Re: [TLS] A new TLS version negotiation mechanism

[Stephen Checkoway <[e-mail]>]

On Mar 11, 2015, at 2:56 PM, Dave Garrett <[e-mail]> wrote:

> On Tuesday, January 20, 2015 11:01:31 pm Xiaoyin Liu wrote:
>> For each site, I made at most four attempts with the following order to fallback:
>> (TLS 1.3, TLS 1.3) -> (TLS 1.0, TLS 1.3) -> (TLS 1.0, TLS 1.2) -> (TLS 1.0, TLS 1.0)
>> where the first is TLS record layer version, and the second is Client Hello version.
>> 
>> Here is the result:
>> (1) Number of sites scanned: 1,000,001
>> (2) Number of DNS Error: 45,402
>> (3) Number of sites that refuse TCP connection on port 443 (RST, timeout): 289,334
>> (4) Number of sites that fail sending ServerHello in all 4 attempts: 238,846
>> (5) Number of sites that are tolerant to (TLS1.3, TLS1.3): 397,152 (93.1%)
>> (6) Number of sites that need to fallback to (TLS1.0, TLS1.3): 22,461 (5.3%)
>> (7) Number of sites that need to fallback to (TLS1.0, TLS1.2): 6,352 (1.5%)
>> (8) Number of sites that need to fallback to (TLS1.0, TLS1.0): 454 (0.1%)
>> 
>> The total number of TLS enabled sites is 426,419. TLS 1.3 intolerant sites (7 and 8) are about 1.6%.

Most of this is about the record layer version (which really seems silly to change given that the record layer isn't changing).

The real data here is that 1.5% of servers are intolerant of 1.3 but tolerate 1.2. So that was (a) and (b) in my list but it's pretty hard to measure (c): servers that aren't maintained or can't be upgraded.

I remain unconvinced, but others can weigh in.

-- 
Stephen Checkoway