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Fixes CORS

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This commit is contained in:
Manu Mtz.-Almeida 2015-11-12 01:17:15 +01:00
parent 322e348743
commit b08ec4416c
4 changed files with 276 additions and 218 deletions
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140
config.go
View File

@ -2,10 +2,6 @@ package cors
import (
"net/http"
"net/textproto"
"strconv"
"strings"
"time"
"github.com/gin-gonic/gin"
)
@ -14,25 +10,21 @@ type cors struct {
allowAllOrigins bool
allowedOriginFunc func(string) bool
allowedOrigins []string
allowedMethods []string
allowedHeaders []string
exposedHeaders []string
normalHeaders http.Header
preflightHeaders http.Header
}
func newCors(c Config) *cors {
if err := c.Validate(); err != nil {
func newCors(config Config) *cors {
if err := config.Validate(); err != nil {
panic(err.Error())
}
return &cors{
allowedOriginFunc: c.AllowOriginFunc,
allowAllOrigins: c.AllowAllOrigins,
allowedOrigins: normalize(c.AllowedOrigins),
allowedMethods: normalize(c.AllowedMethods),
allowedHeaders: normalize(c.AllowedHeaders),
normalHeaders: generateNormalHeaders(c),
preflightHeaders: generatePreflightHeaders(c),
allowedOriginFunc: config.AllowOriginFunc,
allowAllOrigins: config.AllowAllOrigins,
allowedOrigins: normalize(config.AllowedOrigins),
normalHeaders: generateNormalHeaders(config),
preflightHeaders: generatePreflightHeaders(config),
}
}
@ -43,135 +35,47 @@ func (cors *cors) applyCors(c *gin.Context) {
return
}
if !cors.validateOrigin(origin) {
goto failed
c.AbortWithStatus(http.StatusForbidden)
return
}
if c.Request.Method == "OPTIONS" {
if !cors.handlePreflight(c) {
goto failed
}
} else if !cors.handleNormal(c) {
goto failed
}
if cors.allowAllOrigins {
c.Header("Access-Control-Allow-Origin", "*")
cors.handlePreflight(c)
} else {
cors.handleNormal(c)
}
if !cors.allowAllOrigins {
c.Header("Access-Control-Allow-Origin", origin)
}
return
failed:
c.AbortWithStatus(http.StatusForbidden)
}
func (cors *cors) validateOrigin(origin string) bool {
if cors.allowAllOrigins {
return true
}
if cors.allowedOriginFunc != nil {
return cors.allowedOriginFunc(origin)
}
for _, value := range cors.allowedOrigins {
if value == origin {
return true
}
}
return false
}
func (cors *cors) validateMethod(method string) bool {
for _, value := range cors.allowedMethods {
if strings.EqualFold(value, method) {
return true
}
if cors.allowedOriginFunc != nil {
return cors.allowedOriginFunc(origin)
}
return false
}
func (cors *cors) validateHeader(header string) bool {
for _, value := range cors.allowedHeaders {
if strings.EqualFold(value, header) {
return true
}
}
return false
}
func (cors *cors) handlePreflight(c *gin.Context) bool {
func (cors *cors) handlePreflight(c *gin.Context) {
c.AbortWithStatus(200)
if !cors.validateMethod(c.Request.Header.Get("Access-Control-Request-Method")) {
return false
}
if !cors.validateHeader(c.Request.Header.Get("Access-Control-Request-Header")) {
return false
}
header := c.Writer.Header()
for key, value := range cors.preflightHeaders {
c.Writer.Header()[key] = value
header[key] = value
}
return true
}
func (cors *cors) handleNormal(c *gin.Context) bool {
func (cors *cors) handleNormal(c *gin.Context) {
header := c.Writer.Header()
for key, value := range cors.normalHeaders {
c.Writer.Header()[key] = value
header[key] = value
}
return true
}
func generateNormalHeaders(c Config) http.Header {
