Description
The X25519 x86_64 assembly implementation fails to clear the most significant bit during the final modular reduction, so the computed result may not be fully reduced modulo the field prime 2^255 - 19. This can leave the field element in a non-canonical form, producing an incorrect result from the scalar multiplication and potentially a wrong shared secret. The final carry-propagation chains in the x64 and AVX2 reduction routines could overflow into the top bit, and the high limb was not masked afterward, so the 255-bit field element was left non-canonical.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
wolfSSL wolfSSL
Default version status: unaffected
5.6.4 to ≤ 5.9.1affected