Init

jwtauth.go

@@ -0,0 +1,109 @@
+package jwtauth
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"github.com/dgrijalva/jwt-go"
+	"github.com/pressly/chi"
+	"golang.org/x/net/context"
+)
+
+var (
+	errUnauthorized = errors.New("unauthorized token")
+)
+
+type JwtAuth struct {
+	signKey   []byte
+	verifyKey []byte
+	signer    jwt.SigningMethod
+}
+
+// verifyKey is only for RSA
+func New(alg string, signKey []byte, verifyKey []byte) *JwtAuth {
+	return &JwtAuth{
+		signKey:   signKey,
+		verifyKey: verifyKey,
+		signer:    jwt.GetSigningMethod(alg),
+	}
+}
+
+func (ja *JwtAuth) Handle(paramAliases ...string) func(chi.Handler) chi.Handler {
+	return func(next chi.Handler) chi.Handler {
+		hfn := func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+
+			var tokenStr string
+			var err error
+
+			// Get token from query params
+			tokenStr = r.URL.Query().Get("jwt")
+
+			// Get token from other query param aliases
+			if tokenStr == "" && paramAliases != nil && len(paramAliases) > 0 {
+				for _, p := range paramAliases {
+					tokenStr = r.URL.Query().Get(p)
+					if tokenStr != "" {
+						break
+					}
+				}
+			}
+
+			// Get token from authorization header
+			if tokenStr == "" {
+				bearer := r.Header.Get("Authorization")
+				if len(bearer) > 7 && strings.ToUpper(bearer[0:6]) == "BEARER" {
+					tokenStr = bearer[7:]
+				}
+			}
+
+			// Get token from cookie
+			if tokenStr == "" {
+				cookie, err := r.Cookie("jwt")
+				if err == nil {
+					tokenStr = cookie.Value
+				}
+			}
+
+			// Token is required, cya
+			if tokenStr == "" {
+				err = errUnauthorized
+			}
+
+			// Verify the token
+			token, err := ja.Decode(tokenStr)
+			if err != nil || !token.Valid || token.Method != ja.signer {
+				http.Error(w, errUnauthorized.Error(), 401)
+				return
+			}
+
+			ctx = context.WithValue(ctx, "jwt", token.Raw)
+			ctx = context.WithValue(ctx, "jwt.token", token)
+
+			next.ServeHTTPC(ctx, w, r)
+		}
+		return chi.HandlerFunc(hfn)
+	}
+}
+
+func (ja *JwtAuth) Handler(next chi.Handler) chi.Handler {
+	return ja.Handle("")(next)
+}
+
+func (ja *JwtAuth) Encode(claims map[string]interface{}) (t *jwt.Token, tokenString string, err error) {
+	t = jwt.New(ja.signer)
+	t.Claims = claims
+	tokenString, err = t.SignedString(ja.signKey)
+	t.Raw = tokenString
+	return
+}
+
+func (ja *JwtAuth) Decode(tokenString string) (t *jwt.Token, err error) {
+	return jwt.Parse(tokenString, func(t *jwt.Token) (interface{}, error) {
+		if ja.verifyKey != nil && len(ja.verifyKey) > 0 {
+			return ja.verifyKey, nil
+		} else {
+			return ja.signKey, nil
+		}
+	})
+}