Re: Pre-Master Key (PRG) (Firefox)

On Wed, Aug 19, 2015 at 4:54 AM, konstantinos Alexiou <
[email protected]> wrote:

> As known, during the ClientKeyExchange phase of the Handshake of TLS, the
> client generates a 48-byte random number called premaster secret using a
> Pseudo Random Generator which is used to calculate the master key and the
> key sessions.
>
>  I would like to know which Pseudo Random Generator functions are used to
> compute and produce the pre-master Secret which are used in TLS1.2 in
> firefox.
>


As you know, the PMS is generated differently in the RSA and DH cases.  I
assume you're talking about the RSA case, since that's the only one where
the PRNG feeds directly into the PMS.  The short answer is that it uses the
same PRNG as everything else in NSS.  Here are some links if you want to
look in more detail:

https://dxr.mozilla.org/mozilla-central/source/security/nss/lib/ssl/ssl3con.c#5898
https://dxr.mozilla.org/mozilla-central/source/security/nss/lib/ssl/ssl3con.c#9324
https://dxr.mozilla.org/mozilla-central/source/security/nss/lib/softoken/pkcs11c.c#3862
https://dxr.mozilla.org/mozilla-central/source/security/nss/lib/freebl/drbg.c#567




> Thank you very much in advance.
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