Create IoT Edge device certificates

README.md

Devvice Certificate Creation

Problems with OpenSSL 3.2.0

Creation of the CA certificate signing request fails with the follwing error

80A027F501000000:error:11000079:X509 V3 routines:v2i_AUTHORITY_KEYID:no issuer certificate:crypto/x509/v3_akid.c:156:
80A027F501000000:error:11000080:X509 V3 routines:X509V3_EXT_nconf_int:error in extension:crypto/x509/v3_conf.c:48:section=v3_intermediate_ca, name=authorityKeyIdentifier, value=keyid:always,issuer:always

This seems to be because we're doing something wrong. It is the authorityKeyIdentifier = keyid:always,issuer:always in the .cfg that now fails from this version of OpenSSL. Commenting it out in the config file solves the problem

See https://github.com/openssl/openssl/blob/openssl-3.2.0/CHANGES.md (search for authorityKeyIdentifier = none)

create_device_certs.sh

#!/usr/bin/env bash

set -e

# Setup
DEVICE_ID="$1"
CONFIG_FILE="openssl_root_ca.cnf"

# Existing Intermediate CA Certificate & Key
# CA_INTERMEDIATE_CERT="ROOTS/Recycleye_IOT_Intermediate_CA.crt.pem"
CA_INTERMEDIATE_CERT_FULL="ROOTS/Recycleye_IOT_Intermediate_CA_full_chain.crt.pem"
CA_INTERMEDIATE_KEY="ROOTS/Recycleye_IOT_Intermediate_CA.key.pem"
CA_ROOT_CERT="ROOTS/Recycleye_IOT_CA.pem"

OUTDIR="certificates/${DEVICE_ID}-certificates"
CONFIG_FILE_TEMP="${OUTDIR}/${CONFIG_FILE}.tmp"
mkdir -p "$OUTDIR"

# Add the device id as commonName to the config file
# Should be able to use CN = $ENV::DEVICE_ID in the conf file but it doesn't work
sed "s/DEVICE_ID/${DEVICE_ID}/g" ${CONFIG_FILE} >"${CONFIG_FILE_TEMP}"

# 1. Generate the device private key
echo "--> Generate device private key"
openssl genrsa -out "${OUTDIR}/device.key.pem" 4096 &>/dev/null
chmod 444 "${OUTDIR}/device.key.pem"
echo "    ... ${OUTDIR}/device.key.pem"

# 2. Generate a certificate signing request for the device identity certificate
echo "--> Generate certificate signing request for device identity certificate"
openssl req -new \
    -config "${CONFIG_FILE_TEMP}" \
    -key "${OUTDIR}/device.key.pem" \
    -out "${OUTDIR}/device.csr" &>/dev/null
echo "    ... ${OUTDIR}/device.csr"

# view the CSR with
# openssl req -noout -text -in "${OUTDIR}/device.csr"

# 3. Create the device certificate using the CSR
echo "--> Generate the device identity certificate using our intermediate ca cert"
openssl x509 -req \
    -days 3650 \
    -in "${OUTDIR}/device.csr" \
    -CA "${CA_INTERMEDIATE_CERT_FULL}" \
    -CAkey "${CA_INTERMEDIATE_KEY}" \
    -CAcreateserial \
    -out "${OUTDIR}/device.cert.pem" \
    -extfile "${CONFIG_FILE_TEMP}" \
    -extensions user_crt &>/dev/null
echo "    ... ${OUTDIR}/device.cert.pem"

# Look at a certificate Subject (in sensible format) with
# openssl x509 -in "${OUTDIR}/device.cert.pem" -noout -subject -nameopt oneline,-esc_msb

# 4. Create full chain device certificate
echo "--> Generate a full chain device certificate (with ca intermediate full chain cert)"
cat "${OUTDIR}/device.cert.pem" "${CA_INTERMEDIATE_CERT_FULL}" >"${OUTDIR}/device-full-chain.cert.pem"
echo "    ... ${OUTDIR}/device-full-chain.cert.pem"

