niki/vendor/github.com/golang-jwt/jwt/token.go

package jwt

import (
	"encoding/base64"
	"encoding/json"
	"strings"
	"time"
)

// TimeFunc provides the current time when parsing token to validate "exp" claim (expiration time).

// You can override it to use another time value.  This is useful for testing or if your

// server uses a different time zone than your tokens.

var TimeFunc = time.Now

// Parse methods use this callback function to supply

// the key for verification.  The function receives the parsed,

// but unverified Token.  This allows you to use properties in the

// Header of the token (such as `kid`) to identify which key to use.

type Keyfunc func(*Token) (interface{}, error)

// A JWT Token.  Different fields will be used depending on whether you're

// creating or parsing/verifying a token.

type Token struct {
	Raw string // The raw token.  Populated when you Parse a token

	Method SigningMethod // The signing method used or to be used

	Header map[string]interface{} // The first segment of the token

	Claims Claims // The second segment of the token

	Signature string // The third segment of the token.  Populated when you Parse a token

	Valid bool // Is the token valid?  Populated when you Parse/Verify a token

}

// Create a new Token.  Takes a signing method

func New(method SigningMethod) *Token {

	return NewWithClaims(method, MapClaims{})

}

func NewWithClaims(method SigningMethod, claims Claims) *Token {

	return &Token{

		Header: map[string]interface{}{

			"typ": "JWT",

			"alg": method.Alg(),
		},

		Claims: claims,

		Method: method,
	}

}

// Get the complete, signed token

func (t *Token) SignedString(key interface{}) (string, error) {

	var sig, sstr string

	var err error

	if sstr, err = t.SigningString(); err != nil {

		return "", err

	}

	if sig, err = t.Method.Sign(sstr, key); err != nil {

		return "", err

	}

	return strings.Join([]string{sstr, sig}, "."), nil

}

// Generate the signing string.  This is the

// most expensive part of the whole deal.  Unless you

// need this for something special, just go straight for

// the SignedString.

func (t *Token) SigningString() (string, error) {

	var err error

	parts := make([]string, 2)

	for i := range parts {

		var jsonValue []byte

		if i == 0 {

			if jsonValue, err = json.Marshal(t.Header); err != nil {

				return "", err

			}

		} else {

			if jsonValue, err = json.Marshal(t.Claims); err != nil {

				return "", err

			}

		}

		parts[i] = EncodeSegment(jsonValue)

	}

	return strings.Join(parts, "."), nil

}

// Parse, validate, and return a token.

// keyFunc will receive the parsed token and should return the key for validating.

// If everything is kosher, err will be nil

func Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {

	return new(Parser).Parse(tokenString, keyFunc)

}

func ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error) {

	return new(Parser).ParseWithClaims(tokenString, claims, keyFunc)

}

// Encode JWT specific base64url encoding with padding stripped

func EncodeSegment(seg []byte) string {

	return base64.RawURLEncoding.EncodeToString(seg)

}

// Decode JWT specific base64url encoding with padding stripped

func DecodeSegment(seg string) ([]byte, error) {

	return base64.RawURLEncoding.DecodeString(seg)

}