
|
||||
|
||||
```
|
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ssh-keygen -N "" -f <server_privatekey_filepath>
|
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```
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||||
|
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|
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## Run the server
|
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|
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|
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```
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go run -v -tags logtrace ./cmd/ssh/main.go -h <host> -p <port> [--dbdir <dbpath>] <server_privatekey_filepath>
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```
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||||
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||||
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## Connect to the server
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```
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ssh [-v] -T -p <port> -i <client_publickey_filepath> <host>
|
||||
```
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115
cmd/ssh/main.go
Normal file
115
cmd/ssh/main.go
Normal file
@ -0,0 +1,115 @@
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package main
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import (
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"context"
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"flag"
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"fmt"
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"path"
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"os"
|
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"os/signal"
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"sync"
|
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"syscall"
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|
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"git.defalsify.org/vise.git/db"
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"git.defalsify.org/vise.git/engine"
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"git.defalsify.org/vise.git/logging"
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||||
|
||||
"git.grassecon.net/urdt/ussd/internal/ssh"
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)
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var (
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wg sync.WaitGroup
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keyStore db.Db
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logg = logging.NewVanilla()
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scriptDir = path.Join("services", "registration")
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)
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func main() {
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var dbDir string
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var resourceDir string
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var size uint
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var engineDebug bool
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var stateDebug bool
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var host string
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var port uint
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flag.StringVar(&dbDir, "dbdir", ".state", "database dir to read from")
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flag.StringVar(&resourceDir, "resourcedir", path.Join("services", "registration"), "resource dir")
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flag.BoolVar(&engineDebug, "engine-debug", false, "use engine debug output")
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flag.BoolVar(&stateDebug, "state-debug", false, "use engine debug output")
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flag.UintVar(&size, "s", 160, "max size of output")
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flag.StringVar(&host, "h", "127.0.0.1", "http host")
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flag.UintVar(&port, "p", 7122, "http port")
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flag.Parse()
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sshKeyFile := flag.Arg(0)
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_, err := os.Stat(sshKeyFile)
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if err != nil {
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fmt.Fprintf(os.Stderr, "cannot open ssh server private key file: %v\n", err)
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os.Exit(1)
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}
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ctx := context.Background()
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logg.WarnCtxf(ctx, "!!!!! WARNING WARNING WARNING")
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logg.WarnCtxf(ctx, "!!!!! =======================")
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logg.WarnCtxf(ctx, "!!!!! This is not a production ready server!")
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logg.WarnCtxf(ctx, "!!!!! Do not expose to internet and only use with tunnel!")
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logg.WarnCtxf(ctx, "!!!!! (See ssh -L <...>)")
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logg.Infof("start command", "dbdir", dbDir, "resourcedir", resourceDir, "outputsize", size, "keyfile", sshKeyFile, "host", host, "port", port)
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pfp := path.Join(scriptDir, "pp.csv")
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cfg := engine.Config{
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Root: "root",
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OutputSize: uint32(size),
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FlagCount: uint32(16),
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}
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if stateDebug {
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cfg.StateDebug = true
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}
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if engineDebug {
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cfg.EngineDebug = true
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}
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authKeyStore, err := ssh.NewSshKeyStore(ctx, dbDir)
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if err != nil {
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fmt.Fprintf(os.Stderr, "keystore file open error: %v", err)
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os.Exit(1)
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}
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defer func () {
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logg.TraceCtxf(ctx, "shutdown auth key store reached")
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err = authKeyStore.Close()
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if err != nil {
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logg.ErrorCtxf(ctx, "keystore close error", "err", err)
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}
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}()
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cint := make(chan os.Signal)
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cterm := make(chan os.Signal)
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signal.Notify(cint, os.Interrupt, syscall.SIGINT)
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signal.Notify(cterm, os.Interrupt, syscall.SIGTERM)
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runner := &ssh.SshRunner{
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Cfg: cfg,
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Debug: engineDebug,
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FlagFile: pfp,
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DbDir: dbDir,
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ResourceDir: resourceDir,
