verify response body with expected keywords (trufflesecurity#1419)

* verify response body with expected keywords

* remove debug log

* add extra test case

* migrate from ioutil to io

* close body and only check for one keyword

* cleanup

pkg/common/utils.go

@@ -1,5 +1,11 @@
 package common
 
+import (
+	"bufio"
+	"io"
+	"strings"
+)
+
 func AddStringSliceItem(item string, slice *[]string) {
 	for _, i := range *slice {
 		if i == item {
@@ -17,3 +23,16 @@ func RemoveStringSliceItem(item string, slice *[]string) {
 		}
 	}
 }
+
+func ResponseContainsSubstring(reader io.ReadCloser, target string) (bool, error) {
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		if strings.Contains(scanner.Text(), target) {
+			return true, nil
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return false, err
+	}
+	return false, nil
+}

pkg/common/utils_test.go

@@ -1,7 +1,9 @@
 package common
 
 import (
+	"io"
 	"reflect"
+	"strings"
 	"testing"
 )
 
@@ -74,3 +76,60 @@ func TestRemoveItem(t *testing.T) {
 		}
 	}
 }
+
+// Test ParseResponseForKeywords with a reader that contains the keyword and a reader that doesn't.
+func TestParseResponseForKeywords(t *testing.T) {
+	testCases := []struct {
+		name     string
+		input    string
+		keyword  string
+		expected bool
+	}{
+		{
+			name:     "Should find keyword",
+			input:    "ey: abc",
+			keyword:  "ey",
+			expected: true,
+		},
+		{
+			name:     "Should not find keyword",
+			input:    "fake response",
+			keyword:  "ey",
+			expected: false,
+		},
+		{
+			name:     "Empty string",
+			input:    "",
+			keyword:  "ey",
+			expected: false,
+		},
+		{
+			name:     "Keyword at end",
+			input:    "abc ey",
+			keyword:  "ey",
+			expected: true,
+		},
+		{
+			name:     "Keyword at start",
+			input:    "ey abc",
+			keyword:  "ey",
+			expected: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			testReader := strings.NewReader(tc.input)
+			testReadCloser := io.NopCloser(testReader)
+			found, err := ResponseContainsSubstring(testReadCloser, tc.keyword)
+
+			if err != nil {
+				t.Errorf("Error: %v", err)
+			}
+
+			if found != tc.expected {
+				t.Errorf("Expected %v, got %v", tc.expected, found)
+			}
+		})
+	}
+}

pkg/detectors/docusign/docusign.go

@@ -3,10 +3,8 @@ package docusign
 import (
 	"context"
 	"encoding/base64"
-	"encoding/json"
 	"fmt"
 	"github.com/go-errors/errors"
-	"io"
 	"net/http"
 	"regexp"
 	"strings"
@@ -83,25 +81,15 @@ func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (result
 					return nil, errors.WrapPrefix(err, "Error making request", 0)
 				}
 
-				// Read the response body
-				body, err := io.ReadAll(res.Body)
-
-				if err != nil {
-					return nil, errors.WrapPrefix(err, "Error reading response body", 0)
-				}
-
-				// Close the response body
+				verifiedBodyResponse, err := common.ResponseContainsSubstring(res.Body, "ey")
 				res.Body.Close()
 
-				// Parse the response body into a Response struct
-				var parsedResponse Response
-				err = json.Unmarshal(body, &parsedResponse)
 				if err != nil {
-					return nil, errors.WrapPrefix(err, "Error parsing response", 0)
+					return nil, err
 				}
 
 				if err == nil {
-					if res.StatusCode >= 200 && res.StatusCode < 300 && strings.HasPrefix(parsedResponse.AccessToken, "ey") {
+					if res.StatusCode >= 200 && res.StatusCode < 300 && verifiedBodyResponse {
 						s1.Verified = true
 					} else {
 						// This function will check false positives for common test words, but also it will make sure the key appears 'random' enough to be a real key.