Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

HRR verifications #378

Closed
wants to merge 3 commits into from
Closed

HRR verifications #378

wants to merge 3 commits into from

Conversation

ocheron
Copy link
Contributor

@ocheron ocheron commented Jul 12, 2019

Adds missing verifications or alerts regarding HRR like stability of version and cipher.

Removes the possibility of infinite loop and adds the requirement from
RFC 8446 section 4.1.4:

   If a client receives a second HelloRetryRequest in the same
   connection (i.e., where the ClientHello was itself in response to a
   HelloRetryRequest), it MUST abort the handshake with an
   "unexpected_message" alert.
Removes use of 'error' and replaces with alert specified in RFC 8446
section 4.1.4:

   Servers MUST ensure that they negotiate the same cipher suite when
   receiving a conformant updated ClientHello (if the server selects
   the cipher suite as the first step in the negotiation, then this
   will happen automatically).  Upon receiving the ServerHello,
   clients MUST check that the cipher suite supplied in the
   ServerHello is the same as that in the HelloRetryRequest and
   otherwise abort the handshake with an "illegal_parameter" alert.
Adds the check listed in RFC 8446 section 4.1.4:

   The value of selected_version in the HelloRetryRequest
   "supported_versions" extension MUST be retained in the ServerHello,
   and a client MUST abort the handshake with an "illegal_parameter"
   alert if the value changes.
Copy link
Collaborator

@kazu-yamamoto kazu-yamamoto left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM

kazu-yamamoto added a commit to kazu-yamamoto/hs-tls that referenced this pull request Jul 16, 2019
@kazu-yamamoto
Copy link
Collaborator

Merged.

@ocheron ocheron deleted the hrr-verif branch July 17, 2019 18:08
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants