What is the ruling of Islamic law regarding a brother embracing his sister and kissing her on the cheek, with mutual respect between them?

There is no harm in affection and friendship between two men as long as there are no sexual inclinations involved. There is also no harm in a friend sharing details of his life and secrets with his friend, as long as it does not involve open disclosure or revealing sins and misdeeds that Allah the Almighty has concealed for His servant. For disclosing them openly is not permissible, due to the Prophet's (peace be upon him) saying: "Whoever is afflicted with any of these impurities should conceal himself with the concealment of Allah." And due to his saying: "All of my Ummah are forgiven except for those who openly disclose their sins. And indeed, part of open disclosure is that a man commits an act at night, and then in the morning, when Allah has concealed it for him, he says: 'O so-and-so, last night I did such-and-such.' He spent the night with his Lord concealing him, and then in the morning, he uncovers Allah’s concealment from himself."