Add checksum in gitian build scripts for ossl

This adds a checksum in the gitian build script to make sure that
ossl tool and theuni's patch matches what is expected. Also changes
the url to use https and adds the same instructions to the release docs.

contrib/gitian-build.py

@@ -51,8 +51,10 @@ def build():
     os.chdir('gitian-builder')
     os.makedirs('inputs', exist_ok=True)
 
-    subprocess.check_call(['wget', '-N', '-P', 'inputs', 'http://downloads.sourceforge.net/project/osslsigncode/osslsigncode/osslsigncode-1.7.1.tar.gz'])
+    subprocess.check_call(['wget', '-N', '-P', 'inputs', 'https://downloads.sourceforge.net/project/osslsigncode/osslsigncode/osslsigncode-1.7.1.tar.gz'])
     subprocess.check_call(['wget', '-N', '-P', 'inputs', 'https://bitcoincore.org/cfields/osslsigncode-Backports-to-1.7.1.patch'])
+    subprocess.check_call(["echo 'a8c4e9cafba922f89de0df1f2152e7be286aba73f78505169bc351a7938dd911 inputs/osslsigncode-Backports-to-1.7.1.patch' | sha256sum -c"], shell=True)
+    subprocess.check_call(["echo 'f9a8cdb38b9c309326764ebc937cba1523a3a751a7ab05df3ecc99d18ae466c9 inputs/osslsigncode-1.7.1.tar.gz' | sha256sum -c"], shell=True)
     subprocess.check_call(['make', '-C', '../bitcoin/depends', 'download', 'SOURCES_PATH=' + os.getcwd() + '/cache/common'])
 
     if args.linux:

doc/release-process.md

@@ -87,7 +87,9 @@ Ensure gitian-builder is up-to-date:
     pushd ./gitian-builder
     mkdir -p inputs
     wget -P inputs https://bitcoincore.org/cfields/osslsigncode-Backports-to-1.7.1.patch
+    echo 'a8c4e9cafba922f89de0df1f2152e7be286aba73f78505169bc351a7938dd911 inputs/osslsigncode-Backports-to-1.7.1.patch' | sha256sum -c
     wget -P inputs https://downloads.sourceforge.net/project/osslsigncode/osslsigncode/osslsigncode-1.7.1.tar.gz
+    echo 'f9a8cdb38b9c309326764ebc937cba1523a3a751a7ab05df3ecc99d18ae466c9 inputs/osslsigncode-1.7.1.tar.gz' | sha256sum -c
     popd
 
 Create the macOS SDK tarball, see the [macOS readme](README_osx.md) for details, and copy it into the inputs directory.