Last year I hacked up a tool in frustration called Red Light Green Light (rlgl) -- a proof-of-concept effort to demonstrate a git-centric way to manage "quality gates" in a CI/CD pipeline.
A CI/CD quality gate is a process that evaluates the quality of a software artefact before allowing …
So here's an interesting picture from Ledger. Check out the chewy center on the right -- that APP is a moxie binary!
Image credit: Ledger's blog
Ledger, the hardware bitcoin wallet company, just announced BOLOS, the "Blockchain Open Ledger Operating Systems". What's most interesting to me, however, is that they have …
While there are many existing technologies to frustrate remote attackers, it can be fun to think up novel protections that might be used to layer on additional defences.
Consider, for instance, that remote code execution through attacks like buffer overflows depends on knowledge of the remote systems' instruction set. Knowledge …
A very meta photo of me at the Toronto Bitcoin Developer Meetup yesterday, explaining moxie, and the value of a security oriented VM (moxiebox).
Photo used by permission from Jan Miranda.
Moxie was assigned an official ELF machine number this week! You can check it out here: http://www.sco.com/developers/gabi/latest/ch4.eheader.html.
All ELF files start with a header describing properties of the object at hand. One of the most important properties is the 'machine' type …
You may recall that moxie supports two instructions lengths: 16- and 48-bit. Today I'm introducing a few 32-bit instructions as well.
Previously, moxie's "load and store with offset" instructions were defined as...
Load offset, long. Loads into $rA the 32-bit value from memory pointed at by …
ldo.l 00001100AAAABBBB iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
The bitcoin team has been exercising moxie in ways that it hasn't been stressed before. For example, they've been examining the code quality for their crypto libraries like libsecp256k1, an elliptical curve crypto library in C. One of their first feedbacks here was that moxie provides no native way to …
One of the more interesting developments around moxie is the adoption
of the moxie
architecture by
the core bitcoin developers (Jeff
Garzik, in particular), for an
experimental project called
moxiebox.
To quote Jeff...
The goal is to provide a secure, sandboxed execution mechanism that enables deterministic input, processing and output …
I had finally had enough of the wiki spammers, and decided to migrate all of my content over to a static github hosted site. I believe all of the blog entries migrated over now, and I'm in the process of migrating the wiki content over to pages you can link …
Moxie zero-extends all 8 and 16-bit loads from memory. Until recently, however, the GCC port didn't understand how loads worked, and would always shift loaded values back and forth to either empty out the upper bits or sign-extend the loaded value. While correct, it was overly bloated. If we're loading …