Files
clan-core/clanServices/ssl/default.nix
2025-10-31 17:11:27 +01:00

112 lines
3.3 KiB
Nix

/*
Set up a CA chain for the clan. There will be one root CA for each instance
of the ssl service, then each host has its own host CA that is signed by the
instance-wide root CA.
Trusting the root CA, will result in also trusting the individual host CAs,
as they are signed by it.
Hosts can then use their respective host CAs to expose SSL secured services.
*/
{
exports,
config,
lib,
...
}:
{
_class = "clan.service";
manifest.name = "clan-core/ssl";
manifest.description = "Set up a CA infrastucture for your clan";
manifest.readme = builtins.readFile ./README.md;
# Generate a root CA for each instances of the ssl module.
exports = lib.mapAttrs' (instanceName: _: {
"ssl/${instanceName}///".vars.generators.ssl-root-ca =
{ config, ... }:
{
files.key = { };
files.cert.secret = false;
runtimeInputs = [
config.pkgs.pkgs.openssl
];
script = ''
# Generate CA private key (4096-bit RSA)
openssl genrsa -out "$out/key" 4096
# Generate self-signed CA certificate (valid for 10 years)
openssl req -new -x509 \
-key "$out/key" \
-out "$out/cert" \
-days 3650 \
-subj "/C=US/ST=State/L=City/O=Organization/OU=IT/CN=Root CA" \
-sha256
'';
};
}) config.instances;
roles.default = {
description = "Generate a host CA, signed by the root CA and trust the root CA";
perInstance =
{
instanceName,
machine,
...
}:
{
# Generate a host CA, which depends on (is signed by) the root CA
exports = {
"ssl/${instanceName}/default/${machine.name}/".vars.generators.ssl-host-ca =
{ config, ... }:
{
dependencies = {
ssl-root-ca = exports."ssl/${instanceName}///".vars.generators.ssl-root-ca;
};
files.key = { };
files.cert.secret = false;
runtimeInputs = [
config.pkgs.pkgs.openssl
];
script = ''
# Generate intermediate CA private key (4096-bit RSA)
openssl genrsa -out "$out/key" 4096
# Generate Certificate Signing Request (CSR) for intermediate CA
openssl req -new \
-key "$out/key" \
-out "$out/csr" \
-subj "/C=US/ST=State/L=City/O=Organization/OU=IT/CN=Host CA"
# Sign the CSR with the root CA to create the intermediate certificate
openssl x509 -req \
-in "$out/csr" \
-CA "$dependencies/ssl-root-ca/cert" \
-CAkey "$dependencies/ssl-root-ca/key" \
-CAcreateserial \
-out "$out/cert" \
-days 3650 \
-sha256 \
-extfile <(printf "basicConstraints=CA:TRUE\nkeyUsage=keyCertSign,cRLSign")
'';
};
};
nixosModule =
{ ... }:
{
# We trust the (public) root CA certificate on all machines with this role
security.pki.certificateFiles = [
exports."ssl/${instanceName}///".vars.generators.ssl-root-ca.files.cert.path
];
};
};
};
}