cors/cors.go
Manu Mtz.-Almeida b08ec4416c Fixes CORS
2015-11-12 01:17:15 +01:00

94 lines
2.8 KiB
Go

package cors
import (
"errors"
"strings"
"time"
"github.com/gin-gonic/gin"
)
type Config struct {
AllowAllOrigins bool
// 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.
// Default value is ["*"]
AllowedOrigins []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 AllowedOrigins is ignored.
AllowOriginFunc func(origin string) bool
// AllowedMethods is a list of methods the client is allowed to use with
// cross-domain requests. Default value is simple methods (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 time.Duration
}
func (c *Config) AddAllowedMethods(methods ...string) {
c.AllowedMethods = append(c.AllowedMethods, methods...)
}
func (c *Config) AddAllowedHeaders(headers ...string) {
c.AllowedHeaders = append(c.AllowedHeaders, headers...)
}
func (c *Config) AddExposedHeaders(headers ...string) {
c.ExposedHeaders = append(c.ExposedHeaders, headers...)
}
func (c Config) Validate() error {
if c.AllowAllOrigins && (c.AllowOriginFunc != nil || len(c.AllowedOrigins) > 0) {
return errors.New("conflict settings: all origins are allowed. AllowOriginFunc or AllowedOrigins is not needed")
}
if !c.AllowAllOrigins && c.AllowOriginFunc == nil && len(c.AllowedOrigins) == 0 {
return errors.New("conflict settings: all origins disabled")
}
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://")
}
}
return nil
}
func DefaultConfig() Config {
return Config{
AllowAllOrigins: true,
AllowedMethods: []string{"GET", "POST", "PUT", "HEAD"},
AllowedHeaders: []string{"Content-Type"},
AllowCredentials: false,
MaxAge: 12 * time.Hour,
}
}
func Default() gin.HandlerFunc {
return New(DefaultConfig())
}
func New(config Config) gin.HandlerFunc {
cors := newCors(config)
return func(c *gin.Context) {
cors.applyCors(c)
}
}