headers := make(http.Header)
if c.AllowCredentials {
headers.Set("Access-Control-Allow-Credentials", "true")
}
if len(c.ExposedHeaders) > 0 {
headers.Set("Access-Control-Expose-Headers", strings.Join(c.ExposedHeaders, ", "))
}
if c.AllowAllOrigins {
headers.Set("Access-Control-Allow-Origin", "*")
} else {
headers.Set("Vary", "Origin")
}
return headers
}
func generatePreflightHeaders(c Config) http.Header {
headers := make(http.Header)
if c.AllowCredentials {
headers.Set("Access-Control-Allow-Credentials", "true")
}
if len(c.AllowedMethods) > 0 {
value := strings.Join(c.AllowedMethods, ", ")
headers.Set("Access-Control-Allow-Methods", value)
}
if len(c.AllowedHeaders) > 0 {
value := strings.Join(c.AllowedHeaders, ", ")
headers.Set("Access-Control-Allow-Headers", value)
}
if c.MaxAge > time.Duration(0) {
value := strconv.FormatInt(int64(c.MaxAge/time.Second), 10)
headers.Set("Access-Control-Max-Age", value)
}
if c.AllowAllOrigins {
headers.Set("Access-Control-Allow-Origin", "*")
} else {
headers.Set("Vary", "Origin")
}
return headers
}
func normalize(values []string) []string {
if values == nil {
return nil
}
distinctMap := make(map[string]bool, len(values))
normalized := make([]string, 0, len(values))
for _, value := range values {
value = strings.TrimSpace(value)
value = textproto.CanonicalMIMEHeaderKey(value)
if _, seen := distinctMap[value]; !seen {
normalized = append(normalized, value)
distinctMap[value] = true
}
}
return normalized
}

18
cors.go
View File

@ -9,7 +9,6 @@ import (
)
type Config struct {
AbortOnError bool
AllowAllOrigins bool
// AllowedOrigins is a list of origins a cross-domain request can be executed from.
@ -64,9 +63,6 @@ func (c Config) Validate() error {
if !c.AllowAllOrigins && c.AllowOriginFunc == nil && len(c.AllowedOrigins) == 0 {
return errors.New("conflict settings: all origins disabled")
}
if c.AllowOriginFunc != nil && len(c.AllowedOrigins) > 0 {
return errors.New("conflict settings: if a allow origin func is provided, AllowedOrigins is not needed")
}
for _, origin := range c.AllowedOrigins {
if !strings.HasPrefix(origin, "http://") && !strings.HasPrefix(origin, "https://") {
return errors.New("bad origin: origins must include http:// or https://")
@ -77,11 +73,9 @@ func (c Config) Validate() error {
func DefaultConfig() Config {
return Config{
AbortOnError: false,
AllowAllOrigins: true,
AllowedMethods: []string{"GET", "POST", "PUT", "PATCH", "HEAD"},
AllowedHeaders: []string{"Content-Type"},
//ExposedHeaders: "",
AllowAllOrigins: true,
AllowedMethods: []string{"GET", "POST", "PUT", "HEAD"},
AllowedHeaders: []string{"Content-Type"},
AllowCredentials: false,
MaxAge: 12 * time.Hour,
}
@ -92,10 +86,8 @@ func Default() gin.HandlerFunc {
}
func New(config Config) gin.HandlerFunc {
s := newCors(config)
// Algorithm based in http://www.html5rocks.com/static/images/cors_server_flowchart.png
cors := newCors(config)
return func(c *gin.Context) {
s.applyCors(c)
cors.applyCors(c)
}
}

267
cors_test.go
View File

@ -4,6 +4,7 @@ import (
"net/http"
"net/http/httptest"
"testing"
"time"
"github.com/gin-gonic/gin"
"github.com/stretchr/testify/assert"
@ -34,12 +35,6 @@ func TestBadConfig(t *testing.T) {
AllowOriginFunc: func(origin string) bool { return false },
})
})
assert.Panics(t, func() {
New(Config{
AllowedOrigins: []string{"http://google.com"},
AllowOriginFunc: func(origin string) bool { return false },
})
})
assert.Panics(t, func() {
New(Config{
