[erlang-questions] SSL and hardcoded DH prime

[Alexander Petrovsky]

Yeah, Ingela, thanks! About default value and dh, dhfile options I know.
The main question - is the any reasons don’t generate DH prime in real-time?

чт, 23 авг. 2018 г. в 20:12, Ingela Andin <ingela.andin@REDACTED>:

> Hi!
>
> It is only the default value that is hard coded (a recommend value), you
> may configure your own parameters with dh or dhfile option.
>
> Regards Ingela
>
> Den tors 23 aug. 2018 kl 16:57 skrev Alexander Petrovsky <
> askjuise@REDACTED>:
>
>> Hello!
>>
>> We have stumble upon default DH prime (2048 bits) in Erlang when we try
>> to establish TLS session with cisco spa303 (VoIP hardphone)
>> via TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x0039) cipher suite. Unfortunately,
>> this hardphone can work only with 1024 bit DH prime.
>>
>> I wonder, why Ingela hardcoded this DH prime -
>> https://github.com/erlang/otp/commit/3458af579af6600870c5ada69b81085f47e9f52b
>>
>> In my synthetical tests, new DH prime generation is fast enough
>> (crypto:strong_rand_bytes(256)), about 17 us in 99 percentile in 1000000
>> iterations.
>>
>> Why Ingela has hardcoded this DH prime and is any reason why I shouldn't
>> generate DH prime in real-time?
>>
>> --
>> Петровский Александр / Alexander Petrovsky,
>>
>> Skype: askjuise
>> Phone: +7 931 9877991
>>
>> _______________________________________________
>> erlang-questions mailing list
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>>
> --
Петровский Александр / Alexander Petrovsky,

Skype: askjuise
Phone: +7 931 9877991
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