After the Civil War, some southern states established the Black Codes, which included regulations such as black people needing to sign yearly employment contracts. Which passage of the 14th amendment did this violate?

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside… nor shall any State deprive any person of life, liberty, or property, without due process of law, nor deny to any person within its jurisdiction the equal protection of the laws.