Implementing JWKs

README.md

@@ -41,6 +41,13 @@ jwtware.New(config ...jwtware.Config) func(*fiber.Ctx) error
 | Claims | `jwt.Claim` | Claims are extendable claims data defining token content. | `jwt.MapClaims{}` |
 | TokenLookup | `string` | TokenLookup is a string in the form of `<source>:<name>` that is used | `"header:Authorization"` |
 | AuthScheme | `string` |AuthScheme to be used in the Authorization header. | `"Bearer"` |
+| KeySetURL | `string` |KeySetURL location of JSON file with signing keys. | `""` |
+| KeyRefreshSuccessHandler | `func(j *KeySet)` |KeyRefreshSuccessHandler defines a function which is executed for a valid refresh of signing keys.| `nil` |
+| KeyRefreshErrorHandler | `func(j *KeySet, err error)` |KeyRefreshErrorHandler defines a function which is executed for an invalid refresh of signing keys. | `nil` |
+| KeyRefreshInterval | `*time.Duration` |KeyRefreshInterval is the duration to refresh the JWKs in the background via a new HTTP request. | `nil` |
+| KeyRefreshRateLimit | `*time.Duration` |KeyRefreshRateLimit limits the rate at which refresh requests are granted.  | `nil` |
+| KeyRefreshTimeout | `*time.Duration` |KeyRefreshTimeout is the duration for the context used to create the HTTP request for a refresh of the JWKs. | `1min` |
+| KeyRefreshUnknownKID | `bool` |KeyRefreshUnknownKID indicates that the JWKs refresh request will occur every time a kid that isn't cached is seen. | `false` |
 
 
 ### HS256 Example
@@ -233,3 +240,6 @@ func restricted(c *fiber.Ctx) error {
 
 ### RS256 Test
 The RS256 is actually identical to the HS256 test above.
+
+### JWKs Test
+The tests are identical to basic `JWT` tests above, with exception that `KeySetURL` to valid public keys collection in JSON format should be supplied.

