licverifier: Validate JWT token expiry (#10253)

With this change the expiry is validated for the license key JWT

pkg/licverifier/verifier.go

@@ -32,20 +32,21 @@ type LicenseVerifier struct {
 
 // LicenseInfo holds customer metadata present in the license key.
 type LicenseInfo struct {
-	Email           string `json:"sub"`         // Email of the license key requestor
-	TeamName        string `json:"teamName"`    // Subnet team name
-	AccountID       int64  `json:"accountId"`   // Subnet account id
-	StorageCapacity int64  `json:"capacity"`    // Storage capacity used in TB
-	ServiceType     string `json:"serviceType"` // Subnet service type
+	Email           string // Email of the license key requestor
+	TeamName        string // Subnet team name
+	AccountID       int64  // Subnet account id
+	StorageCapacity int64  // Storage capacity used in TB
+	ServiceType     string // Subnet service type
 }
 
-// Valid checks if customer metadata from the license key is valid.
-func (li *LicenseInfo) Valid() error {
-	if li.AccountID <= 0 {
-		return errors.New("Invalid accountId in claims")
-	}
-	return nil
-}
+// license key JSON field names
+const (
+	accountID   = "accountId"
+	sub         = "sub"
+	teamName    = "teamName"
+	capacity    = "capacity"
+	serviceType = "serviceType"
+)
 
 // NewLicenseVerifier returns an initialized license verifier with the given
 // ECDSA public key in PEM format.
@@ -59,14 +60,49 @@ func NewLicenseVerifier(pemBytes []byte) (*LicenseVerifier, error) {
 	}, nil
 }
 
+// toLicenseInfo extracts LicenseInfo from claims. It returns an error if any of
+// the claim values are invalid.
+func toLicenseInfo(claims jwt.MapClaims) (LicenseInfo, error) {
+	accID, ok := claims[accountID].(float64)
+	if ok && accID <= 0 {
+		return LicenseInfo{}, errors.New("Invalid accountId in claims")
+	}
+	email, ok := claims[sub].(string)
+	if !ok {
+		return LicenseInfo{}, errors.New("Invalid email in claims")
+	}
+	tName, ok := claims[teamName].(string)
+	if !ok {
+		return LicenseInfo{}, errors.New("Invalid team name in claims")
+	}
+	storageCap, ok := claims[capacity].(float64)
+	if !ok {
+		return LicenseInfo{}, errors.New("Invalid storage capacity in claims")
+	}
+	sType, ok := claims[serviceType].(string)
+	if !ok {
+		return LicenseInfo{}, errors.New("Invalid service type in claims")
+	}
+	return LicenseInfo{
+		Email:           email,
+		TeamName:        tName,
+		AccountID:       int64(accID),
+		StorageCapacity: int64(storageCap),
+		ServiceType:     sType,
+	}, nil
+
+}
+
 // Verify verifies the license key and validates the claims present in it.
 func (lv *LicenseVerifier) Verify(license string) (LicenseInfo, error) {
-	var licInfo LicenseInfo
-	_, err := jwt.ParseWithClaims(license, &licInfo, func(token *jwt.Token) (interface{}, error) {
+	token, err := jwt.ParseWithClaims(license, &jwt.MapClaims{}, func(token *jwt.Token) (interface{}, error) {
 		return lv.ecPubKey, nil
 	})
 	if err != nil {
 		return LicenseInfo{}, fmt.Errorf("Failed to verify license: %s", err)
 	}
-	return licInfo, nil
+	if claims, ok := token.Claims.(*jwt.MapClaims); ok && token.Valid {
+		return toLicenseInfo(*claims)
+	}
+	return LicenseInfo{}, errors.New("Invalid claims found in license")
 }

pkg/licverifier/verifier_test.go

@@ -19,8 +19,18 @@ package licverifier
 import (
 	"fmt"
 	"testing"
+	"time"
+
+	"github.com/dgrijalva/jwt-go"
 )
 
+// at fixes the jwt.TimeFunc at t and calls f in that context.
+func at(t time.Time, f func()) {
+	jwt.TimeFunc = func() time.Time { return t }
+	f()
+	jwt.TimeFunc = time.Now
+}
+
 // TestLicenseVerify tests the license key verification process with a valid and
 // an invalid key.
 func TestLicenseVerify(t *testing.T) {
@@ -48,18 +58,22 @@ mr/cKCUyBL7rcAvg0zNq1vcSrUSGlAmY3SEDCu3GOKnjG/U4E7+p957ocWSV+mQU
 	}
 
 	for i, tc := range testCases {
-		licInfo, err := lv.Verify(tc.lic)
-		if err != nil && tc.shouldPass {
-			t.Fatalf("%d: Expected license to pass verification but failed with %s", i+1, err)
-		}
-		if err == nil {
-			if !tc.shouldPass {
-				t.Fatalf("%d: Expected license to fail verification but passed", i+1)
+		// Fixing the jwt.TimeFunc at 2020-08-05 22:17:43 +0000 UTC to
+		// ensure that the license JWT doesn't expire ever.
+		at(time.Unix(int64(1596665863), 0), func() {
+			licInfo, err := lv.Verify(tc.lic)
+			if err != nil && tc.shouldPass {
+				t.Fatalf("%d: Expected license to pass verification but failed with %s", i+1, err)
 			}
-			if tc.expectedLicInfo != licInfo {
-				t.Fatalf("%d: Expected license info %v but got %v", i+1, tc.expectedLicInfo, licInfo)
+			if err == nil {
+				if !tc.shouldPass {
+					t.Fatalf("%d: Expected license to fail verification but passed", i+1)
+				}
+				if tc.expectedLicInfo != licInfo {
+					t.Fatalf("%d: Expected license info %v but got %v", i+1, tc.expectedLicInfo, licInfo)
+				}
 			}
-		}
+		})
 	}
 }