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| author | jeffro256 <jeffro256@tutanota.com> | 2023-10-23 16:28:02 -0500 |
|---|---|---|
| committer | jeffro256 <jeffro256@tutanota.com> | 2023-10-24 13:00:45 -0500 |
| commit | eae62a07e075acdd8555420f3f961a82eff0a342 (patch) | |
| tree | f578b76a4a05b470e338e9720945b585e02a61c2 | |
| parent | Merge pull request #9014 (diff) | |
| download | monero-eae62a07e075acdd8555420f3f961a82eff0a342.tar.xz | |
ringct: make `rctSigBase` serialization follow strict aliasing rule
Accessing an object of type `char` thru an lvalue of type `crypto::hash8` is undefined behavior.
https://developers.redhat.com/blog/2020/06/03/the-joys-and-perils-of-aliasing-in-c-and-c-part-2
| -rw-r--r-- | src/ringct/rctTypes.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/ringct/rctTypes.h b/src/ringct/rctTypes.h index ab1a26b26..32cd8dc6f 100644 --- a/src/ringct/rctTypes.h +++ b/src/ringct/rctTypes.h @@ -362,11 +362,17 @@ namespace rct { { if (type == RCTTypeBulletproof2 || type == RCTTypeCLSAG || type == RCTTypeBulletproofPlus) { + // Since RCTTypeBulletproof2 enote types, we don't serialize the blinding factor, and only serialize the + // first 8 bytes of ecdhInfo[i].amount ar.begin_object(); - if (!typename Archive<W>::is_saving()) + crypto::hash8 trunc_amount; // placeholder variable needed to maintain "strict aliasing" + if (!typename Archive<W>::is_saving()) // loading memset(ecdhInfo[i].amount.bytes, 0, sizeof(ecdhInfo[i].amount.bytes)); - crypto::hash8 &amount = (crypto::hash8&)ecdhInfo[i].amount; - FIELD(amount); + else // saving + memcpy(trunc_amount.data, ecdhInfo[i].amount.bytes, sizeof(trunc_amount)); + FIELD(trunc_amount); + if (!typename Archive<W>::is_saving()) // loading + memcpy(ecdhInfo[i].amount.bytes, trunc_amount.data, sizeof(trunc_amount)); ar.end_object(); } else |