[tor-dev] Compiling tor against OpenSSL_1_0_2-stable

[Nick Mathewson]

On Mon, Sep 24, 2012 at 4:13 AM, Christian Kujau <lists at nerdbynature.de> wrote:
> Hi,
>
> while trying to compile the latest git-checkout against openssl-1.0.2,
> I've come across the following issues:
 [...]
> While this is really an issue with openssl, I wanted to have this
> documented, just in case anybody else tries the same. If someone knows of
> a better workaround (i.e. compiling just tortls.c with -Wno-error and
> everything else with -Werror), please share! :-)

So, -Werror isn't supposed to be on by default; you only get that if
you configure with --enable-gcc-warnings.  You can get all the
warnings, but with -Werror disabled, by using
--enable-gcc-warnings-advisory instead.

> A bit later, compilation stops again:
>
> ----
>   CCLD   src/or/tor
> src/common/libor-crypto.a(aes.o): In function `aes_crypt':
> aes.c:(.text+0x860): undefined reference to `CRYPTO_ctr128_encrypt'

Well that's certainly annoying.  If you're not feeling hackerish, I'd
suggest backing off to openssl the openssl 1.0.1 branch, which has
actually been, y'know, released. (There's no released openssl 1.0.2
version yet, right?) But if you're willing to hack the Tor code, you
might be able to make CAN_USE_OPENSSL_CTR always undefined in aes.c,
and make USE_EVP_AES_CTR always defined, so that Tor doesn't even
consider using the CRYPTO_ implementation.