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package controllers
import (
"fmt"
"net"
"net/http"
"strconv"
"code.crute.us/mcrute/ssh-proxy/app/middleware"
"code.crute.us/mcrute/ssh-proxy/app/models"
"code.crute.us/mcrute/ssh-proxy/proxy"
"github.com/gorilla/websocket"
"github.com/labstack/echo/v4"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var (
proxyError = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "ssh_proxy",
Name: "proxy_error",
Help: "Total number of errors during proxy setup operation",
}, []string{"type"})
proxySuccess = promauto.NewCounter(prometheus.CounterOpts{
Namespace: "ssh_proxy",
Name: "proxy_success",
Help: "Total number of successful proxy sessions",
})
)
type ProxyHandler struct {
Logger echo.Logger
Upgrader websocket.Upgrader
Users models.UserStore
}
func getConnectAddr(c echo.Context) string {
p, err := strconv.Atoi(c.Param("port"))
if err != nil {
p = 22
}
return fmt.Sprintf("%s:%d", c.Param("host"), p)
}
func (h *ProxyHandler) authorizeRequest(c echo.Context) error {
session := middleware.GetAuthorizedSession(c)
user, err := h.Users.Get(c.Request().Context(), session.UserId)
if err != nil {
return err
}
if !session.HasScope("ssh:proxy") {
proxyError.With(prometheus.Labels{"type": "token_missing_scope"}).Inc()
return fmt.Errorf("Authorized session does not have scope ssh:proxy")
}
host := c.Param("host")
if user.AuthorizedForHost(host) {
h.Logger.Infof("Allowing user %s to proxy to host %s", session.UserId, host)
return nil
}
proxyError.With(prometheus.Labels{"type": "not_authorized"}).Inc()
return fmt.Errorf("User %s not authorized for host %s", session.UserId, host)
}
func (h *ProxyHandler) Handle(c echo.Context) error {
if err := h.authorizeRequest(c); err != nil {
h.Logger.Error(err)
return c.NoContent(http.StatusUnauthorized)
}
wsconn, err := h.Upgrader.Upgrade(c.Response(), c.Request(), nil)
if err != nil {
return err
}
defer wsconn.Close()
proxyconn, err := net.Dial("tcp", getConnectAddr(c))
if err != nil {
return err
}
defer proxyconn.Close()
errc := make(chan error)
ws := &proxy.WebsocketReadWriter{W: wsconn}
proxySuccess.Inc()
go proxy.CopyWithErrors(proxyconn, ws, errc)
go proxy.CopyWithErrors(ws, proxyconn, errc)
<-errc
return nil
}
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