validate keys for idp's with key rotation mechanism

management/server/config.go

@@ -80,6 +80,8 @@ type HttpServerConfig struct {
 	AuthKeysLocation string
 	// OIDCConfigEndpoint is the endpoint of an IDP manager to get OIDC configuration
 	OIDCConfigEndpoint string
+	// KeyRotationEnabled identifies the signing key is currently being rotated or not
+	KeyRotationEnabled bool
 }
 
 // Host represents a Wiretrustee host (e.g. STUN, TURN, Signal)

management/server/jwtclaims/jwtValidator.go

@@ -12,6 +12,9 @@ import (
 	"fmt"
 	"math/big"
 	"net/http"
+	"strconv"
+	"strings"
+	"time"
 
 	"github.com/golang-jwt/jwt"
 	log "github.com/sirupsen/logrus"
@@ -45,7 +48,8 @@ type Options struct {
 
 // Jwks is a collection of JSONWebKey obtained from Config.HttpServerConfig.AuthKeysLocation
 type Jwks struct {
-	Keys []JSONWebKey `json:"keys"`
+	Keys          []JSONWebKey `json:"keys"`
+	expiresInTime time.Time
 }
 
 // JSONWebKey is a representation of a Jason Web Key
@@ -64,7 +68,7 @@ type JWTValidator struct {
 }
 
 // NewJWTValidator constructor
-func NewJWTValidator(issuer string, audienceList []string, keysLocation string) (*JWTValidator, error) {
+func NewJWTValidator(issuer string, audienceList []string, keysLocation string, keyRotationEnabled bool) (*JWTValidator, error) {
 	keys, err := getPemKeys(keysLocation)
 	if err != nil {
 		return nil, err
@@ -89,6 +93,19 @@ func NewJWTValidator(issuer string, audienceList []string, keysLocation string)
 				return token, errors.New("invalid issuer")
 			}
 
+			// If keys are rotated, verify the keys prior to token validation
+			if keyRotationEnabled {
+				// If the keys are invalid, retrieve new ones
+				if !keys.stillValid() {
+
+					keys, err = getPemKeys(keysLocation)
+					if err != nil {
+						log.Errorf("cannot get JSONWebKey: %v", err)
+						return nil, err
+					}
+				}
+			}
+
 			cert, err := getPemCert(token, keys)
 			if err != nil {
 				return nil, err
@@ -154,6 +171,11 @@ func (m *JWTValidator) ValidateAndParse(token string) (*jwt.Token, error) {
 	return parsedToken, nil
 }
 
+// stillValid returns true if the JSONWebKey still valid and have enough time to be used
+func (jwks *Jwks) stillValid() bool {
+	return jwks.expiresInTime.IsZero() && time.Now().Add(5*time.Second).Before(jwks.expiresInTime)
+}
+
 func getPemKeys(keysLocation string) (*Jwks, error) {
 	resp, err := http.Get(keysLocation)
 	if err != nil {
@@ -167,6 +189,10 @@ func getPemKeys(keysLocation string) (*Jwks, error) {
 		return jwks, err
 	}
 
+	cacheControlHeader := resp.Header.Get("Cache-Control")
+	expiresIn := getMaxAgeFromCacheHeader(cacheControlHeader)
+	jwks.expiresInTime = time.Now().Add(time.Duration(expiresIn) * time.Second)
+
 	return jwks, err
 }
 
@@ -248,3 +274,26 @@ func convertExponentStringToInt(stringExponent string) (int, error) {
 
 	return int(exponent), nil
 }
+
+// getMaxAgeFromCacheHeader extracts max-age directive from the Cache-Control header
+func getMaxAgeFromCacheHeader(cacheControl string) int {
+	// Split into individual directives
+	directives := strings.Split(cacheControl, ",")
+
+	for _, directive := range directives {
+		directive = strings.TrimSpace(directive)
+		if strings.HasPrefix(directive, "max-age=") {
+			// Extract the max-age value
+			maxAgeStr := strings.TrimPrefix(directive, "max-age=")
+			maxAge, err := strconv.Atoi(maxAgeStr)
+			if err != nil {
+				log.Debugf("error parsing max-age: %v", err)
+				return 0
+			}
+
+			return maxAge
+		}
+	}
+
+	return 0
+}