Merge bitcoin/bitcoin#25625: test: add test for decoding PSBT with per-input preimage types

71a751f6c3e8912e1b1cfe388e593309d210e576 test: add test for decoding PSBT with per-input preimage types (Sebastian Falbesoner)
faf43378e223c563b0741c28a4b5406f471c1332 refactor: move helper `random_bytes` to util library (Sebastian Falbesoner)
fdc1ca389646a55c4d9cb2a79feaa69f90b18c67 test: add constants for PSBT key types (BIP 174) (Sebastian Falbesoner)
1b035c03f9fbbdf7a13663a35d75fb2428f44743 refactor: move PSBT(Map) helpers from signet miner to test framework (Sebastian Falbesoner)
7c0dfec2dd9998932d13dd183c3ce4b22bd5851b refactor: move `from_binary` helper from signet miner to test framework (Sebastian Falbesoner)
597a4b35f6e11d0ec5181e0d4d2d8f9bbf59898a scripted-diff: rename `FromBinary` helper to `from_binary` (signet miner) (Sebastian Falbesoner)

Pull request description:

  This PR adds missing test coverage for the `decodepsbt` RPC in the case that a PSBT with on of the per-input preimage types (`PSBT_IN_RIPEMD160`, `PSBT_IN_SHA256`, `PSBT_IN_HASH160`, `PSBT_IN_HASH256`; see [BIP 174](https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki#Specification)) is passed. As preparation, the first four commits move the already existing helpers for (de)serialization of PSBTs and PSBTMaps from the signet miner to the test framework (in a new module `psbt.py`), which should be quite useful for further tests to easily create PSBTs.

ACKs for top commit:
  achow101:
    ACK 71a751f6c3e8912e1b1cfe388e593309d210e576

Tree-SHA512: 04f2671612d94029da2ac8dc15ff93c4c8fcb73fe0b8cf5970509208564df1f5e32319b53ae998dd6e544d37637a9b75609f27a3685da51f603f6ed0555635fb

1 files changed, 14 insertions, 0 deletions

diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index e6d9f9ae3a..4a68312379 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -208,6 +208,20 @@ def tx_from_hex(hex_string):
     return from_hex(CTransaction(), hex_string)
 
 
+# like from_hex, but without the hex part
+def from_binary(cls, stream):
+    """deserialize a binary stream (or bytes object) into an object"""
+    # handle bytes object by turning it into a stream
+    was_bytes = isinstance(stream, bytes)
+    if was_bytes:
+        stream = BytesIO(stream)
+    obj = cls()
+    obj.deserialize(stream)
+    if was_bytes:
+        assert len(stream.read()) == 0
+    return obj
+
+
 # Objects that map to bitcoind objects, which can be serialized/deserialized