Added the skip_verification option.

Makefile

@@ -10,9 +10,6 @@ GOTEST=$(GO) test
 GOCOVER=$(GO) tool cover
 XCADDY=xcaddy
 
-example:
-	$(XCADDY) run -config=example/caddy.json
-
 debug:
 	XCADDY_DEBUG=1 $(XCADDY) build --with github.com/ggicci/caddy-jwt=$(shell pwd)
 
@@ -24,4 +21,4 @@ test/cover:
 test/report:
 	$(GOCOVER) -html=main.cover.out
 
-.PHONY: example debug test test/cover test/report
+.PHONY: debug test test/cover test/report

README.md

@@ -118,10 +118,12 @@ Module **caddy-jwt** behaves like a **"JWT Validator"**. The authentication flow
    │  3. cookies      │
    └────────┬─────────┘
             │
-    ┌───────▼────────┐
-    │   is valid?    │
-    │using `sign_key`├────NO───────┐
-    └───────┬────────┘             │
+    ┌───────▼───────────┐
+    │     is valid?     │
+    │  using `sign_key` │
+    │ or validation is  │
+    │     disabled      ├─NO───────┐
+    └───────┬───────────┘          │
             │YES                   │
 ┌───────────▼───────────┐          │
 │Populate {http.user.id}│          │

caddyfile.go

@@ -40,6 +40,8 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
 				if !h.AllArgs(&ja.JWKURL) {
 					return nil, h.Errf("invalid jwk_url: %q", ja.JWKURL)
 				}
+			case "skip_verification":
+				ja.SkipVerification = true
 			case "from_query":
 				ja.FromQuery = h.RemainingArgs()
 

caddyfile_test.go

@@ -174,3 +174,38 @@ func TestParseMetaClaim(t *testing.T) {
 		}
 	}
 }
+
+func TestParsingCaddyfileWithSkipVerification(t *testing.T) {
+	helper := httpcaddyfile.Helper{
+		Dispenser: caddyfile.NewTestDispenser(`
+	jwtauth {
+		skip_verification
+		from_query access_token token _tok
+		from_header X-Api-Key
+		from_cookies user_session SESSID
+		issuer_whitelist https://api.example.com
+		audience_whitelist https://api.example.io https://learn.example.com
+		user_claims uid user_id login username
+		meta_claims "IsAdmin -> is_admin" "gender"
+	}
+	`),
+	}
+	expectedJA := &JWTAuth{
+		SkipVerification:  true,
+		FromQuery:         []string{"access_token", "token", "_tok"},
+		FromHeader:        []string{"X-Api-Key"},
+		FromCookies:       []string{"user_session", "SESSID"},
+		IssuerWhitelist:   []string{"https://api.example.com"},
+		AudienceWhitelist: []string{"https://api.example.io", "https://learn.example.com"},
+		UserClaims:        []string{"uid", "user_id", "login", "username"},
+		MetaClaims:        map[string]string{"IsAdmin": "is_admin", "gender": "gender"},
+	}
+
+	h, err := parseCaddyfile(helper)
+	assert.Nil(t, err)
+	auth, ok := h.(caddyauth.Authentication)
+	assert.True(t, ok)
+	jsonConfig, ok := auth.ProvidersRaw["jwt"]
+	assert.True(t, ok)
+	assert.Equal(t, caddyconfig.JSON(expectedJA, nil), jsonConfig)
+}

jwt.go

@@ -52,7 +52,7 @@ type JWTAuth struct {
 	// If you'd like to use JWK, set this field and leave SignKey unset.
 	JWKURL string `json:"jwk_url"`
 
-	// SignAlgorithm is the the signing algorithm used. Available values are defined in
+	// SignAlgorithm is the signing algorithm used. Available values are defined in
 	// https://www.rfc-editor.org/rfc/rfc7518#section-3.1
 	// This is an optional field, which is used for determining the signing algorithm.
 	// We will try to determine the algorithm automatically from the following sources:
@@ -61,6 +61,19 @@ type JWTAuth struct {
 	// 3. The value set here.
 	SignAlgorithm string `json:"sign_alg"`
 
+	// SkipVerification disables the verification of the JWT token signature.
+	//
+	// Use this option with caution, as it bypasses JWT signature verification.
+	// This can be useful if the token's signature has already been verified before
+	// reaching this proxy server or will be verified later, preventing redundant
+	// verifications and handling of the same token multiple times.
+	//
+	// This is particularly relevant if you want to use this plugin for routing
+	// based on the JWT payload, while avoiding unnecessary signature checks.
+	//
+	// This flag also disables usage and check of both JWKURL and SignAlgorithm options.
+	SkipVerification bool `json:"skip_verification"`
+
 	// FromQuery defines a list of names to get tokens from the query parameters
 	// of an HTTP request.
 	//
@@ -182,6 +195,26 @@ func (ja *JWTAuth) refreshJWKCache() {
 
 // Validate implements caddy.Validator interface.
 func (ja *JWTAuth) Validate() error {
+	if !ja.SkipVerification {
+		if err := ja.validateSignatureKeys(); err != nil {
+			return err
+		}
+	}
+
+	if len(ja.UserClaims) == 0 {
+		ja.UserClaims = []string{
+			"sub",
+		}
+	}
+	for claim, placeholder := range ja.MetaClaims {
+		if claim == "" || placeholder == "" {
+			return fmt.Errorf("invalid meta claim: %s -> %s", claim, placeholder)
+		}
+	}
+	return nil
+}
+
+func (ja *JWTAuth) validateSignatureKeys() error {
 	if ja.usingJWK() {
 		ja.setupJWKLoader()
 	} else {
@@ -205,16 +238,6 @@ func (ja *JWTAuth) Validate() error {
 		}
 	}
 
