The problem is that the fix Bug#29784 was mistakenly
reverted when updating YaSSL to a newer version.

The solution is to re-apply the fix and this time
actually add a meaningful test case so that possible
regressions are caught.

extra/yassl/taocrypt/src/coding.cpp:
  Fixed buffer allocation to compute the proper maximum
  decoded size: (EncodedLength * 3/4) + 3
mysql-test/std_data/server8k-cert.pem:
  Update certificate.
mysql-test/std_data/server8k-key.pem:
  Update key.
mysql-test/t/ssl_8k_key-master.opt:
  Start the server using the certificate and key that
  triggers the problem.