feat: adds 3-level certificate chain generation script

Signed-off-by: Akhilesh Kr. Yadav <akhileshkr.yadav@Akhileshs-MacBook-Air.local>

Signed-off-by: Akhilesh Kr. Yadav <akhileshkr.yadav@Akhileshs-MacBook-Air.local>

Makefile

@@ -49,6 +49,11 @@ presubmit:
 .PHONY: licenses
 licenses: ; @./scripts/licenses.sh
 
+.PHONY: certs
+certs:
+	@echo "Generating certificate chain..."
+	@$(SHELL) scripts/gen-certs.sh create
+
 .PHONY: help
 help:
 	@echo "Available targets:"
@@ -58,3 +63,4 @@ help:
 	@echo "  * presubmit:  check you are ready to push your local branch to remote"
 	@echo "  * help:       print this menu"
 	@echo "  * licenses:   check licenses of dependent packages"
+	@echo "  * certs:      generate the certificate chain"

misc/endEntity.key

@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEICoAlM1RuYHR4AdyqUgP6o4rx9XlNa3aj8fBqrTboTSvoAoGCCqGSM49
+AwEHoUQDQgAE22AhzRa88KigQuv2dI2ILdJsLIOmtqzSUrt79UP/98+OYeFclOED
+NjdahFsdZcZ9tyUEUF3I23Prl1RMszEh/Q==
+-----END EC PRIVATE KEY-----

