1 files changed, 181 insertions, 6 deletions

diff --git a/identity/key.go b/identity/key.go
index cc948394..8dd5e8c1 100644
--- a/identity/key.go
+++ b/identity/key.go
@@ -1,18 +1,193 @@
 package identity
 
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/openpgp"
+	"golang.org/x/crypto/openpgp/armor"
+	"golang.org/x/crypto/openpgp/packet"
+
+	"github.com/MichaelMure/git-bug/repository"
+)
+
 type Key struct {
-	// The GPG fingerprint of the key
-	Fingerprint string `json:"fingerprint"`
-	PubKey      string `json:"pub_key"`
+	public  *packet.PublicKey
+	private *packet.PrivateKey
+}
+
+// GenerateKey generate a keypair (public+private)
+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) MarshalJSON() ([]byte, error) {
+	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 {
+	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")
+	}
+
+	reader := packet.NewReader(block.Body)
+	p, err := reader.Next()
+	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) Validate() error {
-	// Todo
+	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 := *k
-	return &clone
+	clone := &Key{}
+
+	pub := *k.public
+	clone.public = &pub
+
+	if k.private != nil {
+		priv := *k.private
+		clone.private = &priv
+	}
+
+	return clone
+}
+
+func (k *Key) EnsurePrivateKey(repo repository.RepoKeyring) error {
+	if k.private != nil {
+		return nil
+	}
+
+	// item, err := repo.Keyring().Get(k.Fingerprint())
+	// if err != nil {
+	// 	return fmt.Errorf("no private key found for %s", k.Fingerprint())
+	// }
+	//
+
+	panic("TODO")
+}
+
+func (k *Key) Fingerprint() string {
+	return string(k.public.Fingerprint[:])
+}
+
+func (k *Key) PGPEntity() *openpgp.Entity {
+	return &openpgp.Entity{
+		PrimaryKey: k.public,
+		PrivateKey: k.private,
+	}
+}
+
+var _ openpgp.KeyRing = &PGPKeyring{}
+
+// PGPKeyring implement a openpgp.KeyRing from an slice of Key
+type PGPKeyring []*Key
+
+func (pk PGPKeyring) KeysById(id uint64) []openpgp.Key {
+	var result []openpgp.Key
+	for _, key := range pk {
+		if key.public.KeyId == id {
+			result = append(result, openpgp.Key{
+				PublicKey:  key.public,
+				PrivateKey: key.private,
+			})
+		}
+	}
+	return result
+}
+
+func (pk PGPKeyring) KeysByIdUsage(id uint64, requiredUsage byte) []openpgp.Key {
+	// the only usage we care about is the ability to sign, which all keys should already be capable of
+	return pk.KeysById(id)
+}
+
+func (pk PGPKeyring) DecryptionKeys() []openpgp.Key {
+	result := make([]openpgp.Key, len(pk))
+	for i, key := range pk {
+		result[i] = openpgp.Key{
+			PublicKey:  key.public,
+			PrivateKey: key.private,
+		}
+	}
+	return result
 }