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fix: ~ecdsa_preprocessing_data cleanses over live std::map/std::vector members (UB + leak) #57

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fix: ~ecdsa_preprocessing_data cleanses over live std::map/std::vector members (UB + leak) #57

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16 changes: 15 additions & 1 deletion include/cosigner/cmp_ecdsa_signing_service.h
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Original file line number Diff line number Diff line change
Expand Up @@ -82,7 +82,21 @@ struct ecdsa_preprocessing_data
byte_vector_t mta_request;
std::map<uint64_t, byte_vector_t> G_proofs;
std::map<uint64_t, ecdsa_signing_public_data> public_data;
~ecdsa_preprocessing_data() {OPENSSL_cleanse(k.data, sizeof(ecdsa_preprocessing_data));}
~ecdsa_preprocessing_data()
{
// Wipe each secret scalar individually. Passing sizeof(ecdsa_preprocessing_data)
// to OPENSSL_cleanse() spans the non-trivial members below (mta_request, G_proofs,
// public_data); since this destructor body runs before the implicit member
// destructors, it would zero the live std::vector/std::map control blocks and the
// subsequent ~vector/~map would then run on zeroed internals (UB + leak).
// Mirrors the correct pattern in eddsa_signature_data (eddsa_online_signing_service.h).
OPENSSL_cleanse(k.data, sizeof(k.data));
OPENSSL_cleanse(gamma.data, sizeof(gamma.data));
OPENSSL_cleanse(a.data, sizeof(a.data));
OPENSSL_cleanse(b.data, sizeof(b.data));
OPENSSL_cleanse(delta.data, sizeof(delta.data));
OPENSSL_cleanse(chi.data, sizeof(chi.data));
}
};

// this class holds the common functionality for cmp_ecdsa_online_signing_service and cmp_ecdsa_offline_signing_service
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