Github Oauth2 verification (#1584)

* Github Oauth2 verification

* Use prefix and include RawV2

* Make gh_oauth2 a new detector

* Remove unused struct

* Remove versioner

* Remove unused code

pkg/detectors/github_oauth2/github_oauth2.go

@@ -0,0 +1,81 @@
+package github_oauth2
+
+import (
+	"context"
+	"regexp"
+	"strings"
+
+	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detectorspb"
+	"golang.org/x/oauth2/clientcredentials"
+	"golang.org/x/oauth2/github"
+)
+
+type Scanner struct{ detectors.EndpointSetter }
+
+// Ensure the Scanner satisfies the interfaces at compile time.
+var _ detectors.Detector = (*Scanner)(nil)
+
+var (
+	// Oauth2 client ID and secret
+	oauth2ClientIDPat     = regexp.MustCompile(detectors.PrefixRegex([]string{"github"}) + `\b([a-f0-9]{20})\b`)
+	oauth2ClientSecretPat = regexp.MustCompile(detectors.PrefixRegex([]string{"github"}) + `\b([a-f0-9]{40})\b`)
+)
+
+const (
+	githubBadVerificationCodeError = "bad_verification_code"
+)
+
+// Keywords are used for efficiently pre-filtering chunks.
+// Use identifiers in the secret preferably, or the provider name.
+func (s Scanner) Keywords() []string {
+	return []string{"github"}
+}
+
+// FromData will find and optionally verify GitHub secrets in a given set of bytes.
+func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (results []detectors.Result, err error) {
+	dataStr := string(data)
+
+	// Oauth2 client ID and secret
+	oauth2ClientIDMatches := oauth2ClientIDPat.FindAllStringSubmatch(dataStr, -1)
+	oauth2ClientSecretMatches := oauth2ClientSecretPat.FindAllStringSubmatch(dataStr, -1)
+
+	for _, idMatch := range oauth2ClientIDMatches {
+		if len(idMatch) != 2 {
+			continue
+		}
+		for _, secretMatch := range oauth2ClientSecretMatches {
+			if len(secretMatch) != 2 {
+				continue
+			}
+
+			s1 := detectors.Result{
+				DetectorType: detectorspb.DetectorType_GitHubOauth2,
+				Raw:          []byte(idMatch[1]),
+				RawV2:        []byte(idMatch[1] + secretMatch[1]),
+			}
+
+			config := &clientcredentials.Config{
+				ClientID:     idMatch[1],
+				ClientSecret: secretMatch[1],
+				TokenURL:     github.Endpoint.TokenURL,
+			}
+			_, err := config.Token(ctx)
+			if err != nil && strings.Contains(err.Error(), githubBadVerificationCodeError) {
+				s1.Verified = true
+			}
+
+			if !s1.Verified && detectors.IsKnownFalsePositive(string(s1.Raw), detectors.DefaultFalsePositives, true) {
+				continue
+			}
+
+			results = append(results, s1)
+		}
+	}
+
+	return
+}
+
+func (s Scanner) Type() detectorspb.DetectorType {
+	return detectorspb.DetectorType_GitHubOauth2
+}

pkg/engine/defaults.go

@@ -556,6 +556,7 @@ import (
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/satismeterwritekey"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/saucelabs"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/scalewaykey"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/github_oauth2"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/scalr"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/scrapeowl"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/scraperapi"
@@ -1530,6 +1531,7 @@ func DefaultDetectors() []detectors.Detector {
 		dockerhub.Scanner{},
 		couchbase.Scanner{},
 		envoyapikey.Scanner{},
+		github_oauth2.Scanner{},
 	}
 
 }

proto/detectors.proto

@@ -932,6 +932,7 @@ enum DetectorType {
   Dockerhub = 921;
   TrufflehogEnterprise = 922;
   EnvoyApiKey = 923;
+  GitHubOauth2 = 924;
 }
 
 message Result {