core: move crypto to core/crypto (#140)

- Move key-holder to authenticator

   Make core.keyHolder public as core.Authenticator, it
   is not required to make this part an interface.

- Make private when there is no need to go public.
- Fix data race

1 files changed, 100 insertions, 0 deletions

diff --git a/core/authenticator.go b/core/authenticator.go
new file mode 100644
index 0000000..480d6cc
--- /dev/null
+++ b/core/authenticator.go
@@ -0,0 +1,100 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus-core library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+)
+
+// Authenticator verify data owner.
+type Authenticator struct {
+	prvKey   crypto.PrivateKey
+	pubKey   crypto.PublicKey
+	sigToPub SigToPubFn
+}
+
+// NewAuthenticator constructs an Authenticator instance.
+func NewAuthenticator(prvKey crypto.PrivateKey, sigToPub SigToPubFn) *Authenticator {
+	return &Authenticator{
+		prvKey:   prvKey,
+		pubKey:   prvKey.PublicKey(),
+		sigToPub: sigToPub,
+	}
+}
+
+// SignBlock signs a types.Block.
+func (au *Authenticator) SignBlock(b *types.Block) (err error) {
+	b.ProposerID = types.NewNodeID(au.pubKey)
+	if b.Hash, err = hashBlock(b); err != nil {
+		return
+	}
+	if b.Signature, err = au.prvKey.Sign(b.Hash); err != nil {
+		return
+	}
+	return
+}
+
+// SignVote signs a types.Vote.
+func (au *Authenticator) SignVote(v *types.Vote) (err error) {
+	v.ProposerID = types.NewNodeID(au.pubKey)
+	v.Signature, err = au.prvKey.Sign(hashVote(v))
+	return
+}
+
+// SignCRS signs CRS signature of types.Block.
+func (au *Authenticator) SignCRS(b *types.Block, crs common.Hash) (err error) {
+	if b.ProposerID != types.NewNodeID(au.pubKey) {
+		err = ErrInvalidProposerID
+		return
+	}
+	b.CRSSignature, err = au.prvKey.Sign(hashCRS(b, crs))
+	return
+}
+
+// VerifyBlock verifies the signature of types.Block.
+func (au *Authenticator) VerifyBlock(b *types.Block) (err error) {
+	hash, err := hashBlock(b)
+	if err != nil {
+		return
+	}
+	if hash != b.Hash {
+		err = ErrIncorrectHash
+		return
+	}
+	pubKey, err := au.sigToPub(b.Hash, b.Signature)
+	if err != nil {
+		return
+	}
+	if !b.ProposerID.Equal(crypto.Keccak256Hash(pubKey.Bytes())) {
+		err = ErrIncorrectSignature
+		return
+	}
+	return
+}
+
+// VerifyVote verifies the signature of types.Vote.
+func (au *Authenticator) VerifyVote(v *types.Vote) (bool, error) {
+	return verifyVoteSignature(v, au.sigToPub)
+}
+
+// VerifyCRS verifies the CRS signature of types.Block.
+func (au *Authenticator) VerifyCRS(b *types.Block, crs common.Hash) (bool, error) {
+	return verifyCRSSignature(b, crs, au.sigToPub)
+}