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// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
// SPDX-License-Identifier: Apache-2.0
package ui // import "miniflux.app/v2/internal/ui"
import (
"crypto/hmac"
"crypto/sha256"
"encoding/base64"
"errors"
"log/slog"
"net/http"
"net/url"
"time"
"miniflux.app/v2/internal/config"
"miniflux.app/v2/internal/crypto"
"miniflux.app/v2/internal/http/request"
"miniflux.app/v2/internal/http/response"
"miniflux.app/v2/internal/http/response/html"
)
func (h *handler) mediaProxy(w http.ResponseWriter, r *http.Request) {
// If we receive a "If-None-Match" header, we assume the media is already stored in browser cache.
if r.Header.Get("If-None-Match") != "" {
w.WriteHeader(http.StatusNotModified)
return
}
encodedDigest := request.RouteStringParam(r, "encodedDigest")
encodedURL := request.RouteStringParam(r, "encodedURL")
if encodedURL == "" {
html.BadRequest(w, r, errors.New("no URL provided"))
return
}
decodedDigest, err := base64.URLEncoding.DecodeString(encodedDigest)
if err != nil {
html.BadRequest(w, r, errors.New("unable to decode this digest"))
return
}
decodedURL, err := base64.URLEncoding.DecodeString(encodedURL)
if err != nil {
html.BadRequest(w, r, errors.New("unable to decode this URL"))
return
}
mac := hmac.New(sha256.New, config.Opts.MediaProxyPrivateKey())
mac.Write(decodedURL)
expectedMAC := mac.Sum(nil)
if !hmac.Equal(decodedDigest, expectedMAC) {
html.Forbidden(w, r)
return
}
u, err := url.Parse(string(decodedURL))
if err != nil {
html.BadRequest(w, r, errors.New("invalid URL provided"))
return
}
if u.Scheme != "http" && u.Scheme != "https" {
html.BadRequest(w, r, errors.New("invalid URL provided"))
return
}
if u.Host == "" {
html.BadRequest(w, r, errors.New("invalid URL provided"))
return
}
if !u.IsAbs() {
html.BadRequest(w, r, errors.New("invalid URL provided"))
return
}
mediaURL := string(decodedURL)
slog.Debug("MediaProxy: Fetching remote resource",
slog.String("media_url", mediaURL),
)
req, err := http.NewRequest("GET", mediaURL, nil)
if err != nil {
html.ServerError(w, r, err)
return
}
// Note: User-Agent HTTP header is omitted to avoid being blocked by bot protection mechanisms.
req.Header.Add("Connection", "close")
forwardedRequestHeader := []string{"Range", "Accept", "Accept-Encoding"}
for _, requestHeaderName := range forwardedRequestHeader {
if r.Header.Get(requestHeaderName) != "" {
req.Header.Add(requestHeaderName, r.Header.Get(requestHeaderName))
}
}
clt := &http.Client{
Transport: &http.Transport{
IdleConnTimeout: time.Duration(config.Opts.MediaProxyHTTPClientTimeout()) * time.Second,
},
Timeout: time.Duration(config.Opts.MediaProxyHTTPClientTimeout()) * time.Second,
}
resp, err := clt.Do(req)
if err != nil {
slog.Error("MediaProxy: Unable to initialize HTTP client",
slog.String("media_url", mediaURL),
slog.Any("error", err),
)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusRequestedRangeNotSatisfiable {
slog.Warn("MediaProxy: "+http.StatusText(http.StatusRequestedRangeNotSatisfiable),
slog.String("media_url", mediaURL),
slog.Int("status_code", resp.StatusCode),
)
html.RequestedRangeNotSatisfiable(w, r, resp.Header.Get("Content-Range"))
return
}
if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusPartialContent {
slog.Warn("MediaProxy: Unexpected response status code",
slog.String("media_url", mediaURL),
slog.Int("status_code", resp.StatusCode),
)
html.NotFound(w, r)
return
}
etag := crypto.HashFromBytes(decodedURL)
response.New(w, r).WithCaching(etag, 72*time.Hour, func(b *response.Builder) {
b.WithStatus(resp.StatusCode)
b.WithHeader("Content-Security-Policy", `default-src 'self'`)
b.WithHeader("Content-Type", resp.Header.Get("Content-Type"))
forwardedResponseHeader := []string{"Content-Encoding", "Content-Type", "Content-Length", "Accept-Ranges", "Content-Range"}
for _, responseHeaderName := range forwardedResponseHeader {
if resp.Header.Get(responseHeaderName) != "" {
b.WithHeader(responseHeaderName, resp.Header.Get(responseHeaderName))
}
}
b.WithBody(resp.Body)
b.WithoutCompression()
b.Write()
})
}
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