Add PublicKeyCodec (#6372)

* Add PublicKeyCodec

* Add tests

* Remove cache codec

* Remove cache codec

* Revert proto changes

* Revert proto changes

* refactor and move docs

* Lint

* Apply suggestions from code review

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

crypto/types/codec.go

@@ -0,0 +1,15 @@
+package types
+
+import (
+	"github.com/tendermint/tendermint/crypto"
+)
+
+// PublicKeyCodec defines a type which can encode and decode crypto.PubKey's
+// to and from protobuf PublicKey's
+type PublicKeyCodec interface {
+	// Encode encodes the crypto.PubKey as a protobuf PublicKey or returns an error
+	Encode(key crypto.PubKey) (*PublicKey, error)
+
+	// Decode decodes a crypto.PubKey from a protobuf PublicKey or returns an error
+	Decode(key *PublicKey) (crypto.PubKey, error)
+}

go.sum

@@ -78,7 +78,6 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
 github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd/go.mod h1:sE/e/2PUdi/liOCUjSTXgM1o87ZssimdTWN964YiIeI=
-github.com/confio/ics23 v0.6.0 h1:bQsi55t2+xjW6EWDl83IBF1VWurplbUu+OT6pukeiEo=
 github.com/confio/ics23-iavl v0.6.0 h1:vVRCuVaP38FCw1kTeEdFuGuiY+2vAGTBQoH7Zxkq/ws=
 github.com/confio/ics23-iavl v0.6.0/go.mod h1:mmXAxD1vWoO0VP8YHu6mM1QHGv71NQqa1iSVm4HeKcY=
 github.com/confio/ics23/go v0.0.0-20200323120010-7d9a00f0a2fa/go.mod h1:W1I3XC8d9N8OTu/ct5VJ84ylcOunZwMXsWkd27nvVts=
@@ -467,8 +466,6 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
-github.com/stretchr/testify v1.6.0 h1:jlIyCplCJFULU/01vCkhKuTyc3OorI3bJFuw6obfgho=
-github.com/stretchr/testify v1.6.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/subosito/gotenv v1.2.0 h1:Slr1R9HxAlEKefgq5jn9U+DnETlIUa6HfgEzj0g5d7s=

