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Zeroize preMasterSecret in hybrid PQ/T error cases #9921

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Zeroize preMasterSecret in hybrid PQ/T error cases #9921

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22 changes: 22 additions & 0 deletions src/tls.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9985,6 +9985,17 @@ static int TLSX_KeyShare_ProcessPqcHybridClient(WOLFSSL* ssl,

ssl->arrays->preMasterSz = ssSzEcc + ssSzPqc;
}
else
#ifdef WOLFSSL_ASYNC_CRYPT
if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
#endif
{
/* Clear the pre master secret buffer to prevent leaking any
* intermediate keys in the error case. Do not use preMasterSz
* here as it may already been set to the ECC shared secret size,
* which would be too small due to the PQC offset case. */
ForceZero(ssl->arrays->preMasterSecret, ENCRYPT_LEN);
}

TLSX_KeyShare_FreeAll(ecc_kse, ssl->heap);
TLSX_KeyShare_FreeAll(pqc_kse, ssl->heap);
Expand Down Expand Up @@ -10721,6 +10732,17 @@ static int TLSX_KeyShare_HandlePqcHybridKeyServer(WOLFSSL* ssl,
* the server side. */
ssl->namedGroup = keyShareEntry->group;
}
else
#ifdef WOLFSSL_ASYNC_CRYPT
if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
#endif
{
/* Clear the pre master secret buffer to prevent leaking any
* intermediate keys in the error case. Do not use preMasterSz
* here as it may already been set to the ECC shared secret size,
* which would be too small due to the PQC offset case. */
ForceZero(ssl->arrays->preMasterSecret, ENCRYPT_LEN);
}

TLSX_KeyShare_FreeAll(ecc_kse, ssl->heap);
TLSX_KeyShare_FreeAll(pqc_kse, ssl->heap);
Expand Down