Does rsa-oaep provide or not plaintext integrity in addition to confidentiality? My own understanding (possibly wrong of course) of RSA-OAEP encryption scheme is that it  provides plaintext integrity (in addition to confidentiality) due to MGF function which for encryption operation, applies to maskeDB sequence which value directly depends of input M (plaintext) message, and is further checked during decryption operation.     However in previous post on that subject, the answer indicated that no public key encryption scheme can satisfy INT-PTXT (nor INT-CTXT) requirements

So is it possible to have confirmation if rsa-oaep insures integrity of input symmetric session key to be encrypted or if it is recommended with rsa-oaep to encrypt a symmetric session key appended with a hash or eventually crc value for insuring integrity ?
RSA-OAEP does not provide "plaintext integrity in addition to confidentiality". ​ By the definition of PKE, anyone with the public key can encrypt whatever plaintexts they choose. ​ In particular, encrypting "a symmetric session key appended with a hash or eventually crc value for insuring integrity" doesn't help. ​ To get integrity, there has to be something [the honest party knows which the adversary doesn't know] or [the honest party can do that the adversary can't do].