std/pubkey.go

@@ -0,0 +1,90 @@
+package std
+
+import (
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/crypto/types"
+	"github.com/cosmos/cosmos-sdk/crypto/types/multisig"
+
+	"github.com/tendermint/tendermint/crypto"
+	ed255192 "github.com/tendermint/tendermint/crypto/ed25519"
+	"github.com/tendermint/tendermint/crypto/secp256k1"
+	"github.com/tendermint/tendermint/crypto/sr25519"
+)
+
+// DefaultPublicKeyCodec implements the standard PublicKeyCodec for the SDK which
+// supports a standard set of public key types
+type DefaultPublicKeyCodec struct{}
+
+var _ types.PublicKeyCodec = DefaultPublicKeyCodec{}
+
+// Decode implements the PublicKeyCodec.Decode method
+func (cdc DefaultPublicKeyCodec) Decode(key *types.PublicKey) (crypto.PubKey, error) {
+	switch key := key.Sum.(type) {
+	case *types.PublicKey_Secp256K1:
+		n := len(key.Secp256K1)
+		if n != secp256k1.PubKeySecp256k1Size {
+			return nil, fmt.Errorf("wrong length %d for secp256k1 public key", n)
+		}
+		var res secp256k1.PubKeySecp256k1
+		copy(res[:], key.Secp256K1)
+		return res, nil
+	case *types.PublicKey_Ed25519:
+		n := len(key.Ed25519)
+		if n != ed255192.PubKeyEd25519Size {
+			return nil, fmt.Errorf("wrong length %d for ed25519 public key", n)
+		}
+		var res ed255192.PubKeyEd25519
+		copy(res[:], key.Ed25519)
+		return res, nil
+	case *types.PublicKey_Sr25519:
+		n := len(key.Sr25519)
+		if n != sr25519.PubKeySr25519Size {
+			return nil, fmt.Errorf("wrong length %d for sr25519 public key", n)
+		}
+		var res sr25519.PubKeySr25519
+		copy(res[:], key.Sr25519)
+		return res, nil
+	case *types.PublicKey_Multisig:
+		pubKeys := key.Multisig.PubKeys
+		resKeys := make([]crypto.PubKey, len(pubKeys))
+		for i, k := range pubKeys {
+			dk, err := cdc.Decode(k)
+			if err != nil {
+				return nil, err
+			}
+			resKeys[i] = dk
+		}
+		return multisig.NewPubKeyMultisigThreshold(int(key.Multisig.K), resKeys), nil
+	default:
+		return nil, fmt.Errorf("can't decode PubKey of type %T. Use a custom PublicKeyCodec instead", key)
+	}
+}
+
+// Encode implements the PublicKeyCodec.Encode method
+func (cdc DefaultPublicKeyCodec) Encode(key crypto.PubKey) (*types.PublicKey, error) {
+	switch key := key.(type) {
+	case secp256k1.PubKeySecp256k1:
+		return &types.PublicKey{Sum: &types.PublicKey_Secp256K1{Secp256K1: key[:]}}, nil
+	case ed255192.PubKeyEd25519:
+		return &types.PublicKey{Sum: &types.PublicKey_Ed25519{Ed25519: key[:]}}, nil
+	case sr25519.PubKeySr25519:
+		return &types.PublicKey{Sum: &types.PublicKey_Sr25519{Sr25519: key[:]}}, nil
+	case multisig.PubKeyMultisigThreshold:
+		pubKeys := key.PubKeys
+		resKeys := make([]*types.PublicKey, len(pubKeys))
+		for i, k := range pubKeys {
+			dk, err := cdc.Encode(k)
+			if err != nil {
+				return nil, err
+			}
+			resKeys[i] = dk
+		}
+		return &types.PublicKey{Sum: &types.PublicKey_Multisig{Multisig: &types.PubKeyMultisigThreshold{
+			K:       uint32(key.K),
+			PubKeys: resKeys,
+		}}}, nil
+	default:
+		return nil, fmt.Errorf("can't encode PubKey of type %T. Use a custom PublicKeyCodec instead", key)
+	}
+}

std/pubkey_test.go

@@ -0,0 +1,41 @@
+package std_test
+
+import (
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/std"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tendermint/tendermint/crypto"
+	"github.com/tendermint/tendermint/crypto/ed25519"
+	"github.com/tendermint/tendermint/crypto/secp256k1"
+	"github.com/tendermint/tendermint/crypto/sr25519"
+
+	"github.com/cosmos/cosmos-sdk/crypto/types/multisig"
+)
+
+func roundTripTest(t *testing.T, pubKey crypto.PubKey) {
+	cdc := std.DefaultPublicKeyCodec{}
+
+	pubKeyEnc, err := cdc.Encode(pubKey)
+	require.NoError(t, err)
+	pubKeyDec, err := cdc.Decode(pubKeyEnc)
+	require.NoError(t, err)
+	require.Equal(t, pubKey, pubKeyDec)
+}
+
+func TestDefaultPublicKeyCodec(t *testing.T) {
+	pubKeySecp256k1 := secp256k1.GenPrivKey().PubKey()
+	roundTripTest(t, pubKeySecp256k1)
+
+	pubKeyEd25519 := ed25519.GenPrivKey().PubKey()
+	roundTripTest(t, pubKeyEd25519)
+
+	pubKeySr25519 := sr25519.GenPrivKey().PubKey()
+	roundTripTest(t, pubKeySr25519)
+
+	pubKeyMultisig := multisig.NewPubKeyMultisigThreshold(2, []crypto.PubKey{
+		pubKeySecp256k1, pubKeyEd25519, pubKeySr25519,
+	})
+	roundTripTest(t, pubKeyMultisig)
+}