scripts/gen-certs.sh

@@ -0,0 +1,161 @@
+#!/bin/bash
+# SPDX-License-Identifier: Apache-2.0
+set -e
+
+ROOT_CERT_NAME=rootCA
+INTERMEDIATE_CERT_NAME=intermediateCA
+END_ENTITY_CERT_NAME=endEntity
+
+THIS_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+MISC_DIR="$THIS_DIR/../misc"
+
+mkdir -p "$MISC_DIR"
+
+function create_root_cert() {
+    if [[ -f "${MISC_DIR}/${ROOT_CERT_NAME}.der" ]]; then
+        echo "Root certificate already exists. Skipping creation."
+        return
+    fi
+    openssl ecparam -name prime256v1 -genkey -noout -out ${MISC_DIR}/${ROOT_CERT_NAME}.key
+    openssl req -x509 -new -nodes -key ${MISC_DIR}/${ROOT_CERT_NAME}.key -sha256 -days 3650 \
+        -subj "/CN=Acme Inc." -out ${MISC_DIR}/${ROOT_CERT_NAME}.crt
+    openssl x509 -in ${MISC_DIR}/${ROOT_CERT_NAME}.crt -outform der -out ${MISC_DIR}/${ROOT_CERT_NAME}.der
+    rm -f ${MISC_DIR}/${ROOT_CERT_NAME}.crt  # Remove the PEM certificate
+    echo "Created ${MISC_DIR}/${ROOT_CERT_NAME}.der and ${MISC_DIR}/${ROOT_CERT_NAME}.key"
+}
+
+function create_intermediate_cert() {
+    if [[ -f "${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.der" ]]; then
+        echo "Intermediate certificate already exists. Skipping creation."
+        return
+    fi
+    openssl ecparam -name prime256v1 -genkey -noout -out ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.key
+    openssl req -new -key ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.key -out ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.csr -subj "/CN=Acme Gizmos"
+    openssl x509 -req -in ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.csr -CA ${MISC_DIR}/${ROOT_CERT_NAME}.der -CAkey ${MISC_DIR}/${ROOT_CERT_NAME}.key -CAcreateserial -out ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.crt -days 1825 -sha256
+    openssl x509 -in ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.crt -outform der -out ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.der
+    rm -f ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.crt  # Remove the PEM certificate
+    echo "Created ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.der and ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.key"
+}
+
+function create_end_entity_cert() {
+    if ([[ -f "${MISC_DIR}/${END_ENTITY_CERT_NAME}.der" ]] && [[ -f "${MISC_DIR}/${END_ENTITY_CERT_NAME}.key" ]]); then
+        echo "End-entity certificate and key already exist. Skipping creation."
+        return
+    fi
+    openssl ecparam -name prime256v1 -genkey -noout -out ${MISC_DIR}/${END_ENTITY_CERT_NAME}.key
+    openssl req -new -key ${MISC_DIR}/${END_ENTITY_CERT_NAME}.key -out ${MISC_DIR}/${END_ENTITY_CERT_NAME}.csr -subj "/CN=Acme Gizmo CoRIM signer"
+    openssl x509 -req -in ${MISC_DIR}/${END_ENTITY_CERT_NAME}.csr -CA ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.der -CAkey ${MISC_DIR}/${INTERMEDIATE_CERT_NAME}.key -CAcreateserial -out ${MISC_DIR}/${END_ENTITY_CERT_NAME}.crt -days 825 -sha256 -CAform der
+    openssl x509 -in ${MISC_DIR}/${END_ENTITY_CERT_NAME}.crt -outform der -out ${MISC_DIR}/${END_ENTITY_CERT_NAME}.der
+    rm -f ${MISC_DIR}/${END_ENTITY_CERT_NAME}.crt  # Remove the PEM certificate
+    echo "Created ${MISC_DIR}/${END_ENTITY_CERT_NAME}.der and ${MISC_DIR}/${END_ENTITY_CERT_NAME}.key"
+}
+
+function clean_intermediate() {
+    pushd "$MISC_DIR" > /dev/null || exit 1
+    echo "rm -f -- *.csr *.srl"
+    rm -f -- *.csr *.srl
+    popd > /dev/null || exit 1
+}
+
+function clean_cert() {
+    pushd "$MISC_DIR" > /dev/null || exit 1
+    local cert="$1"
+    echo "rm -f \"${cert}.der\" \"${cert}.key\""
+    rm -f "${cert}.der" "${cert}.key"
+    popd > /dev/null || exit 1
+}
+
+function clean_all() {
+    clean_intermediate
+    clean_cert "$ROOT_CERT_NAME"
+    clean_cert "$INTERMEDIATE_CERT_NAME"
+    clean_cert "$END_ENTITY_CERT_NAME"
+}
+
+function help() {
+    set +e
+    read -r -d '' usage <<-EOF
+    Usage: gen-certs [-h] [-C] [COMMAND]
+
+    This script is used to (re-)generate certificates used for a veraison
+    deployment. The certificates are signed by a CA certificate called
+    ${ROOT_CERT_NAME}.crt. If this does not exist, a self-signed one will
+    be generated.
+
+    Commands:
+
+    create
+            Create the root, intermediate, and end-entity certificates.
+
+    clean
+            Clean output artifacts for the certificates.
+
+    clean_all
+            Clean both intermediate and output artifacts for everything (including
+            the root CA cert).
+
+    help
+            Print this message and exit (same as -h option).
+
+    Options:
+
+    -h         Print this message and exit.
+    -C         Do not clean up intermediate artifacts (e.g., CSRs).
+
+EOF
+
+    echo "$usage"
+}
+
+function _check_openssl() {
+    if [[ "$(which openssl 2>/dev/null)" == "" ]]; then
+        echo -e "ERROR: openssl executable must be installed to use this command."
+        exit 1
+    fi
+}
+
+function _check_root_cert() {
+    if [[ ! -f "${MISC_DIR}/${ROOT_CERT_NAME}.der" ]]; then
+        create_root_cert
+    fi
+}
+
+_should_clean_intermediate=true
+
+OPTIND=1
+
+while getopts "hC" opt; do
+    case "$opt" in
+        h) help; exit 0;;
+        C) _should_clean_intermediate=false;;
+        *) break;;
+    esac
+done
+
+shift $((OPTIND-1))
+[ "${1:-}" = "--" ] && shift
+
+command=$1
+case $command in
+    help)
+        help
+        exit 0
+        ;;
+    clean)
+        clean_intermediate
+        ;;
+    clean_all)
+        clean_all
+        ;;
+    create)
+        create_root_cert
+        create_intermediate_cert
+        create_end_entity_cert
+        if [[ $_should_clean_intermediate == true ]]; then
+            clean_intermediate
+        fi
+        ;;
+    *)
+        echo -e "ERROR: unexpected command: \"$command\" (use -h for help)"
+        ;;
+esac