diff --git a/scripts/ssm-build-dual.sh b/scripts/ssm-build-dual.sh
new file mode 100755
index 00000000..fe697f54
--- /dev/null
+++ b/scripts/ssm-build-dual.sh
@@ -0,0 +1,165 @@
+#!/bin/bash
+
+# Apel-SSM Build Script 2.0: FPM edition
+# Adapted from the Debian only build script, now with RPM!
+# @Author: Nicholas Whyatt (RedProkofiev@github.com)
+
+# Script runs well with FPM 1.14.2 on ruby 2.7.1, setuptools 51.3.3 on RHEL and Deb platforms
+# Download ruby (if you're locked to 2.5, use RVM) and then run:
+# sudo gem install fpm -v 1.14.2
+# ./ssm-build-dual.sh (deb | rpm) <version> <iteration> <python_root_dir> e.g.
+# ./ssm-build.dual.sh deb 3.4.0 1 /usr/lib/python3.6
+# For SSM 3.4.0 and up.  Versions before that would technically work, but the changelog
+# then was in a Debian format that doesn't parse and fails hard if you want to build RPM.
+
+set -e
+
+usage() {
+    echo "Usage: $0 [options] (deb | rpm) <version> <iteration> <python_root_dir> "
+    echo -e "Build script for Apel-SSM.\n"
+    echo "  -h                    Displays help."
+    echo "  -v                    Verbose FPM output."
+    echo "  -s <source_dir>       Directory of source files.  Defaults to /debbuild/source or SOME RPM DIR."
+    echo -e "  -b <build_dir>        Directory of build files.  Defaults to /debbuild/build or SOME RPM DIR.\n" 1>&2;
+    exit 1;
+}
+
+# Bool flags to prevent automatic overwrite of input
+SOURCE_ASSIGNED=0
+BUILD_ASSIGNED=0
+
+# Configurable options
+while getopts ":hs:b:v" o; do
+    case "${o}" in
+        h)  echo "SSM Help"
+            usage;
+            ;;
+        s)  s=${OPTARG}
+            SOURCE_DIR=$s
+            SOURCE_ASSIGNED=1
+            ;;
+        b)  b=${OPTARG}
+            BUILD_DIR=$b
+            BUILD_ASSIGNED=1
+            ;;
+        v)  VERBOSE="--verbose "
+            ;;
+        *)  usage;
+            ;;
+    esac
+done
+shift $((OPTIND-1))
+
+# Check how any arguments there are
+if [ "$#" -ne 4 ]; then
+    echo "Expected 4 arguments, $# given."
+    usage;
+fi
+
+PACK_TYPE=$1
+VERSION=$2
+ITERATION=$3
+PYTHON_ROOT_DIR=$4 # i.e. /usr/lib/python3.6
+
+# Alter library, build and source directories depending on the package
+if [[ "$PACK_TYPE" = "deb" ]]; then
+    LIB_EXTENSION="/dist-packages"
+    if [[ "$SOURCE_ASSIGNED" = 0 ]]; then
+        SOURCE_DIR=~/debbuild/source
+    fi
+    if [[ "$BUILD_ASSIGNED" = 0 ]]; then
+        BUILD_DIR=~/debbuild/build
+    fi
+elif [[ "$PACK_TYPE" = "rpm" ]]; then
+    LIB_EXTENSION="/site-packages"
+    if [[ "$SOURCE_ASSIGNED" = 0 ]]; then
+        SOURCE_DIR=~/rpmbuild/SOURCES
+    fi
+    if [[ "$BUILD_ASSIGNED" = 0 ]]; then
+        BUILD_DIR=~/rpmbuild/BUILD
+    fi
+else # If package type is neither deb nor rpm, show an error message and exit
+    echo "$0 currently only supports 'deb' and 'rpm' packages."
