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
|
{ config, lib, pkgs, ... }:
with lib;
let
apparmorEnabled = config.security.apparmor.enable;
dnscrypt-proxy = pkgs.dnscrypt-proxy;
cfg = config.services.dnscrypt-proxy;
resolverListFile = "${dnscrypt-proxy}/share/dnscrypt-proxy/dnscrypt-resolvers.csv";
localAddress = "${cfg.localAddress}:${toString cfg.localPort}";
daemonArgs =
[ "--local-address=${localAddress}"
(optionalString cfg.tcpOnly "--tcp-only")
]
++ resolverArgs;
resolverArgs = if (cfg.customResolver != null)
then
[ "--resolver-address=${cfg.customResolver.address}:${toString cfg.customResolver.port}"
"--provider-name=${cfg.customResolver.name}"
"--provider-key=${cfg.customResolver.key}"
]
else
[ "--resolvers-list=${resolverListFile}"
"--resolver-name=${toString cfg.resolverName}"
];
in
{
options = {
services.dnscrypt-proxy = {
enable = mkEnableOption ''
Enable dnscrypt-proxy. The proxy relays regular DNS queries to a
DNSCrypt enabled upstream resolver. The traffic between the
client and the upstream resolver is encrypted and authenticated,
which may mitigate the risk of MITM attacks and third-party
snooping (assuming the upstream is trustworthy).
'';
localAddress = mkOption {
default = "127.0.0.1";
type = types.string;
description = ''
Listen for DNS queries on this address.
'';
};
localPort = mkOption {
default = 53;
type = types.int;
description = ''
Listen on this port.
'';
};
resolverName = mkOption {
default = "opendns";
type = types.nullOr types.string;
description = ''
The name of the upstream DNSCrypt resolver to use. See
<literal>${resolverListFile}</literal> for alternative resolvers
(e.g., if you are concerned about logging and/or server
location).
'';
};
customResolver = mkOption {
default = null;
description = ''
Use a resolver not listed in the upstream list (e.g.,
a private DNSCrypt provider). For advanced users only.
If specified, this option takes precedence.
'';
type = types.nullOr (types.submodule ({ ... }: { options = {
address = mkOption {
type = types.str;
description = "Resolver IP address";
example = "208.67.220.220";
};
port = mkOption {
type = types.int;
description = "Resolver port";
default = 443;
};
name = mkOption {
type = types.str;
description = "Provider fully qualified domain name";
example = "2.dnscrypt-cert.opendns.com";
};
key = mkOption {
type = types.str;
description = "Provider public key";
example = "B735:1140:206F:225D:3E2B:D822:D7FD:691E:A1C3:3CC8:D666:8D0C:BE04:BFAB:CA43:FB79";
}; }; }));
};
tcpOnly = mkOption {
default = false;
type = types.bool;
description = ''
Force sending encrypted DNS queries to the upstream resolver
over TCP instead of UDP (on port 443). Enabling this option may
help circumvent filtering, but should not be used otherwise.
'';
};
};
};
config = mkIf cfg.enable {
assertions = [
{ assertion = (cfg.customResolver != null) || (cfg.resolverName != null);
message = "please configure upstream DNSCrypt resolver";
}
];
security.apparmor.profiles = mkIf apparmorEnabled (singleton (pkgs.writeText "apparmor-dnscrypt-proxy" ''
${dnscrypt-proxy}/bin/dnscrypt-proxy {
/dev/null rw,
/dev/urandom r,
/etc/passwd r,
/etc/group r,
${config.environment.etc."nsswitch.conf".source} r,
${pkgs.glibc}/lib/*.so mr,
${pkgs.tzdata}/share/zoneinfo/** r,
network inet stream,
network inet6 stream,
network inet dgram,
network inet6 dgram,
${pkgs.gcc.cc}/lib/libssp.so.* mr,
${pkgs.libsodium}/lib/libsodium.so.* mr,
${pkgs.systemd}/lib/libsystemd.so.* mr,
${pkgs.xz}/lib/liblzma.so.* mr,
${pkgs.libgcrypt}/lib/libgcrypt.so.* mr,
${pkgs.libgpgerror}/lib/libgpg-error.so.* mr,
${resolverListFile} r,
}
''));
users.extraUsers.dnscrypt-proxy = {
uid = config.ids.uids.dnscrypt-proxy;
description = "dnscrypt-proxy daemon user";
};
users.extraGroups.dnscrypt-proxy.gid = config.ids.gids.dnscrypt-proxy;
systemd.sockets.dnscrypt-proxy = {
description = "dnscrypt-proxy listening socket";
socketConfig = {
ListenStream = "${localAddress}";
ListenDatagram = "${localAddress}";
};
wantedBy = [ "sockets.target" ];
};
systemd.services.dnscrypt-proxy = {
description = "dnscrypt-proxy daemon";
after = [ "network.target" ] ++ optional apparmorEnabled "apparmor.service";
requires = [ "dnscrypt-proxy.socket "] ++ optional apparmorEnabled "apparmor.service";
serviceConfig = {
Type = "simple";
NonBlocking = "true";
ExecStart = "${dnscrypt-proxy}/bin/dnscrypt-proxy ${toString daemonArgs}";
User = "dnscrypt-proxy";
Group = "dnscrypt-proxy";
PrivateTmp = true;
PrivateDevices = true;
};
};
};
}
|