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SrvKeyFile: sshKeyFile,
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Host: host,
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Port: port,
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}
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go func() {
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select {
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case _ = <-cint:
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case _ = <-cterm:
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}
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logg.TraceCtxf(ctx, "shutdown runner reached")
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err := runner.Stop()
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if err != nil {
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logg.ErrorCtxf(ctx, "runner stop error", "err", err)
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}
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}()
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runner.Run(ctx, authKeyStore)
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}
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44
cmd/ssh/sshkey/main.go
Normal file
44
cmd/ssh/sshkey/main.go
Normal file
@ -0,0 +1,44 @@
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package main
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import (
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"context"
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"flag"
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"fmt"
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"os"
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"git.grassecon.net/urdt/ussd/internal/ssh"
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)
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func main() {
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var dbDir string
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var sessionId string
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flag.StringVar(&dbDir, "dbdir", ".state", "database dir to read from")
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flag.StringVar(&sessionId, "i", "", "session id")
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flag.Parse()
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if sessionId == "" {
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fmt.Fprintf(os.Stderr, "empty session id\n")
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os.Exit(1)
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}
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ctx := context.Background()
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sshKeyFile := flag.Arg(0)
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if sshKeyFile == "" {
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fmt.Fprintf(os.Stderr, "missing key file argument\n")
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os.Exit(1)
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}
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store, err := ssh.NewSshKeyStore(ctx, dbDir)
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if err != nil {
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fmt.Fprintf(os.Stderr, "%v\n", err)
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os.Exit(1)
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}
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defer store.Close()
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err = store.AddFromFile(ctx, sshKeyFile, sessionId)
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if err != nil {
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fmt.Fprintf(os.Stderr, "%v\n", err)
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os.Exit(1)
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}
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}
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64
internal/ssh/keystore.go
Normal file
64
internal/ssh/keystore.go
Normal file
@ -0,0 +1,64 @@
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package ssh
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|
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import (
|
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"context"
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"fmt"
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"os"
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"path"
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"golang.org/x/crypto/ssh"
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"git.defalsify.org/vise.git/db"
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"git.grassecon.net/urdt/ussd/internal/storage"
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)
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type SshKeyStore struct {
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store db.Db
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}
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func NewSshKeyStore(ctx context.Context, dbDir string) (*SshKeyStore, error) {
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keyStore := &SshKeyStore{}
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keyStoreFile := path.Join(dbDir, "ssh_authorized_keys.gdbm")
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keyStore.store = storage.NewThreadGdbmDb()
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err := keyStore.store.Connect(ctx, keyStoreFile)
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if err != nil {
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return nil, err
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}
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return keyStore, nil
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}
|
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|
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func(s *SshKeyStore) AddFromFile(ctx context.Context, fp string, sessionId string) error {
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_, err := os.Stat(fp)
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if err != nil {
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return fmt.Errorf("cannot open ssh server public key file: %v\n", err)
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}
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|
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publicBytes, err := os.ReadFile(fp)
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if err != nil {
|
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return fmt.Errorf("Failed to load public key: %v", err)
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}
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pubKey, _, _, _, err := ssh.ParseAuthorizedKey(publicBytes)
|
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if err != nil {
|
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return fmt.Errorf("Failed to parse public key: %v", err)
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}
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k := append([]byte{0x01}, pubKey.Marshal()...)
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s.store.SetPrefix(storage.DATATYPE_CUSTOM)
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logg.Infof("Added key", "sessionId", sessionId, "public key", string(publicBytes))
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return s.store.Put(ctx, k, []byte(sessionId))
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}
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|
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func(s *SshKeyStore) Get(ctx context.Context, pubKey ssh.PublicKey) (string, error) {
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s.store.SetLanguage(nil)
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s.store.SetPrefix(storage.DATATYPE_CUSTOM)
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k := append([]byte{0x01}, pubKey.Marshal()...)
