diff options
Diffstat (limited to 'vendor/github.com/gin-contrib/cors/cors.go')
-rw-r--r-- | vendor/github.com/gin-contrib/cors/cors.go | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/vendor/github.com/gin-contrib/cors/cors.go b/vendor/github.com/gin-contrib/cors/cors.go new file mode 100644 index 000000000..d6d06de03 --- /dev/null +++ b/vendor/github.com/gin-contrib/cors/cors.go @@ -0,0 +1,171 @@ +package cors + +import ( + "errors" + "strings" + "time" + + "github.com/gin-gonic/gin" +) + +// Config represents all available options for the middleware. +type Config struct { + AllowAllOrigins bool + + // AllowOrigins 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. + // Default value is [] + AllowOrigins []string + + // AllowOriginFunc is a custom function to validate the origin. It take the origin + // as argument and returns true if allowed or false otherwise. If this option is + // set, the content of AllowOrigins is ignored. + AllowOriginFunc func(origin string) bool + + // AllowMethods is a list of methods the client is allowed to use with + // cross-domain requests. Default value is simple methods (GET and POST) + AllowMethods []string + + // AllowHeaders is list of non simple headers the client is allowed to use with + // cross-domain requests. + AllowHeaders []string + + // AllowCredentials indicates whether the request can include user credentials like + // cookies, HTTP authentication or client side SSL certificates. + AllowCredentials bool + + // ExposedHeaders indicates which headers are safe to expose to the API of a CORS + // API specification + ExposeHeaders []string + + // MaxAge indicates how long (in seconds) the results of a preflight request + // can be cached + MaxAge time.Duration + + // Allows to add origins like http://some-domain/*, https://api.* or http://some.*.subdomain.com + AllowWildcard bool + + // Allows usage of popular browser extensions schemas + AllowBrowserExtensions bool + + // Allows usage of WebSocket protocol + AllowWebSockets bool + + // Allows usage of file:// schema (dangerous!) use it only when you 100% sure it's needed + AllowFiles bool +} + +// AddAllowMethods is allowed to add custom methods +func (c *Config) AddAllowMethods(methods ...string) { + c.AllowMethods = append(c.AllowMethods, methods...) +} + +// AddAllowHeaders is allowed to add custom headers +func (c *Config) AddAllowHeaders(headers ...string) { + c.AllowHeaders = append(c.AllowHeaders, headers...) +} + +// AddExposeHeaders is allowed to add custom expose headers +func (c *Config) AddExposeHeaders(headers ...string) { + c.ExposeHeaders = append(c.ExposeHeaders, headers...) +} + +func (c Config) getAllowedSchemas() []string { + allowedSchemas := DefaultSchemas + if c.AllowBrowserExtensions { + allowedSchemas = append(allowedSchemas, ExtensionSchemas...) + } + if c.AllowWebSockets { + allowedSchemas = append(allowedSchemas, WebSocketSchemas...) + } + if c.AllowFiles { + allowedSchemas = append(allowedSchemas, FileSchemas...) + } + return allowedSchemas +} + +func (c Config) validateAllowedSchemas(origin string) bool { + allowedSchemas := c.getAllowedSchemas() + for _, schema := range allowedSchemas { + if strings.HasPrefix(origin, schema) { + return true + } + } + return false +} + +// Validate is check configuration of user defined. +func (c *Config) Validate() error { + if c.AllowAllOrigins && (c.AllowOriginFunc != nil || len(c.AllowOrigins) > 0) { + return errors.New("conflict settings: all origins are allowed. AllowOriginFunc or AllowOrigins is not needed") + } + if !c.AllowAllOrigins && c.AllowOriginFunc == nil && len(c.AllowOrigins) == 0 { + return errors.New("conflict settings: all origins disabled") + } + for _, origin := range c.AllowOrigins { + if origin == "*" { + c.AllowAllOrigins = true + return nil + } else if !strings.Contains(origin, "*") && !c.validateAllowedSchemas(origin) { + return errors.New("bad origin: origins must contain '*' or include " + strings.Join(c.getAllowedSchemas(), ",")) + } + } + return nil +} + +func (c Config) parseWildcardRules() [][]string { + var wRules [][]string + + if !c.AllowWildcard { + return wRules + } + + for _, o := range c.AllowOrigins { + if !strings.Contains(o, "*") { + continue + } + + if c := strings.Count(o, "*"); c > 1 { + panic(errors.New("only one * is allowed").Error()) + } + + i := strings.Index(o, "*") + if i == 0 { + wRules = append(wRules, []string{"*", o[1:]}) + continue + } + if i == (len(o) - 1) { + wRules = append(wRules, []string{o[:i-1], "*"}) + continue + } + + wRules = append(wRules, []string{o[:i], o[i+1:]}) + } + + return wRules +} + +// DefaultConfig returns a generic default configuration mapped to localhost. +func DefaultConfig() Config { + return Config{ + AllowMethods: []string{"GET", "POST", "PUT", "PATCH", "DELETE", "HEAD"}, + AllowHeaders: []string{"Origin", "Content-Length", "Content-Type"}, + AllowCredentials: false, + MaxAge: 12 * time.Hour, + } +} + +// Default returns the location middleware with default configuration. +func Default() gin.HandlerFunc { + config := DefaultConfig() + config.AllowAllOrigins = true + return New(config) +} + +// New returns the location middleware with user-defined custom configuration. +func New(config Config) gin.HandlerFunc { + cors := newCors(config) + return func(c *gin.Context) { + cors.applyCors(c) + } +} |