split up library and removed Stop() panic when called twice

token.go

@@ -0,0 +1,104 @@
+// Copyright (C) 2018 Marius Schellenberger
+
+package jwt
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"strings"
+)
+
+// Token is the JWT token representation
+type Token struct {
+	raw          string
+	data         string
+	signature    string
+	rawSignature []byte
+	header       map[string]interface{}
+	Claims       Claims
+}
+
+// String returns the tokens encoded string
+func (t *Token) String() string {
+	return t.raw
+}
+
+// Sig returns the Tokens URLEncoded signature
+func (t *Token) Sig() string {
+	return t.signature
+}
+
+// RawSig returns the Tokens raw signature
+func (t *Token) RawSig() []byte {
+	return t.rawSignature
+}
+
+// Header returns the Tokens header
+func (t *Token) Header() map[string]interface{} {
+	return t.header
+}
+
+// Data returns the first two token fields
+func (t *Token) Data() string {
+	return t.data
+}
+
+// NewToken returns a new *Token using the provided hash algorithm and claims
+// If claims is nil, an empty map is used
+// If hash is nil, HS256 is used
+func NewToken(claims Claims, hash Hash) *Token {
+	if claims == nil {
+		claims = make(Claims)
+	}
+	if hash == nil {
+		hash = NewHS256()
+	}
+	return &Token{
+		header: map[string]interface{}{
+			"alg": hash.Alg(),
+			"typ": typ,
+		},
+		Claims: claims,
+	}
+}
+
+// DecodeToken decodes a raw string token into a *Token object
+func DecodeToken(token string) (t *Token, err error) {
+	if token == "" {
+		return nil, ErrEmptyToken
+	}
+	parts := strings.Split(token, ".")
+	if len(parts) < 3 {
+		return nil, ErrMissingTokenParts
+	}
+	if len(parts) > 3 {
+		return nil, ErrNoJWT
+	}
+	for _, v := range parts {
+		if v == "" {
+			return nil, ErrNoJWT
+		}
+	}
+	t = new(Token)
+	header, err := base64.URLEncoding.DecodeString(parts[0])
+	if err != nil {
+		return
+	}
+	err = json.Unmarshal(header, &t.header)
+	if err != nil {
+		return
+	}
+	claims, err := base64.URLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return
+	}
+	err = json.Unmarshal(claims, &t.Claims)
+	if err != nil {
+		return
+	}
+	t.rawSignature, err = base64.URLEncoding.DecodeString(parts[2])
+	t.signature = parts[2]
+	t.data = strings.Join(parts[:2], ".")
+	t.raw = token
+	return
+}