Implement XSRFIgnoreMethods

README.md

@@ -609,6 +609,21 @@ For more details refer to [Complete Guide of Battle.net OAuth API and Login Butt
 1.	Fill **App name**  and **Description** and **URL** of your site
 1.	In the field **Callback URLs** enter the correct url of your callback handler e.g. https://example.mysite.com/{route}/twitter/callback
 1.	Under **Key and tokens** take note of the **Consumer API Key** and **Consumer API Secret key**. Those will be used as `cid` and `csecret`
+
+## XSRF Protections
+By default, the XSRF protections will apply to all requests which reach the `middlewares.Auth`,
+`middlewares.Admin` or `middlewares.RBAC` middlewares. This will require setting a request header 
+with a key of `<XSRFHeaderKey>` containing the value of the cookie named `<XSRFCookieName>`.
+
+To disable all XSRF protections, set `DisableXSRF` to `true`. This should probably only be used 
+during testing or debugging.
+
+When setting a custom request header is not possible, such as when building a web application which
+is not a Single-Page-Application and HTML link tags are used to navigate pages, specific HTTP methods
+may be excluded using the `XSRFIgnoreMethods` option. For example, to disable GET requests, set this
+option to `XSRFIgnoreMethods: []string{"GET"}`. Adding methods other than GET to this list may result
+in XSRF vulnerabilities.
+
 ## Status
 
 The library extracted from [remark42](https://github.com/umputun/remark) project. The original code in production use on multiple sites and seems to work fine.

auth.go

@@ -46,14 +46,15 @@ type Opts struct {
 	DisableIAT  bool // disable IssuedAt claim
 
 	// optional (custom) names for cookies and headers
-	JWTCookieName   string        // default "JWT"
-	JWTCookieDomain string        // default empty
-	JWTHeaderKey    string        // default "X-JWT"
-	XSRFCookieName  string        // default "XSRF-TOKEN"
-	XSRFHeaderKey   string        // default "X-XSRF-TOKEN"
-	JWTQuery        string        // default "token"
-	SendJWTHeader   bool          // if enabled send JWT as a header instead of cookie
-	SameSiteCookie  http.SameSite // limit cross-origin requests with SameSite cookie attribute
+	JWTCookieName     string        // default "JWT"
+	JWTCookieDomain   string        // default empty
+	JWTHeaderKey      string        // default "X-JWT"
+	XSRFCookieName    string        // default "XSRF-TOKEN"
+	XSRFHeaderKey     string        // default "X-XSRF-TOKEN"
+	XSRFIgnoreMethods []string      // disable XSRF protection for the specified request methods (ex. []string{"GET", "POST")}, default empty
+	JWTQuery          string        // default "token"
+	SendJWTHeader     bool          // if enabled send JWT as a header instead of cookie
+	SameSiteCookie    http.SameSite // limit cross-origin requests with SameSite cookie attribute
 
 	Issuer string // optional value for iss claim, usually the application name, default "go-pkgz/auth"
 

token/jwt.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"slices"
 	"strings"
 	"time"
 
@@ -49,6 +50,10 @@ const (
 	defaultTokenQuery = "token"
 )
 
+var (
+	defaultXSRFIgnoreMethods = []string{}
+)
+
 // Opts holds constructor params
 type Opts struct {
 	SecretReader   Secret
@@ -59,17 +64,18 @@ type Opts struct {
 	DisableXSRF    bool
 	DisableIAT     bool // disable IssuedAt claim
 	// optional (custom) names for cookies and headers
-	JWTCookieName   string
-	JWTCookieDomain string
-	JWTHeaderKey    string
-	XSRFCookieName  string
-	XSRFHeaderKey   string
-	JWTQuery        string
-	AudienceReader  Audience      // allowed aud values
-	Issuer          string        // optional value for iss claim, usually application name
-	AudSecrets      bool          // uses different secret for differed auds. important: adds pre-parsing of unverified token
-	SendJWTHeader   bool          // if enabled send JWT as a header instead of cookie
-	SameSite        http.SameSite // define a cookie attribute making it impossible for the browser to send this cookie cross-site
+	JWTCookieName     string
+	JWTCookieDomain   string
+	JWTHeaderKey      string
+	XSRFCookieName    string
+	XSRFHeaderKey     string
+	XSRFIgnoreMethods []string
+	JWTQuery          string
+	AudienceReader    Audience      // allowed aud values
+	Issuer            string        // optional value for iss claim, usually application name
+	AudSecrets        bool          // uses different secret for differed auds. important: adds pre-parsing of unverified token
+	SendJWTHeader     bool          // if enabled send JWT as a header instead of cookie
+	SameSite          http.SameSite // define a cookie attribute making it impossible for the browser to send this cookie cross-site
 }
 
