Add Robinhood Crypto detector (#3254)

* Add Robinhood Crypto detector

* Address comment - use single keyword

pkg/detectors/robinhoodcrypto/robinhoodcrypto.go

@@ -0,0 +1,195 @@
+package robinhoodcrypto
+
+import (
+	"context"
+	"crypto/ed25519"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	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"
+)
+
+type Scanner struct {
+	client *http.Client
+}
+
+// Ensure the Scanner satisfies the interface at compile time.
+var _ detectors.Detector = (*Scanner)(nil)
+
+var (
+	defaultClient = common.SaneHttpClient()
+
+	// Make sure that your group is surrounded in boundary characters such as below to reduce false positives.
+	// Reference: https://docs.robinhood.com/crypto/trading/#section/Authentication
+	keyPat = regexp.MustCompile(`\b(rh-api-[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12})\b`)
+
+	// Matches base64 strings. Taken from https://stackoverflow.com/a/475217.
+	privKeyBase64Pat = regexp.MustCompile(`(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)`)
+)
+
+// 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{"rh-api-"}
+}
+
+// FromData will find and optionally verify RobinhoodCrypto 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)
+
+	apiKeyMatches := make(map[string]struct{})
+	for _, match := range keyPat.FindAllStringSubmatch(dataStr, -1) {
+		apiKeyMatches[match[1]] = struct{}{}
+	}
+
+	base64PrivateKeyMatches := make(map[string]struct{})
+	for _, match := range privKeyBase64Pat.FindAllString(dataStr, -1) {
+		base64PrivateKeyMatches[match] = struct{}{}
+	}
+
+	for apiKey := range apiKeyMatches {
+		for base64PrivateKey := range base64PrivateKeyMatches {
+			s1 := detectors.Result{
+				DetectorType: detectorspb.DetectorType_RobinhoodCrypto,
+				Raw:          []byte(apiKey),
+				RawV2:        []byte(apiKey + base64PrivateKey),
+			}
+
+			if verify {
+				client := s.client
+				if client == nil {
+					client = defaultClient
+				}
+
+				isVerified, extraData, verificationErr := verifyMatch(ctx, client, apiKey, base64PrivateKey)
+				s1.Verified = isVerified
+				s1.ExtraData = extraData
+				s1.SetVerificationError(verificationErr, apiKey, base64PrivateKey)
+			}
+
+			results = append(results, s1)
+		}
+	}
+
+	return
+}
+
+func verifyMatch(ctx context.Context, client *http.Client, apiKey, base64PrivateKey string) (
+	bool, map[string]string, error,
+) {
+	// Decode the base64 private key.
+	privateBytes, err := base64.StdEncoding.DecodeString(base64PrivateKey)
+	if err != nil {
+		return false, nil, fmt.Errorf("failed to decode base64 private key: %w", err)
+	}
+
+	// Sanity check the private key length.
+	if len(privateBytes) < 32 {
+		return false, nil, fmt.Errorf("private key is too short, expected at least 32 bytes, got %d", len(privateBytes))
+	}
+
+	// Create the private key from the seed.
+	privateKey := ed25519.NewKeyFromSeed(privateBytes[:32])
+
+	// Draft the message to be signed.
+	// Reference: https://docs.robinhood.com/crypto/trading/#section/Authentication/Headers-and-Signature
+	var (
+		timestamp = fmt.Sprint(time.Now().UTC().Unix())
+		path      = "/api/v1/crypto/trading/accounts/"
+		method    = http.MethodGet
+		body      = ""
+	)
+
+	message := apiKey + timestamp + path + method + body
+	signature := ed25519.Sign(privateKey, []byte(message))
+
+	req, err := http.NewRequestWithContext(ctx, method, "https://trading.robinhood.com/"+path, strings.NewReader(body))
+	if err != nil {
+		return false, nil, nil
+	}
+
+	// Set the required headers.
+	headers := map[string]string{
+		"x-api-key":   apiKey,
+		"x-signature": base64.StdEncoding.EncodeToString(signature),
+		"x-timestamp": timestamp,
+	}
+	for key, value := range headers {
+		req.Header.Add(key, value)
+	}
+
+	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 {
+	// StatusOK: The secret is verified.
+	case http.StatusOK:
+		// Include the additional information returned by the endpoint.
+		if len(res.Header) > 0 && res.Header.Get("Content-Type") == "application/json" {
+			response := struct {
+				AccountNumber       string `json:"account_number"`
+				Status              string `json:"status"`
+				BuyingPower         string `json:"buying_power"`
+				BuyingPowerCurrency string `json:"buying_power_currency"`
+			}{}
+
+			if err = json.NewDecoder(res.Body).Decode(&response); err != nil {
+				return true, nil, fmt.Errorf("failed to obtain additional information: %w", err)
+			}
+
+			return true, map[string]string{"Robinhood Crypto Account Number": response.AccountNumber}, nil
+		}
+
+		// The secret is verified, but there is no additional information.
+		return true, nil, nil
+
+	// StatusForbidden: The secret is valid, but the credentials do not have access to the endpoint.
+	case http.StatusForbidden:
+		return true, map[string]string{"Explanation": "Valid credentials without access to Get Crypto Trading Account Details API"}, nil
+
+	// StatusUnauthorized:
+	// Two scenarios can happen,
+	// 		1. The secret is verified, but is currently inactive.
+	// 		2. The secret is determinately not verified.
+	case http.StatusUnauthorized:
+		// Check if the secret is verified but currently inactive.
+		// We want to handle this case because an inactive secret can be activated in the future, at which point it
+		// becomes a security risk.
+		if len(res.Header) > 0 && res.Header.Get("Content-Type") == "text/plain" {
+			body, err := io.ReadAll(res.Body)
+			if err != nil {
+				// The secret is considered verified but inactive only if the body suggests so. Since the body is not
+				// readable, we cannot determine if the secret is verified but inactive.
+				return false, nil, fmt.Errorf("failed to read response body: %w", err)
+			}
+
+			if strings.TrimSpace(string(body)) == "API credential is not active." {
+				return true, map[string]string{"Explanation": "Valid credentials in inactive state"}, nil
+			}
+		}
+
+		// The secret is determinately not verified (nothing to do)
+		return false, nil, nil
+	default:
+		return false, nil, fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
+	}
+}
+
+func (s Scanner) Type() detectorspb.DetectorType {
+	return detectorspb.DetectorType_RobinhoodCrypto
+}