We noticed that Bitcoin Core fails due to extra data after PSBT while rust-bitcoin seems not checking it. See: bitcoinfuzz/bitcoinfuzz#43

From @apoelstra:

Yep, you can see that https://docs.rs/bitcoin/0.32.0/src/bitcoin/psbt/mod.rs.html#1197-1200 (a) calls Psbt::deserialize rather than encode::deserialize (PSBT has its own serialization module which does not have any no-trailing-data-checks) and (b) does not do any additional checks.

Definitely from_str should have a max length check. Doesn't look like we have any from_slice type method but if we do then it should also do a check.