[TLS] RFC-4366-bis and the unrecognized_name(112) alert
"Yngve Nysaeter Pettersen" <yngve@opera.com> Tue, 25 May 2010 13:43 UTC
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Date: Tue, 25 May 2010 15:42:42 +0200
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From: Yngve Nysaeter Pettersen <yngve@opera.com>
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Subject: [TLS] RFC-4366-bis and the unrecognized_name(112) alert
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Hello all, In the past few of weeks a couple of servers supporting SNI has come to my attention because they send the Warning alert "unrecognized_name" (112) in response to their actual name (that is, it should have recognized the name, and not sent that Warning). It seems like these servers have started to use the SNI functionality in the underlying TLS implementation, but that there is a problem with configuring the handling of the extension and keeping it in sync with the rest of the configuration. That is a problem for the vendor. RFC 4366-bis currently says: If the server understood the client hello extension but does not recognize any of the server names, it SHOULD send an unrecognized_name(112) alert (which MAY be fatal). My question is: What should a client do if it receives this alert as a Warning? AFAICT there are several options: - Ignore it (several clients appears to do this currently). If so, what is the use-case for this warning? - Always ask the user. He or she probably won't understand the issue, and will click through anyway. - Check the certificate, and either warn the user if it does not match (which all browsers would do anyway without the alert; so why need the alert?), or escalate to Fatal. - Always escalate to Fatal (which is what Opera currently does) What was the original reasoning for making the alert only optionally Fatal? Why not always Fatal, or always Warning? May I suggest that the spec is updated with some advice for how a client should behave when it receives the alert as a Warning? -- Sincerely, Yngve N. Pettersen ******************************************************************** Senior Developer Email: yngve@opera.com Opera Software ASA http://www.opera.com/ Phone: +47 24 16 42 60 Fax: +47 24 16 40 01 ********************************************************************
- [TLS] RFC-4366-bis and the unrecognized_name(112)… Yngve Nysaeter Pettersen
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Yngve Nysaeter Pettersen
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Yngve Nysaeter Pettersen
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Marsh Ray
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Marsh Ray
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Saint-Andre
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- [TLS] [Fwd: Re: RFC-4366-bis and the unrecognized… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Marsh Ray
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Gutmann
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Donald Eastlake
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Sean Turner
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… t.petch
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Paul Hoffman
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Marsh Ray
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Saint-Andre
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Joseph Salowey (jsalowey)
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Marsh Ray
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Nikos Mavrogiannopoulos
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Michael D'Errico
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Sylvester
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Sylvester
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Peter Sylvester
- Re: [TLS] RFC-4366-bis and the unrecognized_name(… Martin Rex