spring-security-samples/servlet/spring-boot/java/authentication/mfa/x509+webauthn/etc/generate-cert

#!/bin/bash
set -euo pipefail

CN="${1:-}"
HOST="${2:-}"

if [[ -z "$CN" || -z "$HOST" ]]; then
  echo "Usage: $0 <CN> <HOST>" >&2
  exit 1
fi

# Set up working temp dir
WORKDIR=$(mktemp -d)
trap "rm -rf $WORKDIR" EXIT

CA_KEY="ca.key"
CA_CERT="ca.pem"

# === Ensure CA exists ===
if [[ ! -f $CA_KEY || ! -f $CA_CERT ]]; then
  echo "🔧 Generating CA..."
  openssl genrsa -out $CA_KEY 4096
  openssl req -x509 -new -nodes -key $CA_KEY -sha256 -days 3650 -out $CA_CERT \
    -subj "/CN=Local Dev CA"
fi

# === Generate key and CSR ===
openssl genrsa -out "$WORKDIR/key.pem" 2048
openssl req -new -key "$WORKDIR/key.pem" -out "$WORKDIR/cert.csr" \
  -subj "/CN=$CN"

cat > "$WORKDIR/cert.ext" <<EOF
authorityKeyIdentifier=keyid,issuer
basicConstraints=CA:FALSE
keyUsage = digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth, clientAuth
subjectAltName = DNS:$HOST
EOF

# === Sign cert ===
openssl x509 -req \
  -in "$WORKDIR/cert.csr" \
  -CA "$CA_CERT" -CAkey "$CA_KEY" -CAcreateserial \
  -out "$WORKDIR/cert.pem" -days 825 -sha256 -extfile "$WORKDIR/cert.ext"

# === Build full chain and mark alias ===
cat "$WORKDIR/cert.pem" "$CA_CERT" > "$WORKDIR/chain.pem"
cp "$CA_CERT" "$WORKDIR/ca.pem"
echo "$CN" > "$WORKDIR/alias"

# === Emit tarball to stdout ===
tar -C "$WORKDIR" -cf - cert.pem key.pem chain.pem ca.pem alias