AllowedOrigins: []string{"google.com"},
@ -49,10 +44,10 @@ func TestBadConfig(t *testing.T) {
func TestNormalize(t *testing.T) {
values := normalize([]string{
"http-access ", "post", "POST", " poSt ",
"http-Access ", "Post", "POST", " poSt ",
"HTTP-Access", "",
})
assert.Equal(t, values, []string{"Http-Access", "Post", ""})
assert.Equal(t, values, []string{"http-access", "post", ""})
values = normalize(nil)
assert.Nil(t, values)
@ -61,91 +56,189 @@ func TestNormalize(t *testing.T) {
assert.Equal(t, values, []string{})
}
func TestGenerateNormalHeaders(t *testing.T) {
func TestGenerateNormalHeaders_AllowAllOrigins(t *testing.T) {
header := generateNormalHeaders(Config{
AllowAllOrigins: false,
})
assert.Contains(t, header.Get("Access-Control-Allow-Origin"), "")
assert.Contains(t, header.Get("Vary"), "Origin")
assert.Equal(t, header.Get("Access-Control-Allow-Origin"), "")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 1)
header = generateNormalHeaders(Config{
AllowAllOrigins: true,
})
assert.Contains(t, header.Get("Access-Control-Allow-Origin"), "*")
assert.Contains(t, header.Get("Vary"), "")
header = generateNormalHeaders(Config{
AllowCredentials: true,
})
assert.Contains(t, header.Get("Access-Control-Allow-Credentials"), "true")
header = generateNormalHeaders(Config{
AllowCredentials: false,
})
assert.Contains(t, header.Get("Access-Control-Allow-Credentials"), "")
header = generateNormalHeaders(Config{
ExposedHeaders: []string{"x-user", "xpassword"},
})
assert.Contains(t, header.Get("Access-Control-Expose-Headers"), "x-user, xpassword")
assert.Equal(t, header.Get("Access-Control-Allow-Origin"), "*")
assert.Equal(t, header.Get("Vary"), "")
assert.Len(t, header, 1)
}
//
// func TestDeny0(t *testing.T) {
// called := false
//
// router := gin.New()
// router.Use(New(Config{
// AllowedOrigins: []string{"http://example.com"},
// }))
// router.GET("/", func(c *gin.Context) {
// called = true
// })
// w := httptest.NewRecorder()
// req, _ := http.NewRequest("GET", "/", nil)
// req.Header.Set("Origin", "https://example.com")
// router.ServeHTTP(w, req)
//
// assert.True(t, called)
// assert.NotContains(t, w.Header(), "Access-Control")
// }
//
// func TestDenyAbortOnError(t *testing.T) {
// called := false
//
// router := gin.New()
// router.Use(New(Config{
// AbortOnError: true,
// AllowedOrigins: []string{"http://example.com"},
// }))
// router.GET("/", func(c *gin.Context) {
// called = true
// })
//
// w := httptest.NewRecorder()
// req, _ := http.NewRequest("GET", "/", nil)
// req.Header.Set("Origin", "https://example.com")
// router.ServeHTTP(w, req)
//
// assert.False(t, called)
// assert.NotContains(t, w.Header(), "Access-Control")
// }
//
// func TestDeny2(t *testing.T) {
//
// }
// func TestDeny3(t *testing.T) {
//
// }
//
// func TestPasses0(t *testing.T) {
//
// }
//
// func TestPasses1(t *testing.T) {
//
// }
//
// func TestPasses2(t *testing.T) {
//
// }
func TestGenerateNormalHeaders_AllowCredentials(t *testing.T) {
header := generateNormalHeaders(Config{
AllowCredentials: true,
})
assert.Equal(t, header.Get("Access-Control-Allow-Credentials"), "true")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestGenerateNormalHeaders_ExposedHeaders(t *testing.T) {
header := generateNormalHeaders(Config{
ExposedHeaders: []string{"X-user", "xPassword"},
})
assert.Equal(t, header.Get("Access-Control-Expose-Headers"), "x-user, xpassword")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestGeneratePreflightHeaders(t *testing.T) {
