token.go

package sdk

import (
	"fmt"
	"strings"
	"time"
)

// expiryDelta determines how much earlier a token should be considered
// expired than its actual expiration time. It is used to avoid late
// expirations due to client-server time mismatches.
const expiryDelta = 10 * time.Second

// Token represents an OIDC token
type Token struct {
	// IDToken is the OIDC access token that authorizes and authenticates
	// the requests.
	IDToken string

	// Expiry is the expiration time of the access token.
	//
	// A zero value means the token never expires.
	Expiry time.Time

	// Scope is the scope of the access token
	Scope []string
}

// Expired reports whether the token is expired, and will start
// to return false 10s before the actual expiration time.
func (t *Token) Expired() bool {
	if t.Expiry.IsZero() {
		return false
	}

	return t.Expiry.Round(0).Add(-expiryDelta).Before(time.Now())
}

// tokenJson represents an OAuth token response
type tokenJSON struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`

	ExpiresIn int    `json:"expires_in"`
	Scope     string `json:"scope"`
}

func (t *tokenJSON) expiry() (exp time.Time) {
	if v := t.ExpiresIn; v != 0 {
		return time.Now().Add(time.Duration(v) * time.Second)
	}
	return
}

func (t *tokenJSON) scope() []string {
	if len(t.Scope) > 0 {
		return strings.Split(t.Scope, " ")
	}

	return []string{}
}

// OAuthError represents an OAuth error response.
type OAuthError struct {
	Err         string `json:"error"`
	Description string `json:"error_description,omitempty"`
}

func (e *OAuthError) Error() string {
	if len(e.Description) > 0 {
		return fmt.Sprintf("%s: %s", e.Err, e.Description)
	}
	return e.Err
}