1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
|
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.security.acme;
certOpts = { name, ... }: {
options = {
webroot = mkOption {
type = types.str;
example = "/var/lib/acme/acme-challenges";
description = ''
Where the webroot of the HTTP vhost is located.
<filename>.well-known/acme-challenge/</filename> directory
will be created below the webroot if it doesn't exist.
<literal>http://example.org/.well-known/acme-challenge/</literal> must also
be available (notice unencrypted HTTP).
'';
};
domain = mkOption {
type = types.str;
default = name;
description = "Domain to fetch certificate for (defaults to the entry name)";
};
email = mkOption {
type = types.nullOr types.str;
default = null;
description = "Contact email address for the CA to be able to reach you.";
};
user = mkOption {
type = types.str;
default = "root";
description = "User running the ACME client.";
};
group = mkOption {
type = types.str;
default = "root";
description = "Group running the ACME client.";
};
allowKeysForGroup = mkOption {
type = types.bool;
default = false;
description = ''
Give read permissions to the specified group
(<option>security.acme.cert.<name>.group</option>) to read SSL private certificates.
'';
};
postRun = mkOption {
type = types.lines;
default = "";
example = "systemctl reload nginx.service";
description = ''
Commands to run after new certificates go live. Typically
the web server and other servers using certificates need to
be reloaded.
Executed in the same directory with the new certificate.
'';
};
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"
]);
default = [ "fullchain.pem" "full.pem" "key.pem" "account_key.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.
'';
};
activationDelay = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Systemd time span expression to delay copying new certificates to main
state directory. See <citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>.
'';
};
preDelay = mkOption {
type = types.lines;
default = "";
description = ''
Commands to run after certificates are re-issued but before they are
activated. Typically the new certificate is published to DNS.
Executed in the same directory with the new certificate.
'';
};
extraDomains = mkOption {
type = types.attrsOf (types.nullOr types.str);
default = {};
example = literalExample ''
{
"example.org" = "/srv/http/nginx";
"mydomain.org" = null;
}
'';
description = ''
A list of extra domain names, which are included in the one certificate to be issued, with their
own server roots if needed.
'';
};
};
};
in
{
###### interface
options = {
security.acme = {
directory = mkOption {
default = "/var/lib/acme";
type = types.str;
description = ''
Directory where certs and other state will be stored by default.
'';
};
validMin = mkOption {
type = types.int;
default = 30 * 24 * 3600;
description = "Minimum remaining validity before renewal in seconds.";
};
renewInterval = mkOption {
type = types.str;
default = "weekly";
description = ''
Systemd calendar expression when to check for renewal. See
<citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>.
'';
};
preliminarySelfsigned = mkOption {
type = types.bool;
default = true;
description = ''
Whether a preliminary self-signed certificate should be generated before
doing ACME requests. This can be useful when certificates are required in
a webserver, but ACME needs the webserver to make its requests.
With preliminary self-signed certificate the webserver can be started and
can later reload the correct ACME certificates.
'';
};
production = mkOption {
type = types.bool;
default = true;
description = ''
If set to true, use Let's Encrypt's production environment
instead of the staging environment. The main benefit of the
staging environment is to get much higher rate limits.
See
<literal>https://letsencrypt.org/docs/staging-environment</literal>
for more detail.
'';
};
certs = mkOption {
default = { };
type = with types; attrsOf (submodule certOpts);
description = ''
Attribute set of certificates to get signed and renewed.
'';
example = literalExample ''
{
"example.com" = {
webroot = "/var/www/challenges/";
email = "foo@example.com";
extraDomains = { "www.example.com" = null; "foo.example.com" = "/var/www/foo/"; };
};
"bar.example.com" = {
webroot = "/var/www/challenges/";
email = "bar@example.com";
};
}
'';
};
};
};
###### implementation
config = mkMerge [
(mkIf (cfg.certs != { }) {
systemd.services = let
services = concatLists servicesLists;
servicesLists = mapAttrsToList certToServices cfg.certs;
certToServices = cert: data:
let
cpath = lpath + optionalString (data.activationDelay != null) ".staging";
lpath = "${cfg.directory}/${cert}";
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)
++ optionals (!cfg.production) ["--server" "https://acme-staging.api.letsencrypt.org/directory"];
acmeService = {
description = "Renew ACME Certificate for ${cert}";
after = [ "network.target" "network-online.target" ];
wants = [ "network-online.target" ];
serviceConfig = {
Type = "oneshot";
SuccessExitStatus = [ "0" "1" ];
PermissionsStartOnly = true;
User = data.user;
Group = data.group;
PrivateTmp = true;
};
path = with pkgs; [ simp_le systemd ];
preStart = ''
mkdir -p '${cfg.directory}'
chown 'root:root' '${cfg.directory}'
chmod 755 '${cfg.directory}'
if [ ! -d '${cpath}' ]; then
mkdir '${cpath}'
fi
chmod ${rights} '${cpath}'
chown -R '${data.user}:${data.group}' '${cpath}'
mkdir -p '${data.webroot}/.well-known/acme-challenge'
chown -R '${data.user}:${data.group}' '${data.webroot}/.well-known/acme-challenge'
'';
script = ''
cd '${cpath}'
set +e
simp_le ${escapeShellArgs cmdline}
EXITCODE=$?
set -e
echo "$EXITCODE" > /tmp/lastExitCode
exit "$EXITCODE"
'';
postStop = ''
cd '${cpath}'
if [ -e /tmp/lastExitCode ] && [ "$(cat /tmp/lastExitCode)" = "0" ]; then
${if data.activationDelay != null then ''
${data.preDelay}
if [ -d '${lpath}' ]; then
systemd-run --no-block --on-active='${data.activationDelay}' --unit acme-setlive-${cert}.service
else
systemctl --wait start acme-setlive-${cert}.service
fi
'' else data.postRun}
# noop ensuring that the "if" block is non-empty even if
# activationDelay == null and postRun == ""
true
fi
'';
before = [ "acme-certificates.target" ];
wantedBy = [ "acme-certificates.target" ];
};
delayService = {
description = "Set certificate for ${cert} live";
path = with pkgs; [ rsync ];
serviceConfig = {
Type = "oneshot";
};
script = ''
rsync -a --delete-after '${cpath}/' '${lpath}'
'';
postStop = data.postRun;
};
selfsignedService = {
description = "Create preliminary self-signed certificate for ${cert}";
path = [ pkgs.openssl ];
preStart = ''
if [ ! -d '${cpath}' ]
then
mkdir -p '${cpath}'
chmod ${rights} '${cpath}'
chown '${data.user}:${data.group}' '${cpath}'
fi
'';
script =
''
workdir="$(mktemp -d)"
# Create CA
openssl genrsa -des3 -passout pass:xxxx -out $workdir/ca.pass.key 2048
openssl rsa -passin pass:xxxx -in $workdir/ca.pass.key -out $workdir/ca.key
openssl req -new -key $workdir/ca.key -out $workdir/ca.csr \
-subj "/C=UK/ST=Warwickshire/L=Leamington/O=OrgName/OU=Security Department/CN=example.com"
openssl x509 -req -days 1 -in $workdir/ca.csr -signkey $workdir/ca.key -out $workdir/ca.crt
# Create key
openssl genrsa -des3 -passout pass:xxxx -out $workdir/server.pass.key 2048
openssl rsa -passin pass:xxxx -in $workdir/server.pass.key -out $workdir/server.key
openssl req -new -key $workdir/server.key -out $workdir/server.csr \
-subj "/C=UK/ST=Warwickshire/L=Leamington/O=OrgName/OU=IT Department/CN=example.com"
openssl x509 -req -days 1 -in $workdir/server.csr -CA $workdir/ca.crt \
-CAkey $workdir/ca.key -CAserial $workdir/ca.srl -CAcreateserial \
-out $workdir/server.crt
# Copy key to destination
cp $workdir/server.key ${cpath}/key.pem
# Create fullchain.pem (same format as "simp_le ... -f fullchain.pem" creates)
cat $workdir/{server.crt,ca.crt} > "${cpath}/fullchain.pem"
# Create full.pem for e.g. lighttpd
cat $workdir/{server.key,server.crt,ca.crt} > "${cpath}/full.pem"
# Give key acme permissions
chown '${data.user}:${data.group}' "${cpath}/"{key,fullchain,full}.pem
chmod ${rights} "${cpath}/"{key,fullchain,full}.pem
'';
serviceConfig = {
Type = "oneshot";
PermissionsStartOnly = true;
PrivateTmp = true;
User = data.user;
Group = data.group;
};
unitConfig = {
# Do not create self-signed key when key already exists
ConditionPathExists = "!${cpath}/key.pem";
};
before = [
"acme-selfsigned-certificates.target"
];
wantedBy = [
"acme-selfsigned-certificates.target"
];
};
in (
[ { name = "acme-${cert}"; value = acmeService; } ]
++ optional cfg.preliminarySelfsigned { name = "acme-selfsigned-${cert}"; value = selfsignedService; }
++ optional (data.activationDelay != null) { name = "acme-setlive-${cert}"; value = delayService; }
);
servicesAttr = listToAttrs services;
injectServiceDep = {
after = [ "acme-selfsigned-certificates.target" ];
wants = [ "acme-selfsigned-certificates.target" "acme-certificates.target" ];
};
in
servicesAttr //
(if config.services.nginx.enable then { nginx = injectServiceDep; } else {}) //
(if config.services.lighttpd.enable then { lighttpd = injectServiceDep; } else {});
systemd.timers = flip mapAttrs' cfg.certs (cert: data: nameValuePair
("acme-${cert}")
({
description = "Renew ACME Certificate for ${cert}";
wantedBy = [ "timers.target" ];
timerConfig = {
OnCalendar = cfg.renewInterval;
Unit = "acme-${cert}.service"
|