First, don't obsess too much about your password digest. I know this is head-explodey considering the source, but all I'm trying to do by ranting about it is to get people to stop using SHA1 (or SHA256 or Whirlpool or whatever) hashes. The risk to your users for doing that bit wrong is not very high.
Second, my advice about how to do crypto security is very simple:
* Use PGP for data at rest.
* Use TLS for data in motion.
Do not trust your own judgement (say, by using OTR because it "feels" like most of what you need, or trusting that you'll use Keyczar safely) on anything else without a formal external review. In practice, you will almost never need anything more than TLS or PGP.
Okay, but in the more general case, where something literally does not exist for a particular platform/language and my choices are "write it myself" or "don't use that platform/language", is there any way to feel confident that a choice to write it myself will not be a hideously wrong decision?
I'm not Thomas Ptacek, but I think his answer would be something to the effect of "to be really confident, get tens of thousands of dollars worth of code review before shipping." You may be prominent enough in the CL/hypothetical crypto-less platform community to get most of that for free, but that's the value of the validation needed.
Second, my advice about how to do crypto security is very simple:
* Use PGP for data at rest.
* Use TLS for data in motion.
Do not trust your own judgement (say, by using OTR because it "feels" like most of what you need, or trusting that you'll use Keyczar safely) on anything else without a formal external review. In practice, you will almost never need anything more than TLS or PGP.