Can. 959 - In the sacrament of penance the faithful, confessing their sins to a legitimate minister, being sorry for them, and at the same time proposing to reform, obtain from God forgiveness of sins committed after baptism through the absolution imparted by the same minister; and they likewise are reconciled with the Church which they have wounded by sinning.

Can. 960 -  Individual and integral confession and absolution constitute the only ordinary way by which the faithful person who is aware of serious sin is reconciled with God and with the Church; only physical or moral impossibility excuses the person from confession of this type, in which case reconciliation can take place in other ways.

Can. 965 - Only a priest is the minister of the sacrament of penance.

Can. 978 - §1. In hearing confessions the priest is to remember that he acts as a judge as well as a healer and is placed by God as the minister of divine justice as well as of mercy, concerned with the divine honor and the salvation of souls.
§2. In the administration of the sacrament, the confessor, as a minister of the Church, is to adhere faithfully to the doctrine of the magisterium and the norms enacted by competent authority.

Can. 983 - §1. The sacramental seal is inviolable; therefore it is a crime for a confessor in any way to betray a penitent by word or in any other manner or for any reason.
§2. An interpreter, if there is one present, is also obliged to preserve the secret, and also all others to whom knowledge of sins from confession shall come in any way.

Can. 987 -  In order to recieve the salvific remedy of the sacrament of penance, the Christian faithful ought to be so disposed that, having repudiated the sins committed and having a purpose of amendment, they are converted to God.

Can. 988 - §1. A member of the Christian faithful is obliged to confess in kind and in number all serious sins committed after baptism and not yet directly remitted through the keys of the Church nor acknowledged in individual confession, of which one is conscious after diligent examination of conscience.
§2. It is to be recommended to the Christian faithful that venial sins also be confessed.