include pastebin

This commit is contained in:
Barak Michener 2020-11-13 20:52:44 -08:00
parent 13a0b53e3e
commit 83b37864ef
9 changed files with 188 additions and 14 deletions

3
.gitignore vendored
View file

@ -16,3 +16,6 @@
# vendor/
id_ed25519
id_ed25519.pub
ussher
pastedir/

View file

@ -6,6 +6,7 @@ import (
"net/http"
"github.com/barakmich/ussher"
"github.com/spf13/viper"
)
func main() {
@ -17,12 +18,19 @@ func main() {
Keystore: ussher.AcceptAllKeys(),
HTTPMux: http.NewServeMux(),
SSHApps: make(map[string]ussher.SSHApp),
BaseURL: "http://localhost:8080/",
}
defer config.CloseApps()
err := ussher.RegisterEchoApp(config)
if err != nil {
fmt.Println(err)
}
v := viper.New()
v.Set("datadir", "./pastedir")
err = ussher.RegisterPastebin(config, v)
if err != nil {
fmt.Println(err)
}
go runHTTPServer(config)
err = ussher.RunSSHServer(config)
if err != nil {

View file

@ -15,6 +15,7 @@ type Config struct {
HTTPPort int
SSHApps map[string]SSHApp
HTTPMux *http.ServeMux
BaseURL string
}
func (c *Config) GetPrivateKey() (ssh.Signer, error) {

View file

@ -12,9 +12,10 @@ type echoHandler struct {
count int
}
func (e *echoHandler) HandleExec(_ string, conn *ssh.ServerConn, channel ssh.Channel) {
func (e *echoHandler) HandleExec(_ string, conn *ssh.ServerConn, channel ssh.Channel) error {
e.count += 1
io.Copy(channel, channel)
_, err := io.Copy(channel, channel)
return err
}
func (e *echoHandler) Close() error {

4
go.mod
View file

@ -3,6 +3,8 @@ module github.com/barakmich/ussher
go 1.14
require (
github.com/spf13/viper v1.7.1 // indirect
github.com/prometheus/common v0.4.0
github.com/spf13/viper v1.7.1
go.etcd.io/bbolt v1.3.2
golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
)

5
go.sum
View file

@ -14,7 +14,9 @@ dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7
github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hCbHZ8TKRvWD2dDTCfh9M9ya+I9JpbB7O8o=
github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
@ -131,6 +133,7 @@ github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDf
github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
github.com/prometheus/common v0.4.0 h1:7etb9YClo3a6HjLzfl6rIQaU+FDfi0VSX39io3aQ+DM=
github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
@ -139,6 +142,7 @@ github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6So
github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
github.com/sirupsen/logrus v1.2.0 h1:juTguoYk5qI21pwyTXY3B3Y5cOTH3ZUyZCg1v/mihuo=
github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
@ -276,6 +280,7 @@ google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a/go.mod h1:n3cpQtvx
google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

