Is there a collection of regexes for viewing keys, sapling address, taddress, UAs, etc … ?
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Hey, good q. I’m a humble man so I just rock stuff like:
Sapling zaddr: /^zs[a-z0-9]{76}$/
VK: /^zxviews[a-z0-9]{278}$/
Full UA looks like it’s something like: /^u1[a-z0-9]{211}$/
Orchard-only / Sapling-only UA’s something like: /^u1[a-z0-9]{104}$/
Looks like there’s room for variance on UA’s, and I will confess ZIP-32 and other cryptographic specs are near-meaningless to me! YMMV
Yeah they’re simplistic and only partially validate the key. I think there are some invalid characters we could omit from matching, but these have been good enough for my purposes so far.
I guess the short answer is, (I think) no. There’s not an organized collection! 
Hopefully this discussion gives us one!
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This isn’t quite regexes, but we have been working on a new zcash_address Rust crate specifically for parsing Zcash addresses (and now also Unified Full/Incoming Viewing Keys). The first version of this crate will be published in the next week or so, ahead of zcashd 5.0.0. In the meantime, you can view its current API (and WIP documentation) here:
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So, this would be called a “Sapling Incoming Viewing Key” specifically? I wonder if there is a quick resource that just explains the different kinds of viewing keys briefly and has their formats/regex? Orchard VKs are different and have different pattern?
That’s a sapling extended full viewing key. For a complete description, refer to Zip 32.
https://zips.z.cash/zip-0032
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I’m seeing ^u1[a-z0-9]{104}$ - did you put 176 for a reason or … ?
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UAs are of variable length, depending on the receivers they contain.
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Or … what? Did I do it for no reason?
Yes, I did it for a reason. But I certainly don’t remember what it was. 
It’s not what I ended up using on the testnet faucet 
So while it’s possible it was a special case, it’s also reasonably likely the reason was “user error”. I updated my post with what I ended up using in the faucet: {211}
It looks like there’s variance in length! I think the 104 is for orchard-only (sapling-only looks the same to me at a glance). Let us know what you learn and please share when you’ve hammered out a nicer regex!
Hrm, I’m thinking about limiting and validating the p2p address on free2z …
BUT, with the different kinds of addresses and also the potential to do zip321 payment URIs, it’s a much harder problem than I was thinking … maybe I will continue to allow anything. But, I’ve also begun thinking about security of this…
To validate UA addresses in Zenith, I’m using a regex of ^u1[a-z0-9]$ and validating that the string is Bech32m encoded.
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