From dd7b82b0fbb3e040b987f85b666bb178ecf2c0b1 Mon Sep 17 00:00:00 2001
From: Richard Gomez <rmgomez368@gmail.com>
Date: Sat, 11 May 2024 15:50:48 -0400
Subject: [PATCH] feat(sendgrid): update detector

---
 pkg/detectors/sendgrid/sendgrid.go | 103 ++++++++++++++++++-----------
 1 file changed, 65 insertions(+), 38 deletions(-)

diff --git a/pkg/detectors/sendgrid/sendgrid.go b/pkg/detectors/sendgrid/sendgrid.go
index e00cb2a2e748..936004a047e0 100644
--- a/pkg/detectors/sendgrid/sendgrid.go
+++ b/pkg/detectors/sendgrid/sendgrid.go
@@ -2,11 +2,14 @@ package sendgrid
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
-	regexp "github.com/wasilibs/go-re2"
+	"io"
 	"net/http"
 	"strings"
 
+	regexp "github.com/wasilibs/go-re2"
+
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detectorspb"
 
@@ -23,7 +26,7 @@ var _ detectors.Detector = (*Scanner)(nil)
 var (
 	defaultClient = common.SaneHttpClient()
 
-	keyPat = regexp.MustCompile(detectors.PrefixRegex([]string{"sendgrid"}) + `(SG\.[\w\-_]{20,24}\.[\w\-_]{39,50})\b`)
+	keyPat = regexp.MustCompile(`\bSG\.[\w\-]{20,24}\.[\w\-]{39,50}\b`)
 )
 
 // Keywords are used for efficiently pre-filtering chunks.
@@ -36,53 +39,27 @@ func (s Scanner) Keywords() []string {
 func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (results []detectors.Result, err error) {
 	dataStr := string(data)
 
-	matches := keyPat.FindAllStringSubmatch(dataStr, -1)
-
-	for _, match := range matches {
-		if len(match) != 2 {
-			continue
-		}
-		resMatch := strings.TrimSpace(match[1])
+	uniqueMatches := make(map[string]struct{})
+	for _, match := range keyPat.FindAllStringSubmatch(dataStr, -1) {
+		uniqueMatches[match[0]] = struct{}{}
+	}
 
+	for token := range uniqueMatches {
 		s1 := detectors.Result{
 			DetectorType: detectorspb.DetectorType_SendGrid,
-			Raw:          []byte(resMatch),
-		}
-		s1.ExtraData = map[string]string{
-			"rotation_guide": "https://howtorotate.com/docs/tutorials/sendgrid/",
+			Raw:          []byte(token),
 		}
 
 		if verify {
-			// there are a few endpoints we can check, but templates seems the least sensitive.
-			// 403 will be issued if the scope is wrong but the key is correct
-			baseURL := "https://api.sendgrid.com/v3/templates"
-
 			client := s.client
 			if client == nil {
 				client = defaultClient
 			}
 
-			// test `read_user` scope
-			req, err := http.NewRequestWithContext(ctx, "GET", baseURL, nil)
-			if err != nil {
-				continue
-			}
-			req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", resMatch))
-			req.Header.Add("Content-Type", "application/json")
-			res, err := client.Do(req)
-			if err == nil {
-				res.Body.Close() // The request body is unused.
-
-				// 200 means good key and has `templates` scope
-				// 403 means good key but not the right scope
-				// 401 is bad key
-				if res.StatusCode == http.StatusOK || res.StatusCode == http.StatusForbidden {
-					s1.Verified = true
-				} else if res.StatusCode != http.StatusUnauthorized {
-					err = fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
-					s1.SetVerificationError(err, resMatch)
-				}
-			}
+			verified, extraData, verificationErr := verifyToken(ctx, client, token)
+			s1.Verified = verified
+			s1.ExtraData = extraData
+			s1.SetVerificationError(verificationErr)
 		}
 
 		results = append(results, s1)
@@ -91,6 +68,56 @@ func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (result
 	return
 }
 
+func verifyToken(ctx context.Context, client *http.Client, token string) (bool, map[string]string, error) {
+	// Check the scopes assigned to the api key.
+	// https://docs.sendgrid.com/api-reference/api-key-permissions/retrieve-a-list-of-scopes-for-which-this-user-has-access
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, "https://api.sendgrid.com/v3/scopes", nil)
+	if err != nil {
+		return false, nil, err
+	}
+
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+	req.Header.Set("Content-Type", "application/json")
+	res, err := client.Do(req)
+	if err != nil {
+		return false, nil, err
+	}
+	defer func() {
+		_, _ = io.Copy(io.Discard, res.Body)
+		_ = res.Body.Close()
+	}()
+
+	switch res.StatusCode {
+	case http.StatusOK:
+		extraData := map[string]string{
+			"rotation_guide": "https://howtorotate.com/docs/tutorials/sendgrid/",
+		}
+
+		var scopesRes scopesResponse
+		if err := json.NewDecoder(res.Body).Decode(&scopesRes); err != nil {
+			return false, nil, err
+		}
+
+		if len(scopesRes.Scopes) > 0 {
+			extraData["scopes"] = strings.Join(scopesRes.Scopes, ",")
+		}
+
+		return true, extraData, nil
+	case http.StatusUnauthorized:
+		// 401 means the key is definitively invalid.
+		return false, nil, nil
+	case http.StatusForbidden:
+		// 403 means good key but not the right scope
+		return true, nil, nil
+	default:
+		return false, nil, fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
+	}
+}
+
+type scopesResponse struct {
+	Scopes []string `json:"scopes"`
+}
+
 func (s Scanner) Type() detectorspb.DetectorType {
 	return detectorspb.DetectorType_SendGrid
 }