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Commit | Line | Data |
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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
6016fcb0 | 2 | |
096cbdce | 3 | #if !ENABLE_DNS_OVER_TLS || !DNS_OVER_TLS_USE_GNUTLS |
6016fcb0 IT |
4 | #error This source file requires DNS-over-TLS to be enabled and GnuTLS to be available. |
5 | #endif | |
6 | ||
6016fcb0 IT |
7 | #include <gnutls/socket.h> |
8 | ||
bb42782b | 9 | #include "iovec-util.h" |
72938b93 YW |
10 | #include "resolved-dns-stream.h" |
11 | #include "resolved-dnstls.h" | |
be28f72d | 12 | #include "resolved-manager.h" |
72938b93 | 13 | |
7f95bb22 | 14 | #define TLS_PROTOCOL_PRIORITY "NORMAL:-VERS-ALL:+VERS-TLS1.3:+VERS-TLS1.2" |
fd421c4a | 15 | DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(gnutls_session_t, gnutls_deinit, NULL); |
6016fcb0 | 16 | |
aa892849 | 17 | static ssize_t dnstls_stream_vec_push(gnutls_transport_ptr_t p, const giovec_t *iov, int iovcnt) { |
6016fcb0 IT |
18 | int r; |
19 | ||
20 | assert(p); | |
21 | ||
22 | r = dns_stream_writev((DnsStream*) p, (const struct iovec*) iov, iovcnt, DNS_STREAM_WRITE_TLS_DATA); | |
23 | if (r < 0) { | |
24 | errno = -r; | |
25 | return -1; | |
26 | } | |
27 | ||
28 | return r; | |
29 | } | |
30 | ||
31 | int dnstls_stream_connect_tls(DnsStream *stream, DnsServer *server) { | |
b9c54c46 | 32 | _cleanup_(gnutls_deinitp) gnutls_session_t gs = NULL; |
6016fcb0 IT |
33 | int r; |
34 | ||
35 | assert(stream); | |
36 | assert(server); | |
37 | ||
38 | r = gnutls_init(&gs, GNUTLS_CLIENT | GNUTLS_ENABLE_FALSE_START | GNUTLS_NONBLOCK); | |
39 | if (r < 0) | |
40 | return r; | |
41 | ||
42 | /* As DNS-over-TLS is a recent protocol, older TLS versions can be disabled */ | |
7f95bb22 | 43 | r = gnutls_priority_set_direct(gs, TLS_PROTOCOL_PRIORITY, NULL); |
6016fcb0 IT |
44 | if (r < 0) |
45 | return r; | |
46 | ||
e22c5b20 | 47 | r = gnutls_credentials_set(gs, GNUTLS_CRD_CERTIFICATE, stream->manager->dnstls_data.cert_cred); |
6016fcb0 IT |
48 | if (r < 0) |
49 | return r; | |
50 | ||
51 | if (server->dnstls_data.session_data.size > 0) { | |
52 | gnutls_session_set_data(gs, server->dnstls_data.session_data.data, server->dnstls_data.session_data.size); | |
53 | ||
54 | // Clear old session ticket | |
55 | gnutls_free(server->dnstls_data.session_data.data); | |
56 | server->dnstls_data.session_data.data = NULL; | |
57 | server->dnstls_data.session_data.size = 0; | |
58 | } | |
59 | ||
7f2f4fac | 60 | if (server->manager->dns_over_tls_mode == DNS_OVER_TLS_YES) { |
eec394f1 JT |
61 | if (server->server_name) |
62 | gnutls_session_set_verify_cert(gs, server->server_name, 0); | |
63 | else { | |
64 | stream->dnstls_data.validation.type = GNUTLS_DT_IP_ADDRESS; | |
65 | if (server->family == AF_INET) { | |
66 | stream->dnstls_data.validation.data = (unsigned char*) &server->address.in.s_addr; | |
67 | stream->dnstls_data.validation.size = 4; | |
68 | } else { | |
69 | stream->dnstls_data.validation.data = server->address.in6.s6_addr; | |
70 | stream->dnstls_data.validation.size = 16; | |
71 | } | |
72 | gnutls_session_set_verify_cert2(gs, &stream->dnstls_data.validation, 1, 0); | |
7f2f4fac | 73 | } |
7f2f4fac | 74 | } |
4310bfc2 | 75 | |
2e22a54f GL |
76 | if (server->server_name) { |
77 | r = gnutls_server_name_set(gs, GNUTLS_NAME_DNS, server->server_name, strlen(server->server_name)); | |
78 | if (r < 0) | |
