This change boosts SSL handshake performance from 2,627 to ~10,000 per
second which is the same level of performance as NGINX at establishing
secure connections. That's impressive if we consider that redbean is a
forking frontend application server. This was accomplished by:
1. Enabling either SSL session caching or SSL tickets. We choose to
use tickets since they reduce network round trips too and that's
a more important metric than wrk'ing localhost.
2. Fixing mbedtls_mpi_sub_abs() which is the most frequently called
function. It's called about 12,000 times during an SSL handshake
since it's the basis of most arithmetic operations like addition
and for some strange reason it was designed to make two needless
copies in addition to calling malloc and free. That's now fixed.
3. Improving TLS output buffering during the SSL handshake only, so
that only a single is write and read system call is needed until
blocking on the ping pong.
redbean will now do a better job wiping sensitive memory from a child
process as soon as it's not needed. The nice thing about fork is it's
much faster than reverse proxying so the goal is to use the different
address spaces along with setuid() to minimize the risk that a server
key will be compromised in the event that application code is hacked.
This change enables Address Sanitizer systemically w/ `make MODE=dbg`.
Our version of Rust's `unsafe` keyword is named `noasan` which is used
for two functions that do aligned memory chunking, like `strcpy.c` and
we need to fix the tiny DEFLATE code, but that's it everything else is
fabulous you can have all the fischer price security blankets you need
Best of all is we're now able to use the ASAN data in Blinkenlights to
colorize the memory dumps. See the screenshot below of a test program:
https://justine.lol/blinkenlights/asan.png
Which is operating on float arrays stored on the stack, with red areas
indicating poisoned memory, and the green areas indicate valid memory.
- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader
- Whipped up a webserver named redbean. It services 150k requests per
second on a single core. Bundling assets inside zip enables extremely
fast serving for two reasons. The first is that zip central directory
lookups go faster than stat() system calls. The second is that both
zip and gzip content-encoding use DEFLATE, therefore, compressed
responses can be served via the sendfile() system call which does an
in-kernel copy directly from the zip executable structure. Also note
that red bean zip executables can be deployed easily to all platforms,
since these native executables work on Linux, Mac, BSD, and Windows.
- Address sanitizer now works very well
I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.
https://justine.storage.googleapis.com/emulator625.mp4
