distribution/vendor/github.com/dgrijalva/jwt-go/claims.go
Sebastiaan van Stijn c5679da3a1
[release/2.7] vendor: github.com/golang-jwt/jwt v3.2.1
to address CVE-2020-26160

full diff: a601269ab7...v3.2.2

3.2.1 release notes
---------------------------------------

- Import Path Change: See MIGRATION_GUIDE.md for tips on updating your code
  Changed the import path from github.com/dgrijalva/jwt-go to github.com/golang-jwt/jwt
- Fixed type confusion issue between string and []string in VerifyAudience.
  This fixes CVE-2020-26160

3.2.2 release notes
---------------------------------------

- Starting from this release, we are adopting the policy to support the most 2
  recent versions of Go currently available. By the time of this release, this
  is Go 1.15 and 1.16.
- Fixed a potential issue that could occur when the verification of exp, iat
  or nbf was not required and contained invalid contents, i.e. non-numeric/date.
  Thanks for @thaJeztah for making us aware of that and @giorgos-f3 for originally
  reporting it to the formtech fork.
- Added support for EdDSA / ED25519.
- Optimized allocations.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2021-08-10 13:05:39 +02:00

146 lines
3.9 KiB
Go

package jwt
import (
"crypto/subtle"
"fmt"
"time"
)
// For a type to be a Claims object, it must just have a Valid method that determines
// if the token is invalid for any supported reason
type Claims interface {
Valid() error
}
// Structured version of Claims Section, as referenced at
// https://tools.ietf.org/html/rfc7519#section-4.1
// See examples for how to use this with your own claim types
type StandardClaims struct {
Audience string `json:"aud,omitempty"`
ExpiresAt int64 `json:"exp,omitempty"`
Id string `json:"jti,omitempty"`
IssuedAt int64 `json:"iat,omitempty"`
Issuer string `json:"iss,omitempty"`
NotBefore int64 `json:"nbf,omitempty"`
Subject string `json:"sub,omitempty"`
}
// Validates time based claims "exp, iat, nbf".
// There is no accounting for clock skew.
// As well, if any of the above claims are not in the token, it will still
// be considered a valid claim.
func (c StandardClaims) Valid() error {
vErr := new(ValidationError)
now := TimeFunc().Unix()
// The claims below are optional, by default, so if they are set to the
// default value in Go, let's not fail the verification for them.
if !c.VerifyExpiresAt(now, false) {
delta := time.Unix(now, 0).Sub(time.Unix(c.ExpiresAt, 0))
vErr.Inner = fmt.Errorf("token is expired by %v", delta)
vErr.Errors |= ValidationErrorExpired
}
if !c.VerifyIssuedAt(now, false) {
vErr.Inner = fmt.Errorf("Token used before issued")
vErr.Errors |= ValidationErrorIssuedAt
}
if !c.VerifyNotBefore(now, false) {
vErr.Inner = fmt.Errorf("token is not valid yet")
vErr.Errors |= ValidationErrorNotValidYet
}
if vErr.valid() {
return nil
}
return vErr
}
// Compares the aud claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool {
return verifyAud([]string{c.Audience}, cmp, req)
}
// Compares the exp claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool {
return verifyExp(c.ExpiresAt, cmp, req)
}
// Compares the iat claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool {
return verifyIat(c.IssuedAt, cmp, req)
}
// Compares the iss claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool {
return verifyIss(c.Issuer, cmp, req)
}
// Compares the nbf claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool {
return verifyNbf(c.NotBefore, cmp, req)
}
// ----- helpers
func verifyAud(aud []string, cmp string, required bool) bool {
if len(aud) == 0 {
return !required
}
// use a var here to keep constant time compare when looping over a number of claims
result := false
var stringClaims string
for _, a := range aud {
if subtle.ConstantTimeCompare([]byte(a), []byte(cmp)) != 0 {
result = true
}
stringClaims = stringClaims + a
}
// case where "" is sent in one or many aud claims
if len(stringClaims) == 0 {
return !required
}
return result
}
func verifyExp(exp int64, now int64, required bool) bool {
if exp == 0 {
return !required
}
return now <= exp
}
func verifyIat(iat int64, now int64, required bool) bool {
if iat == 0 {
return !required
}
return now >= iat
}
func verifyIss(iss string, cmp string, required bool) bool {
if iss == "" {
return !required
}
if subtle.ConstantTimeCompare([]byte(iss), []byte(cmp)) != 0 {
return true
} else {
return false
}
}
func verifyNbf(nbf int64, now int64, required bool) bool {
if nbf == 0 {
return !required
}
return now >= nbf
}