Re: [TLS] Review of draft-ietf-tls-rfc4366-bis-04
Eric Rescorla <ekr@networkresonance.com> Fri, 24 April 2009 22:47 UTC
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Date: Fri, 24 Apr 2009 15:51:34 -0700
From: Eric Rescorla <ekr@networkresonance.com>
To: Simon Josefsson <simon@josefsson.org>
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Cc: TLS@ietf.org
Subject: Re: [TLS] Review of draft-ietf-tls-rfc4366-bis-04
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At Sat, 25 Apr 2009 00:46:58 +0200, Simon Josefsson wrote: > > "Joseph Salowey (jsalowey)" <jsalowey@cisco.com> writes: > > > This is a working group last call for comments on > > draft-ietf-tls-rfc4366-bis-04 prior to sending this document on to the > > IESG for publication as a proposed standard RFC. The document and > > revision history can be found here: > > > > http://tools.ietf.org/html/draft-ietf-tls-rfc4366-bis-04 > > > > > > Please send any comments to the list by May 15, 2009. > > Hi. The document looks good in general, however I have two comments: > > 1) > > RFC 4366 contains: > > struct { > opaque url<1..2^16-1>; > Boolean hash_present; > select (hash_present) { > case false: struct {}; > case true: SHA1Hash; > } hash; > } URLAndOptionalHash; > > The draft changes the struct to: > > struct { > opaque url<1..2^16-1>; > opaque SHA1Hash[20]; > } URLAndHash; > > An RFC 4366 implementation that receives a RFC4366bis struct will reject > the encoding as corrupt, and possibly refuse the connection. > > Likewise, an RFC 4366bis implementations will reject a RFC4366 struct. > > It is possible to implement a parser that will accept both structs, but > this is not discussed nor suggested by the document. > > I suggest that a padding byte is inserted as follows: > > struct { > opaque url<1..2^16-1>; > opaque padding<1>; > opaque SHA1Hash[20]; > } URLAndHash; > > And some text is added: > > The "padding" byte MUST be 0x01. It is present to make the structure > backwards compatible. > > TLS 1.2 also changed old structs, let's not make the same mistake again. Oh, good catch. I would leave it as-is in 4366 and simply say // Must be true... -Ekr
- [TLS] Working Group Last Call for draft-ietf-tls-… Joseph Salowey (jsalowey)
- [TLS] Review of draft-ietf-tls-rfc4366-bis-04 Simon Josefsson
- Re: [TLS] Review of draft-ietf-tls-rfc4366-bis-04 Eric Rescorla
- Re: [TLS] Working Group Last Call for draft-ietf-… Pasi.Eronen