The Catholic Church professes one Baptism of water. Many people today believe that there are two other types of Baptisms: a Baptism of Desire, and a Baptism of Blood. Its proponents believe that BoD and BoB have the same effect as the normal Baptism, specifically removing original sin and mortal sins.
Baptism of Desire is condemned here:
Pope Paul III, The Council of Trent, Can. 2 on the Sacrament of Baptism, Sess. 7, 1547, “If anyone shall say that real and natural water is not necessary for baptism, and on that account those words of Our Lord Jesus Christ: ‘Unless a man be born again of water and the Holy Spirit’ [John 3:5], are distorted into some sort of metaphor: let him be anathema.”
Baptism of Blood is condemned here:
Pope Eugene IV, Council of Florence, “Cantate Domino,” 1441, “The Holy Roman Church firmly believes, professes and preaches that all those who are outside the Catholic Church, not only pagans but also Jews or heretics and schismatics, cannot share in eternal life and will go into the everlasting fire which was prepared for the devil and his angels, unless they are joined to the Church before the end of their lives; that the unity of this ecclesiastical body is of such importance that only for those who abide in it do the Church’s sacraments contribute to salvation and do fasts, almsgiving and other works of piety and practices of the Christian militia produce eternal rewards; and that nobody can be saved, no matter how much he has given away in alms and even if he has shed blood in the name of Christ, unless he has persevered in the bosom and unity of the Catholic Church.”
Traditionally the Catholic Church taught that after the promulgation of the Gospel only Catholics could get into Heaven as Pope Eugene IV indicates above. However these days, if you ask someone:
"Did the Muslim/Jew/Pagan/Atheist get into Heaven?" They will say, "I cannot judge, even though the person rejected the Gospel for their entire life, he could have received a Baptism of Desire." Then if you want to really make them mad ask if the person needs to actually desire Baptism to get a "Baptism of Desire", they will usually say "No."
Baptism of Desire was the key to the promotion of universal salvation:
“Cardinal” Joseph Ratzinger, Truth and Tolerance, 2004, p. 207: “The fact that in every age there have been, and still are, ‘pagan saints’ is because everywhere and in every age – albeit often with difficulty and in fragmentary fashion – the speech of the ‘heart’ can be heard, because God’s Torah may be heard within ourselves
I expect to get a bunch of comments that the Council of Florence isn't infallible.
If you would like more references please consult this document.