Function verifySASLClientProof

server/authentication_scram.go:296–314

verifySASLClientProof verifies that the proof given by the client in valid. Returns the base64-encoded ServerSignature, which verifies (to the client) that the server has proper access to the client's authentication information.

(user auth.Role, saslInitial SASLInitial, saslContinue SASLContinue, saslResponse SASLResponse)

// ServerSignature, which verifies (to the client) that the server has proper access to the client's authentication
// information.
func verifySASLClientProof(user auth.Role, saslInitial SASLInitial, saslContinue SASLContinue, saslResponse SASLResponse) (string, error) {
	if !user.CanLogin || user.Password == nil {
		return "", errors.Errorf(`password authentication failed for user "%s"`, user.Name)
	}
	// TODO: check the "valid until" time
	clientProof := rfc5802.Base64ToOctetString(saslResponse.ClientProof)
	authMessage := fmt.Sprintf("%s,%s,%s", saslInitial.MessageBare(), saslContinue.Encode().Data, saslResponse.MessageWithoutProof())
	clientSignature := rfc5802.ClientSignature(user.Password.StoredKey, authMessage)
	if len(clientProof) != len(clientSignature) {
		return "", errors.Errorf(`password authentication failed for user "%s"`, user.Name)
	}
	clientKey := clientSignature.Xor(clientProof)
	storedKey := rfc5802.StoredKey(clientKey)
	if !storedKey.Equals(user.Password.StoredKey) {
		return "", errors.Errorf(`password authentication failed for user "%s"`, user.Name)
	}
	serverSignature := rfc5802.ServerSignature(user.Password.ServerKey, authMessage)
	return serverSignature.ToBase64(), nil
}

// Base64Header returns the base64-encoded GS2 header and channel binding data.
func (si SASLInitial) Base64Header() string {