433e375def
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.
60 lines
1.7 KiB
Go
60 lines
1.7 KiB
Go
// sign-checksums signs the dist/checksums.txt file with an ed25519 private
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// key and writes the base64-encoded signature to the path given by -out.
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//
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// Usage (from release workflow):
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//
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// go run ./scripts/sign-checksums \
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// -key "$RELEASE_SIGNING_KEY" \
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// -in dist/checksums.txt \
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// -out dist/checksums.txt.sig
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//
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// The companion CLI verifier (internal/upgrade/signature.go) requires the
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// signature to be base64 text, so emitting base64 + trailing newline makes
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// the artifact safe to inspect with `cat` / the GitHub release UI.
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package main
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import (
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"crypto/ed25519"
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"encoding/base64"
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"flag"
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"fmt"
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"os"
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)
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func main() {
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keyB64 := flag.String("key", "", "base64-encoded ed25519 private key (PrivateKeySize = 64 bytes)")
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in := flag.String("in", "", "path to file to sign")
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out := flag.String("out", "", "path to write the base64-encoded signature")
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flag.Parse()
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if *keyB64 == "" || *in == "" || *out == "" {
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fmt.Fprintln(os.Stderr, "usage: sign-checksums -key <base64> -in <path> -out <path>")
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os.Exit(2)
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}
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keyBytes, err := base64.StdEncoding.DecodeString(*keyB64)
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if err != nil {
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fail("decode key: %v", err)
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}
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if len(keyBytes) != ed25519.PrivateKeySize {
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fail("private key size %d, expected %d", len(keyBytes), ed25519.PrivateKeySize)
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}
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priv := ed25519.PrivateKey(keyBytes)
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content, err := os.ReadFile(*in)
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if err != nil {
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fail("read input: %v", err)
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}
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sig := ed25519.Sign(priv, content)
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encoded := base64.StdEncoding.EncodeToString(sig) + "\n"
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if err := os.WriteFile(*out, []byte(encoded), 0o644); err != nil {
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fail("write signature: %v", err)
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}
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fmt.Printf("Signed %s (%d bytes) → %s\n", *in, len(content), *out)
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}
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func fail(format string, args ...any) {
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fmt.Fprintf(os.Stderr, format+"\n", args...)
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os.Exit(1)
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}
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