 // NewService makes JWT service
@@ -90,6 +96,10 @@ func NewService(opts Opts) *Service {
 	setDefault(&res.Issuer, defaultIssuer)
 	setDefault(&res.JWTCookieDomain, defaultJWTCookieDomain)
 
+	if opts.XSRFIgnoreMethods == nil {
+		opts.XSRFIgnoreMethods = defaultXSRFIgnoreMethods
+	}
+
 	if opts.TokenDuration == 0 {
 		res.TokenDuration = defaultTokenDuration
 	}
@@ -293,7 +303,7 @@ func (j *Service) Get(r *http.Request) (Claims, string, error) {
 		return Claims{}, "", fmt.Errorf("token expired")
 	}
 
-	if j.DisableXSRF {
+	if j.DisableXSRF || slices.Contains(j.XSRFIgnoreMethods, r.Method) {
 		return claims, tokenString, nil
 	}
 

token/jwt_test.go

@@ -471,6 +471,53 @@ func TestJWT_SetAndGetWithXsrfMismatch(t *testing.T) {
 	assert.Equal(t, claims, c)
 }
 
+func TestJWT_GetWithXsrfMismatchOnIgnoredMethod(t *testing.T) {
+	j := NewService(Opts{SecretReader: SecretFunc(mockKeyStore), SecureCookies: false,
+		TokenDuration: time.Hour, CookieDuration: days31,
+		JWTCookieName: jwtCustomCookieName, JWTHeaderKey: jwtCustomHeaderKey,
+		XSRFCookieName: xsrfCustomCookieName, XSRFHeaderKey: xsrfCustomHeaderKey,
+		ClaimsUpd: ClaimsUpdFunc(func(claims Claims) Claims {
+			claims.User.SetStrAttr("stra", "stra-val")
+			claims.User.SetBoolAttr("boola", true)
+			return claims
+		}),
+		Issuer:     "remark42",
+		DisableIAT: true,
+	})
+
+	claims := testClaims
+	claims.SessionOnly = true
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/valid" {
+			_, e := j.Set(w, claims)
+			require.NoError(t, e)
+			w.WriteHeader(200)
+		}
+	}))
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL + "/valid")
+	require.Nil(t, err)
+	assert.Equal(t, 200, resp.StatusCode)
+
+	j.XSRFIgnoreMethods = []string{"GET"}
+	req := httptest.NewRequest("GET", "/valid", nil)
+	req.AddCookie(resp.Cookies()[0])
+	req.Header.Add(xsrfCustomHeaderKey, "random id wrong")
+	_, _, err = j.Get(req)
+	require.NoError(t, err, "xsrf mismatch, but ignored")
+
+	j.DisableXSRF = true
+	j.XSRFIgnoreMethods = []string{}
+	req = httptest.NewRequest("GET", "/valid", nil)
+	req.AddCookie(resp.Cookies()[0])
+	req.Header.Add(xsrfCustomHeaderKey, "random id wrong")
+	c, _, err := j.Get(req)
+	require.NoError(t, err, "xsrf mismatch, but ignored")
+	claims.User.Audience = c.Audience // set aud to user because we don't do the normal Get call
+	assert.Equal(t, claims, c)
+}
+
 func TestJWT_SetAndGetWithCookiesExpired(t *testing.T) {
 	j := NewService(Opts{SecretReader: SecretFunc(mockKeyStore), SecureCookies: false,
 		TokenDuration: time.Hour, CookieDuration: days31,