Filing on behalf of a user in #chromium:

"""
To quote a couple specifications:
<https://tools.ietf.org/html/rfc6066#section-3> (SNI)
	"HostName" contains the fully qualified DNS hostname of the server,
	as understood by the client.  The hostname is represented as a byte
	string using ASCII encoding without a trailing dot.

<https://tools.ietf.org/html/rfc7230#section-5.4> (HTTP)
	A client MUST send a Host header field in all HTTP/1.1 request
	messages.  If the target URI includes an authority component, then
a
	client MUST send a field-value for Host that is identical to that
	authority component, excluding any userinfo subcomponent and its
"@"
	delimiter (Section 2.7.1).

That means that the SNI host name and HTTP Host header do not always match.
The SNI host name must never have a trailing dot, but the HTTP Host header
must reflect a host name that is identical to the host name of the URI, so
if the URI's host has a trailing dot, the HTTP Host header must include
that trailing dot.

For example, if the URI of a page is <https://sni.velox.ch./>, the
following values should be sent by the Web browser:
SNI host: sni.velox.ch
HTTP host: sni.velox.ch.

However, Chromium sends "sni.velox.ch." as the SNI host name, causing the
server to throw an error.
"""

rsleevi, can you take a look?