TUN-7424: Add CORS headers to host_details responses

go.mod

@@ -66,6 +66,7 @@ require (
 	github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 // indirect
 	github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 // indirect
 	github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 // indirect
+	github.com/go-chi/cors v1.2.1 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect

go.sum

@@ -156,6 +156,8 @@ github.com/gin-gonic/gin v1.6.3/go.mod h1:75u5sXoLsGZoRN5Sgbi1eraJ4GU3++wFwWzhwv
 github.com/gin-gonic/gin v1.8.1 h1:4+fr/el88TOO3ewCmQr8cx/CtZ/umlIRIs5M4NTNjf8=
 github.com/go-chi/chi/v5 v5.0.8 h1:lD+NLqFcAi1ovnVZpsnObHGW4xb4J8lNmoYVfECH1Y0=
 github.com/go-chi/chi/v5 v5.0.8/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/go-chi/cors v1.2.1 h1:xEC8UT3Rlp2QuWNEr4Fs/c2EAGVKBwy/1vHx3bppil4=
+github.com/go-chi/cors v1.2.1/go.mod h1:sSbTewc+6wYHBBCW7ytsFSn836hqM7JxpglAy2Vzc58=
 github.com/go-errors/errors v1.4.2 h1:J6MZopCL4uSllY1OfXM374weqZFFItUbrImctkmUxIA=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=

management/service.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/cors"
 	"github.com/google/uuid"
 	"github.com/rs/zerolog"
 	"nhooyr.io/websocket"
@@ -67,7 +68,17 @@ func New(managementHostname string,
 	r.Get("/ping", ping)
 	r.Head("/ping", ping)
 	r.Get("/logs", s.logs)
-	r.Get("/host_details", s.getHostDetails)
+	r.Route("/host_details", func(r chi.Router) {
+		// CORS middleware required to allow dash to access management.argotunnel.com requests
+		r.Use(cors.Handler(cors.Options{
+			// Allows for any subdomain of cloudflare.com
+			AllowedOrigins: []string{"https://*.cloudflare.com"},
+			// Required to present cookies or other authentication across origin boundries
+			AllowCredentials: true,
+			MaxAge:           300, // Maximum value not ignored by any of major browsers
+		}))
+		r.Get("/", s.getHostDetails)
+	})
 	s.router = r
 	return s
 }

vendor/github.com/go-chi/cors/LICENSE

@@ -0,0 +1,21 @@
+Copyright (c) 2014 Olivier Poitrey <rs@dailymotion.com>
+Copyright (c) 2016-Present https://github.com/go-chi authors
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/go-chi/cors/README.md

@@ -0,0 +1,39 @@
+# CORS net/http middleware
+
+[go-chi/cors](https://github.com/go-chi/cors) is a fork of [github.com/rs/cors](https://github.com/rs/cors) that
+provides a `net/http` compatible middleware for performing preflight CORS checks on the server side. These headers
+are required for using the browser native [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API).
+
+This middleware is designed to be used as a top-level middleware on the [chi](https://github.com/go-chi/chi) router.
+Applying with within a `r.Group()` or using `With()` will not work without routes matching `OPTIONS` added.
+
+## Usage
+
+```go
+func main() {
+  r := chi.NewRouter()
+
+  // Basic CORS
+  // for more ideas, see: https://developer.github.com/v3/#cross-origin-resource-sharing
+  r.Use(cors.Handler(cors.Options{
+    // AllowedOrigins:   []string{"https://foo.com"}, // Use this to allow specific origin hosts
+    AllowedOrigins:   []string{"https://*", "http://*"},
+    // AllowOriginFunc:  func(r *http.Request, origin string) bool { return true },
+    AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+    AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
+    ExposedHeaders:   []string{"Link"},
+    AllowCredentials: false,
+    MaxAge:           300, // Maximum value not ignored by any of major browsers
+  }))
+
+  r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+    w.Write([]byte("welcome"))
+  })
+
+  http.ListenAndServe(":3000", r)
+}
+```
+
+## Credits
+
+All credit for the original work of this middleware goes out to [github.com/rs](github.com/rs).