config.go

@@ -0,0 +1,179 @@
+package jwtware
+
+import (
+	"strings"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/golang-jwt/jwt/v4"
+)
+
+// KeyRefreshSuccessHandler is a function signature that consumes a set of signing key set.
+// Presence of original signing key set allows to update configuration or stop background refresh.
+type KeyRefreshSuccessHandler func(j *KeySet)
+
+// KeyRefreshErrorHandler is a function signature that consumes a set of signing key set and an error.
+// Presence of original signing key set allows to update configuration or stop background refresh.
+type KeyRefreshErrorHandler func(j *KeySet, err error)
+
+// Config defines the config for JWT middleware
+type Config struct {
+	// Filter defines a function to skip middleware.
+	// Optional. Default: nil
+	Filter func(*fiber.Ctx) bool
+
+	// SuccessHandler defines a function which is executed for a valid token.
+	// Optional. Default: nil
+	SuccessHandler fiber.Handler
+
+	// ErrorHandler defines a function which is executed for an invalid token.
+	// It may be used to define a custom JWT error.
+	// Optional. Default: 401 Invalid or expired JWT
+	ErrorHandler fiber.ErrorHandler
+
+	// Signing key to validate token. Used as fallback if SigningKeys has length 0.
+	// Required. This, SigningKeys or KeySetUrl.
+	SigningKey interface{}
+
+	// Map of signing keys to validate token with kid field usage.
+	// Required. This, SigningKey or KeySetUrl.
+	SigningKeys map[string]interface{}
+
+	// URL where set of private keys could be downloaded.
+	// Required. This, SigningKey or SigningKeys.
+	KeySetURL string
+
+	// KeyRefreshSuccessHandler defines a function which is executed on successful refresh of key set.
+	// Optional. Default: nil
+	KeyRefreshSuccessHandler KeyRefreshSuccessHandler
+
+	// KeyRefreshErrorHandler defines a function which is executed for refresh key set failure.
+	// Optional. Default: nil
+	KeyRefreshErrorHandler KeyRefreshErrorHandler
+
+	// KeyRefreshInterval is the duration to refresh the JWKs in the background via a new HTTP request. If this is not nil,
+	// then a background refresh will be requested in a separate goroutine at this interval until the JWKs method
+	// EndBackground is called.
+	// Optional. If set, the value will be used only if `KeySetUrl` is also present
+	KeyRefreshInterval *time.Duration
+
+	// KeyRefreshRateLimit limits the rate at which refresh requests are granted. Only one refresh request can be queued
+	// at a time any refresh requests received while there is already a queue are ignored. It does not make sense to
+	// have RefreshInterval's value shorter than this.
+	// Optional. If set, the value will be used only if `KeySetUrl` is also present
+	KeyRefreshRateLimit *time.Duration
+
+	// KeyRefreshTimeout is the duration for the context used to create the HTTP request for a refresh of the JWKs. This
+	// defaults to one minute. This is only effectual if RefreshInterval is not nil.
+	// Optional. If set, the value will be used only if `KeySetUrl` is also present
+	KeyRefreshTimeout *time.Duration
+
+	// KeyRefreshUnknownKID indicates that the JWKs refresh request will occur every time a kid that isn't cached is seen.
+	// Without specifying a RefreshInterval a malicious client could self-sign X JWTs, send them to this service,
+	// then cause potentially high network usage proportional to X.
+	// Optional. If set, the value will be used only if `KeySetUrl` is also present
+	KeyRefreshUnknownKID *bool
+
+	// Signing method, used to check token signing method.
+	// Optional. Default: "HS256".
+	// Possible values: "HS256", "HS384", "HS512", "ES256", "ES384", "ES512", "RS256", "RS384", "RS512"
+	SigningMethod string
+
+	// Context key to store user information from the token into context.
+	// Optional. Default: "user".
+	ContextKey string
+
+	// Claims are extendable claims data defining token content.
+	// Optional. Default value jwt.MapClaims
+	Claims jwt.Claims
+
+	// TokenLookup is a string in the form of "<source>:<name>" that is used
+	// to extract token from the request.
+	// Optional. Default value "header:Authorization".
+	// Possible values:
+	// - "header:<name>"
+	// - "query:<name>"
+	// - "param:<name>"
+	// - "cookie:<name>"
+	TokenLookup string
+
+	// AuthScheme to be used in the Authorization header.
+	// Optional. Default: "Bearer".
+	AuthScheme string
+
+	keyFunc jwt.Keyfunc
+}
+
+// makeCfg function will check correctness of supplied configuration
+// and will complement it with default values instead of missing ones
+func makeCfg(config []Config) (cfg Config) {
+	if len(config) > 0 {
+		cfg = config[0]
+	}
+	if cfg.SuccessHandler == nil {
+		cfg.SuccessHandler = func(c *fiber.Ctx) error {
+			return c.Next()
+		}
+	}
+	if cfg.ErrorHandler == nil {
+		cfg.ErrorHandler = func(c *fiber.Ctx, err error) error {
+			if err.Error() == "Missing or malformed JWT" {
+				return c.Status(fiber.StatusBadRequest).SendString("Missing or malformed JWT")
+			}
+			return c.Status(fiber.StatusUnauthorized).SendString("Invalid or expired JWT")
+		}
+	}
+	if cfg.SigningKey == nil && len(cfg.SigningKeys) == 0 && cfg.KeySetURL == "" {
+		panic("Fiber: JWT middleware requires signing key or url where to download one")
+	}
+	if cfg.SigningMethod == "" && cfg.KeySetURL == "" {
+		cfg.SigningMethod = "HS256"
+	}
+	if cfg.ContextKey == "" {
+		cfg.ContextKey = "user"
+	}
+	if cfg.Claims == nil {
+		cfg.Claims = jwt.MapClaims{}
+	}
+	if cfg.TokenLookup == "" {
+		cfg.TokenLookup = defaultTokenLookup
+	}
+	if cfg.AuthScheme == "" {
+		cfg.AuthScheme = "Bearer"
+	}
+	if cfg.KeyRefreshTimeout == nil {
+		cfg.KeyRefreshTimeout = &defaultKeyRefreshTimeout
+	}
+	if cfg.KeySetURL != "" {
+		jwks := &KeySet{
+			Config: &cfg,
+		}
+		cfg.keyFunc = jwks.keyFunc()
+	} else {
+		cfg.keyFunc = jwtKeyFunc(cfg)
+	}
+	return cfg
+}
+
+// getExtractors function will create a slice of functions which will be used
+// for token sarch  and will perform extraction of the value
+func (cfg *Config) getExtractors() []jwtExtractor {
+	// Initialize
+	extractors := make([]jwtExtractor, 0)
+	rootParts := strings.Split(cfg.TokenLookup, ",")
+	for _, rootPart := range rootParts {
+		parts := strings.Split(strings.TrimSpace(rootPart), ":")
+
+		switch parts[0] {
+		case "header":
+			extractors = append(extractors, jwtFromHeader(parts[1], cfg.AuthScheme))
+		case "query":
+			extractors = append(extractors, jwtFromQuery(parts[1]))
+		case "param":
+			extractors = append(extractors, jwtFromParam(parts[1]))
+		case "cookie":
+			extractors = append(extractors, jwtFromCookie(parts[1]))
+		}
+	}
+	return extractors
+}

