I realize the deal with the Reichskonkordat. This was in 1933 when Hitler was rising to power. When a country undergoes a major shift in politics, the Church is naturally concerned about her members. So, this pact was signed. The terms of the pact were such as to guarantee that Catholics could still freely worship as they did prior to Hitler, that the Vatican (a sovreign nation) could communicate with the Catholic churches in Germany, That the Church could collect taxes from it's own churches, that Catholic bishops would uphold the German consitution/government, that teachers of the Catholic faith in public schools be chosen by Catholic bishops, Catholic organizations would have the freedom to operate as normal, and that priests/bishops could not join political parties or act on behalf of them.
Mind you, this was a pact between the Vatican, a soverign entity/nation, and Germany which was also a soverign nation. Germany had a whole new form of government, and the Vatican wanted to maintain diplomatic ties with the nation for the sake of the very many Catholics living in it. The Vatican wanted to protect the interests of the Catholic Church and its members, and Germany wanted to ensure that the Church wouldn't try to usurp power by speaking against this new form of government. The Vatican wasn't wild and crazy about the new government, but it wanted to ensure that Catholics would have the same rights as before. They had no idea of the monster Hitler would become. Many of the greatest world leaders did not. It doesn't matter that Hitler had been baptized Catholic. Being baptized doesn't prevent one from existing as a horrible human being.
Once the world saw what Hitler was really trying to do, they were abhored, including the Church. As the Nazi party began to violate the terms of the Reichskonkordat, Pope Pius XI spoke out quite clearly against Germany in his encyclical called
"Mit brennender Sorge" in 1937. Cardinal Pacelli is believed responsible for suggesting this bit of the encyclical:
"Whoever exalts race, or the people, or the state, or a particular form of state, or the depositories of power, or any other fundamental value of the human community—however necessary and honorable be their function in worldly things—whoever raises these notions above their standard value and divinizes them to an idolatrous level, distorts and perverts an order of the world planned and created by God." Cardinal Eugenio Pacelli is the man we now refer to as Pope Pius XII.
Basically, a yes, a treaty was signed between Germany and the Vatican in 1933. By 1937 it had been violated by Germany, and the Church finally realized the danger of the Nazi party as the Nazis promoted an ideal of nationalism, racial superiority, and the pagan ideology creeping into German politics as something very much against Christian ideals.
As for what the Church did do for the Jews, check these links:
Jewish Virtual Library
Controversy over the Church's involvement (also from the above group).
And when it boils down to it...yes, the Church should have done more. The world should have done more. Some sent armies. Some did otherwise. The Church did more than most nations, excluding the efforts of the Allied armies, to save Jews. I'm sure many local Protestant churches did their part as well.