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In TLS-SNI-01/02 there's SAN-A and SAN-B (added in 02). These are random values. Those random values are all known to the attacker. Importantly, they contain n
by rgbrenner 9y ago
In TLS-SNI-01/02 there's SAN-A and SAN-B (added in 02). These are random values.
Those random values are all known to the attacker. Importantly, they contain no information on which (real) domain these random values correspond to.
These random values are the only values sent and used by LE to verify domain ownership.
How would a provider map random values to a domain? Only LE knows what random values correspond to which domains.
- DanielDent 9y agoThis spec may only be usable by provider issuing certificates they manage on behalf of their customers. It's possible the protocol is unusable on a shared IP address for customer-managed certificates. Even today, there are many hosting companies where you can go ahead and setup an account for "gmail.com" - and they will happily direct messages from their customers intended for "gmail.com". And there are hosting control panels where their "solution" to this problem is to have a hardcoded list of high value targets for which end customers cannot create accounts. But the general issue is that providers need to be mindful of what changes they make to their routing tables. Not all inputs to the system are trustworthy.