| 1 | package daemon |
| 2 | |
| 3 | import ( |
| 4 | "crypto/sha256" |
| 5 | "encoding/hex" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "net/http" |
| 10 | "os" |
| 11 | "sync" |
| 12 | |
| 13 | "github.com/FelineStateMachine/tinyrelay/internal/event" |
| 14 | ) |
| 15 | |
| 16 | // A NIP-98 payload hash must match before Git can mutate the repository. |
| 17 | // Spooling keeps that ordering without allocating memory proportional to a |
| 18 | // pack's size. GitRelay closes the replacement body on every request exit. |
| 19 | func spoolGitPayload(r *http.Request, proof event.Event) error { |
| 20 | if r.Body == nil || r.Body == http.NoBody { |
| 21 | return nil |
| 22 | } |
| 23 | file, err := os.CreateTemp("" , "tiny-git-authorized-*" ) |
| 24 | if err != nil { |
| 25 | return fmt.Errorf("spool Git authorization: %w" , err) |
| 26 | } |
| 27 | keep := false |
| 28 | defer func() { |
| 29 | if !keep { |
| 30 | _ = file.Close() |
| 31 | _ = os.Remove(file.Name()) |
| 32 | } |
| 33 | }() |
| 34 | hash := sha256.New() |
| 35 | n, err := io.Copy(io.MultiWriter(file, hash), r.Body) |
| 36 | if err != nil { |
| 37 | return fmt.Errorf("read Git authorization payload: %w" , err) |
| 38 | } |
| 39 | if n == 0 { |
| 40 | return nil |
| 41 | } |
| 42 | if event.Tag(proof, "payload" ) != hex.EncodeToString(hash.Sum(nil)) { |
| 43 | return errors.New("auth-required: token payload hash does not match the body" ) |
| 44 | } |
| 45 | if _, err := file.Seek(0, io.SeekStart); err != nil { |
| 46 | return fmt.Errorf("rewind Git authorization payload: %w" , err) |
| 47 | } |
| 48 | r.Body = &gitPayloadBody{File: file, original: r.Body} |
| 49 | keep = true |
| 50 | return nil |
| 51 | } |
| 52 | |
| 53 | type gitPayloadBody struct { |
| 54 | *os.File |
| 55 | original io.ReadCloser |
| 56 | once sync.Once |
| 57 | err error |
| 58 | } |
| 59 | |
| 60 | func (b *gitPayloadBody) Close() error { |
| 61 | b.once.Do(func() { |
| 62 | b.err = errors.Join(b.File.Close(), os.Remove(b.Name()), b.original.Close()) |
| 63 | }) |
| 64 | return b.err |
| 65 | } |