出口节点嗅探

出口节点嗅探指运行你线路最后一个中继的人读取流量中未加密的部分 - 这就是在 tor 上用裸 http 不是好主意的原因。

traffic leaving a tor exit relay toward a plain http site arrives decrypted at the exit. a malicious or curious exit operator can log destinations, inject content into pages, and capture anything sent in cleartext - login forms, session cookies, message boards without tls. this is not hypothetical: researchers have repeatedly run exits that harvested credentials to demonstrate the risk, and the demonstration results were ugly every time.

https collapses most of the attack: with transport encryption, the exit sees only the domain (via sni) and encrypted blobs. certificate warnings over tor deserve genuine respect - they may indicate exactly this kind of interception rather than an innocent misconfiguration.

onion services sidestep the exit entirely. traffic to a .onion address never leaves the tor network, so there is no exit hop positioned to observe it, and the self-authenticating address provides end-to-end cryptographic assurance without any certificate authority.

practical rules fall out cleanly: never submit credentials over plain http on tor, prefer onion addresses over clearnet mirrors when they exist, and take broken-padlock warnings seriously instead of clicking through them.