TLS Scripts

This repository contains a set of scripts for generating test TLS certificates. The main entry point is generate-certs.sh, which orchestrates creation of:

• A Root CA (self-signed)
• Two Intermediate CAs (issued by the Root CA), named inter-ca-1 and inter-ca-2
• A Server certificate/key
• A Client certificate/key

You can specify who issues the server or client certificate via environment variables:

• SERVER_CERT_ISSUER
• CLIENT_CERT_ISSUER

By default:

• The server certificate is issued by inter-ca-1
• The client certificate is issued by inter-ca-2

Note: These scripts are intended only for testing. For production-grade Public Key Infrastructure (PKI) you should consider tools such as Cloudflare cfssl or other more fully-featured PKI solutions.

Components & Script Breakdown

Each script can be run independently, provided their required input files (from preceding steps) are present and haven’t been removed.

1. Root CA — 00-generate-root-ca.sh

Sets up the Root CA with configurable distinguished name (DN) parameters via environment variables, falling back to defaults when not provided:

CA_C="${TLS_DN_C:-SE}"         # Country
CA_ST="${TLS_DN_ST:-Stockholm}"# State or Province
CA_L="${TLS_DN_L:-Stockholm}"  # Locality (City)
CA_O="${TLS_DN_O:-MyOrgName}"  # Organization
CA_OU="${TLS_DN_OU:-MyRootCA}" # Organizational Unit
CA_CN="MyRootCA"               # Common Name

2. Intermediate CA — 01-issue-inter-ca.sh

Creates one or more intermediate CAs under the Root CA. The DN fields are similarly configurable:

CA_C="${TLS_DN_C:-SE}"
CA_ST="${TLS_DN_ST:-Stockholm}"
CA_L="${TLS_DN_L:-Stockholm}"
CA_O="${TLS_DN_O:-MyOrgName}"
CA_OU="${TLS_DN_OU:-MyIntermediateCA}"
CA_CN="${TLS_INTER_CA_CN:-MyIntermediateCA-}"  # You can specify the suffix or override

3. Server Certificate — 02-issue-server-cert.sh

Generates a server certificate. Key DN fields and Subject Alternative Names (SANs) are configurable via environment variables. The certificate issuer can be chosen (default: inter-ca-1).

DN_C="${TLS_DN_C:-SE}"
DN_ST="${TLS_DN_ST:-Stockholm}"
DN_L="${TLS_DN_L:-Stockholm}"
DN_O="${TLS_DN_O:-MyOrgName}"
DN_OU="${TLS_DN_OU:-MyService}"
DN_CN="${TLS_SERVER_COMMON_NAME:-localhost}"

# Optional SANs
TLS_SERVER_IP     # IP address to include in SAN if set
TLS_SERVER_DNS    # DNS name in SAN if set

SERVER_CERT_ISSUER=inter-ca-1  # or “ca” … depends on your setup

4. Client Certificate — 03-issue-client-cert.sh

Similar approach as for the server, but for client-side certificate:

CL_C="${TLS_DN_C:-SE}"
CL_ST="${TLS_DN_ST:-Stockholm}"
CL_L="${TLS_DN_L:-Stockholm}"
CL_O="${TLS_DN_O:-MyOrgName}"
CL_OU="${TLS_DN_OU:-MyServiceClient}"
CL_CN="${TLS_CLIENT_COMMON_NAME:-localhost}"

CLIENT_CERT_ISSUER=inter-ca-2

Cryptographic Algorithms Supported

You can choose the type of cryptographic key via the ALG environment variable. Options:

• rsa: Generates a 2048-bit RSA key (key size is fixed in the current scripts)
• rsa-pss: Generates an RSA-PSS key (uses Probabilistic Signature Scheme, also known as PSS padding).
  This option is more secure for signatures. Currently, it applies only to client certificates —
  server certificates will continue to use standard RSA.
• ec: Generates an ECDSA key using curve prime256v1
• dsa: Generates a DSA key