[openssl-users] Authentication over ECDHE

[Jakob Bohm]

On 29/12/2018 22:33, Richard Levitte wrote:
> In message <20181229.170846.804158981742723988.levitte at openssl.org> on Sat, 29 Dec 2018 17:08:46 +0100 (CET), Richard Levitte <levitte at openssl.org> said:
>
>> In message <38b97114-0c66-40ed-f631-58aa20940a3a at gmx.de> on Sat, 29 Dec 2018 14:19:47 +0100, "C.Wehrmeyer" <c.wehrmeyer at gmx.de> said:
>>
> ...
>>> What's wrong with that, you ask? Let me show you how I'd have done
>>> that:
>>>
>>>> static const unsigned char ssl3_pad_1[] =
>>>> {
>>>>      "66666666"
>>>>      "66666666"
>>>>      "66666666"
>>>>      "66666666"
>>>>      "66666666"
>>>>      "66666666"
>>>> };
>>>>
>>>> static const unsigned char*ssl3_pad_2[] =
>>>> {
>>>>      "\\\\\\\\\\\\\\\\"
>>>>      "\\\\\\\\\\\\\\\\"
>>>>      "\\\\\\\\\\\\\\\\"
>>>>      "\\\\\\\\\\\\\\\\"
>>>>      "\\\\\\\\\\\\\\\\"
>>>>      "\\\\\\\\\\\\\\\\"
>>>> };
>>> So, no. I don't trust anyone. Especially not this mess of a code.
>> You do know that your string insert NUL bytes, right?  If you have a
>> look at how they're used, you might see why those stray NUL bytes
>> aren't a good thing.
> Never mind this remark...  For some reason, my brain added commas
> after each partial string.  Meh...
>

It still inserts NUL bytes at the end of each array, changing
sizeof(array) as well as cache access patterns (and thus side
channel effects).

Enjoy

Jakob
-- 
Jakob Bohm, CIO, Partner, WiseMo A/S.  https://www.wisemo.com
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