79 | return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to set server name: %s", gnutls_strerror(r)); | |
80 | } | |
81 | ||
6016fcb0 IT |
82 | gnutls_handshake_set_timeout(gs, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT); |
83 | ||
84 | gnutls_transport_set_ptr2(gs, (gnutls_transport_ptr_t) (long) stream->fd, stream); | |
aa892849 | 85 | gnutls_transport_set_vec_push_function(gs, &dnstls_stream_vec_push); |
6016fcb0 IT |
86 | |
87 | stream->encrypted = true; | |
88 | stream->dnstls_data.handshake = gnutls_handshake(gs); | |
89 | if (stream->dnstls_data.handshake < 0 && gnutls_error_is_fatal(stream->dnstls_data.handshake)) | |
90 | return -ECONNREFUSED; | |
91 | ||
92 | stream->dnstls_data.session = TAKE_PTR(gs); | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | void dnstls_stream_free(DnsStream *stream) { | |
98 | assert(stream); | |
99 | assert(stream->encrypted); | |
100 | ||
101 | if (stream->dnstls_data.session) | |
102 | gnutls_deinit(stream->dnstls_data.session); | |
103 | } | |
104 | ||
04c4d919 | 105 | int dnstls_stream_on_io(DnsStream *stream, uint32_t revents) { |
6016fcb0 IT |
106 | int r; |
107 | ||
108 | assert(stream); | |
109 | assert(stream->encrypted); | |
110 | assert(stream->dnstls_data.session); | |
111 | ||
112 | if (stream->dnstls_data.shutdown) { | |
113 | r = gnutls_bye(stream->dnstls_data.session, GNUTLS_SHUT_RDWR); | |
ba6aaf57 IT |
114 | if (r == GNUTLS_E_AGAIN) { |
115 | stream->dnstls_events = gnutls_record_get_direction(stream->dnstls_data.session) == 1 ? EPOLLOUT : EPOLLIN; | |
6016fcb0 | 116 | return -EAGAIN; |
ba6aaf57 | 117 | } else if (r < 0) |
6016fcb0 IT |
118 | log_debug("Failed to invoke gnutls_bye: %s", gnutls_strerror(r)); |
119 | ||
ba6aaf57 | 120 | stream->dnstls_events = 0; |
6016fcb0 IT |
121 | stream->dnstls_data.shutdown = false; |
122 | dns_stream_unref(stream); | |
123 | return DNSTLS_STREAM_CLOSED; | |
124 | } else if (stream->dnstls_data.handshake < 0) { | |
125 | stream->dnstls_data.handshake = gnutls_handshake(stream->dnstls_data.session); | |
ba6aaf57 IT |
126 | if (stream->dnstls_data.handshake == GNUTLS_E_AGAIN) { |
127 | stream->dnstls_events = gnutls_record_get_direction(stream->dnstls_data.session) == 1 ? EPOLLOUT : EPOLLIN; | |
6016fcb0 | 128 | return -EAGAIN; |
ba6aaf57 | 129 | } else if (stream->dnstls_data.handshake < 0) { |
6016fcb0 IT |
130 | log_debug("Failed to invoke gnutls_handshake: %s", gnutls_strerror(stream->dnstls_data.handshake)); |
131 | if (gnutls_error_is_fatal(stream->dnstls_data.handshake)) | |
132 | return -ECONNREFUSED; | |
133 | } | |
ba6aaf57 IT |
134 | |
135 | stream->dnstls_events = 0; | |
6016fcb0 IT |
136 | } |
137 | ||
138 | return 0; | |
139 | } | |
140 | ||
141 | int dnstls_stream_shutdown(DnsStream *stream, int error) { | |
142 | int r; | |
143 | ||
144 | assert(stream); | |
145 | assert(stream->encrypted); | |
146 | assert(stream->dnstls_data.session); | |
147 | ||
5238e957 | 148 | /* Store TLS Ticket for faster successive TLS handshakes */ |
6016fcb0 IT |
149 | if (stream->server && stream->server->dnstls_data.session_data.size == 0 && stream->dnstls_data.handshake == GNUTLS_E_SUCCESS) |
150 | gnutls_session_get_data2(stream->dnstls_data.session, &stream->server->dnstls_data.session_data); | |
151 | ||
152 | if (IN_SET(error, ETIMEDOUT, 0)) { | |
153 | r = gnutls_bye(stream->dnstls_data.session, GNUTLS_SHUT_RDWR); | |
154 | if (r == GNUTLS_E_AGAIN) { | |
