论文标题
Dragonblood仍在泄漏:野外实用的基于缓存的侧通道
Dragonblood is Still Leaking: Practical Cache-based Side-Channel in the Wild
论文作者
论文摘要
最近,DragonBlood攻击引起了人们对WPA-3实施安全性的新兴趣,尤其是在许多开源库上部署的蜻蜓代码。一项攻击涉及在身份验证过程中保护用户密码的保护。在密码身份验证密钥交换(PAKE)协议中,称为Dragonfly,秘密,即密码被映射到椭圆曲线点。此操作很敏感,因为它涉及秘密密码,因此其对侧通道攻击的阻力至关重要。在最初披露DragonBlood之后,我们注意到这种特殊的攻击仅由少数几个实现对此进行了修补。 在这项工作中,我们表明,披露Dragonblood后实现的补丁不足。我们利用了最先进的技术来扩展原始攻击,表明我们只能使用DragonBlood攻击所需的三分之一的测量来恢复密码。我们主要对两个开源项目进行攻击:IWD(INET无线守护程序)和Freeradius,以强调我们攻击的实用性。实际上,由英特尔撰写的IWD软件包已经部署在Arch Linux发行版中,该分发是在安全专家中众所周知的,旨在为WPA \ _supplicant提供替代方案。至于Freeradius,它被广泛部署和维护良好的上游开源项目。我们发布了攻击概念的完整证明,并积极参与修补脆弱代码的过程。在这里,从向后的兼容性角度来看,我们建议将无分支实现作为缓解技术,因为它在Hostapd中使用的是非常简单,并且它可以忽略不计。
Recently, the Dragonblood attacks have attracted new interests on the security of WPA-3 implementation and in particular on the Dragonfly code deployed on many open-source libraries. One attack concerns the protection of users passwords during authentication. In the Password Authentication Key Exchange (PAKE) protocol called Dragonfly, the secret, namely the password, is mapped to an elliptic curve point. This operation is sensitive, as it involves the secret password, and therefore its resistance against side-channel attacks is of utmost importance. Following the initial disclosure of Dragonblood, we notice that this particular attack has been partially patched by only a few implementations. In this work, we show that the patches implemented after the disclosure of Dragonblood are insufficient. We took advantage of state-of-the-art techniques to extend the original attack, demonstrating that we are able to recover the password with only a third of the measurements needed in Dragonblood attack. We mainly apply our attack on two open-source projects: iwd (iNet Wireless Daemon) and FreeRADIUS, in order underline the practicability of our attack. Indeed, the iwd package, written by Intel, is already deployed in the Arch Linux distribution, which is well-known among security experts, and aims to offer an alternative to wpa\_supplicant. As for FreeRADIUS, it is widely deployed and well-maintained upstream open-source project. We publish a full Proof of Concept of our attack, and actively participated in the process of patching the vulnerable code. Here, in a backward compatibility perspective, we advise the use of a branch-free implementation as a mitigation technique, as what was used in hostapd, due to its quite simplicity and its negligible incurred overhead.