add GCP application default credentials detector (#2530)

* add GCP application default credentials detector

* add a comment

* update Keywords to better match the key

---------

Co-authored-by: Ahrav Dutta <ahrav.dutta@trufflesec.com>
This commit is contained in:
kenzht 2024-04-02 02:27:40 +08:00 committed by GitHub
parent 1c727b66c0
commit 0d3023fe74
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
5 changed files with 417 additions and 15 deletions

View file

@ -0,0 +1,164 @@
package gcpapplicationdefaultcredentials
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"strings"
regexp "github.com/wasilibs/go-re2"
"github.com/trufflesecurity/trufflehog/v3/pkg/common"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detectorspb"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
)
type Scanner struct {
client *http.Client
}
// Ensure the Scanner satisfies the interface at compile time.
var _ detectors.Detector = (*Scanner)(nil)
var (
defaultClient = common.SaneHttpClient()
keyPat = regexp.MustCompile(`\{[^{]+client_secret[^}]+\}`)
)
type gcpApplicationDefaultCredentials struct {
ClientID string `json:"client_id"`
ClientSecret string `json:"client_secret"`
RefreshToken string `json:"refresh_token"`
Type string `json:"type"`
}
// 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{".apps.googleusercontent.com"}
}
// FromData will find and optionally verify Gcpapplicationdefaultcredentials 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)
matches := keyPat.FindAllString(dataStr, -1)
for _, match := range matches {
key := match
// Detect keys by unmarshalling the data.
creds := gcpApplicationDefaultCredentials{}
err := json.Unmarshal([]byte(key), &creds)
if err != nil {
continue
}
// Trim prefix (".apps.googleusercontent.com") because it will be labeled as false positive
detectedClientID, _, _ := strings.Cut(creds.ClientID, ".")
s1 := detectors.Result{
DetectorType: detectorspb.DetectorType_GCPApplicationDefaultCredentials,
Raw: []byte(detectedClientID),
}
if verify {
client := s.client
if client == nil {
client = defaultClient
}
// Use marshalled credential to verify if the found key is active
credBytes, _ := json.Marshal(creds)
isVerified, extraData, verificationErr := verifyMatch(ctx, client, string(credBytes))
s1.Verified = isVerified
s1.ExtraData = extraData
s1.SetVerificationError(verificationErr, match)
}
// 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.
if !s1.Verified && detectors.IsKnownFalsePositive(string(s1.Raw), detectors.DefaultFalsePositives, true) {
continue
}
results = append(results, s1)
}
return
}
func verifyMatch(ctx context.Context, client *http.Client, token string) (bool, map[string]string, error) {
// First load the credential from the found key
credentials, err := google.CredentialsFromJSON(ctx, []byte(token), "https://www.googleapis.com/auth/cloud-platform")
if err != nil {
return false, nil, err
}
// Credential not loaded. Not sure this can happend but it should be labeled unverified.
if credentials == nil {
return false, nil, nil
}
// Get token from the credentials
gcpToken, err := credentials.TokenSource.Token()
if err != nil {
// Return verification error if the error is temporary
// See https://pkg.go.dev/golang.org/x/oauth2/google#AuthenticationError.Temporary for details
var temporaryError *(google.AuthenticationError)
if errors.As(err, &temporaryError) {
if err.(*google.AuthenticationError).Temporary() {
return false, nil, err
}
}
return false, nil, nil
}
// Return verification error if the retrieved token is invalid
if !gcpToken.Valid() {
return false, nil, err
}
// Build request to call an IAM endpoint
req, err := http.NewRequestWithContext(ctx, http.MethodGet, "https://iam.googleapis.com/v1/roles", nil)
if err != nil {
return false, nil, nil
}
// If we are not using a faketransport, leave it as is because the test wants to modify the response. Otherwise, set the retrieved token to the client.
if _, ok := client.Transport.(common.FakeTransport); !ok {
client.Transport = &oauth2.Transport{
Source: credentials.TokenSource,
}
}
res, err := client.Do(req)
if err != nil {
return false, nil, err
}
defer func() {
_, _ = io.Copy(io.Discard, res.Body)
_ = res.Body.Close()
}()
if res.StatusCode >= 200 && res.StatusCode < 300 {
// If the endpoint returns useful information, we can return it as a map.
return true, nil, nil
} else if res.StatusCode == 401 {
// The secret is determinately not verified (nothing to do)
return false, nil, nil
} else {
err = fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
return false, nil, err
}
}
func (s Scanner) Type() detectorspb.DetectorType {
return detectorspb.DetectorType_GCPApplicationDefaultCredentials
}

