if err != nil {
				return nil, err
			}
			return []string{ret}, nil
		}
		claims = append(claims, s[begin+1:end])
		begin = end + 1
	}
	return claims, nil
}

func MetadataStringMatcherForJWTClaim(claim string, m *matcherpb.StringMatcher) *matcherpb.MetadataMatcher {
	return MetadataValueMatcherForJWTClaim(claim, &matcherpb.ValueMatcher{
		MatchPattern: &matcherpb.ValueMatcher_StringMatch{
			StringMatch: m,

				matchSub = matchAny
			}
		default:
			matchSub = matcher.StringMatcherExact(sub, false)
			matchIss = matcher.StringMatcherExact(iss, false)
		}
		im := MetadataStringMatcherForJWTClaim("iss", matchIss)
		sm := MetadataStringMatcherForJWTClaim("sub", matchSub)
		or = append(or, principalAnd([]*rbacpb.Principal{principalMetadata(im), principalMetadata(sm)}))
	}
	if len(or) == 1 {
		return or[0], nil