You should take a look at the declaration of independence for the US. There are two types of right. The first kind is agreed upon by society like you said, the

You should take a look at the declaration of independence for the US. There are two types of right. The first kind is agreed upon by society like you said, the second kind are inherent to anyone and they originate from a common understanding of a creator endowing all humans with equal rights. Self evident rights to "life, liberty and the pursuit of happiness" as they put it. But regardless of origin, a constitution defines what the country is made up of. Constitutional rights are a contract where the government is allowed to govern and secure the people if and only if they secure those rights and follow the articles of the constitution.