vendor/github.com/go-chi/cors/cors.go

@@ -0,0 +1,400 @@
+// cors package is net/http handler to handle CORS related requests
+// as defined by http://www.w3.org/TR/cors/
+//
+// You can configure it by passing an option struct to cors.New:
+//
+//     c := cors.New(cors.Options{
+//         AllowedOrigins: []string{"foo.com"},
+//         AllowedMethods: []string{"GET", "POST", "DELETE"},
+//         AllowCredentials: true,
+//     })
+//
+// Then insert the handler in the chain:
+//
+//     handler = c.Handler(handler)
+//
+// See Options documentation for more options.
+//
+// The resulting handler is a standard net/http handler.
+package cors
+
+import (
+	"log"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// Options is a configuration container to setup the CORS middleware.
+type Options struct {
+	// AllowedOrigins is a list of origins a cross-domain request can be executed from.
+	// If the special "*" value is present in the list, all origins will be allowed.
+	// An origin may contain a wildcard (*) to replace 0 or more characters
+	// (i.e.: http://*.domain.com). Usage of wildcards implies a small performance penalty.
+	// Only one wildcard can be used per origin.
+	// Default value is ["*"]
+	AllowedOrigins []string
+
+	// AllowOriginFunc is a custom function to validate the origin. It takes the origin
+	// as argument and returns true if allowed or false otherwise. If this option is
+	// set, the content of AllowedOrigins is ignored.
+	AllowOriginFunc func(r *http.Request, origin string) bool
+
+	// AllowedMethods is a list of methods the client is allowed to use with
+	// cross-domain requests. Default value is simple methods (HEAD, GET and POST).
+	AllowedMethods []string
+
+	// AllowedHeaders is list of non simple headers the client is allowed to use with
+	// cross-domain requests.
+	// If the special "*" value is present in the list, all headers will be allowed.
+	// Default value is [] but "Origin" is always appended to the list.
+	AllowedHeaders []string
+
+	// ExposedHeaders indicates which headers are safe to expose to the API of a CORS
+	// API specification
+	ExposedHeaders []string
+
+	// AllowCredentials indicates whether the request can include user credentials like
+	// cookies, HTTP authentication or client side SSL certificates.
+	AllowCredentials bool
+
+	// MaxAge indicates how long (in seconds) the results of a preflight request
+	// can be cached
+	MaxAge int
+
+	// OptionsPassthrough instructs preflight to let other potential next handlers to
+	// process the OPTIONS method. Turn this on if your application handles OPTIONS.
+	OptionsPassthrough bool
+
+	// Debugging flag adds additional output to debug server side CORS issues
+	Debug bool
+}
+
+// Logger generic interface for logger
+type Logger interface {
+	Printf(string, ...interface{})
+}
+
+// Cors http handler
+type Cors struct {
+	// Debug logger
+	Log Logger
+
+	// Normalized list of plain allowed origins
+	allowedOrigins []string
+
+	// List of allowed origins containing wildcards
+	allowedWOrigins []wildcard
+
+	// Optional origin validator function
+	allowOriginFunc func(r *http.Request, origin string) bool
+
+	// Normalized list of allowed headers
+	allowedHeaders []string
+
+	// Normalized list of allowed methods
+	allowedMethods []string
+
+	// Normalized list of exposed headers
+	exposedHeaders []string
+	maxAge         int
+
+	// Set to true when allowed origins contains a "*"
+	allowedOriginsAll bool
+
+	// Set to true when allowed headers contains a "*"
+	allowedHeadersAll bool
+
+	allowCredentials  bool
+	optionPassthrough bool
+}
+
+// New creates a new Cors handler with the provided options.
+func New(options Options) *Cors {
+	c := &Cors{
+		exposedHeaders:    convert(options.ExposedHeaders, http.CanonicalHeaderKey),
+		allowOriginFunc:   options.AllowOriginFunc,
+		allowCredentials:  options.AllowCredentials,
+		maxAge:            options.MaxAge,
+		optionPassthrough: options.OptionsPassthrough,
+	}
+	if options.Debug && c.Log == nil {
+		c.Log = log.New(os.Stdout, "[cors] ", log.LstdFlags)
+	}
+
+	// Normalize options
+	// Note: for origins and methods matching, the spec requires a case-sensitive matching.
