}
		pk.add(key.Kid, pkey)
	}

	return nil
}

func (pk *publicKeys) add(keyID string, key interface{}) {
	pk.Lock()
	defer pk.Unlock()

	pk.pkMap[keyID] = key
}

func (pk *publicKeys) get(kid string) interface{} {
	pk.RLock()
	defer pk.RUnlock()
	return pk.pkMap[kid]
}

// PopulatePublicKey - populates a new publickey from the JWKS URL.
func (r *Config) PopulatePublicKey(arn arn.ARN) error {

		// Check if the access key is part of users credentials.
		u, ok := globalIAMSys.GetUser(req.Context(), claims.AccessKey)
		if !ok {
			return nil, nil, false, errInvalidAccessKeyID
		}
		ucred := u.Credentials
		// get embedded claims
		eclaims, s3Err := checkClaimsFromToken(req, ucred)
		if s3Err != ErrNone {
			return nil, nil, false, errAuthentication
		}

		for k, v := range eclaims {
			claims.MapClaims[k] = v
		}