The send screen labelled any prefix+length match as a "Valid" address, so a
mistyped address that still matched the pattern passed the gate. Add pure,
offline checksum validation — Base58Check (transparent R-addresses) and Bech32
(Sapling zs-addresses) — and require it in the validity check. Both verifiers are
version-byte/HRP agnostic (the HRP is taken from the string, the Base58 checksum
is chain-independent), so a correct implementation never rejects a genuine
address while catching transcription errors. Works for both build variants
(no daemon round-trip), unit-tested against standard BIP173 / Base58Check vectors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
DanS
070a516f4e