|
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v, err := s.store.Get(ctx, k)
|
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if err != nil {
|
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return "", err
|
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}
|
||||
return string(v), nil
|
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}
|
||||
|
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func(s *SshKeyStore) Close() error {
|
||||
return s.store.Close()
|
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}
|
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284
internal/ssh/ssh.go
Normal file
284
internal/ssh/ssh.go
Normal file
@ -0,0 +1,284 @@
|
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package ssh
|
||||
|
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import (
|
||||
"context"
|
||||
"encoding/hex"
|
||||
"encoding/base64"
|
||||
"errors"
|
||||
"fmt"
|
||||
"net"
|
||||
"os"
|
||||
"sync"
|
||||
|
||||
"golang.org/x/crypto/ssh"
|
||||
|
||||
"git.defalsify.org/vise.git/engine"
|
||||
"git.defalsify.org/vise.git/logging"
|
||||
"git.defalsify.org/vise.git/resource"
|
||||
"git.defalsify.org/vise.git/state"
|
||||
|
||||
"git.grassecon.net/urdt/ussd/internal/handlers"
|
||||
"git.grassecon.net/urdt/ussd/internal/storage"
|
||||
)
|
||||
|
||||
var (
|
||||
logg = logging.NewVanilla().WithDomain("ssh")
|
||||
)
|
||||
|
||||
type auther struct {
|
||||
Ctx context.Context
|
||||
keyStore *SshKeyStore
|
||||
auth map[string]string
|
||||
}
|
||||
|
||||
func NewAuther(ctx context.Context, keyStore *SshKeyStore) *auther {
|
||||
return &auther{
|
||||
Ctx: ctx,
|
||||
keyStore: keyStore,
|
||||
auth: make(map[string]string),
|
||||
}
|
||||
}
|
||||
|
||||
func(a *auther) Check(conn ssh.ConnMetadata, pubKey ssh.PublicKey) (*ssh.Permissions, error) {
|
||||
va, err := a.keyStore.Get(a.Ctx, pubKey)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ka := hex.EncodeToString(conn.SessionID())
|
||||
a.auth[ka] = va
|
||||
fmt.Fprintf(os.Stderr, "connect: %s -> %s\n", ka, va)
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
func(a *auther) FromConn(c *ssh.ServerConn) (string, error) {
|
||||
if c == nil {
|
||||
return "", errors.New("nil server conn")
|
||||
}
|
||||
if c.Conn == nil {
|
||||
return "", errors.New("nil underlying conn")
|
||||
}
|
||||
return a.Get(c.Conn.SessionID())
|
||||
}
|
||||
|
||||
|
||||
func(a *auther) Get(k []byte) (string, error) {
|
||||
ka := hex.EncodeToString(k)
|
||||
v, ok := a.auth[ka]
|
||||
if !ok {
|
||||
return "", errors.New("not found")
|
||||
}
|
||||
return v, nil
|
||||
}
|
||||
|
||||
func(s *SshRunner) serve(ctx context.Context, sessionId string, ch ssh.NewChannel, en engine.Engine) error {
|
||||
if ch == nil {
|
||||
return errors.New("nil channel")
|
||||
}
|
||||
if ch.ChannelType() != "session" {
|
||||
ch.Reject(ssh.UnknownChannelType, "that is not the channel you are looking for")
|
||||
return errors.New("not a session")
|
||||
}
|
||||
channel, requests, err := ch.Accept()
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
defer channel.Close()
|
||||
s.wg.Add(1)
|
||||
go func(reqIn <-chan *ssh.Request) {
|
||||
defer s.wg.Done()
|
||||
for req := range reqIn {
|
||||
req.Reply(req.Type == "shell", nil)
|
||||
}
|
||||
_ = requests
|
||||
}(requests)
|
||||
|
||||
cont, err := en.Exec(ctx, []byte{})
|
||||
if err != nil {
|
||||
return fmt.Errorf("initial engine exec err: %v", err)
|
||||
}
|
||||
|
||||
var input [state.INPUT_LIMIT]byte
|
||||
for cont {
|
||||
c, err := en.Flush(ctx, channel)
|
||||
if err != nil {
|
||||
return fmt.Errorf("flush err: %v", err)
|
||||
}
|
||||
_, err = channel.Write([]byte{0x0a})
|
||||
if err != nil {
|
||||
return fmt.Errorf("newline err: %v", err)
|
||||
}
|
||||
c, err = channel.Read(input[:])
|
||||
if err != nil {
|
||||
return fmt.Errorf("read input fail: %v", err)
|
||||
}
|
||||
logg.TraceCtxf(ctx, "input read", "c", c, "input", input[:c-1])
|
||||
cont, err = en.Exec(ctx, input[:c-1])
|
||||
if err != nil {
|
||||
return fmt.Errorf("engine exec err: %v", err)
|
||||
}
|
||||
logg.TraceCtxf(ctx, "exec cont", "cont", cont, "en", en)
|
||||
_ = c
|
||||
}
|
||||
c, err := en.Flush(ctx, channel)
|
||||
if err != nil {
|
||||
return fmt.Errorf("last flush err: %v", err)
