jwt: add the (last) helper: VerifyRefreshToken

_examples/auth/jwt/refresh-token/main.go

@@ -60,7 +60,8 @@ func main() {
 	// http://localhost:8080/protected?token={access_token} (200)
 	// http://localhost:8080/protected?token={refresh_token} (401)
 	// http://localhost:8080/refresh?token={refresh_token}
-	// OR (request JSON{refresh_token = {refresh_token}}) (200) (response JSON {access_token, refresh_token})
+	// OR http://localhost:8080/refresh (request JSON{refresh_token = {refresh_token}}) (200) (response JSON {access_token, refresh_token})
+	// OR http://localhost:8080/refresh (request PLAIN TEXT of {refresh_token}) (200) (response JSON {access_token, refresh_token})
 	// http://localhost:8080/refresh?token={access_token} (401)
 	app.Listen(":8080")
 }
@@ -95,45 +96,36 @@ func generateTokenPair(ctx iris.Context, j *jwt.JWT) {
 }
 
 func refreshToken(ctx iris.Context, j *jwt.JWT) {
-	var tokenPair jwt.TokenPair
+	/*
+		We could pass a jwt.Claims pointer as the second argument,
+		but we don't have to because the method already returns
+		the standard JWT claims information back to us:
+		refresh, err := VerifyRefreshToken(ctx, nil)
+	*/
 
-	if token := ctx.URLParam("token"); token != "" {
-		// Grab the refresh token from the url argument.
-		tokenPair.RefreshToken = token
-	} else {
-		// Otherwise grab the refresh token from a JSON body (you can let it fetch by URL parameter too but
-		// it's common practice that you read it from a json body as
-		// it may contain the access token too (the same response we sent on generateTokenPair)).
-		err := ctx.ReadJSON(&tokenPair)
-		if err != nil {
-			ctx.StatusCode(iris.StatusBadRequest)
-			return
-		}
-	}
+	// Assuming you have access to the current user, e.g. sessions.
+	//
+	// Simulate a database call against our jwt subject
+	// to make sure that this refresh token is a pair generated by this user.
+	// * Note: You can remove the ExpectSubject and do this validation later on by yourself.
+	currentUserID := "53afcf05-38a3-43c3-82af-8bbbe0e4a149"
 
-	var refreshClaims jwt.Claims
-	_, err := j.VerifyTokenString(ctx, tokenPair.RefreshToken, &refreshClaims, jwt.ExpectRefreshToken)
+	// Verify the refresh token, which its subject MUST match the "currentUserID".
+	_, err := j.VerifyRefreshToken(ctx, nil, jwt.ExpectSubject(currentUserID))
 	if err != nil {
 		ctx.Application().Logger().Debugf("verify refresh token: %v", err)
 		ctx.StatusCode(iris.StatusUnauthorized)
 		return
 	}
 
-	// Assuming you have access to the current user, e.g. sessions.
-	//
-	// Simulate a database call against our jwt subject
-	// to make sure that this refresh token is a pair generated by this user.
+	/* Custom validation checks can be performed after Verify calls too:
 	currentUserID := "53afcf05-38a3-43c3-82af-8bbbe0e4a149"
-
-	userID := refreshClaims.Subject
+	userID := refresh.Claims.Subject
 	if userID != currentUserID {
 		ctx.StopWithStatus(iris.StatusUnauthorized)
 		return
 	}
-	//
-	// Otherwise, the request must contain the (old) access token too,
-	// even if it's invalid, we can still fetch its fields, such as the user id.
-	// [...leave it for you]
+	*/
 
