When running Android Studio 2.3.1 on Linux, there may be a link error along these lines:
cmake android libssl.so.1.0.0: cannot open shared object file: No such file or directory
This is due to more recent versions of openssl being installed, but for some reason this version is hard coded into CMAKE and Android Studio.
The solution is along these lines for a Debian system:
sudo apt install build-essential wget https://www.openssl.org/source/old/1.0.0/openssl-1.0.0t.tar.gz tar zxvf ../openssl-1.0.0t.tar.gz cd openssl-1.0.0t/ ./config -fPIC shared zlib-dynamic make sudo cp libssl* /usr/local/lib/ sudo cp libcrypto* /usr/local/lib/ sudo ldconfig