View file

@ -0,0 +1,230 @@
//go:build detectors
// +build detectors
package gcpapplicationdefaultcredentials
import (
"context"
"fmt"
"testing"
"time"
"github.com/google/go-cmp/cmp"
"github.com/google/go-cmp/cmp/cmpopts"
"github.com/trufflesecurity/trufflehog/v3/pkg/common"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
"github.com/trufflesecurity/trufflehog/v3/pkg/engine/ahocorasick"
"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detectorspb"
)
var (
validTestString = `{'client_id': '191375729402-oiuj2498ry3497gjveoierj8294jfj41.apps.googleusercontent.com', 'client_secret': 'z-OIFJWEOIJGWER91834325R', 'refresh_token': '1//0_joijgor3i4ut98579862709342j3kjJOIE02834jijfewoifjowiejfhghyzznfoiwejfwnvuhewiufnwinciwu_-o2i3jjfcc', 'type': 'authorized_user'}`
)
func TestGcpapplicationdefaultcredentials_Pattern(t *testing.T) {
d := Scanner{}
ahoCorasickCore := ahocorasick.NewAhoCorasickCore([]detectors.Detector{d})
tests := []struct {
name string
input string
want []string
}{
{
name: "typical pattern",
input: `{
"client_id": "191375729402-oiuj2498ry3497gjveoierj8294jfj41.apps.googleusercontent.com",
"client_secret": "z-OIFJWEOIJGWER91834325R",
"refresh_token": "1//0_joijgor3i4ut98579862709342j3kjJOIE02834jijfewoifjowiejfhghyzznfoiwejfwnvuhewiufnwinciwu_-o2i3jjfcc",
"type": "authorized_user"
}`,
want: []string{"191375729402-oiuj2498ry3497gjveoierj8294jfj41"},
},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
chunkSpecificDetectors := make(map[ahocorasick.DetectorKey]detectors.Detector, 2)
ahoCorasickCore.PopulateMatchingDetectors(test.input, chunkSpecificDetectors)
if len(chunkSpecificDetectors) == 0 {
t.Errorf("keywords '%v' not matched by: %s", d.Keywords(), test.input)
return
}
results, err := d.FromData(context.Background(), false, []byte(test.input))
if err != nil {
t.Errorf("error = %v", err)
return
}
if len(results) != len(test.want) {
if len(results) == 0 {
t.Errorf("did not receive result")
} else {
t.Errorf("expected %d results, only received %d", len(test.want), len(results))
}
return
}
actual := make(map[string]struct{}, len(results))
for _, r := range results {
if len(r.RawV2) > 0 {
actual[string(r.RawV2)] = struct{}{}
} else {
actual[string(r.Raw)] = struct{}{}
}
}
expected := make(map[string]struct{}, len(test.want))
for _, v := range test.want {
expected[v] = struct{}{}
}
if diff := cmp.Diff(expected, actual); diff != "" {
t.Errorf("%s diff: (-want +got)\n%s", test.name, diff)
}
})
}
}
func TestGcpapplicationdefaultcredentials_FromChunk(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
testSecrets, err := common.GetSecret(ctx, "trufflehog-testing", "detectors5")
if err != nil {
t.Fatalf("could not get test secrets from GCP: %s", err)
}
secret := testSecrets.MustGetField("GCPAPPLICATIONDEFAULTCREDENTIALS")
inactiveSecret := testSecrets.MustGetField("GCPAPPLICATIONDEFAULTCREDENTIALS_INACTIVE")
type args struct {
ctx context.Context
data []byte
verify bool
}
tests := []struct {
name string
s Scanner
args args
want []detectors.Result
wantErr bool
wantVerificationErr bool
}{
{
name: "found, verified",
s: Scanner{},
args: args{
ctx: context.Background(),
data: []byte(fmt.Sprintf("You can find a gcpapplicationdefaultcredentials secret %s within", secret)),
verify: true,
},
want: []detectors.Result{
{
DetectorType: detectorspb.DetectorType_GCPApplicationDefaultCredentials,
Verified: true,
},
},
wantErr: false,
wantVerificationErr: false,
},
{
name: "found, unverified",
s: Scanner{},
args: args{
ctx: context.Background(),
data: []byte(fmt.Sprintf("You can find a gcpapplicationdefaultcredentials secret %s within but not valid", inactiveSecret)), // the secret would satisfy the regex but not pass validation
verify: true,
},
want: []detectors.Result{
{
DetectorType: detectorspb.DetectorType_GCPApplicationDefaultCredentials,
Verified: false,
},
},
wantErr: false,
wantVerificationErr: false,
},
{
name: "not found",
s: Scanner{},
args: args{
ctx: context.Background(),
data: []byte("You cannot find the secret within"),
verify: true,
},
want: nil,
wantErr: false,
wantVerificationErr: false,
},
{
name: "found, would be verified if not for timeout",
s: Scanner{client: common.SaneHttpClientTimeOut(1 * time.Microsecond)},
args: args{
ctx: context.Background(),
data: []byte(fmt.Sprintf("You can find a gcpapplicationdefaultcredentials secret %s within", secret)),
verify: true,
},
want: []detectors.Result{
{
DetectorType: detectorspb.DetectorType_GCPApplicationDefaultCredentials,
Verified: false,
},
},
wantErr: false,
wantVerificationErr: true,
},
{
name: "found, verified but unexpected api surface",
s: Scanner{client: common.ConstantResponseHttpClient(404, "")},
args: args{
ctx: context.Background(),
data: []byte(fmt.Sprintf("You can find a gcpapplicationdefaultcredentials secret %s within", secret)),
verify: true,
},
want: []detectors.Result{
{
DetectorType: detectorspb.DetectorType_GCPApplicationDefaultCredentials,
Verified: false,
},
},
wantErr: false,
wantVerificationErr: true,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := tt.s.FromData(tt.args.ctx, tt.args.verify, tt.args.data)
if (err != nil) != tt.wantErr {
t.Errorf("Gcpapplicationdefaultcredentials.FromData() error = %v, wantErr %v", err, tt.wantErr)
return
}
for i := range got {
if len(got[i].Raw) == 0 {
t.Fatalf("no raw secret present: \n %+v", got[i])
}
if (got[i].VerificationError() != nil) != tt.wantVerificationErr {
t.Fatalf("wantVerificationError = %v, verification error = %v", tt.wantVerificationErr, got[i].VerificationError())
}
}
ignoreOpts := cmpopts.IgnoreFields(detectors.Result{}, "Raw", "verificationError")
if diff := cmp.Diff(got, tt.want, ignoreOpts); diff != "" {
t.Errorf("Gcpapplicationdefaultcredentials.FromData() %s diff: (-got +want)\n%s", tt.name, diff)
}
})
}
}
func BenchmarkFromData(benchmark *testing.B) {
ctx := context.Background()
s := Scanner{}
for name, data := range detectors.MustGetBenchmarkData() {
benchmark.Run(name, func(b *testing.B) {
b.ResetTimer()
for n := 0; n < b.N; n++ {
_, err := s.FromData(ctx, false, data)
if err != nil {
b.Fatal(err)
}
}
})
}
}