+    usage;
+fi
+
+# Directory cleaning and repository management
+# Create SSM and DEB dir (if not present)
+mkdir -p "$SOURCE_DIR"
+mkdir -p "$BUILD_DIR"
+
+# Clean up any previous build
+rm -rf "${SOURCE_DIR:?}"/*
+rm -rf "${BUILD_DIR:?}"/*
+
+# Get and extract the source
+TAR_FILE=${VERSION}-${ITERATION}.tar.gz
+TAR_URL=https://github.com/apel/ssm/archive/$TAR_FILE
+wget --no-check-certificate "$TAR_URL" -O "$TAR_FILE"
+tar xvf "$TAR_FILE" -C "$SOURCE_DIR"
+rm -f "$TAR_FILE"
+
+# Get supplied Python version
+PY_VERSION="$(basename "$PYTHON_ROOT_DIR")"
+PY_NUM=${PY_VERSION#python}
+
+# Universal FPM Call
+FPM_CORE="fpm -s python \
+    -t $PACK_TYPE \
+    -n apel-ssm \
+    -v $VERSION \
+    --iteration $ITERATION \
+    -m \"Apel Administrators <apel-admins@stfc.ac.uk>\" \
+    --description \"Secure Stomp Messenger (SSM).\" \
+    --no-auto-depends "
+
+# Simple Python filter for version specific FPM
+if [[ ${PY_NUM:0:1} == "3" ]]; then
+    echo "Building $VERSION iteration $ITERATION for Python $PY_NUM as $PACK_TYPE."
+
+    # python-stomp < 5.0.0 to python-stomp, python to python3/pip3
+    # edited python-pip3 to python-pip
+    FPM_PYTHON="--depends python3 \
+        --depends python-pip3 \
+        --depends 'python-stomp' \
+        --depends python-ldap \
+        --depends libssl-dev \
+        --depends libsasl2-dev \
+        --depends openssl "
+
+elif [[ ${PY_NUM:0:1} == "2" ]]; then
+    echo "Building $VERSION iteration $ITERATION for Python $PY_NUM as $PACK_TYPE."
+
+    FPM_PYTHON="--depends python2.7 \
+        --depends python-pip \
+        --depends 'python-stomp < 5.0.0' \
+        --depends python-ldap \
+        --depends libssl-dev \
+        --depends libsasl2-dev \
+        --depends openssl "
+fi
+
+# python-bin must always be specified in modern linux
+PACKAGE_VERSION="--$PACK_TYPE-changelog $SOURCE_DIR/ssm-$VERSION-$ITERATION/CHANGELOG \
+    --python-bin /usr/bin/$PY_VERSION \
+    --python-install-lib $PYTHON_ROOT_DIR$LIB_EXTENSION \
+    --exclude *.pyc \
+    --package $BUILD_DIR \
+    $SOURCE_DIR/ssm-$VERSION-$ITERATION/setup.py"
+
+# Construct and evaluate the primary FPM call
+BUILD_PACKAGE_COMMAND=${FPM_CORE}${FPM_PYTHON}${VERBOSE}${PACKAGE_VERSION}
+eval "$BUILD_PACKAGE_COMMAND"
+
+# When installed, use pleaserun to perform system specific service setup
+fpm -s pleaserun -t "$PACK_TYPE" \
+-n apel-ssm-service \
+-v "$VERSION" \
+--iteration "$ITERATION" \
+-m "Apel Administrators <apel-admins@stfc.ac.uk>" \
+--description "Secure Stomp Messenger (SSM) Service Daemon files." \
+--architecture all \
+--no-auto-depends \
+--depends apel-ssm \
+--package "$BUILD_DIR" \
+/usr/bin/ssmreceive
diff --git a/setup.py b/setup.py
index 8c5f84d1..a495ca0c 100644
--- a/setup.py
+++ b/setup.py
@@ -51,11 +51,15 @@ def main():
           download_url='https://github.com/apel/ssm/releases',
           license='Apache License, Version 2.0',
           install_requires=[
-              'stomp.py<5.0.0', 'python-ldap<3.4.0', 'setuptools',
+              'cryptography==3.3.0',
+              'stomp.py<5.0.0',
+              'python-ldap<3.4.0',
+              'setuptools',
+              'pyopenssl<=21.0.0',
           ],
           extras_require={
-              'AMS': ['argo-ams-library'],
-              'daemon': ['python-daemon<=2.3.0'],
+              'AMS': ['argo-ams-library', 'certifi<2020.4.5.2', ],
+              'daemon': ['python-daemon<=2.3.0', ],
               'dirq': ['dirq'],
           },
           packages=find_packages(exclude=['bin', 'test']),