header := generatePreflightHeaders(Config{
AllowAllOrigins: false,
})
assert.Equal(t, header.Get("Access-Control-Allow-Origin"), "")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 1)
header = generateNormalHeaders(Config{
AllowAllOrigins: true,
})
assert.Equal(t, header.Get("Access-Control-Allow-Origin"), "*")
assert.Equal(t, header.Get("Vary"), "")
assert.Len(t, header, 1)
}
func TestGeneratePreflightHeaders_AllowCredentials(t *testing.T) {
header := generatePreflightHeaders(Config{
AllowCredentials: true,
})
assert.Equal(t, header.Get("Access-Control-Allow-Credentials"), "true")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestGeneratePreflightHeaders_AllowedMethods(t *testing.T) {
header := generatePreflightHeaders(Config{
AllowedMethods: []string{"GET ", "post", "PUT", " put "},
})
assert.Equal(t, header.Get("Access-Control-Allow-Methods"), "get, post, put")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestGeneratePreflightHeaders_AllowedHeaders(t *testing.T) {
header := generatePreflightHeaders(Config{
AllowedHeaders: []string{"X-user", "Content-Type"},
})
assert.Equal(t, header.Get("Access-Control-Allow-Headers"), "x-user, content-type")
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestGeneratePreflightHeaders_MaxAge(t *testing.T) {
header := generatePreflightHeaders(Config{
MaxAge: 12 * time.Hour,
})
assert.Equal(t, header.Get("Access-Control-Max-Age"), "43200") // 12*60*60
assert.Equal(t, header.Get("Vary"), "Origin")
assert.Len(t, header, 2)
}
func TestValidateOrigin(t *testing.T) {
cors := newCors(Config{
AllowAllOrigins: true,
})
assert.True(t, cors.validateOrigin("http://google.com"))
assert.True(t, cors.validateOrigin("https://google.com"))
assert.True(t, cors.validateOrigin("example.com"))
cors = newCors(Config{
AllowedOrigins: []string{"https://google.com", "https://github.com"},
AllowOriginFunc: func(origin string) bool {
return (origin == "http://news.ycombinator.com")
},
})
assert.False(t, cors.validateOrigin("http://google.com"))
assert.True(t, cors.validateOrigin("https://google.com"))
assert.True(t, cors.validateOrigin("https://github.com"))
assert.True(t, cors.validateOrigin("http://news.ycombinator.com"))
assert.False(t, cors.validateOrigin("http://example.com"))
assert.False(t, cors.validateOrigin("google.com"))
}
func TestPasses0(t *testing.T) {
called := false
router := gin.New()
router.Use(New(Config{
AllowedOrigins: []string{"http://google.com"},
AllowedMethods: []string{" GeT ", "get", "post", "PUT ", "Head", "POST"},
AllowedHeaders: []string{"Content-type", "timeStamp "},
ExposedHeaders: []string{"Data", "x-User"},
AllowCredentials: true,
MaxAge: 12 * time.Hour,
AllowOriginFunc: func(origin string) bool {
return origin == "http://github.com"
},
}))
router.GET("/", func(c *gin.Context) {
called = true
})
w := httptest.NewRecorder()
req, _ := http.NewRequest("GET", "/", nil)
router.ServeHTTP(w, req)
assert.True(t, called)
assert.NotContains(t, w.Header(), "Access-Control-Allow-Origin")
assert.NotContains(t, w.Header(), "Access-Control-Allow-Credentials")
assert.NotContains(t, w.Header(), "Access-Control-Expose-Headers")
called = false
w = httptest.NewRecorder()
req, _ = http.NewRequest("GET", "/", nil)
req.Header.Set("Origin", "http://google.com")
router.ServeHTTP(w, req)
assert.True(t, called)
assert.Equal(t, w.Header().Get("Access-Control-Allow-Origin"), "http://google.com")
