There are many problems that hinder building language bindings to NaCl. See, for example, node-nacl:
https://github.com/thejh/node-nacl
See the giant warning in bold at the top:
"WARNING: This library DOES NOT WORK on 64-bit systems, and there's nothing I can do about it before the next version of NaCl is available."
Much of the assembly in NaCl is presently NOT position independent code which causes many of these sorts of problems. djb has admitted as much and sought to fix these sorts of problems.
Here is what djb had to say in email recently:
"More language support. The real work here is making everything PIC. Of course, if what matters is the API rather than speed, then achieving PIC is easy: just remove the asm."
At the very least, djb recognizes that removing the ASM is a simple and valid option for achieving PIC now without additional work on the assembly code. In the meantime he is doing a lot of that work inside SUPERCOP.
There's also the elephant in the room: Windows. NaCl doesn't support Windows. NaCl will likely never support Windows. Sodium supports Windows.
As a result, all this stuff is excruciatingly tuned.
In the meantime, people continue to use OpenSSL because using NaCl is too hard
FWIW, that warning is...incorrect. Anyone who actually wants to use NaCl with Node.js (and we do) can trivially get a 64-bit build (it's even done through Python). I don't disagree that the original author of node-nacl wasn't skilled enough to do it though.
> There's also the elephant in the room: Windows. NaCl doesn't support Windows.
Say what? NaCl supports Windows just fine – it's just djb's 'do' build script that doesn't, along with how to get a random number. There's absolutely nothing to prevent anyone from using NaCl on Windows, if they are willing to integrate it into a normal Windows build system (which is...trivial) and make a few, trivial, API updates.
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Having addressed those mis-understandings, Sodium is a welcome development and will certainly make it easier for people to develop bindings to NaCl.
You realize you're describing exactly what Sodium fixes (portable build system + randombytes for Windows), right? That was my original point.