> I am far from a rust expert, but from a short look at stackoverflow copying between two slices of different sizes seems to be a for loop away and I saw no mention of unsafe.
You can do this, but, what are you copying and why?
The C code is just trying to copy the expected amount of data from the receive buffer into the send buffer. Under attack the receive buffer is actually nowhere near big enough to do that, but C doesn't care, which is why Heartbleed exists.
You can't write that mistake in Rust, even if you insist on painstakingly writing it out as a for loop, if we have a 20 byte receive slice, and we ask for receive[1000] that'll panic
To leak the data in Rust, you need to re-architect the software, you need to consciously plan for leaking the data in your software. "This code is to help us leak important secrets, and then this structure here enables the leaked data to be fed into data sent to an attacker".
You can do this, but, what are you copying and why?
The C code is just trying to copy the expected amount of data from the receive buffer into the send buffer. Under attack the receive buffer is actually nowhere near big enough to do that, but C doesn't care, which is why Heartbleed exists.
You can't write that mistake in Rust, even if you insist on painstakingly writing it out as a for loop, if we have a 20 byte receive slice, and we ask for receive[1000] that'll panic
To leak the data in Rust, you need to re-architect the software, you need to consciously plan for leaking the data in your software. "This code is to help us leak important secrets, and then this structure here enables the leaked data to be fed into data sent to an attacker".