advanced mac cleaner remove stack exchange

inspect, intercept and modify the resulting bytes on the wire.inject data of their own before and after the secret value that he wants to obtain.The attacker is interested in data that gets protected with SSL, and he can: The Poodle attack works in a chosen-plaintext context, like BEAST and CRIME before it. This is the important point: there are bytes in the record that can be changed without the recipient minding in the slightest way. These bytes are removed, and, crucially, their contents are ignored. This is made so that decryption works.Ĭonsider the decryption of a record: 3DES-CBC decryption is applied, then the very last byte is inspected: it should contain a value between 0 and 7, and that tells us how many other bytes were added for padding. Moreover, if n bytes are added at that step, then the last of these bytes must have value n-1. Then 1 to 8 bytes are appended, so that the total length is a multiple of 8. A MAC is computed over the record data (and the record sequence number, and some other header data) and appended to the data. For instance, suppose that 3DES is used, with 8-byte blocks. In a nutshell: when SSL 3.0 uses a block cipher in CBC mode, the encryption process for a record uses padding so that the data length is a multiple of the block size. The TLS versions are not affected (neither is DTLS). Please note that we are talking about the old SSL 3.0, not TLS 1.0 or later. It is a protocol flaw, not an implementation issue every implementation of SSL 3.0 suffers from it. The 'Poodle' vulnerability, released on October 14th, 2014, is an attack on the SSL 3.0 protocol.

Advanced mac cleaner remove stack exchange