46 lines
946 B
Go
46 lines
946 B
Go
package main
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import (
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"net/http"
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)
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const (
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cspHeader = "Content-Security-Policy"
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rpHeader = "Referrer-Policy"
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frameOptionsHeader = "X-Frame-Options"
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)
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type csp struct {
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h http.Handler
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opts CSPOptions
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}
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type CSPOptions struct {
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policy string
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referrerPolicy string
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frame string
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}
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func (c csp) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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// only add a CSP if one is not already set
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if existing := w.Header().Get(cspHeader); existing == "" {
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w.Header().Add(cspHeader, c.opts.policy)
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}
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// only add a Referrer Policy if one is not already set
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if existing := w.Header().Get(rpHeader); existing == "" {
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w.Header().Add(rpHeader, c.opts.referrerPolicy)
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}
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w.Header().Set(frameOptionsHeader, c.opts.frame)
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c.h.ServeHTTP(w, r)
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}
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func ContentSecurityPolicy(o CSPOptions) func(http.Handler) http.Handler {
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fn := func(h http.Handler) http.Handler {
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return csp{h, o}
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}
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return fn
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}
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