1 files changed, 234 insertions, 0 deletions
diff --git a/entities/identity/key.go b/entities/identity/key.go
new file mode 100644
index 00000000..82b9b95c
--- /dev/null
+++ b/entities/identity/key.go
@@ -0,0 +1,234 @@
+package identity
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	"github.com/ProtonMail/go-crypto/openpgp"
+	"github.com/ProtonMail/go-crypto/openpgp/armor"
+	"github.com/ProtonMail/go-crypto/openpgp/packet"
+	"github.com/pkg/errors"
+
+	"github.com/MichaelMure/git-bug/repository"
+)
+
+var errNoPrivateKey = fmt.Errorf("no private key")
+
+type Key struct {
+	public  *packet.PublicKey
+	private *packet.PrivateKey
+}
+
+// GenerateKey generate a keypair (public+private)
+// The type and configuration of the key is determined by the default value in go's OpenPGP.
+func GenerateKey() *Key {
+	entity, err := openpgp.NewEntity("", "", "", &packet.Config{
+		// The armored format doesn't include the creation time, which makes the round-trip data not being fully equal.
+		// We don't care about the creation time so we can set it to the zero value.
+		Time: func() time.Time {
+			return time.Time{}
+		},
+	})
+	if err != nil {
+		panic(err)
+	}
+	return &Key{
+		public:  entity.PrimaryKey,
+		private: entity.PrivateKey,
+	}
+}
+
+// generatePublicKey generate only a public key (only useful for testing)
+// See GenerateKey for the details.
+func generatePublicKey() *Key {
+	k := GenerateKey()
+	k.private = nil
+	return k
+}
+
+func (k *Key) Public() *packet.PublicKey {
+	return k.public
+}
+
+func (k *Key) Private() *packet.PrivateKey {
+	return k.private
+}
+
+func (k *Key) Validate() error {
+	if k.public == nil {
+		return fmt.Errorf("nil public key")
+	}
+	if !k.public.CanSign() {
+		return fmt.Errorf("public key can't sign")
+	}
+
+	if k.private != nil {
+		if !k.private.CanSign() {
+			return fmt.Errorf("private key can't sign")
+		}
+	}
+
+	return nil
+}
+
+func (k *Key) Clone() *Key {
+	clone := &Key{}
+
+	pub := *k.public
+	clone.public = &pub
+
+	if k.private != nil {
+		priv := *k.private
+		clone.private = &priv
+	}
+
+	return clone
+}
+
+func (k *Key) MarshalJSON() ([]byte, error) {
+	// Serialize only the public key, in the armored format.
+	var buf bytes.Buffer
+	w, err := armor.Encode(&buf, openpgp.PublicKeyType, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	err = k.public.Serialize(w)
+	if err != nil {
+		return nil, err
+	}
+	err = w.Close()
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(buf.String())
+}
+
+func (k *Key) UnmarshalJSON(data []byte) error {
+	// De-serialize only the public key, in the armored format.
+	var armored string
+	err := json.Unmarshal(data, &armored)
+	if err != nil {
+		return err
+	}
+
+	block, err := armor.Decode(strings.NewReader(armored))
+	if err == io.EOF {
+		return fmt.Errorf("no armored data found")
+	}
+	if err != nil {
+		return err
+	}
+
+	if block.Type != openpgp.PublicKeyType {
+		return fmt.Errorf("invalid key type")
+	}
+
+	p, err := packet.Read(block.Body)
+	if err != nil {
+		return errors.Wrap(err, "failed to read public key packet")
+	}
+
+	public, ok := p.(*packet.PublicKey)
+	if !ok {
+		return errors.New("got no packet.publicKey")
+	}
+
+	// The armored format doesn't include the creation time, which makes the round-trip data not being fully equal.
+	// We don't care about the creation time so we can set it to the zero value.
+	public.CreationTime = time.Time{}
+
+	k.public = public
+	return nil
+}
+
+func (k *Key) loadPrivate(repo repository.RepoKeyring) error {
+	item, err := repo.Keyring().Get(k.public.KeyIdString())
+	if err == repository.ErrKeyringKeyNotFound {
+		return errNoPrivateKey
+	}
+	if err != nil {
+		return err
+	}
+
+	block, err := armor.Decode(bytes.NewReader(item.Data))
+	if err == io.EOF {
+		return fmt.Errorf("no armored data found")
+	}
+	if err != nil {
+		return err
+	}
+
+	if block.Type != openpgp.PrivateKeyType {
+		return fmt.Errorf("invalid key type")
+	}
+
+	p, err := packet.Read(block.Body)
+	if err != nil {
+		return errors.Wrap(err, "failed to read private key packet")
+	}
+
+	private, ok := p.(*packet.PrivateKey)
+	if !ok {
+		return errors.New("got no packet.privateKey")
+	}
+
+	// The armored format doesn't include the creation time, which makes the round-trip data not being fully equal.
+	// We don't care about the creation time so we can set it to the zero value.
+	private.CreationTime = time.Time{}
+
+	k.private = private
+	return nil
+}
+
+// ensurePrivateKey attempt to load the corresponding private key if it is not loaded already.
+// If no private key is found, returns errNoPrivateKey
+func (k *Key) ensurePrivateKey(repo repository.RepoKeyring) error {
+	if k.private != nil {
+		return nil
+	}
+
+	return k.loadPrivate(repo)
+}
+
+func (k *Key) storePrivate(repo repository.RepoKeyring) error {
+	var buf bytes.Buffer
+	w, err := armor.Encode(&buf, openpgp.PrivateKeyType, nil)
+	if err != nil {
+		return err
+	}
+	err = k.private.Serialize(w)
+	if err != nil {
+		return err
+	}
+	err = w.Close()
+	if err != nil {
+		return err
+	}
+
+	return repo.Keyring().Set(repository.Item{
+		Key:  k.public.KeyIdString(),
+		Data: buf.Bytes(),
+	})
+}
+
+func (k *Key) PGPEntity() *openpgp.Entity {
+	uid := packet.NewUserId("", "", "")
+	return &openpgp.Entity{
+		PrimaryKey: k.public,
+		PrivateKey: k.private,
+		Identities: map[string]*openpgp.Identity{
+			uid.Id: {
+				Name:   uid.Id,
+				UserId: uid,
+				SelfSignature: &packet.Signature{
+					IsPrimaryId: func() *bool { b := true; return &b }(),
+				},
+			},
+		},
+	}
+}