View file

@ -1,23 +1,158 @@
package pastebin
package ussher
import (
"bytes"
"crypto/sha256"
"encoding/base64"
"errors"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"os"
"path"
"path/filepath"
"strings"
"sync"
"github.com/barakmich/ussher"
"github.com/prometheus/common/log"
"github.com/spf13/viper"
bolt "go.etcd.io/bbolt"
"golang.org/x/crypto/ssh"
)
const DefaultBinLinkLen = 4
type pastebin struct {
sync.Mutex
db *bolt.DB
datadir string
config *Config
}
func (p *pastebin) HandleExec(appstring string, conn *ssh.ServerConn, channel ssh.Channel) {
func (p *pastebin) HandleExec(appstring string, conn *ssh.ServerConn, channel ssh.Channel) error {
commands := strings.Split(appstring, " ")
if len(commands) == 1 {
return p.handleNewFile(channel)
}
switch commands[1] {
case "create":
return p.handleNewFile(channel)
case "get":
return p.getFileSSH(commands[2:], channel)
}
return nil
}
func (p *pastebin) getFileSSH(commands []string, channel ssh.Channel) error {
if len(commands) == 0 {
return errors.New("Need to provide a shortlink string or URL of file to get")
}
key := commands[0]
if u, err := url.Parse(commands[0]); err == nil {
if strings.HasPrefix(u.Scheme, "http") {
id, err := p.getIDfromURL(u)
if err != nil {
return err
}
key = id
}
}
f, err := p.getFileFromID(key)
if err != nil {
return err
}
_, err = io.Copy(channel, f)
return err
}
func (p *pastebin) getFileFromID(id string) (*os.File, error) {
var shasum []byte
err := p.db.Update(func(tx *bolt.Tx) error {
bucket, err := tx.CreateBucketIfNotExists([]byte("pastebin"))
if err != nil {
return err
}
v := bucket.Get([]byte(id))
if v == nil {
return os.ErrNotExist
}
shasum = v
return nil
})
if err != nil {
return nil, err
}
urlenc := base64.URLEncoding.EncodeToString(shasum)
filename := filepath.Join(p.datadir, urlenc)
return os.Open(filename)
}
func (p *pastebin) getIDfromURL(u *url.URL) (string, error) {
if u == nil {
panic("nil URL")
}
components := strings.Split(u.Path, "/")
if len(components) < 2 {
return "", errors.New("Incomplete URL")
}
return components[2], nil
}
func (p *pastebin) handleNewFile(channel ssh.Channel) error {
f, err := ioutil.TempFile(p.datadir, "pastebin_*")
if err != nil {
return err
}
tempname := f.Name()
hasher := sha256.New()
tee := io.TeeReader(channel, hasher)
_, err = io.Copy(f, tee)
if err != nil {
f.Close()
return err
}
f.Close()
shasum := hasher.Sum(nil)
urlenc := base64.URLEncoding.EncodeToString(shasum)
err = os.Rename(tempname, filepath.Join(p.datadir, urlenc))
if err != nil {
return err
}
shorturlLen := DefaultBinLinkLen
err = p.db.Update(func(tx *bolt.Tx) error {
bucket, err := tx.CreateBucketIfNotExists([]byte("pastebin"))
if err != nil {
return err
}
for {
v := bucket.Get([]byte(urlenc[:shorturlLen]))
if v == nil {
break
}
if bytes.Equal(v, shasum) {
// We already have the file! We just overwrote it.
// Return the same shortlink
break
}
shorturlLen += 1
}
return bucket.Put([]byte(urlenc[:shorturlLen]), shasum)
})
if err != nil {
return err
}
shortlink := path.Join(p.config.BaseURL, "p", urlenc[:shorturlLen])
_, err = fmt.Fprintln(channel, shortlink)
return err
}
func (p *pastebin) Close() error {
return p.db.Close()
}
func (p *pastebin) ServeHTTP(w http.ResponseWriter, req *http.Request) {
@ -25,17 +160,31 @@ func (p *pastebin) ServeHTTP(w http.ResponseWriter, req *http.Request) {
w.WriteHeader(http.StatusBadRequest)
return
}
id := req.URL.Path
fmt.Println("got id", id)
id, err := p.getIDfromURL(req.URL)
if err != nil {
w.WriteHeader(http.StatusBadRequest)
return
}
f, err := p.getFileFromID(id)
if err != nil {
w.WriteHeader(http.StatusNotFound)
return
}
_, err = io.Copy(w, f)
if err != nil {
log.Errorln(err)
}
return
}
func RegisterPastebin(config *ussher.Config, configNS *viper.Viper) error {
func RegisterPastebin(config *Config, configNS *viper.Viper) error {
path, err := filepath.Abs(configNS.GetString("datadir"))
if err != nil {
return err
}
p := &pastebin{
datadir: path,
config: config,
}
db, err := bolt.Open(filepath.Join(p.datadir, "index.db"), 0600, nil)
if err != nil {
@ -44,5 +193,6 @@ func RegisterPastebin(config *ussher.Config, configNS *viper.Viper) error {
p.db = db
config.HTTPMux.Handle("/p/", p)
config.SSHApps["pastebin"] = p
return nil
}

View file

@ -3,6 +3,6 @@ package ussher
import "golang.org/x/crypto/ssh"
type SSHApp interface {
HandleExec(appstring string, conn *ssh.ServerConn, channel ssh.Channel)
HandleExec(appstring string, conn *ssh.ServerConn, channel ssh.Channel) error
Close() error
}

View file

@ -86,16 +86,20 @@ func handleChannel(newChannel ssh.NewChannel, conn *ssh.ServerConn, config *Conf
exit = true
case "exec":
appstring := string(req.Payload[4:]) // skip the first four bytes, which are length of string
appspaced := strings.SplitN(appstring, " ", 1)
appspaced := strings.SplitN(appstring, " ", 2)
if len(appspaced) == 0 {
exit = true
break
}
v, ok := config.SSHApps[appspaced]
v, ok := config.SSHApps[appspaced[0]]
if ok {
v.HandleExec(appstring, conn, connection)
err := v.HandleExec(appstring, conn, connection)
if err != nil {
fmt.Fprintln(connection.Stderr(), err)
log.Printf("Got error while handling ssh session: %s", err)
}
} else {
log.Printf("Can't find app %s", appname)
log.Printf("Can't find app %s", appspaced[0])
}
exit = true
default: