Merge pull request #77578 from m1cr0man/master

Replace simp-le with lego and support DNS-01 challenge
This commit is contained in:
Florian Klink 2020-02-10 11:47:30 +01:00 committed by GitHub
commit 4e0fea3fe2
6 changed files with 256 additions and 61 deletions

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@ -4304,6 +4304,12 @@
email = "wheatdoge@gmail.com";
name = "Tim Liou";
};
m1cr0man = {
email = "lucas+nix@m1cr0man.com";
github = "m1cr0man";
githubId = 3044438;
name = "Lucas Savva";
};
m3tti = {
email = "mathaeus.peter.sander@gmail.com";
name = "Mathaeus Sander";

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@ -660,6 +660,21 @@ auth required pam_succeed_if.so uid >= 1000 quiet
<literal>PRETTY_NAME</literal> in <literal>/etc/os-release</literal>
now uses the short rather than full version string.
</para>
</listitem>
<listitem>
<para>
The ACME module has switched from simp-le to <link xlink:href="https://github.com/go-acme/lego">lego</link>
which allows us to support DNS-01 challenges and wildcard certificates. The following options have been added:
<link linkend="opt-security.acme.acceptTerms">security.acme.acceptTerms</link>,
<link linkend="opt-security.acme.certs">security.acme.certs.&lt;name&gt;.dnsProvider</link>,
<link linkend="opt-security.acme.certs">security.acme.certs.&lt;name&gt;.credentialsFile</link>,
<link linkend="opt-security.acme.certs">security.acme.certs.&lt;name&gt;.dnsPropagationCheck</link>.
As well as this, the options <literal>security.acme.acceptTerms</literal> and either
<literal>security.acme.email</literal> or <literal>security.acme.certs.&lt;name&gt;.email</literal>
must be set in order to use the ACME module.
Certificates will be regenerated anew on the next renewal date. The credentials for simp-le are
preserved and thus it is possible to roll back to previous versions without breaking certificate
generation.
</listitem>
<listitem>
<para>

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@ -1,7 +1,5 @@
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.security.acme;
@ -9,7 +7,8 @@ let
certOpts = { name, ... }: {
options = {
webroot = mkOption {
type = types.str;
type = types.nullOr types.str;
default = null;
example = "/var/lib/acme/acme-challenges";
description = ''
Where the webroot of the HTTP vhost is located.
@ -38,7 +37,7 @@ let
email = mkOption {
type = types.nullOr types.str;
default = null;
default = cfg.email;
description = "Contact email address for the CA to be able to reach you.";
};
@ -76,20 +75,6 @@ let
'';
};
plugins = mkOption {
type = types.listOf (types.enum [
"cert.der" "cert.pem" "chain.pem" "external.sh"
"fullchain.pem" "full.pem" "key.der" "key.pem" "account_key.json" "account_reg.json"
]);
default = [ "fullchain.pem" "full.pem" "key.pem" "account_key.json" "account_reg.json" ];
description = ''
Plugins to enable. With default settings simp_le will
store public certificate bundle in <filename>fullchain.pem</filename>,
private key in <filename>key.pem</filename> and those two previous
files combined in <filename>full.pem</filename> in its state directory.
'';
};
directory = mkOption {
type = types.str;
readOnly = true;
@ -111,6 +96,46 @@ let
own server roots if needed.
'';
};
keyType = mkOption {
type = types.str;
default = "ec384";
description = ''
Key type to use for private keys.
For an up to date list of supported values check the --key-type option
at https://go-acme.github.io/lego/usage/cli/#usage.
'';
};
dnsProvider = mkOption {
type = types.nullOr types.str;
default = null;
example = "route53";
description = ''
DNS Challenge provider. For a list of supported providers, see the "code"
field of the DNS providers listed at https://go-acme.github.io/lego/dns/.
'';
};
credentialsFile = mkOption {
type = types.path;
description = ''
Path to an EnvironmentFile for the cert's service containing any required and
optional environment variables for your selected dnsProvider.
To find out what values you need to set, consult the documentation at
https://go-acme.github.io/lego/dns/ for the corresponding dnsProvider.
'';
example = "/var/src/secrets/example.org-route53-api-token";
};
dnsPropagationCheck = mkOption {
type = types.bool;
default = true;
description = ''
Toggles lego DNS propagation check, which is used alongside DNS-01
challenge to ensure the DNS entries required are available.
'';
};
};
};
@ -130,14 +155,21 @@ in
(mkRemovedOptionModule [ "security" "acme" "directory"] "ACME Directory is now hardcoded to /var/lib/acme and its permisisons are managed by systemd. See https://github.com/NixOS/nixpkgs/issues/53852 for more info.")
(mkRemovedOptionModule [ "security" "acme" "preDelay"] "This option has been removed. If you want to make sure that something executes before certificates are provisioned, add a RequiredBy=acme-\${cert}.service to the service you want to execute before the cert renewal")
(mkRemovedOptionModule [ "security" "acme" "activationDelay"] "This option has been removed. If you want to make sure that something executes before certificates are provisioned, add a RequiredBy=acme-\${cert}.service to the service you want to execute before the cert renewal")
(mkChangedOptionModule [ "security" "acme" "validMin"] [ "security" "acme" "validMinDays"] (config: config.security.acme.validMin / (24 * 3600)))
];
options = {
security.acme = {
validMin = mkOption {
validMinDays = mkOption {
type = types.int;
default = 30 * 24 * 3600;
description = "Minimum remaining validity before renewal in seconds.";
default = 30;
description = "Minimum remaining validity before renewal in days.";
};
email = mkOption {
type = types.nullOr types.str;
default = null;
description = "Contact email address for the CA to be able to reach you.";
};
renewInterval = mkOption {
@ -173,6 +205,15 @@ in
'';
};
acceptTerms = mkOption {
type = types.bool;
default = false;
description = ''
Accept the CA's terms of service. The default provier is Let's Encrypt,
you can find their ToS at https://letsencrypt.org/repository/
'';
};
certs = mkOption {
default = { };
type = with types; attrsOf (submodule certOpts);
@ -204,27 +245,55 @@ in
config = mkMerge [
(mkIf (cfg.certs != { }) {
assertions = let
certs = (mapAttrsToList (k: v: v) cfg.certs);
in [
{
assertion = all (certOpts: certOpts.dnsProvider == null || certOpts.webroot == null) certs;
message = ''
Options `security.acme.certs.<name>.dnsProvider` and
`security.acme.certs.<name>.webroot` are mutually exclusive.
'';
}
{
assertion = cfg.email != null || all (certOpts: certOpts.email != null) certs;
message = ''
You must define `security.acme.certs.<name>.email` or
`security.acme.email` to register with the CA.
'';
}
{
assertion = cfg.acceptTerms;
message = ''
You must accept the CA's terms of service before using
the ACME module by setting `security.acme.acceptTerms`
to `true`. For Let's Encrypt's ToS see https://letsencrypt.org/repository/
'';
}
];
systemd.services = let
services = concatLists servicesLists;
servicesLists = mapAttrsToList certToServices cfg.certs;
certToServices = cert: data:
let
# StateDirectory must be relative, and will be created under /var/lib by systemd
lpath = "acme/${cert}";
apath = "/var/lib/${lpath}";
spath = "/var/lib/acme/.lego";
rights = if data.allowKeysForGroup then "750" else "700";
cmdline = [ "-v" "-d" data.domain "--default_root" data.webroot "--valid_min" cfg.validMin ]
++ optionals (data.email != null) [ "--email" data.email ]
++ concatMap (p: [ "-f" p ]) data.plugins
++ concatLists (mapAttrsToList (name: root: [ "-d" (if root == null then name else "${name}:${root}")]) data.extraDomains)
globalOpts = [ "-d" data.domain "--email" data.email "--path" "." "--key-type" data.keyType ]
++ optionals (cfg.acceptTerms) [ "--accept-tos" ]
++ optionals (data.dnsProvider != null && !data.dnsPropagationCheck) [ "--dns.disable-cp" ]
++ concatLists (mapAttrsToList (name: root: [ "-d" name ]) data.extraDomains)
++ (if data.dnsProvider != null then [ "--dns" data.dnsProvider ] else [ "--http" "--http.webroot" data.webroot ])
++ optionals (cfg.server != null || data.server != null) ["--server" (if data.server == null then cfg.server else data.server)];
runOpts = escapeShellArgs (globalOpts ++ [ "run" ]);
renewOpts = escapeShellArgs (globalOpts ++ [ "renew" "--days" (toString cfg.validMinDays) ]);
acmeService = {
description = "Renew ACME Certificate for ${cert}";
after = [ "network.target" "network-online.target" ];
wants = [ "network-online.target" ];