+	// As it may error prone, we chose to ignore the spec here.
+
+	// Allowed Origins
+	if len(options.AllowedOrigins) == 0 {
+		if options.AllowOriginFunc == nil {
+			// Default is all origins
+			c.allowedOriginsAll = true
+		}
+	} else {
+		c.allowedOrigins = []string{}
+		c.allowedWOrigins = []wildcard{}
+		for _, origin := range options.AllowedOrigins {
+			// Normalize
+			origin = strings.ToLower(origin)
+			if origin == "*" {
+				// If "*" is present in the list, turn the whole list into a match all
+				c.allowedOriginsAll = true
+				c.allowedOrigins = nil
+				c.allowedWOrigins = nil
+				break
+			} else if i := strings.IndexByte(origin, '*'); i >= 0 {
+				// Split the origin in two: start and end string without the *
+				w := wildcard{origin[0:i], origin[i+1:]}
+				c.allowedWOrigins = append(c.allowedWOrigins, w)
+			} else {
+				c.allowedOrigins = append(c.allowedOrigins, origin)
+			}
+		}
+	}
+
+	// Allowed Headers
+	if len(options.AllowedHeaders) == 0 {
+		// Use sensible defaults
+		c.allowedHeaders = []string{"Origin", "Accept", "Content-Type"}
+	} else {
+		// Origin is always appended as some browsers will always request for this header at preflight
+		c.allowedHeaders = convert(append(options.AllowedHeaders, "Origin"), http.CanonicalHeaderKey)
+		for _, h := range options.AllowedHeaders {
+			if h == "*" {
+				c.allowedHeadersAll = true
+				c.allowedHeaders = nil
+				break
+			}
+		}
+	}
+
+	// Allowed Methods
+	if len(options.AllowedMethods) == 0 {
+		// Default is spec's "simple" methods
+		c.allowedMethods = []string{http.MethodGet, http.MethodPost, http.MethodHead}
+	} else {
+		c.allowedMethods = convert(options.AllowedMethods, strings.ToUpper)
+	}
+
+	return c
+}
+
+// Handler creates a new Cors handler with passed options.
+func Handler(options Options) func(next http.Handler) http.Handler {
+	c := New(options)
+	return c.Handler
+}
+
+// AllowAll create a new Cors handler with permissive configuration allowing all
+// origins with all standard methods with any header and credentials.
+func AllowAll() *Cors {
+	return New(Options{
+		AllowedOrigins: []string{"*"},
+		AllowedMethods: []string{
+			http.MethodHead,
+			http.MethodGet,
+			http.MethodPost,
+			http.MethodPut,
+			http.MethodPatch,
+			http.MethodDelete,
+		},
+		AllowedHeaders:   []string{"*"},
+		AllowCredentials: false,
+	})
+}
+
+// Handler apply the CORS specification on the request, and add relevant CORS headers
+// as necessary.
+func (c *Cors) Handler(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodOptions && r.Header.Get("Access-Control-Request-Method") != "" {
+			c.logf("Handler: Preflight request")
+			c.handlePreflight(w, r)
+			// Preflight requests are standalone and should stop the chain as some other
+			// middleware may not handle OPTIONS requests correctly. One typical example
+			// is authentication middleware ; OPTIONS requests won't carry authentication
+			// headers (see #1)
+			if c.optionPassthrough {
+				next.ServeHTTP(w, r)
+			} else {
+				w.WriteHeader(http.StatusOK)
+			}
+		} else {
+			c.logf("Handler: Actual request")
+			c.handleActualRequest(w, r)
+			next.ServeHTTP(w, r)
+		}
+	})
+}
+
+// handlePreflight handles pre-flight CORS requests
+func (c *Cors) handlePreflight(w http.ResponseWriter, r *http.Request) {
+	headers := w.Header()
+	origin := r.Header.Get("Origin")
+
+	if r.Method != http.MethodOptions {
+		c.logf("Preflight aborted: %s!=OPTIONS", r.Method)
+		return
+	}
+	// Always set Vary headers
+	// see https://github.com/rs/cors/issues/10,
+	//     https://github.com/rs/cors/commit/dbdca4d95feaa7511a46e6f1efb3b3aa505bc43f#commitcomment-12352001
+	headers.Add("Vary", "Origin")
+	headers.Add("Vary", "Access-Control-Request-Method")
+	headers.Add("Vary", "Access-Control-Request-Headers")
+
+	if origin == "" {
+		c.logf("Preflight aborted: empty origin")
+		return
+	}
+	if !c.isOriginAllowed(r, origin) {
+		c.logf("Preflight aborted: origin '%s' not allowed", origin)
+		return
+	}
+
+	reqMethod := r.Header.Get("Access-Control-Request-Method")
+	if !c.isMethodAllowed(reqMethod) {
+		c.logf("Preflight aborted: method '%s' not allowed", reqMethod)
+		return
+	}
+	reqHeaders := parseHeaderList(r.Header.Get("Access-Control-Request-Headers"))