config_test.go

@@ -0,0 +1,84 @@
+package jwtware
+
+import (
+	"testing"
+)
+
+func TestPanicOnMissingConfiguration(t *testing.T) {
+	t.Parallel()
+
+	defer func() {
+		// Assert
+		if err := recover(); err == nil {
+			t.Fatalf("Middleware should panic on missing configuration")
+		}
+	}()
+
+	// Arrange
+	config := make([]Config, 0)
+
+	// Act
+	makeCfg(config)
+}
+
+func TestDefaultConfiguration(t *testing.T) {
+	t.Parallel()
+
+	defer func() {
+		// Assert
+		if err := recover(); err != nil {
+			t.Fatalf("Middleware should not panic")
+		}
+	}()
+
+	// Arrange
+	config := append(make([]Config, 0), Config{
+		SigningKey: "",
+	})
+
+	// Act
+	cfg := makeCfg(config)
+
+	// Assert
+	if cfg.SigningMethod != HS256 {
+		t.Fatalf("Default signing method should be 'HS256'")
+	}
+	if cfg.ContextKey != "user" {
+		t.Fatalf("Default context key should be 'user'")
+	}
+	if cfg.Claims == nil {
+		t.Fatalf("Default claims should not be 'nil'")
+	}
+
+	if cfg.TokenLookup != defaultTokenLookup {
+		t.Fatalf("Default token lookup should be '%v'", defaultTokenLookup)
+	}
+	if cfg.AuthScheme != "Bearer" {
+		t.Fatalf("Default auth scheme should be 'Bearer'")
+	}
+}
+
+func TestExtractorsInitialization(t *testing.T) {
+	t.Parallel()
+
+	defer func() {
+		// Assert
+		if err := recover(); err != nil {
+			t.Fatalf("Middleware should not panic")
+		}
+	}()
+
+	// Arrange
+	cfg := Config{
+		SigningKey:  "",
+		TokenLookup: defaultTokenLookup + ",query:token,param:token,cookie:token,something:something",
+	}
+
+	// Act
+	extractors := cfg.getExtractors()
+
+	// Assert
+	if len(extractors) != 4 {
+		t.Fatalf("Extractors should not be created for invalid lookups")
+	}
+}