change(rpc): add validateaddress method

[arya2]

Motivation

Mining pools may use this RPC to check addresses.

Closes #5722.

This method returns isvalid: false in zcashd for shielded addresses, it currently checks Sapling addresses in Zebra but not Sprout, Orchard, or Unified addresses.

Specifications

https://zcash.github.io/rpc/validateaddress.html

Solution

• Add zcash_address to parse raw address
• Add Address enum in zebra-chain for converting ZcashAddress
• Add response type for validate address

Review

Part of regular scheduled work.

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

Follow Up Work

• Add support for Sprout/Orchard/Unified addresses in primitives::Address
• Add pubkey and scriptPubKey fields

[teor2345]

Thanks for this, I like the design here!

This method returns isvalid: false in zcashd for shielded addresses, it currently checks Sapling addresses in Zebra but not Sprout, Orchard, or Unified addresses.

I think we might want to match zcashd's behaviour for Sapling?

Otherwise nodes might try to build a transparent coinbase transaction with a Sapling address, which could cause them to fail or crash.

[teor2345]

Also there seems to be a merge conflict, can you rebase when you do your fixes?

[arya2]

I think we might want to match zcashd's behaviour for Sapling?

I'm not sure and that's safer, so, fixed in fde96d5.

Also there seems to be a merge conflict, can you rebase when you do your fixes?

Yep, I resolved those too (albeit with a merge).

[codecov]

Codecov Report

Merging #6086 (a45bff8) into main (1b12011) will decrease coverage by 0.01%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6086      +/-   ##
==========================================
- Coverage   78.06%   78.05%   -0.01%     
==========================================
  Files         304      304              
  Lines       39027    39027              
==========================================
- Hits        30465    30462       -3     
- Misses       8562     8565       +3     

[teor2345]

Looks good!

Needs further testing

[teor2345]

Can you please do a zcash-rpc-diff for this new RPC?

(Maybe we should have a testing checklist somewhere.)

[arya2]

Can you please do a zcash-rpc-diff for this new RPC?

Yep:

Request:
validateaddress t3hgskquvKKoCtvxw86yN7q8bzwRxNgUZmc

Querying zebrad main chain at height >=1970386...

real    0m0.002s
user    0m0.002s
sys     0m0.000s

Querying zcashd main chain at height >=1830188...

real    0m0.003s
user    0m0.000s
sys     0m0.002s


Response diff between zebrad and zcashd:
--- /tmp/tmp.CZTvJsjeXg.rpc-diff/zebrad-main-1970386-validateaddress.json       2023-02-02 16:02:12.119542563 -0500
+++ /tmp/tmp.CZTvJsjeXg.rpc-diff/zcashd-main-1830188-validateaddress.json       2023-02-02 16:02:12.129542563 -0500
@@ -1,5 +1,8 @@
 {
   "isvalid": true,
   "address": "t3hgskquvKKoCtvxw86yN7q8bzwRxNgUZmc",
+  "scriptPubKey": "a914fdaa2e848fa9813b6bbc7e5f8cbd9c0724dca7d087",
+  "ismine": false,
+  "iswatchonly": false,
   "isscript": true
 }

Request:
validateaddress zs1knzgnu5l7h62qexv8mwv8dysr9qum9e5mtxju7hazz9qk8cpgw5uf3c3qd4n62qhdfy7q53z2c0

Querying zebrad main chain at height >=1970389...

real    0m0.002s
user    0m0.002s
sys     0m0.000s

Querying zcashd main chain at height >=1830504...

real    0m0.002s
user    0m0.002s
sys     0m0.000s


Response diff between zebrad and zcashd:
RPC responses were identical

/tmp/tmp.DmkpELZsdx.rpc-diff/zebrad-main-1970389-validateaddress.json:
{
  "isvalid": false
}

This brought my attention to a mismatch where Zebra was returning conversion errors.

Fixed in a45bff8.

[teor2345]

Thanks for the testing!