assert.Equal(t, w.Header().Get("Access-Control-Allow-Credentials"), "true")
assert.Equal(t, w.Header().Get("Access-Control-Expose-Headers"), "data, x-user")
called = false
w = httptest.NewRecorder()
req, _ = http.NewRequest("GET", "/", nil)
req.Header.Set("Origin", "https://google.com")
router.ServeHTTP(w, req)
assert.False(t, called)
assert.NotContains(t, w.Header(), "Access-Control-Allow-Origin")
assert.NotContains(t, w.Header(), "Access-Control-Allow-Credentials")
assert.NotContains(t, w.Header(), "Access-Control-Expose-Headers")
called = false
w = httptest.NewRecorder()
req, _ = http.NewRequest("OPTIONS", "/", nil)
req.Header.Set("Origin", "http://github.com")
router.ServeHTTP(w, req)
assert.False(t, called)
assert.Equal(t, w.Header().Get("Access-Control-Allow-Origin"), "http://github.com")
assert.Equal(t, w.Header().Get("Access-Control-Allow-Credentials"), "true")
assert.Equal(t, w.Header().Get("Access-Control-Allow-Methods"), "get, post, put, head")
assert.Equal(t, w.Header().Get("Access-Control-Allow-Headers"), "content-type, timestamp")
assert.Equal(t, w.Header().Get("Access-Control-Max-Age"), "43200")
called = false
w = httptest.NewRecorder()
req, _ = http.NewRequest("OPTIONS", "/", nil)
req.Header.Set("Origin", "http://example.com")
router.ServeHTTP(w, req)
assert.False(t, called)
assert.NotContains(t, w.Header(), "Access-Control-Allow-Origin")
assert.NotContains(t, w.Header(), "Access-Control-Allow-Credentials")
assert.NotContains(t, w.Header(), "Access-Control-Allow-Methods")
assert.NotContains(t, w.Header(), "Access-Control-Allow-Headers")
assert.NotContains(t, w.Header(), "Access-Control-Max-Age")
}
func TestPasses1(t *testing.T) {
}
func TestPasses2(t *testing.T) {
}

69
utils.go Normal file
View File

@ -0,0 +1,69 @@
package cors
import (
"net/http"
"strconv"
"strings"
"time"
)
func generateNormalHeaders(c Config) http.Header {
headers := make(http.Header)
if c.AllowCredentials {
headers.Set("Access-Control-Allow-Credentials", "true")
}
if len(c.ExposedHeaders) > 0 {
exposedHeaders := normalize(c.ExposedHeaders)
headers.Set("Access-Control-Expose-Headers", strings.Join(exposedHeaders, ", "))
}
if c.AllowAllOrigins {
headers.Set("Access-Control-Allow-Origin", "*")
} else {
headers.Set("Vary", "Origin")
}
return headers
}
func generatePreflightHeaders(c Config) http.Header {
headers := make(http.Header)
if c.AllowCredentials {
headers.Set("Access-Control-Allow-Credentials", "true")
}
if len(c.AllowedMethods) > 0 {
allowedMethods := normalize(c.AllowedMethods)
value := strings.Join(allowedMethods, ", ")
headers.Set("Access-Control-Allow-Methods", value)
}
if len(c.AllowedHeaders) > 0 {
allowedHeaders := normalize(c.AllowedHeaders)
value := strings.Join(allowedHeaders, ", ")
headers.Set("Access-Control-Allow-Headers", value)
}
if c.MaxAge > time.Duration(0) {
value := strconv.FormatInt(int64(c.MaxAge/time.Second), 10)
headers.Set("Access-Control-Max-Age", value)
}
if c.AllowAllOrigins {
headers.Set("Access-Control-Allow-Origin", "*")
} else {
headers.Set("Vary", "Origin")
}
return headers
}
func normalize(values []string) []string {
if values == nil {
return nil
}
distinctMap := make(map[string]bool, len(values))
normalized := make([]string, 0, len(values))
for _, value := range values {
value = strings.TrimSpace(value)
value = strings.ToLower(value)
if _, seen := distinctMap[value]; !seen {
normalized = append(normalized, value)
distinctMap[value] = true
}
}
return normalized
}