View file

@ -280,6 +280,7 @@ import (
fullstoryv2 "github.com/trufflesecurity/trufflehog/v3/pkg/detectors/fullstory/v2"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/fxmarket"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/gcp"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/gcpapplicationdefaultcredentials"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/geckoboard"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/gemini"
"github.com/trufflesecurity/trufflehog/v3/pkg/detectors/gengo"
@ -1596,6 +1597,7 @@ func DefaultDetectors() []detectors.Detector {
googleoauth2.Scanner{},
dockerhubv2.Scanner{},
&jupiterone.Scanner{},
gcpapplicationdefaultcredentials.Scanner{},
}
}

View file

@ -1081,6 +1081,7 @@ const (
DetectorType_FlyIO DetectorType = 980
DetectorType_BuiltWith DetectorType = 981
DetectorType_JupiterOne DetectorType = 982
DetectorType_GCPApplicationDefaultCredentials DetectorType = 983
)
// Enum value maps for DetectorType.
@ -2065,6 +2066,7 @@ var (
980: "FlyIO",
981: "BuiltWith",
982: "JupiterOne",
983: "GCPApplicationDefaultCredentials",
}
DetectorType_value = map[string]int32{
"Alibaba": 0,
@ -3038,14 +3040,15 @@ var (
"AzureDevopsPersonalAccessToken": 972,
"AzureFunctionKey": 973,
"AzureMLWebServiceClassicIdentifiableKey": 974,
"AzureSasToken": 975,
"AzureSearchAdminKey": 976,
"AzureSearchQueryKey": 977,
"AzureManagementCertificate": 978,
"AzureSQL": 979,
"FlyIO": 980,
"BuiltWith": 981,
"JupiterOne": 982,
"AzureSasToken": 975,
"AzureSearchAdminKey": 976,
"AzureSearchQueryKey": 977,
"AzureManagementCertificate": 978,
"AzureSQL": 979,
"FlyIO": 980,
"BuiltWith": 981,
"JupiterOne": 982,
"GCPApplicationDefaultCredentials": 983,
}
)
@ -3426,7 +3429,7 @@ var file_detectors_proto_rawDesc = []byte{
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@ -4428,12 +4431,14 @@ var file_detectors_proto_rawDesc = []byte{
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}
var (

View file

@ -992,6 +992,7 @@ enum DetectorType {
FlyIO = 980;
BuiltWith = 981;
JupiterOne = 982;
GCPApplicationDefaultCredentials = 983;
}
message Result {