unarr/scripts/sign-checksums/main.go

61 lines
1.7 KiB
Go
Raw Permalink Normal View History

fix(security): UPnP opt-in, bounded SSE reader, signed self-update Phase 2 security audit follow-up. Three independent hardenings against the unauthenticated daemon surface, the long-lived agent SSE stream and the self-update channel. UPnP is now opt-in. The stream port + /hls endpoints have no auth, so publishing them on the WAN via the gateway was a default that exposed active downloads to anyone scanning the operator's external IP. New config downloads.enable_upnp (default false) gates the mapping; LAN and Tailscale clients continue to work unchanged. A startup log makes the new default visible. The agent SSE reader now uses a bounded bufio.Scanner instead of an unbounded ReadString. A hostile or buggy server can no longer grow daemon memory by streaming a single line forever or by emitting unbounded data: continuation lines — both are capped at 256 KiB and 1 MiB respectively, and an error is surfaced so SignalLoop reconnects. Self-update now verifies an ed25519 signature over checksums.txt when the binary was built with a release public key embedded (injected via goreleaser ldflags from RELEASE_SIGNING_PUBKEY). The companion scripts/sign-checksums runs in the release workflow when both the public-key variable and the private-key secret are present, uploading checksums.txt.sig next to the existing checksums file. Builds without the embedded key continue to update with SHA256-only verification; a --allow-unsigned flag is provided so users on a signed build can still install pre-signing releases or recover from an accidental unsigned release. A new scripts/gen-release-key helper documents the one-time keypair generation procedure required before flipping signing on.
2026-05-15 17:29:22 +02:00
// sign-checksums signs the dist/checksums.txt file with an ed25519 private
// key and writes the base64-encoded signature to the path given by -out.
//
// Usage (from release workflow):
//
// go run ./scripts/sign-checksums \
// -key "$RELEASE_SIGNING_KEY" \
// -in dist/checksums.txt \
// -out dist/checksums.txt.sig
//
// The companion CLI verifier (internal/upgrade/signature.go) requires the
// signature to be base64 text, so emitting base64 + trailing newline makes
// the artifact safe to inspect with `cat` / the GitHub release UI.
package main
import (
"crypto/ed25519"
"encoding/base64"
"flag"
"fmt"
"os"
)
func main() {
keyB64 := flag.String("key", "", "base64-encoded ed25519 private key (PrivateKeySize = 64 bytes)")
in := flag.String("in", "", "path to file to sign")
out := flag.String("out", "", "path to write the base64-encoded signature")
flag.Parse()
if *keyB64 == "" || *in == "" || *out == "" {
fmt.Fprintln(os.Stderr, "usage: sign-checksums -key <base64> -in <path> -out <path>")
os.Exit(2)
}
keyBytes, err := base64.StdEncoding.DecodeString(*keyB64)
if err != nil {
fail("decode key: %v", err)
}
if len(keyBytes) != ed25519.PrivateKeySize {
fail("private key size %d, expected %d", len(keyBytes), ed25519.PrivateKeySize)
}
priv := ed25519.PrivateKey(keyBytes)
content, err := os.ReadFile(*in)
if err != nil {
fail("read input: %v", err)
}
sig := ed25519.Sign(priv, content)
encoded := base64.StdEncoding.EncodeToString(sig) + "\n"
if err := os.WriteFile(*out, []byte(encoded), 0o644); err != nil {
fail("write signature: %v", err)
}
fmt.Printf("Signed %s (%d bytes) → %s\n", *in, len(content), *out)
}
func fail(format string, args ...any) {
fmt.Fprintf(os.Stderr, format+"\n", args...)
os.Exit(1)
}