Snippet for verifying a SHA256 hash of a downloaded file in bash

This snippet will download openssl and verify the hash against a hard-coded value. This is useful on old operating systems (specifically CentOS 5.11) that can't actually establish an SSL connection to lots of sites.

#!/bin/bash

SSL_VERSION=1.0.2d
SSL_SHA256=671c36487785628a703374c652ad2cebea45fa920ae5681515df25d9f2c9a8c8
RETRIEVED_HASH=$(wget -q -O - http://www.openssl.org/source/openssl-${SSL_VERSION}.tar.gz | tee openssl-${SSL_VERSION}.tar.gz | sha256sum | cut -d' ' -f1)
if [ "${RETRIEVED_HASH}" != "${SSL_SHA256}" ]; then
  echo "Bad hash for openssl-${SSL_VERSION}.tar.gz, quitting"
  exit 1
fi