 	// All OK, re-generate the new pair and send to client.
 	generateTokenPair(ctx, j)

context/context.go

@@ -2410,7 +2410,28 @@ func (ctx *Context) ReadMsgPack(ptr interface{}) error {
 // If a GET method request then it reads from a form (or URL Query), otherwise
 // it tries to match (depending on the request content-type) the data format e.g.
 // JSON, Protobuf, MsgPack, XML, YAML, MultipartForm and binds the result to the "ptr".
+// As a special case if the "ptr" was a pointer to string or []byte
+// then it will bind it to the request body as it is.
 func (ctx *Context) ReadBody(ptr interface{}) error {
+
+	// If the ptr is string or byte, read the body as it's.
+	switch v := ptr.(type) {
+	case *string:
+		b, err := ctx.GetBody()
+		if err != nil {
+			return err
+		}
+
+		*v = string(b)
+	case *[]byte:
+		b, err := ctx.GetBody()
+		if err != nil {
+			return err
+		}
+
+		copy(*v, b)
+	}
+
 	if ctx.Method() == http.MethodGet {
 		if ctx.Request().URL.RawQuery != "" {
 			// try read from query.

middleware/jwt/jwt.go

@@ -395,6 +395,32 @@ func (j *JWT) VerifyToken(ctx *context.Context, claimsPtr interface{}, expectati
 	return j.VerifyTokenString(ctx, token, claimsPtr, expectations...)
 }
 
+// VerifyRefreshToken like the `VerifyToken` but it verifies a refresh token one instead.
+// If the implementation does not fill the application's requirements,
+// you can ignore this method and still use the `VerifyToken` for refresh tokens too.
+//
+// This method adds the ExpectRefreshToken expectation and it
+// tries to read the refresh token from raw body or,
+// if content type was application/json, then it extracts the token
+// from the JSON request body's {"refresh_token": "$token"} key.
+func (j *JWT) VerifyRefreshToken(ctx *context.Context, claimsPtr interface{}, expectations ...Expectation) (*TokenInfo, error) {
+	token := j.RequestToken(ctx)
+	if token == "" {
+		var tokenPair TokenPair // read "refresh_token" from JSON.
+		if ctx.GetContentTypeRequested() == context.ContentJSONHeaderValue {
+			ctx.ReadJSON(&tokenPair) // ignore error.
+			token = tokenPair.RefreshToken
+			if token == "" {
+				return nil, ErrMissing
+			}
+		} else {
+			ctx.ReadBody(&token)
+		}
+	}
+
+	return j.VerifyTokenString(ctx, token, claimsPtr, append(expectations, ExpectRefreshToken)...)
+}
+
 // RequestToken extracts the token from the request.
 func (j *JWT) RequestToken(ctx *context.Context) (token string) {
 	for _, extract := range j.Extractors {
@@ -536,10 +562,34 @@ func (j *JWT) VerifyTokenString(ctx *context.Context, token string, dest interfa
 		tokenMaxAger tokenWithMaxAge
 	)
 
-	if err = parsedToken.Claims(j.VerificationKey, dest, &claims, &tokenMaxAger); err != nil {
+	var (
+		ignoreDest      = dest == nil
+		ignoreVarClaims bool
+	)
+	if !ignoreDest { // if dest was not nil, check if the dest is already a standard claims pointer.
+		_, ignoreVarClaims = dest.(*Claims)
+	}
+
+	// Ensure read the standard claims one  if dest was Claims or was nil.
+	// (it wont break anything if we unmarshal them twice though, we just do it for performance reasons).
+	var pointers = []interface{}{&tokenMaxAger}
+	if !ignoreDest {
+		pointers = append(pointers, dest)
+	}
+	if !ignoreVarClaims {
+		pointers = append(pointers, &claims)
+	}
+	if err = parsedToken.Claims(j.VerificationKey, pointers...); err != nil {
 		return nil, err
 	}
 
+	// Set the std claims, if missing from receiver so the expectations and validation still work.
+	if ignoreVarClaims {
+		claims = *dest.(*Claims)
+	} else if ignoreDest {
+		dest = &claims
+	}
+
 	expectMaxAge := j.MaxAge
 
 	// Build the Expected value.
@@ -594,11 +644,13 @@ func (j *JWT) VerifyTokenString(ctx *context.Context, token string, dest interfa
 		}
 	}
 
+	if !ignoreDest {
 		if ut, ok := dest.(TokenSetter); ok {
 			// The u.Token is empty even if we set it and export it on JSON structure.
 			// Set it manually.
 			ut.SetToken(token)
 		}
+	}
 
 	// Set the information.
 	tokenInfo := &TokenInfo{