On Wed, Jan 24, 2024 at 10:47:22PM -0500, James Bottomley wrote: > On Wed, 2024-01-24 at 14:57 -0500, Kent Overstreet wrote: > > On Wed, Jan 24, 2024 at 02:43:21PM -0500, James Bottomley wrote: > > > On Wed, 2024-01-24 at 13:50 -0500, Kent Overstreet wrote: > > > > > To illustrate the problem with cryptography in rust: just > > > > > because it's rust safe doesn't mean its correct or bug free. > > > > > Crypto functions are the most difficult to get right > > > > > (algorithmically, regardless of memory safety). Look at this > > > > > Medium report on the top ten bugs in blockchain: > > > > > > > > > > https://medium.com/rektoff/top-10-vulnerabilities-in-substrate-based-blockchains-using-rust-d454279521ff > > > > > > > > > > Number 1 is a rust crypto vulnerability due to insecure > > > > > randomness in a random number generating function (note it was > > > > > rust safe code just not properly checked for algorithmic issues > > > > > by a cryptographer). > > > > > > > > > > The reason for using the kernel functions is that they are > > > > > vetted by cryptographers and crafted for our environment. > > > > > > > > Are you arguing that typical kernel code is more secure than > > > > typical Rust code? > > > > > > For crypto code? Absolutely, that's what the example above showed. > > > It's pretty much impossible to use an insecure rng in the kernel if > > > you plug into one of our existing APIs. That's obviously not > > > necessarily true if you pull a random one from crates.io. > > > > > > James > > > > I can just as easily use prandom.h instead of random.h in the kernel; > > Neither of which would be insecure ... Are you claiming that /* Pseudo random number generator from numerical recipes. */ static inline u32 next_pseudo_random32(u32 seed) { return seed * 1664525 + 1013904223; } is a secure RNG? > > > this just comes down to Rust not being able to save you from > > arbitrary logic errors. But all the data we have so far from CVEs and > > bug reports shows that Rust code is _dramatically_ more secure than > > any C code, even kernel code. > > I've said it thrice the bellman cried and what I tell you three times > is true. > > Back in the real world, the literature seems to show that rust code has > about the same bug density as any other code (including C). You might want to re-read that literature...
