Add Crypto patch for EC_GROUP_new_curve_GF2m

[Gsantomaggio]

In openssl 1.0.1e EC_GROUP_new_curve_GF2m function is wrapped by #ifndef OPENSSL_NO_EC2M.
We have to check whether OPENSSL_NO_EC2M is set, and if it is, then we do not have EC_GROUP_new_curve_GF2m function and do not HAVE_EC.

Currently there is this kind of the problem:

Erlang/OTP 21 [erts-10.1.1] [source] [64-bit] [smp:2:2] [ds:2:2:10] [async-threads:1] [hipe]

Eshell V10.1.1  (abort with ^G)
1> l(crypto).
{module,crypto}
2> crypto:generate_key(ecdh, secp112r2).
** exception error: bad argument
     in function  crypto:ec_key_generate/2
        called as crypto:ec_key_generate({{prime_field,<<219,124,42,191,98,227,94,102,128,118,190,173,32,139>>},{<<97,39,194,76,5,243,138,10,170,246,92,14,240,44>>,
                             <<81,222,241,129,93,181,237,116,252,195,76,133,215,9>>,
                    <<0,39,87,161,17,77,105,110,103,104,117,97,81,117,83,22,192,94,11,212>>},<<4,75,163,10,181,232,146,180,225,100,157,208,146,134,67,173,205,70,245,136,46,55,71,222,243,...>>,
                            <<54,223,10,175,216,184,215,89,124,161,5,32,208,75>>,<<4>>},
                                         undefined)
3>

I remember that we met this problem before.

With this patch the result will be:

Eshell V10.1.1  (abort with ^G)
1>  crypto:generate_key(ecdh, secp112r2).
notsup
2>

Notes:
1 - Copied from https://build.opensuse.org/package/view_file/devel:languages:erlang:Factory/erlang/crypto.patch?expand=1&rev=92106653f72b30973f28170277fa4b0e
2 - also in the last release
3- Even if there is a way, to enable Enable Elliptical Curve Diffie-Hellman (ECDHE) in Linux, I think that it shouldn't be done :)

[michaelklishin]

Thank you!

[michaelklishin]

Should we backport this to the 20.x and 19.x branches?

[Gsantomaggio]

Yes, but I think that we have to check the diff file https://github.com/rabbitmq/erlang-rpm/blob/master/otp-0008-crypto.patch

Will check/try and will prepare another PR for 20.x and 19.x branches

[Gsantomaggio]

Do you want also update the https://github.com/rabbitmq/erlang-rpm/tree/erlang-20.1.x branch?
The patch for 20.3 should be compatible.

[michaelklishin]

Nope, we only maintain the most recent minor for 20.x.