Files
gopeed/internal/protocol/hls/crypto.go
T
sun 4f74101b3a feat(hls): add native HLS (m3u8) download protocol
New hls protocol in internal/protocol/hls (registered ahead of http):
- master playlist variant picking (highest bandwidth), RFC3986 segment
  URL resolution, fMP4 init segments, EXT-X-BYTERANGE, EXT-X-GAP skip
- AES-128 decryption with mid-playlist key rotation and sequence-derived
  IVs; explicit errors for live streams, SAMPLE-AES and multi-period fMP4
- concurrent segment downloads with retry, journal-based resume across
  pause/app restarts, automatic in-order merge into a single .ts/.mp4
- best-effort Content-Length probing for determinate progress
- anti-hotlink Referer/Cookie/UA via task extra headers (Go transport
  does not filter them)

Core: fix SchemeFilter extension match for URLs with query strings
(also benefits .torrent links); Flutter: Protocol.hls enum, hls protocol
config model (prevents config round-trip wipe) and HLS settings block
with localized labels in all 22 locales.

Tests: parser/crypto unit tests, httptest e2e (Referer-enforced CDN,
encrypted streams, byterange, pause/resume, store/restore) and an
opt-in live-site acceptance gate (HLS_LIVE_URL).
2026-09-14 09:55:31 +08:00

60 lines
1.6 KiB
Go

package hls
import (
"crypto/aes"
"crypto/cipher"
"fmt"
)
// decryptAES128 decrypts an AES-128-CBC encrypted segment and strips PKCS7
// padding. data length must be a multiple of the AES block size.
func decryptAES128(data, key, iv []byte) ([]byte, error) {
if len(key) != 16 {
return nil, fmt.Errorf("invalid AES-128 key size %d", len(key))
}
if len(iv) != 16 {
return nil, fmt.Errorf("invalid AES-128 IV size %d", len(iv))
}
if len(data) == 0 || len(data)%aes.BlockSize != 0 {
return nil, fmt.Errorf("invalid AES-128 data size %d", len(data))
}
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
plain := make([]byte, len(data))
cipher.NewCBCDecrypter(block, iv).CryptBlocks(plain, data)
return pkcs7Unpad(plain, aes.BlockSize)
}
func pkcs7Unpad(data []byte, blockSize int) ([]byte, error) {
if len(data) == 0 {
return nil, fmt.Errorf("empty plaintext")
}
pad := int(data[len(data)-1])
if pad == 0 || pad > blockSize || pad > len(data) {
return nil, fmt.Errorf("invalid PKCS7 padding")
}
for _, b := range data[len(data)-pad:] {
if int(b) != pad {
return nil, fmt.Errorf("invalid PKCS7 padding")
}
}
return data[:len(data)-pad], nil
}
// sequenceIV derives the default per-segment IV mandated by RFC 8216: the
// segment media sequence number as a 16-byte big-endian integer.
func sequenceIV(sequence int64) []byte {
iv := make([]byte, 16)
iv[8] = byte(sequence >> 56)
iv[9] = byte(sequence >> 48)
iv[10] = byte(sequence >> 40)
iv[11] = byte(sequence >> 32)
iv[12] = byte(sequence >> 24)
iv[13] = byte(sequence >> 16)
iv[14] = byte(sequence >> 8)
iv[15] = byte(sequence)
return iv
}