Golang AES decrypt video before streaming it though http - go

Question

Im trying to stream AES encrypted video file; however we need to decrypt it on the fly before streaming it though http
how to write the output of decrypted data to http writer
package main
import (
"crypto/aes"
"crypto/cipher"
"io"
"log"
"net/http"
"os"
)
var key []byte = []byte("yourAESPrivateKey")
func ServeHTTP(w http.ResponseWriter, r *http.Request) {
inFile, err := os.Open("2.ts")
if err != nil {
log.Fatal(err)
}
defer inFile.Close()
block, err := aes.NewCipher(key)
if err != nil {
log.Fatal(err)
return
}
var iv [aes.BlockSize]byte
stream := cipher.NewOFB(block, iv[:])
w.Header().Set("Content-type", "video/mp4")
writer := &cipher.StreamWriter{S: stream, W: w}
if _, err := io.Copy(writer, inFile); err != nil {
log.Fatal(err)
return
}
//http.ServeContent(w, r, "video.mp4", time.Now(), inFile)
}
func main() {
http.HandleFunc("/", ServeHTTP)
http.ListenAndServe(":2020", nil)
}

Answer 1

i have enhanced my code
so if i requested an encrypted file, the server will decrypt it and serve it properly, however i have another problem as below
the problem now is that i get corrupted file if file exceeds certain size.
i have done some tests on text files for debugging purposes and so i can post data results here (big corrupted file) check the end of the file
package main
import (
"crypto/aes"
"crypto/cipher"
"log"
"net/http"
"os"
"time"
)
type cipherHttpWriter struct {
http.ResponseWriter
}
func (c cipherHttpWriter) Write(b []byte) (int, error) {
var key []byte = []byte("we!#09bsa$.a-ala.HJOqweK45aghf&A")
block, err := aes.NewCipher(key)
if err != nil {
return 0, err
}
var iv [aes.BlockSize]byte
stream := cipher.NewOFB(block, iv[:])
streamWriter := &cipher.StreamWriter{S: stream, W: c.ResponseWriter}
defer streamWriter.Close()
return streamWriter.Write(b)
}
func ServeHTTP(w http.ResponseWriter, r *http.Request) {
inFile, err := os.Open(string(r.URL.Path[1:]))
if err != nil {
log.Fatal(err)
}
defer inFile.Close()
writer := cipherHttpWriter{}
writer.ResponseWriter = w
http.ServeContent(writer, r, "", time.Now(), inFile)
}
func main() {
http.HandleFunc("/", ServeHTTP)
http.ListenAndServe(":2020", nil)
}