Display exploit codes information for each detected CVE-IDs (#729)

* add exploit

* bug fix while loading config in TUI, display in format-full-text

* fix readme

exploit/util.go

@@ -0,0 +1,133 @@
+/* Vuls - Vulnerability Scanner
+Copyright (C) 2016  Future Architect, Inc. Japan.
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package exploit
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/cenkalti/backoff"
+	"github.com/future-architect/vuls/util"
+	"github.com/parnurzeal/gorequest"
+)
+
+type response struct {
+	request request
+	json    string
+}
+
+func getCvesViaHTTP(cveIDs []string, urlPrefix string) (
+	responses []response, err error) {
+	nReq := len(cveIDs)
+	reqChan := make(chan request, nReq)
+	resChan := make(chan response, nReq)
+	errChan := make(chan error, nReq)
+	defer close(reqChan)
+	defer close(resChan)
+	defer close(errChan)
+
+	go func() {
+		for _, cveID := range cveIDs {
+			reqChan <- request{
+				cveID: cveID,
+			}
+		}
+	}()
+
+	concurrency := 10
+	tasks := util.GenWorkers(concurrency)
+	for i := 0; i < nReq; i++ {
+		tasks <- func() {
+			select {
+			case req := <-reqChan:
+				url, err := util.URLPathJoin(
+					urlPrefix,
+					req.cveID,
+				)
+				if err != nil {
+					errChan <- err
+				} else {
+					util.Log.Debugf("HTTP Request to %s", url)
+					httpGet(url, req, resChan, errChan)
+				}
+			}
+		}
+	}
+
+	timeout := time.After(2 * 60 * time.Second)
+	var errs []error
+	for i := 0; i < nReq; i++ {
+		select {
+		case res := <-resChan:
+			responses = append(responses, res)
+		case err := <-errChan:
+			errs = append(errs, err)
+		case <-timeout:
+			return nil, fmt.Errorf("Timeout Fetching OVAL")
+		}
+	}
+	if len(errs) != 0 {
+		return nil, fmt.Errorf("Failed to fetch OVAL. err: %v", errs)
+	}
+	return
+}
+
+type request struct {
+	osMajorVersion string
+	packName       string
+	isSrcPack      bool
+	cveID          string
+}
+
+func httpGet(url string, req request, resChan chan<- response, errChan chan<- error) {
+	var body string
+	var errs []error
+	var resp *http.Response
+	count, retryMax := 0, 3
+	f := func() (err error) {
+		//  resp, body, errs = gorequest.New().SetDebug(config.Conf.Debug).Get(url).End()
+		resp, body, errs = gorequest.New().Get(url).End()
+		if 0 < len(errs) || resp == nil || resp.StatusCode != 200 {
+			count++
+			if count == retryMax {
+				return nil
+			}
+			return fmt.Errorf("HTTP GET error: %v, url: %s, resp: %v",
+				errs, url, resp)
+		}
+		return nil
+	}
+	notify := func(err error, t time.Duration) {
+		util.Log.Warnf("Failed to HTTP GET. retrying in %s seconds. err: %s", t, err)
+	}
+	err := backoff.RetryNotify(f, backoff.NewExponentialBackOff(), notify)
+	if err != nil {
+		errChan <- fmt.Errorf("HTTP Error %s", err)
+		return
+	}
+	if count == retryMax {
+		errChan <- fmt.Errorf("HRetry count exceeded")
+		return
+	}
+
+	resChan <- response{
+		request: req,
+		json:    body,
+	}
+}