PoC of kernel.org proxy

proxy/main.go

@@ -0,0 +1,115 @@
+package main
+
+import (
+    "fmt"
+    "io"
+    "bytes"
+    "regexp"
+    "strings"
+    "compress/gzip"
+    "net/url"
+    "net/http"
+    "net/http/httputil"
+    "golang.org/x/text/encoding/charmap"
+)
+
+func main() {
+    proxy := &httputil.ReverseProxy{
+        Rewrite: func(r *httputil.ProxyRequest) {
+            host, _ := Yadro2Kernel(r.In.Host, true)
+            url, err := url.Parse("https://" + host)
+            
+            if err != nil {
+                // TODO...
+            }
+
+            r.SetURL(url)
+
+            // We only support gzip decoding
+            r.Out.Header.Set("Accept-Encoding", "gzip")
+        },
+        ModifyResponse: func(r *http.Response) error {
+            // Disable security policy because of the domain restrictions.
+            r.Header.Del("Content-Security-Policy")
+
+            // Skip non-html pages.
+            contentType := r.Header.Get("Content-Type")
+            if !strings.HasPrefix(contentType, "text/") {
+                return nil
+            }
+
+            // Read response body into data. If body is encoded, decode it.
+            var data []byte
+
+            switch r.Header.Get("Content-Encoding") {
+            case "gzip":
+                reader, _ := gzip.NewReader(r.Body)
+                data, _ = io.ReadAll(reader)
+                r.Body.Close()
+            default:
+                data, _ = io.ReadAll(r.Body)
+                r.Body.Close()
+            }
+
+            // Modify the response.
+            data = modifyResponse(data)
+
+            // Remove headers that mess with body encoding and set the body.
+            r.Header.Del("Content-Encoding")
+            r.Header.Del("Content-Length")
+            // r.Header.Set("Content-Type", "text/html; charset=windows-1251")
+
+            r.Body = io.NopCloser(bytes.NewReader(data))
+            
+            return nil
+        },
+    }
+
+    http.ListenAndServe("localhost:8000", proxy)
+}
+
+func replaceDomains(response []byte) []byte {
+    re := regexp.MustCompile(`(?i)[A-Za-z\-\.]*\.?kernel\.org`)
+    response = re.ReplaceAllFunc(response, func(original_raw []byte) []byte {
+        kernel := strings.ToLower(string(original_raw))
+
+        // Strip `www.`
+        kernel = strings.TrimPrefix(kernel, "www.")
+
+        yadro, exists := Kernel2Yadro(kernel)
+
+        if !exists {
+            return original_raw
+        }
+
+        return []byte(yadro)
+    })
+
+    return response
+}
+
+func translateWithPromtPuppies(response []byte) []byte {
+    enc := charmap.Windows1251.NewEncoder()
+    cp1521, _ := enc.Bytes(response)
+
+    req, _ := http.NewRequest("POST", "http://localhost:2390/", bytes.NewReader(cp1521))  // TODO
+
+    resp, err := http.DefaultClient.Do(req)
+    fmt.Println(err)
+    fmt.Println(resp.StatusCode)
+
+    response, _ = io.ReadAll(resp.Body)
+    dec, _ := charmap.Windows1251.NewDecoder().Bytes(response)
+    // fmt.Println(len(dec))
+    // fmt.Println(string(dec))
+
+    resp.Body.Close()
+    
+    return dec
+}
+
+func modifyResponse(response []byte) []byte {
+    response = replaceDomains(response)
+    response = translateWithPromtPuppies(response)
+    return response
+}