# 5. Create device CA certificate CSR
echo "--> Generate certificate signing request for device ca certificate"
openssl req -new \
    -config "${CONFIG_FILE_TEMP}" \
    -key "${OUTDIR}/device.key.pem" \
    -extensions v3_intermediate_ca \
    -out "${OUTDIR}/device-ca.csr" &>/dev/null
echo "    ... ${OUTDIR}/device-ca.csr"

# 6. Create device CA certifiate
echo "--> Generate the device ca certificate using our intermediate ca cert"
openssl x509 -req \
    -days 3650 \
    -in "${OUTDIR}/device-ca.csr" \
    -CA "${CA_INTERMEDIATE_CERT_FULL}" \
    -CAkey "${CA_INTERMEDIATE_KEY}" \
    -CAcreateserial \
    -out "${OUTDIR}/device-ca.cert.pem" \
    -extfile "${CONFIG_FILE_TEMP}" \
    -extensions v3_intermediate_ca &>/dev/null
echo "    ... ${OUTDIR}/device-ca.cert.pem"

# 7. Create full chain device CA certificate
echo "--> Generate a full chain device ca certificate (with ca intermediate full chain cert)"
cat "${OUTDIR}/device-ca.cert.pem" "${CA_INTERMEDIATE_CERT_FULL}" >"${OUTDIR}/device-ca-full-chain.cert.pem"
echo "    ... ${OUTDIR}/device-ca-full-chain.cert.pem"

# 8. Copy & rename certs for device
echo "--> Copy & rename certificates to copy to device"
mkdir -p "$OUTDIR/to-device"
cp "${OUTDIR}/device-ca-full-chain.cert.pem" "$OUTDIR/to-device/device-ca.crt"
cp "${OUTDIR}/device-full-chain.cert.pem" "${OUTDIR}/to-device/device.crt"
cp "${OUTDIR}/device.key.pem" "${OUTDIR}/to-device/device.key"
cp "${CA_ROOT_CERT}" "${OUTDIR}/to-device/ca.crt"
echo "    ... ${OUTDIR}/to-device"

rm -f "${CONFIG_FILE_TEMP}"

openssl_root_ca.cnf

[req]
default_bits           = 4096
distinguished_name     = req_distinguished_name
string_mask            = utf8only
default_md             = sha256
prompt                 = no

# add extentions to CA certificates
#x509_extensions        = v3_ca

# add extensions to certificate signing requests (CSRs)
x509_extensions        = user_crt
req_extensions         = v3_req

[req_distinguished_name]
# See https://en.wikipedia.org/wiki/Certificate_signing_request
C                      = UK
O                      = Recycleye
#CN                     = ${ENV::DEVICE_ID}
CN                     = DEVICE_ID
emailAddress           = security@recycleye.com

# [v3_ca]
# # x509v3 extensions for CA certificates
# subjectKeyIdentifier = hash
# authorityKeyIdentifier = keyid:always,issuer
# basicConstraints = critical,CA:true
# nsComment = "OpenSSL Generated Certificate"

[v3_req]
# x509v3 extensions for CA certificates
basicConstraints       = CA:FALSE
extendedKeyUsage       = clientAuth, emailProtection
keyUsage               = critical, nonRepudiation, digitalSignature, keyEncipherment

[user_crt]
# Extensions for client (device) certificates
subjectKeyIdentifier   = hash
basicConstraints       = CA:FALSE
extendedKeyUsage       = clientAuth, emailProtection
nsCertType             = client, email
authorityKeyIdentifier = keyid:always,issuer:always
nsComment              = "OpenSSL Generated Client Certificate"
keyUsage               = critical, nonRepudiation, digitalSignature, keyEncipherment


[v3_intermediate_ca]
# Extensions for a typical intermediate CA
basicConstraints       = critical, CA:true
subjectKeyIdentifier   = hash
authorityKeyIdentifier = keyid:always,issuer:always
keyUsage               = critical, digitalSignature, cRLSign, keyCertSign