[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/auth/jwt.go b/vendor/go.etcd.io/etcd/auth/jwt.go
new file mode 100644
index 0000000..c22ef89
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/jwt.go
@@ -0,0 +1,184 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"errors"
+	"time"
+
+	jwt "github.com/dgrijalva/jwt-go"
+	"go.uber.org/zap"
+)
+
+type tokenJWT struct {
+	lg         *zap.Logger
+	signMethod jwt.SigningMethod
+	key        interface{}
+	ttl        time.Duration
+	verifyOnly bool
+}
+
+func (t *tokenJWT) enable()                         {}
+func (t *tokenJWT) disable()                        {}
+func (t *tokenJWT) invalidateUser(string)           {}
+func (t *tokenJWT) genTokenPrefix() (string, error) { return "", nil }
+
+func (t *tokenJWT) info(ctx context.Context, token string, rev uint64) (*AuthInfo, bool) {
+	// rev isn't used in JWT, it is only used in simple token
+	var (
+		username string
+		revision uint64
+	)
+
+	parsed, err := jwt.Parse(token, func(token *jwt.Token) (interface{}, error) {
+		if token.Method.Alg() != t.signMethod.Alg() {
+			return nil, errors.New("invalid signing method")
+		}
+		switch k := t.key.(type) {
+		case *rsa.PrivateKey:
+			return &k.PublicKey, nil
+		case *ecdsa.PrivateKey:
+			return &k.PublicKey, nil
+		default:
+			return t.key, nil
+		}
+	})
+
+	if err != nil {
+		if t.lg != nil {
+			t.lg.Warn(
+				"failed to parse a JWT token",
+				zap.String("token", token),
+				zap.Error(err),
+			)
+		} else {
+			plog.Warningf("failed to parse jwt token: %s", err)
+		}
+		return nil, false
+	}
+
+	claims, ok := parsed.Claims.(jwt.MapClaims)
+	if !parsed.Valid || !ok {
+		if t.lg != nil {
+			t.lg.Warn("invalid JWT token", zap.String("token", token))
+		} else {
+			plog.Warningf("invalid jwt token: %s", token)
+		}
+		return nil, false
+	}
+
+	username = claims["username"].(string)
+	revision = uint64(claims["revision"].(float64))
+
+	return &AuthInfo{Username: username, Revision: revision}, true
+}
+
+func (t *tokenJWT) assign(ctx context.Context, username string, revision uint64) (string, error) {
+	if t.verifyOnly {
+		return "", ErrVerifyOnly
+	}
+
+	// Future work: let a jwt token include permission information would be useful for
+	// permission checking in proxy side.
+	tk := jwt.NewWithClaims(t.signMethod,
+		jwt.MapClaims{
+			"username": username,
+			"revision": revision,
+			"exp":      time.Now().Add(t.ttl).Unix(),
+		})
+
+	token, err := tk.SignedString(t.key)
+	if err != nil {
+		if t.lg != nil {
+			t.lg.Warn(
+				"failed to sign a JWT token",
+				zap.String("user-name", username),
+				zap.Uint64("revision", revision),
+				zap.Error(err),
+			)
+		} else {
+			plog.Debugf("failed to sign jwt token: %s", err)
+		}
+		return "", err
+	}
+
+	if t.lg != nil {
+		t.lg.Info(
+			"created/assigned a new JWT token",
+			zap.String("user-name", username),
+			zap.Uint64("revision", revision),
+			zap.String("token", token),
+		)
+	} else {
+		plog.Debugf("jwt token: %s", token)
+	}
+	return token, err
+}
+
+func newTokenProviderJWT(lg *zap.Logger, optMap map[string]string) (*tokenJWT, error) {
+	var err error
+	var opts jwtOptions
+	err = opts.ParseWithDefaults(optMap)
+	if err != nil {
+		if lg != nil {
+			lg.Warn("problem loading JWT options", zap.Error(err))
+		} else {
+			plog.Errorf("problem loading JWT options: %s", err)
+		}
+		return nil, ErrInvalidAuthOpts
+	}
+
+	var keys = make([]string, 0, len(optMap))
+	for k := range optMap {
+		if !knownOptions[k] {
+			keys = append(keys, k)
+		}
+	}
+	if len(keys) > 0 {
+		if lg != nil {
+			lg.Warn("unknown JWT options", zap.Strings("keys", keys))
+		} else {
+			plog.Warningf("unknown JWT options: %v", keys)
+		}
+	}
+
+	key, err := opts.Key()
+	if err != nil {
+		return nil, err
+	}
+
+	t := &tokenJWT{
+		lg:         lg,
+		ttl:        opts.TTL,
+		signMethod: opts.SignMethod,
+		key:        key,
+	}
+
+	switch t.signMethod.(type) {
+	case *jwt.SigningMethodECDSA:
+		if _, ok := t.key.(*ecdsa.PublicKey); ok {
+			t.verifyOnly = true
+		}
+	case *jwt.SigningMethodRSA, *jwt.SigningMethodRSAPSS:
+		if _, ok := t.key.(*rsa.PublicKey); ok {
+			t.verifyOnly = true
+		}
+	}
+
+	return t, nil
+}