155 | if (!stream->dnstls_data.shutdown) { | |
156 | stream->dnstls_data.shutdown = true; | |
157 | dns_stream_ref(stream); | |
158 | return -EAGAIN; | |
159 | } | |
160 | } else if (r < 0) | |
161 | log_debug("Failed to invoke gnutls_bye: %s", gnutls_strerror(r)); | |
162 | } | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
aa892849 | 167 | ssize_t dnstls_stream_writev(DnsStream *stream, const struct iovec *iov, size_t iovcnt) { |
6016fcb0 IT |
168 | ssize_t ss; |
169 | ||
170 | assert(stream); | |
171 | assert(stream->encrypted); | |
172 | assert(stream->dnstls_data.session); | |
aa892849 | 173 | assert(iov); |
c24e0dbe | 174 | assert(iovec_total_size(iov, iovcnt) > 0); |
6016fcb0 | 175 | |
aa892849 JB |
176 | gnutls_record_cork(stream->dnstls_data.session); |
177 | ||
178 | for (size_t i = 0; i < iovcnt; i++) { | |
179 | ss = gnutls_record_send( | |
180 | stream->dnstls_data.session, | |
181 | iov[i].iov_base, iov[i].iov_len); | |
182 | if (ss < 0) | |
183 | break; | |
184 | } | |
185 | ||
186 | ss = gnutls_record_uncork(stream->dnstls_data.session, 0); | |
6016fcb0 | 187 | if (ss < 0) |
79893116 | 188 | switch (ss) { |
6016fcb0 IT |
189 | case GNUTLS_E_INTERRUPTED: |
190 | return -EINTR; | |
191 | case GNUTLS_E_AGAIN: | |
192 | return -EAGAIN; | |
193 | default: | |
baaa35ad ZJS |
194 | return log_debug_errno(SYNTHETIC_ERRNO(EPIPE), |
195 | "Failed to invoke gnutls_record_send: %s", | |
196 | gnutls_strerror(ss)); | |
6016fcb0 IT |
197 | } |
198 | ||
199 | return ss; | |
200 | } | |
201 | ||
202 | ssize_t dnstls_stream_read(DnsStream *stream, void *buf, size_t count) { | |
203 | ssize_t ss; | |
204 | ||
205 | assert(stream); | |
206 | assert(stream->encrypted); | |
207 | assert(stream->dnstls_data.session); | |
208 | assert(buf); | |
209 | ||
210 | ss = gnutls_record_recv(stream->dnstls_data.session, buf, count); | |
211 | if (ss < 0) | |
79893116 | 212 | switch (ss) { |
6016fcb0 IT |
213 | case GNUTLS_E_INTERRUPTED: |
214 | return -EINTR; | |
215 | case GNUTLS_E_AGAIN: | |
216 | return -EAGAIN; | |
217 | default: | |
baaa35ad ZJS |
218 | return log_debug_errno(SYNTHETIC_ERRNO(EPIPE), |
219 | "Failed to invoke gnutls_record_recv: %s", | |
220 | gnutls_strerror(ss)); | |
6016fcb0 IT |
221 | } |
222 | ||
223 | return ss; | |
224 | } | |
225 | ||
e22c5b20 | 226 | void dnstls_server_free(DnsServer *server) { |
6016fcb0 IT |
227 | assert(server); |
228 | ||
e22c5b20 IT |
229 | if (server->dnstls_data.session_data.data) |
230 | gnutls_free(server->dnstls_data.session_data.data); | |
6016fcb0 IT |
231 | } |
232 | ||
71a681ae | 233 | int dnstls_manager_init(Manager *manager) { |
e22c5b20 IT |
234 | int r; |
235 | assert(manager); | |
6016fcb0 | 236 | |
71a681ae | 237 | r = gnutls_certificate_allocate_credentials(&manager->dnstls_data.cert_cred); |
e22c5b20 | 238 | if (r < 0) |
71a681ae IT |
239 | return -ENOMEM; |
240 | ||
4310bfc2 IT |
241 | r = gnutls_certificate_set_x509_system_trust(manager->dnstls_data.cert_cred); |
242 | if (r < 0) | |
243 | log_warning("Failed to load system trust store: %s", gnutls_strerror(r)); | |
244 | ||
71a681ae | 245 | return 0; |
e22c5b20 | 246 | } |
6016fcb0 | 247 | |
e22c5b20 IT |
248 | void dnstls_manager_free(Manager *manager) { |
249 | assert(manager); | |
250 | ||
251 | if (manager->dnstls_data.cert_cred) | |
252 | gnutls_certificate_free_credentials(manager->dnstls_data.cert_cred); | |
6016fcb0 | 253 | } |