-	if len(ja.UserClaims) == 0 {
-		ja.UserClaims = []string{
-			"sub",
-		}
-	}
-	for claim, placeholder := range ja.MetaClaims {
-		if claim == "" || placeholder == "" {
-			return fmt.Errorf("invalid meta claim: %s -> %s", claim, placeholder)
-		}
-	}
 	return nil
 }
 
@@ -277,7 +300,14 @@ func (ja *JWTAuth) Authenticate(rw http.ResponseWriter, r *http.Request) (User,
 			continue
 		}
 
-		gotToken, err = jwt.ParseString(tokenString, jwt.WithKeyProvider(ja.keyProvider()))
+		jwtOptions := []jwt.ParseOption{
+			jwt.WithVerify(!ja.SkipVerification),
+		}
+		if !ja.SkipVerification {
+			jwtOptions = append(jwtOptions, jwt.WithKeyProvider(ja.keyProvider()))
+		}
+		gotToken, err = jwt.ParseString(tokenString, jwtOptions...)
+
 		checked[tokenString] = struct{}{}
 
 		logger := ja.logger.With(zap.String("token_string", desensitizedTokenString(tokenString)))

jwt_test.go

@@ -191,6 +191,17 @@ func TestValidate_usingJWK(t *testing.T) {
 	assert.Nil(t, err)
 }
 
+// TestValidate_SkipVerification checks that validation does not fail when
+// SkipVerification is enabled and no keys are provided. This ensures that
+// enabling SkipVerification bypasses signature and keys validation without errors.
+func TestValidate_SkipVerification(t *testing.T) {
+	// skipping verification
+	ja := &JWTAuth{
+		SkipVerification: true,
+	}
+	assert.NoError(t, ja.Validate())
+}
+
 func TestValidate_InvalidMetaClaims(t *testing.T) {
 	ja := &JWTAuth{
 		SignKey: TestSignKey,
@@ -247,6 +258,87 @@ func TestAuthenticate_FromCustomHeader(t *testing.T) {
 	assert.Equal(t, User{ID: "ggicci"}, gotUser)
 }
 
+func TestAuthenticate_FromQueryWithSkipVerification(t *testing.T) {
+	var (
+		claims = MapClaims{"sub": "ggicci"}
+		ja     = &JWTAuth{
+			FromQuery:        []string{"access_token", "token"},
+			SkipVerification: true,
+			logger:           testLogger,
+		}
+		tokenString = issueTokenString(claims)
+
+		err           error
+		rw            *httptest.ResponseRecorder
+		r             *http.Request
+		params        url.Values
+		gotUser       User
+		authenticated bool
+	)
+	assert.Nil(t, ja.Validate())
+
+	// trying "access_token" without signature key
+	rw = httptest.NewRecorder()
+	r, _ = http.NewRequest("GET", "/", nil)
+	params = make(url.Values)
+	params.Add("access_token", tokenString)
+	r.URL.RawQuery = params.Encode()
+	gotUser, authenticated, err = ja.Authenticate(rw, r)
+	assert.Nil(t, err)
+	assert.True(t, authenticated)
+	assert.Equal(t, User{ID: "ggicci"}, gotUser)
+
+	// invalid "token" without signature key
+	rw = httptest.NewRecorder()
+	r, _ = http.NewRequest("GET", "/", nil)
+	params = make(url.Values)
+	params.Add("access_token", tokenString+"INVALID")
+	params.Add("token", tokenString)
+	r.URL.RawQuery = params.Encode()
+	gotUser, authenticated, err = ja.Authenticate(rw, r)
+	assert.Nil(t, err)
+	assert.True(t, authenticated)
+	assert.Equal(t, User{ID: "ggicci"}, gotUser)
+}
+
+func TestAuthenticate_PopulateUserMetadataWithSkipVerification(t *testing.T) {
+	ja := &JWTAuth{
+		SkipVerification: true,
+		MetaClaims: map[string]string{
+			"jti":                            "jti",
+			"IsAdmin":                        "is_admin",
+			"settings.role":                  "role",
+			"settings.payout.paypal.enabled": "is_paypal_enabled",
+		},
+		logger: testLogger,
+	}
+	assert.Nil(t, ja.Validate())
+
+	claimsWithMetadata := MapClaims{
+		"jti":     "a976475a-186a-4c1f-b182-95b3f886e2b4",
+		"sub":     "ggicci",
+		"IsAdmin": true,
+		"settings": map[string]interface{}{
+			"role": "admin",
+			"payout": map[string]interface{}{
+				"paypal": map[string]interface{}{
+					"enabled": true,
+				},
+			},
+		},
+	}
+	rw := httptest.NewRecorder()
+	r, _ := http.NewRequest("GET", "/", nil)
+	r.Header.Add("Authorization", issueTokenString(claimsWithMetadata))
+	gotUser, authenticated, err := ja.Authenticate(rw, r)
+	assert.Nil(t, err)
+	assert.True(t, authenticated)
+	assert.Equal(t, "a976475a-186a-4c1f-b182-95b3f886e2b4", gotUser.Metadata["jti"])
+	assert.Equal(t, "true", gotUser.Metadata["is_admin"])
+	assert.Equal(t, "admin", gotUser.Metadata["role"])
+	assert.Equal(t, "true", gotUser.Metadata["is_paypal_enabled"])
+}
+
 func TestAuthenticate_FromQuery(t *testing.T) {
 	var (
 		claims = MapClaims{"sub": "ggicci"}