mfer/mfer/manifest.go
sneak 4a2060087d Add GPG signature verification on manifest load
- Implement gpgVerify function that creates a temporary keyring to verify
  detached signatures against embedded public keys
- Signature verification happens during deserialization after hash
  validation but before decompression
- Extract signatureString() as a method on manifest for generating the
  canonical signature string (MAGIC-UUID-MULTIHASH)
- Add --require-signature flag to check command to mandate signature from
  a specific GPG key ID
- Expose IsSigned() and Signer() methods on Checker for signature status
2025-12-18 05:56:16 -08:00

60 lines
1.5 KiB
Go

package mfer
import (
"bytes"
"encoding/hex"
"errors"
"fmt"
"github.com/multiformats/go-multihash"
)
// manifest holds the internal representation of a manifest file.
// Use NewManifestFromFile or NewManifestFromReader to load an existing manifest,
// or use Builder to create a new one.
type manifest struct {
pbInner *MFFile
pbOuter *MFFileOuter
output *bytes.Buffer
signingOptions *SigningOptions
}
func (m *manifest) String() string {
count := 0
if m.pbInner != nil {
count = len(m.pbInner.Files)
}
return fmt.Sprintf("<Manifest count=%d>", count)
}
// Files returns all file entries from a loaded manifest.
func (m *manifest) Files() []*MFFilePath {
if m.pbInner == nil {
return nil
}
return m.pbInner.Files
}
// signatureString generates the canonical string used for signing/verification.
// Format: MAGIC-UUID-MULTIHASH where UUID and multihash are hex-encoded.
// Requires pbOuter to be set with Uuid and Sha256 fields.
func (m *manifest) signatureString() (string, error) {
if m.pbOuter == nil {
return "", errors.New("pbOuter not set")
}
if len(m.pbOuter.Uuid) == 0 {
return "", errors.New("UUID not set")
}
if len(m.pbOuter.Sha256) == 0 {
return "", errors.New("SHA256 hash not set")
}
mh, err := multihash.Encode(m.pbOuter.Sha256, multihash.SHA2_256)
if err != nil {
return "", fmt.Errorf("failed to encode multihash: %w", err)
}
uuidStr := hex.EncodeToString(m.pbOuter.Uuid)
mhStr := hex.EncodeToString(mh)
return fmt.Sprintf("%s-%s-%s", MAGIC, uuidStr, mhStr), nil
}