wolfSSL RISC-V RV32I Architectures Timing Side-Channel Vulnerability in 64-Bit Multiplication

A timing side-channel vulnerability has been identified in wolfSSL version 5.8.4 on RISC-V RV32I architectures. The issue arises because the software implementation of 64-bit multiplication lacks constant-time execution. Instead, the compiler-inserted __muldi3 subroutine operates in variable time, depending on the values of the operands. This inconsistency affects several special math functions, such as sp_256_mul_9 and sp_256_sqr_9, potentially allowing an attacker to exploit the timing variations and extract sensitive cryptographic information.

Impact

Exploitation of this vulnerability could lead to a timing side-channel attack, where an adversary could gain access to sensitive cryptographic data by analyzing the time variations in the multiplication operations.

Remediation

Users can update to wolfSSL version 5.8.5 or later, where this vulnerability has been addressed.