|
||||
}
|
||||
_ = c
|
||||
return nil
|
||||
}
|
||||
|
||||
type SshRunner struct {
|
||||
Ctx context.Context
|
||||
Cfg engine.Config
|
||||
FlagFile string
|
||||
DbDir string
|
||||
ResourceDir string
|
||||
Debug bool
|
||||
SrvKeyFile string
|
||||
Host string
|
||||
Port uint
|
||||
wg sync.WaitGroup
|
||||
lst net.Listener
|
||||
}
|
||||
|
||||
func(s *SshRunner) Stop() error {
|
||||
return s.lst.Close()
|
||||
}
|
||||
|
||||
func(s *SshRunner) GetEngine(sessionId string) (engine.Engine, func(), error) {
|
||||
ctx := s.Ctx
|
||||
menuStorageService := storage.NewMenuStorageService(s.DbDir, s.ResourceDir)
|
||||
|
||||
err := menuStorageService.EnsureDbDir()
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
rs, err := menuStorageService.GetResource(ctx)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
pe, err := menuStorageService.GetPersister(ctx)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
userdatastore, err := menuStorageService.GetUserdataDb(ctx)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
dbResource, ok := rs.(*resource.DbResource)
|
||||
if !ok {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
lhs, err := handlers.NewLocalHandlerService(s.FlagFile, true, dbResource, s.Cfg, rs)
|
||||
lhs.SetDataStore(&userdatastore)
|
||||
lhs.SetPersister(pe)
|
||||
lhs.Cfg.SessionId = sessionId
|
||||
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
hl, err := lhs.GetHandler()
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
en := lhs.GetEngine()
|
||||
en = en.WithFirst(hl.Init)
|
||||
if s.Debug {
|
||||
en = en.WithDebug(nil)
|
||||
}
|
||||
// TODO: this is getting very hacky!
|
||||
closer := func() {
|
||||
err := menuStorageService.Close()
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "menu storage service cleanup fail", "err", err)
|
||||
}
|
||||
}
|
||||
return en, closer, nil
|
||||
}
|
||||
|
||||
// adapted example from crypto/ssh package, NewServerConn doc
|
||||
func(s *SshRunner) Run(ctx context.Context, keyStore *SshKeyStore) {
|
||||
running := true
|
||||
|
||||
// TODO: waitgroup should probably not be global
|
||||
defer s.wg.Wait()
|
||||
|
||||
auth := NewAuther(ctx, keyStore)
|
||||
cfg := ssh.ServerConfig{
|
||||
PublicKeyCallback: auth.Check,
|
||||
}
|
||||
|
||||
privateBytes, err := os.ReadFile(s.SrvKeyFile)
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "Failed to load private key", "err", err)
|
||||
}
|
||||
private, err := ssh.ParsePrivateKey(privateBytes)
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "Failed to parse private key", "err", err)
|
||||
}
|
||||
srvPub := private.PublicKey()
|
||||
srvPubStr := base64.StdEncoding.EncodeToString(srvPub.Marshal())
|
||||
logg.InfoCtxf(ctx, "have server key", "type", srvPub.Type(), "public", srvPubStr)
|
||||
cfg.AddHostKey(private)
|
||||
|
||||
s.lst, err = net.Listen("tcp", fmt.Sprintf("%s:%d", s.Host, s.Port))
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
|
||||
for running {
|
||||
conn, err := s.lst.Accept()
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "ssh accept error", "err", err)
|
||||
running = false
|
||||
continue
|
||||
}
|
||||
|
||||
go func(conn net.Conn) {
|
||||
defer conn.Close()
|
||||
for true {
|
||||
srvConn, nC, rC, err := ssh.NewServerConn(conn, &cfg)
|
||||
if err != nil {
|
||||
logg.InfoCtxf(ctx, "rejected client", "err", err)
|
||||
return
|
||||
}
|
||||
logg.DebugCtxf(ctx, "ssh client connected", "conn", srvConn)
|
||||
|
||||
s.wg.Add(1)
|
||||
go func() {
|
||||
ssh.DiscardRequests(rC)
|
||||
s.wg.Done()
|
||||
}()
|
||||
|
||||
sessionId, err := auth.FromConn(srvConn)
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "Cannot find authentication")
|
||||
return
|
||||
}
|
||||
en, closer, err := s.GetEngine(sessionId)
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "engine won't start", "err", err)
|
||||
return
|
||||
}
|
||||
defer func() {
|
||||
err := en.Finish()
|
||||
if err != nil {
|
||||
logg.ErrorCtxf(ctx, "engine won't stop", "err", err)
|
||||
}
|
||||
closer()
|
||||
}()
|
||||
for ch := range nC {
|
||||
err = s.serve(ctx, sessionId, ch, en)
|
||||
logg.ErrorCtxf(ctx, "ssh server finish", "err", err)
|
||||
}
|
||||
}
|
||||
}(conn)
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user