bip375: sync vendored DLEQ code with BIP-374 #2304

pull Bruce039 wants to merge 1 commits into bitcoin:master from Bruce039:bip375-sync-dleq changing 1 files +3 −1

Bruce039 commented at 11:55 AM on September 25, 2026: contributor

bip-0375/deps/dleq.py is a copy of the BIP-374 reference code, used by the BIP-375 validator to check PSBT_GLOBAL_SP_DLEQ / PSBT_IN_SP_DLEQ proofs. It was taken before #2262, so it still uses the raw challenge hash as e and doesn't reject proofs with e >= n.

This applies the same two changes to the copy. After this the functions match bip-0374/reference.py line for line (apart from the unit tests). A challenge hash >= n has negligible probability, so nothing changes in practice: test_runner.py still passes all 42 vectors, and the 17 BIP-374 verify vectors give the same results before and after. It just keeps the copy from drifting from the spec.

bip375: sync vendored DLEQ code with BIP-374

bip-0375/deps/dleq.py is adapted from the BIP-374 reference code but
predates the change that treats the challenge e as a scalar (#2262).
Reduce the challenge hash mod n and reject proofs with e >= n, so the
copy used by the BIP-375 validator matches the current BIP-374
reference.

7999f8aa1c

jonatack added the label Fixups on Sep 25, 2026
jonatack commented at 6:06 PM on September 25, 2026: member
ACK

These may go out of sync again. Out of scope for this PR, but better long-term options might be:
- import from bip-0374/reference.py to have one source of truth, or
- comment in dleq.py to keep in lockstep with bip-0374/reference.py
jonatack merged this on Sep 25, 2026
jonatack closed this on Sep 25, 2026
jonatack commented at 6:38 PM on September 25, 2026: member

import from bip-0374/reference.py to have one source of truth

Done in #2309.

Contributors

Bruce039

jonatack

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Fixups

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#2262 BIP-374: treat challenge hash result `e` as scalar #2309 bip375: import DLEQ from BIP-374 instead of vendoring