add instructions on compiling OpenSSL if needed..

NOTES.md

@@ -3,3 +3,16 @@
 Look at adding Disco support: https://github.com/mimoo/disco/issues/4
 
 Look at: https://github.com/qwj/python-proxy
+
+If you are building on machine w/ an older version of OpenSSL (error: `cryptography.exceptions.UnsupportedAlgorithm: X448 is not supported by this version of OpenSSL.`), you can manually build the package cryptography using a newer version of OpenSSL.  First d/l and build OpenSSL:
+1. Fetch OpenSSL: `wget https://www.openssl.org/source/openssl-1.1.1g.tar.gz`
+2. Verify OpenSSL.  Use GPG or the SHA256.
+3. extract OpenSSL: `tar -xzf openssl-1.1.1g.tar.gz`
+4. Configure OpenSSL: `cd openssl-1.1.1g && ./config`
+5. Build OpenSSL: `cd openssl-1.1.1g && make -j 4`
+
+Now, rebuild the cryptography package w/ the new library:
+1. Uninstall broken package: `pip uninstall cryptography`
+2. Setup build environment: `export CFLAGS=-I<path>/openssl-1.1.1g/include; export LDFLAGS=-L<path>/openssl-1.1.1g`
+3. Build cryptography from source: `pip install --no-binary :all: cryptography`
+4. Setup library path: `export LD_LIBRARY_PATH=<path>/openssl-1.1.1g`