# simp_le uses requests, which uses certifi under the hood,
# which doesn't respect the system trust store.
# At least in the acme test, we provision a fake CA, impersonating the LE endpoint.
# REQUESTS_CA_BUNDLE is a way to teach python requests to use something else
environment.REQUESTS_CA_BUNDLE = "/etc/ssl/certs/ca-certificates.crt";
serviceConfig = {
Type = "oneshot";
# With RemainAfterExit the service is considered active even
@ -233,18 +302,37 @@ in
# the permissions of the StateDirectory get adjusted
# according to the specified group
RemainAfterExit = true;
SuccessExitStatus = [ "0" "1" ];
User = data.user;
Group = data.group;
PrivateTmp = true;
StateDirectory = lpath;
StateDirectory = "acme/.lego ${lpath}";
StateDirectoryMode = rights;
WorkingDirectory = "/var/lib/${lpath}";
ExecStart = "${pkgs.simp_le}/bin/simp_le ${escapeShellArgs cmdline}";
WorkingDirectory = spath;
# Only try loading the credentialsFile if the dns challenge is enabled
EnvironmentFile = if data.dnsProvider != null then data.credentialsFile else null;
ExecStart = pkgs.writeScript "acme-start" ''
#!${pkgs.runtimeShell} -e
${pkgs.lego}/bin/lego ${renewOpts} || ${pkgs.lego}/bin/lego ${runOpts}
'';
ExecStartPost =
let
keyName = builtins.replaceStrings ["*"] ["_"] data.domain;
script = pkgs.writeScript "acme-post-start" ''
#!${pkgs.runtimeShell} -e
cd ${apath}
# Test that existing cert is older than new cert
KEY=${spath}/certificates/${keyName}.key
if [ -e $KEY -a $KEY -nt key.pem ]; then
cp -p ${spath}/certificates/${keyName}.key key.pem
cp -p ${spath}/certificates/${keyName}.crt cert.pem
cp -p ${spath}/certificates/${keyName}.issuer.crt chain.pem
cat cert.pem chain.pem > fullchain.pem
cat key.pem cert.pem chain.pem > full.pem
chmod ${rights} *.pem
chown '${data.user}:${data.group}' *.pem
fi
${data.postRun}
'';
in
@ -276,17 +364,17 @@ in
-out $workdir/server.crt
# Copy key to destination
cp $workdir/server.key /var/lib/${lpath}/key.pem
cp $workdir/server.key ${apath}/key.pem
# Create fullchain.pem (same format as "simp_le ... -f fullchain.pem" creates)
cat $workdir/{server.crt,ca.crt} > "/var/lib/${lpath}/fullchain.pem"
cat $workdir/{server.crt,ca.crt} > "${apath}/fullchain.pem"
# Create full.pem for e.g. lighttpd
cat $workdir/{server.key,server.crt,ca.crt} > "/var/lib/${lpath}/full.pem"
cat $workdir/{server.key,server.crt,ca.crt} > "${apath}/full.pem"
# Give key acme permissions
chown '${data.user}:${data.group}' "/var/lib/${lpath}/"{key,fullchain,full}.pem
chmod ${rights} "/var/lib/${lpath}/"{key,fullchain,full}.pem
chown '${data.user}:${data.group}' "${apath}/"{key,fullchain,full}.pem
chmod ${rights} "${apath}/"{key,fullchain,full}.pem
'';
serviceConfig = {
Type = "oneshot";
@ -297,7 +385,7 @@ in
};
unitConfig = {
# Do not create self-signed key when key already exists
ConditionPathExists = "!/var/lib/${lpath}/key.pem";
ConditionPathExists = "!${apath}/key.pem";
};
};
in (
@ -309,8 +397,7 @@ in
servicesAttr;
systemd.tmpfiles.rules =
flip mapAttrsToList cfg.certs
(cert: data: "d ${data.webroot}/.well-known/acme-challenge - ${data.user} ${data.group}");
map (data: "d ${data.webroot}/.well-known/acme-challenge - ${data.user} ${data.group}") (filter (data: data.webroot != null) (attrValues cfg.certs));
systemd.timers = flip mapAttrs' cfg.certs (cert: data: nameValuePair
("acme-${cert}")
@ -334,7 +421,7 @@ in
];
meta = {
maintainers = with lib.maintainers; [ abbradar fpletz globin ];
maintainers = with lib.maintainers; [ abbradar fpletz globin m1cr0man ];
doc = ./acme.xml;
};
}

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@ -7,7 +7,7 @@
<para>
NixOS supports automatic domain validation &amp; certificate retrieval and
renewal using the ACME protocol. This is currently only implemented by and
for Let's Encrypt. The alternative ACME client <literal>simp_le</literal> is
for Let's Encrypt. The alternative ACME client <literal>lego</literal> is
used under the hood.
</para>
<section xml:id="module-security-acme-prerequisites">

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@ -1,17 +1,50 @@
let
commonConfig = ./common/letsencrypt/common.nix;
dnsScript = {writeScript, dnsAddress, bash, curl}: writeScript "dns-hook.sh" ''
#!${bash}/bin/bash
set -euo pipefail
echo '[INFO]' "[$2]" 'dns-hook.sh' $*
if [ "$1" = "present" ]; then
${curl}/bin/curl --data '{"host": "'"$2"'", "value": "'"$3"'"}' http://${dnsAddress}:8055/set-txt
else
${curl}/bin/curl --data '{"host": "'"$2"'"}' http://${dnsAddress}:8055/clear-txt
fi
'';
in import ./make-test-python.nix {
name = "acme";
nodes = rec {
letsencrypt = ./common/letsencrypt;
letsencrypt = { nodes, lib, ... }: {
imports = [ ./common/letsencrypt ];
networking.nameservers = lib.mkForce [
nodes.dnsserver.config.networking.primaryIPAddress
];
};
acmeStandalone = { config, pkgs, ... }: {
dnsserver = { nodes, pkgs, ... }: {
networking.firewall.allowedTCPPorts = [ 8055 53 ];
networking.firewall.allowedUDPPorts = [ 53 ];
systemd.services.pebble-challtestsrv = {
enable = true;
description = "Pebble ACME challenge test server";
wantedBy = [ "network.target" ];
serviceConfig = {
ExecStart = "${pkgs.pebble}/bin/pebble-challtestsrv -dns01 ':53' -defaultIPv6 '' -defaultIPv4 '${nodes.webserver.config.networking.primaryIPAddress}'";
# Required to bind on privileged ports.
User = "root";
Group = "root";
};
};
};
acmeStandalone = { nodes, lib, config, pkgs, ... }: {
imports = [ commonConfig ];
networking.nameservers = lib.mkForce [
nodes.dnsserver.config.networking.primaryIPAddress
];
networking.firewall.allowedTCPPorts = [ 80 ];
networking.extraHosts = ''
${config.networking.primaryIPAddress} standalone.com
'';
security.acme = {
server = "https://acme-v02.api.letsencrypt.org/dir";
certs."standalone.com" = {
@ -29,14 +62,12 @@ in import ./make-test-python.nix {
};
};
webserver = { config, pkgs, ... }: {
webserver = { nodes, config, pkgs, lib, ... }: {
imports = [ commonConfig ];
networking.firewall.allowedTCPPorts = [ 80 443 ];
networking.extraHosts = ''
${config.networking.primaryIPAddress} a.example.com
${config.networking.primaryIPAddress} b.example.com
'';
networking.nameservers = lib.mkForce [
nodes.dnsserver.config.networking.primaryIPAddress
];
# A target remains active. Use this to probe the fact that
# a service fired eventhough it is not RemainAfterExit
@ -61,14 +92,11 @@ in import ./make-test-python.nix {
nesting.clone = [
({pkgs, ...}: {
networking.extraHosts = ''
${config.networking.primaryIPAddress} b.example.com
'';
systemd.targets."acme-finished-b.example.com" = {};
systemd.services."acme-b.example.com" = {
wants = [ "acme-finished-b.example.com.target" ];
before = [ "acme-finished-b.example.com.target" ];
after = [ "nginx.service" ];
};
services.nginx.virtualHosts."b.example.com" = {
enableACME = true;
@ -79,15 +107,48 @@ in import ./make-test-python.nix {
'';
};
})
({pkgs, config, nodes, lib, ...}: {
security.acme.certs."example.com" = {
domain = "*.example.com";
dnsProvider = "exec";
