peridot/vendor/github.com/go-chi/chi/middleware/content_encoding.go

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2022-07-07 20:11:50 +00:00
package middleware
import (
"net/http"
"strings"
)
// AllowContentEncoding enforces a whitelist of request Content-Encoding otherwise responds
// with a 415 Unsupported Media Type status.
func AllowContentEncoding(contentEncoding ...string) func(next http.Handler) http.Handler {
allowedEncodings := make(map[string]struct{}, len(contentEncoding))
for _, encoding := range contentEncoding {
allowedEncodings[strings.TrimSpace(strings.ToLower(encoding))] = struct{}{}
}
return func(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
requestEncodings := r.Header["Content-Encoding"]
// skip check for empty content body or no Content-Encoding
if r.ContentLength == 0 {
next.ServeHTTP(w, r)
return
}
// All encodings in the request must be allowed
for _, encoding := range requestEncodings {
if _, ok := allowedEncodings[strings.TrimSpace(strings.ToLower(encoding))]; !ok {
w.WriteHeader(http.StatusUnsupportedMediaType)
return
}
}
next.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
}