+	if !c.areHeadersAllowed(reqHeaders) {
+		c.logf("Preflight aborted: headers '%v' not allowed", reqHeaders)
+		return
+	}
+	if c.allowedOriginsAll {
+		headers.Set("Access-Control-Allow-Origin", "*")
+	} else {
+		headers.Set("Access-Control-Allow-Origin", origin)
+	}
+	// Spec says: Since the list of methods can be unbounded, simply returning the method indicated
+	// by Access-Control-Request-Method (if supported) can be enough
+	headers.Set("Access-Control-Allow-Methods", strings.ToUpper(reqMethod))
+	if len(reqHeaders) > 0 {
+
+		// Spec says: Since the list of headers can be unbounded, simply returning supported headers
+		// from Access-Control-Request-Headers can be enough
+		headers.Set("Access-Control-Allow-Headers", strings.Join(reqHeaders, ", "))
+	}
+	if c.allowCredentials {
+		headers.Set("Access-Control-Allow-Credentials", "true")
+	}
+	if c.maxAge > 0 {
+		headers.Set("Access-Control-Max-Age", strconv.Itoa(c.maxAge))
+	}
+	c.logf("Preflight response headers: %v", headers)
+}
+
+// handleActualRequest handles simple cross-origin requests, actual request or redirects
+func (c *Cors) handleActualRequest(w http.ResponseWriter, r *http.Request) {
+	headers := w.Header()
+	origin := r.Header.Get("Origin")
+
+	// Always set Vary, see https://github.com/rs/cors/issues/10
+	headers.Add("Vary", "Origin")
+	if origin == "" {
+		c.logf("Actual request no headers added: missing origin")
+		return
+	}
+	if !c.isOriginAllowed(r, origin) {
+		c.logf("Actual request no headers added: origin '%s' not allowed", origin)
+		return
+	}
+
+	// Note that spec does define a way to specifically disallow a simple method like GET or
+	// POST. Access-Control-Allow-Methods is only used for pre-flight requests and the
+	// spec doesn't instruct to check the allowed methods for simple cross-origin requests.
+	// We think it's a nice feature to be able to have control on those methods though.
+	if !c.isMethodAllowed(r.Method) {
+		c.logf("Actual request no headers added: method '%s' not allowed", r.Method)
+
+		return
+	}
+	if c.allowedOriginsAll {
+		headers.Set("Access-Control-Allow-Origin", "*")
+	} else {
+		headers.Set("Access-Control-Allow-Origin", origin)
+	}
+	if len(c.exposedHeaders) > 0 {
+		headers.Set("Access-Control-Expose-Headers", strings.Join(c.exposedHeaders, ", "))
+	}
+	if c.allowCredentials {
+		headers.Set("Access-Control-Allow-Credentials", "true")
+	}
+	c.logf("Actual response added headers: %v", headers)
+}
+
+// convenience method. checks if a logger is set.
+func (c *Cors) logf(format string, a ...interface{}) {
+	if c.Log != nil {
+		c.Log.Printf(format, a...)
+	}
+}
+
+// isOriginAllowed checks if a given origin is allowed to perform cross-domain requests
+// on the endpoint
+func (c *Cors) isOriginAllowed(r *http.Request, origin string) bool {
+	if c.allowOriginFunc != nil {
+		return c.allowOriginFunc(r, origin)
+	}
+	if c.allowedOriginsAll {
+		return true
+	}
+	origin = strings.ToLower(origin)
+	for _, o := range c.allowedOrigins {
+		if o == origin {
+			return true
+		}
+	}
+	for _, w := range c.allowedWOrigins {
+		if w.match(origin) {
+			return true
+		}
+	}
+	return false
+}
+
+// isMethodAllowed checks if a given method can be used as part of a cross-domain request
+// on the endpoint
+func (c *Cors) isMethodAllowed(method string) bool {
+	if len(c.allowedMethods) == 0 {
+		// If no method allowed, always return false, even for preflight request
+		return false
+	}
+	method = strings.ToUpper(method)
+	if method == http.MethodOptions {
+		// Always allow preflight requests
+		return true
+	}
+	for _, m := range c.allowedMethods {
+		if m == method {
+			return true
+		}
+	}
+	return false
+}
+
+// areHeadersAllowed checks if a given list of headers are allowed to used within
+// a cross-domain request.
+func (c *Cors) areHeadersAllowed(requestedHeaders []string) bool {
+	if c.allowedHeadersAll || len(requestedHeaders) == 0 {
+		return true
+	}
+	for _, header := range requestedHeaders {
+		header = http.CanonicalHeaderKey(header)
+		found := false
+		for _, h := range c.allowedHeaders {
+			if h == header {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return false
+		}
+	}
+	return true
+}

vendor/github.com/go-chi/cors/utils.go

@@ -0,0 +1,70 @@
+package cors
+
+import "strings"
+
+const toLower = 'a' - 'A'
+
+type converter func(string) string
+
+type wildcard struct {
+	prefix string
+	suffix string
+}
+
+func (w wildcard) match(s string) bool {
+	return len(s) >= len(w.prefix+w.suffix) && strings.HasPrefix(s, w.prefix) && strings.HasSuffix(s, w.suffix)
+}
+
+// convert converts a list of string using the passed converter function
+func convert(s []string, c converter) []string {
+	out := []string{}
+	for _, i := range s {
+		out = append(out, c(i))
+	}
+	return out
+}
+
+// parseHeaderList tokenize + normalize a string containing a list of headers
+func parseHeaderList(headerList string) []string {
+	l := len(headerList)
+	h := make([]byte, 0, l)
+	upper := true
+	// Estimate the number headers in order to allocate the right splice size
+	t := 0
+	for i := 0; i < l; i++ {
+		if headerList[i] == ',' {
+			t++
+		}
+	}
+	headers := make([]string, 0, t)
+	for i := 0; i < l; i++ {
+		b := headerList[i]
+		if b >= 'a' && b <= 'z' {
+			if upper {
+				h = append(h, b-toLower)
+			} else {
+				h = append(h, b)
+			}
+		} else if b >= 'A' && b <= 'Z' {
+			if !upper {
+				h = append(h, b+toLower)
+			} else {
+				h = append(h, b)
+			}
+		} else if b == '-' || b == '_' || b == '.' || (b >= '0' && b <= '9') {
+			h = append(h, b)
+		}
+
+		if b == ' ' || b == ',' || i == l-1 {
+			if len(h) > 0 {
+				// Flush the found header
+				headers = append(headers, string(h))
+				h = h[:0]
+				upper = true
+			}
+		} else {
+			upper = b == '-'
+		}
+	}
+	return headers
+}

vendor/modules.txt

@@ -122,6 +122,9 @@ github.com/getsentry/sentry-go/internal/ratelimit
 # github.com/go-chi/chi/v5 v5.0.8
 ## explicit; go 1.14
 github.com/go-chi/chi/v5
+# github.com/go-chi/cors v1.2.1
+## explicit; go 1.14
+github.com/go-chi/cors
 # github.com/go-jose/go-jose/v3 v3.0.0
 ## explicit; go 1.12
 github.com/go-jose/go-jose/v3