dnsPropagationCheck = false;
credentialsFile = with pkgs; writeText "wildcard.env" ''
EXEC_PATH=${dnsScript { inherit writeScript bash curl; dnsAddress = nodes.dnsserver.config.networking.primaryIPAddress; }}
'';
user = config.services.nginx.user;
group = config.services.nginx.group;
};
systemd.targets."acme-finished-example.com" = {};
systemd.services."acme-example.com" = {
wants = [ "acme-finished-example.com.target" ];
before = [ "acme-finished-example.com.target" "nginx.service" ];
wantedBy = [ "nginx.service" ];
};
services.nginx.virtualHosts."c.example.com" = {
forceSSL = true;
sslCertificate = config.security.acme.certs."example.com".directory + "/cert.pem";
sslTrustedCertificate = config.security.acme.certs."example.com".directory + "/full.pem";
sslCertificateKey = config.security.acme.certs."example.com".directory + "/key.pem";
locations."/".root = pkgs.runCommand "docroot" {} ''
mkdir -p "$out"
echo hello world > "$out/index.html"
'';
};
})
];
};
client = commonConfig;
client = {nodes, lib, ...}: {
imports = [ commonConfig ];
networking.nameservers = lib.mkForce [
nodes.dnsserver.config.networking.primaryIPAddress
];
};
};
testScript = {nodes, ...}:
let
newServerSystem = nodes.webserver2.config.system.build.toplevel;
newServerSystem = nodes.webserver.config.system.build.toplevel;
switchToNewServer = "${newServerSystem}/bin/switch-to-configuration test";
in
# Note, wait_for_unit does not work for oneshot services that do not have RemainAfterExit=true,
@ -97,6 +158,17 @@ in import ./make-test-python.nix {
# can use them to probe that a oneshot fired. It is a bit ugly, but it is the best we can do
''
client.start()
dnsserver.start()
letsencrypt.wait_for_unit("default.target")
dnsserver.wait_for_unit("pebble-challtestsrv.service")
client.succeed(
'curl --data \'{"host": "acme-v02.api.letsencrypt.org", "addresses": ["${nodes.letsencrypt.config.networking.primaryIPAddress}"]}\' http://${nodes.dnsserver.config.networking.primaryIPAddress}:8055/add-a'
)
client.succeed(
'curl --data \'{"host": "standalone.com", "addresses": ["${nodes.acmeStandalone.config.networking.primaryIPAddress}"]}\' http://${nodes.dnsserver.config.networking.primaryIPAddress}:8055/add-a'
)
letsencrypt.start()
acmeStandalone.start()
@ -129,5 +201,17 @@ in import ./make-test-python.nix {
client.succeed(
"curl --cacert /tmp/ca.crt https://b.example.com/ | grep -qF 'hello world'"
)
with subtest("Can request wildcard certificates using DNS-01 challenge"):
webserver.succeed(
"${switchToNewServer}"
)
webserver.succeed(
"/run/current-system/fine-tune/child-2/bin/switch-to-configuration test"
)
webserver.wait_for_unit("acme-finished-example.com.target")
client.succeed(
"curl --cacert /tmp/ca.crt https://c.example.com/ | grep -qF 'hello world'"
)
'';
}

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@ -5,5 +5,8 @@ in {
nodes.letsencrypt.config.networking.primaryIPAddress
];
security.acme.acceptTerms = true;
security.acme.email = "webmaster@example.com";
security.pki.certificateFiles = [ letsencrypt-ca ];
}