标题： SSH-密钥：利用网络认证实现无密码SSH 显示英文标题

标题： SSH-Passkeys: Leveraging Web Authentication for Passwordless SSH

摘要： 我们提出一种使用Web身份验证API进行SSH身份验证的方法，使用户能够使用密钥进行无密码的远程服务器登录。 这些是通过认证器在用户代表下管理整个密钥生命周期的凭证，并提供强大的安全保证。 尽管存在已知的缺陷，如网络钓鱼和重复使用，密码仍然是SSH身份验证的主要方式。 SSH的自定义基于密钥的身份验证协议可以缓解这些问题，但仍然容易受到密钥被盗的影响。 此外，其可用性较差，即使是知识丰富的用户也会泄露密钥材料并未能验证指纹。 因此，有效的密钥管理仍然是SSH安全中的一个关键开放领域。 相比之下，WebAuthn是一种现代的身份验证标准，旨在取代密码，代表用户管理密钥。 作为一个网络API，该标准无法直接与SSH集成。 我们提出一个框架，通过使用UNIX可插入认证模块（PAM）将WebAuthn与SSH服务器集成。 我们的方法具有向后兼容性，支持标准的SSH服务器，并且不需要新的客户端软件。 它提供了对静态加密材料的保护，抵抗密钥泄露，防止网络钓鱼，保护隐私并具备证明能力。 这些特性密码或传统的SSH密钥都不具备。 我们通过结构化的概念安全分析验证了这些优势。 我们开发了一个原型实现，并进行了一项用户研究，以量化我们提案的安全优势，用40个SSH用户测试我们的原型。 研究证实了SSH密钥的安全问题，包括20%的参与者泄露了他们的私钥。 我们的SSH密钥有效解决了这些问题：我们发现关键安全错误减少了90%，同时平均认证时间减少了4倍。 显示英文摘要

摘要： We propose a method for using Web Authentication APIs for SSH authentication, enabling passwordless remote server login with passkeys. These are credentials that are managed throughout the key lifecycle by an authenticator on behalf of the user and offer strong security guarantees. Passwords remain the dominant mode of SSH authentication, despite their well known flaws such as phishing and reuse. SSH's custom key-based authentication protocol can alleviate these issues but remains vulnerable to key theft. Additionally, it has poor usability, with even knowledgeable users leaking key material and failing to verify fingerprints. Hence, effective key management remains a critical open area in SSH security. In contrast, WebAuthn is a modern authentication standard designed to replace passwords, managing keys on behalf of the user. As a web API, this standard cannot integrate with SSH directly. We propose a framework to integrate WebAuthn with SSH servers, by using UNIX pluggable authentication modules (PAM). Our approach is backwards-compatible, supports stock SSH servers and requires no new software client-side. It offers protection for cryptographic material at rest, resistance to key leaks, phishing protection, privacy protection and attestation capability. None of these properties are offered by passwords nor traditional SSH keys. We validate these advantages with a structured, conceptual security analysis. We develop a prototype implementation and conduct a user study to quantify the security advantages of our proposal, testing our prototype with 40 SSH users. The study confirms the security problems of SSH-keys, including 20% of the cohort leaking their private keys. Our SSH-passkeys effectively address these problems: we find a 90% reduction in critical security errors, while reducing authentication time by 4x on average.