Add RegisteredClaims (#15)

claims.go

@@ -0,0 +1,11 @@
+package paseto
+
+type RegisteredClaims struct {
+	ID        string       `json:"jti,omitempty"`
+	Audience  string       `json:"aud,omitempty"`
+	Issuer    string       `json:"iss,omitempty"`
+	Subject   string       `json:"sub,omitempty"`
+	ExpiresAt *NumericDate `json:"exp,omitempty"`
+	IssuedAt  *NumericDate `json:"iat,omitempty"`
+	NotBefore *NumericDate `json:"nbf,omitempty"`
+}

errors.go

@@ -7,4 +7,5 @@ var (
 	ErrInvalidTokenAuth     = errors.New("invalid token authentication")
 	ErrIncorrectTokenFormat = errors.New("incorrect token format")
 	ErrIncorrectTokenHeader = errors.New("incorrect token header")
+	ErrDateInvalidFormat    = errors.New("date is not valid")
 )

numeric_date.go

@@ -0,0 +1,38 @@
+package paseto
+
+import (
+	"encoding/json"
+	"math"
+	"strconv"
+	"time"
+)
+
+type NumericDate struct {
+	time.Time
+}
+
+func NewNumericDate(t time.Time) *NumericDate {
+	return &NumericDate{t}
+}
+
+func (t NumericDate) MarshalJSON() ([]byte, error) {
+	if t.IsZero() {
+		return []byte("null"), nil
+	}
+	return []byte(strconv.FormatInt(t.Unix(), 10)), nil
+}
+
+func (t *NumericDate) UnmarshalJSON(data []byte) error {
+	var value json.Number
+	if err := json.Unmarshal(data, &value); err != nil {
+		return ErrDateInvalidFormat
+	}
+	f, err := value.Float64()
+	if err != nil {
+		return ErrDateInvalidFormat
+	}
+	sec, dec := math.Modf(f)
+	ts := time.Unix(int64(sec), int64(dec*1e9))
+	*t = NumericDate{ts}
+	return nil
+}

numeric_date_test.go

@@ -0,0 +1,71 @@
+package paseto
+
+import (
+	"strconv"
+	"testing"
+	"time"
+)
+
+func TestNumericDateMarshal(t *testing.T) {
+	now := time.Now()
+	nowTS := now.Unix()
+
+	testCases := []struct {
+		value *NumericDate
+		want  string
+	}{
+		{NewNumericDate(time.Time{}), `null`},
+		{NewNumericDate(now), strconv.Itoa(int(nowTS))},
+	}
+
+	for _, tc := range testCases {
+		raw, err := tc.value.MarshalJSON()
+		mustOk(t, err)
+		mustEqual(t, string(raw), tc.want)
+	}
+}
+
+func TestNumericDateUnmarshal(t *testing.T) {
+	testCases := []struct {
+		s    string
+		want NumericDate
+	}{
+		{`1588707274`, asNumericDate(1588707274)},
+		{`1588707274.3769999`, asNumericDate(1588707274)},
+		{`"12345"`, asNumericDate(12345)},
+	}
+
+	for _, tc := range testCases {
+		var have NumericDate
+		err := have.UnmarshalJSON([]byte(tc.s))
+		mustOk(t, err)
+		mustEqual(t, have.Unix(), tc.want.Unix())
+	}
+}
+
+func TestNumericDateUnmarshalMalformed(t *testing.T) {
+	testCases := []struct {
+		value string
+	}{
+		{``},
+		{`{}`},
+		{`[{}]`},
+		{`abc12`},
+		{`"abc"`},
+		{`["admin",{}]`},
+		{`["admin",123]`},
+		{`{}`},
+		{`[]`},
+		{`1e+309`},
+	}
+
+	for _, tc := range testCases {
+		var nd NumericDate
+		err := nd.UnmarshalJSON([]byte(tc.value))
+		mustFail(t, err)
+	}
+}
+
+func asNumericDate(n int64) NumericDate {
+	return *NewNumericDate(time.Unix(n, 0))
+}