Unify local and external keys in keybase interface (#117)

* Return errors on priv.Sign(), priv.PubKey()

* Add CreateLedger, CreateOffline

* Add switch on .Sign() for Ledger wallets

* Add offline signing switch on .Sign()

* Use MustUnmarshalBinaryBare()

* Add confirmation to delete offline/Ledger keys

* Lowercase error message

* Add human-readable .GetType() function to Info interface

* Rename CryptoAlgo => SignAlgo

* assert.Nil(t, err) => assert.NoError(t, err)

keys/types.go

@@ -4,54 +4,136 @@ import (
 	crypto "github.com/tendermint/go-crypto"
 )
 
-// Keybase allows simple CRUD on a keystore, as an aid to signing
+// Keybase exposes operations on a generic keystore
 type Keybase interface {
-	// Sign some bytes
-	Sign(name, passphrase string, msg []byte) (crypto.Signature, crypto.PubKey, error)
-	// Create a new keypair
-	Create(name, passphrase string, algo CryptoAlgo) (info Info, seed string, err error)
-	// Recover takes a seedphrase and loads in the key
-	Recover(name, passphrase, seedphrase string) (info Info, erro error)
+
+	// CRUD on the keystore
 	List() ([]Info, error)
 	Get(name string) (Info, error)
-	Update(name, oldpass, newpass string) error
 	Delete(name, passphrase string) error
 
+	// Sign some bytes, looking up the private key to use
+	Sign(name, passphrase string, msg []byte) (crypto.Signature, crypto.PubKey, error)
+
+	// Create a new locally-stored keypair, returning the mnemonic
+	CreateMnemonic(name, passphrase string, algo SignAlgo) (info Info, seed string, err error)
+	// Recover takes a seedphrase and loads in the key
+	Recover(name, passphrase, seedphrase string) (info Info, erro error)
+
+	// Create, store, and return a new Ledger key reference
+	CreateLedger(name string, path crypto.DerivationPath, algo SignAlgo) (info Info, err error)
+
+	// Create, store, and return a new offline key reference
+	CreateOffline(name string, pubkey crypto.PubKey) (info Info, err error)
+
+	// The following operations will *only* work on locally-stored keys
+	Update(name, oldpass, newpass string) error
 	Import(name string, armor string) (err error)
 	ImportPubKey(name string, armor string) (err error)
 	Export(name string) (armor string, err error)
 	ExportPubKey(name string) (armor string, err error)
 }
 
-// Info is the public information about a key
-type Info struct {
+// Publically exposed information about a keypair
+type Info interface {
+	// Human-readable type for key listing
+	GetType() string
+	// Name of the key
+	GetName() string
+	// Public key
+	GetPubKey() crypto.PubKey
+}
+
+var _ Info = &localInfo{}
+var _ Info = &ledgerInfo{}
+var _ Info = &offlineInfo{}
+
+// localInfo is the public information about a locally stored key
+type localInfo struct {
 	Name         string        `json:"name"`
 	PubKey       crypto.PubKey `json:"pubkey"`
 	PrivKeyArmor string        `json:"privkey.armor"`
 }
 
-func newInfo(name string, pub crypto.PubKey, privArmor string) Info {
-	return Info{
+func newLocalInfo(name string, pub crypto.PubKey, privArmor string) Info {
+	return &localInfo{
 		Name:         name,
 		PubKey:       pub,
 		PrivKeyArmor: privArmor,
 	}
 }
 
-// Address is a helper function to calculate the address from the pubkey
-func (i Info) Address() []byte {
-	return i.PubKey.Address()
+func (i localInfo) GetType() string {
+	return "local"
 }
 
-func (i Info) bytes() []byte {
-	bz, err := cdc.MarshalBinaryBare(i)
-	if err != nil {
-		panic(err)
+func (i localInfo) GetName() string {
+	return i.Name
+}
+
+func (i localInfo) GetPubKey() crypto.PubKey {
+	return i.PubKey
+}
+
+// ledgerInfo is the public information about a Ledger key
+type ledgerInfo struct {
+	Name   string                `json:"name"`
+	PubKey crypto.PubKey         `json:"pubkey"`
+	Path   crypto.DerivationPath `json:"path"`
+}
+
+func newLedgerInfo(name string, pub crypto.PubKey, path crypto.DerivationPath) Info {
+	return &ledgerInfo{
+		Name:   name,
+		PubKey: pub,
+		Path:   path,
 	}
-	return bz
 }
 
+func (i ledgerInfo) GetType() string {
+	return "ledger"
+}
+
+func (i ledgerInfo) GetName() string {
+	return i.Name
+}
+
+func (i ledgerInfo) GetPubKey() crypto.PubKey {
+	return i.PubKey
+}
+
+// offlineInfo is the public information about an offline key
+type offlineInfo struct {
+	Name   string        `json:"name"`
+	PubKey crypto.PubKey `json:"pubkey"`
+}
+
+func newOfflineInfo(name string, pub crypto.PubKey) Info {
+	return &offlineInfo{
+		Name:   name,
+		PubKey: pub,
+	}
+}
+
+func (i offlineInfo) GetType() string {
+	return "offline"
+}
+
+func (i offlineInfo) GetName() string {
+	return i.Name
+}
+
+func (i offlineInfo) GetPubKey() crypto.PubKey {
+	return i.PubKey
+}
+
+// encoding info
+func writeInfo(i Info) []byte {
+	return cdc.MustMarshalBinary(i)
+}
+
+// decoding info
 func readInfo(bz []byte) (info Info, err error) {
-	err = cdc.UnmarshalBinaryBare(bz, &info)
+	err = cdc.UnmarshalBinary(bz, &info)
 	return
 }