Created attachment 1114410 [details]
small patch that fixes the issue

Description of problem:

Boost in RHEL/CentOS 7 assumes the TLS library has SSLv3 support


Version-Release number of selected component (if applicable):
boost-1.53.0-25

How reproducible:
always

Steps to Reproduce:
1. Attempt to build software that uses boost against TLS library w/o SSLv3
2.
3.

Actual results:

/usr/include/boost/asio/ssl/impl/context.ipp: In constructor 'boost::asio::ssl::context::context(boost::asio::ssl::context_base::method)':
/usr/include/boost/asio/ssl/impl/context.ipp:61:29: error: '::SSLv3_method' has not been declared
     handle_ = ::SSL_CTX_new(::SSLv3_method());
                             ^
/usr/include/boost/asio/ssl/impl/context.ipp:64:29: error: '::SSLv3_client_method' has not been declared
     handle_ = ::SSL_CTX_new(::SSLv3_client_method());
                             ^
/usr/include/boost/asio/ssl/impl/context.ipp:67:29: error: '::SSLv3_server_method' has not been declared
     handle_ = ::SSL_CTX_new(::SSLv3_server_method()); 


Expected results:

Software should compile

Additional info:

The OpenSSL in RHEL / CentOS 7 has had some EC stuff removed due to possible software patent issues.

For those of us who understand the legal risk but want to build software that needs those features, we can install an alternate TLS implementation to build against.

However when that alternate TLS implementation has removed SSLv3 support, building software against it that uses boost results in the above error.

The patch to fix this is described at https://github.com/boostorg/asio/pull/23/files

Attached is a patch I made against the boost in CentOS 7 src.rpm that implements the above fix and is tested to resolve the issue on my CentOS 7 workstation (building bitcoin-core against LibreSSL)

It should be noted that SSLv3 is extremely old and is no longer considered to be secure and should not be used.

Some distributions, e.g. Debian, have removed SSLv3 from their own OpenSSL implementations and it would not surprise me if Red Hat chose to do the same in the near future.

Removing SSLv3 from OpenSSL would also require this patch, so applying this patch now would not only make things easier for people using alternate TLS implementations, it also would prepare boost in the event that SSLv3 is removed from your own TLS library.