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Commit | Line | Data |
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096cbdce IT |
1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
2 | ||
3 | #if !ENABLE_DNS_OVER_TLS || !DNS_OVER_TLS_USE_OPENSSL | |
4 | #error This source file requires DNS-over-TLS to be enabled and OpenSSL to be available. | |
5 | #endif | |
6 | ||
7 | #include "resolved-dnstls.h" | |
8 | #include "resolved-dns-stream.h" | |
9 | ||
10 | #include <openssl/bio.h> | |
11 | #include <openssl/err.h> | |
12 | ||
13 | DEFINE_TRIVIAL_CLEANUP_FUNC(SSL*, SSL_free); | |
14 | DEFINE_TRIVIAL_CLEANUP_FUNC(BIO*, BIO_free); | |
15 | ||
04c4d919 IT |
16 | static int dnstls_flush_write_buffer(DnsStream *stream) { |
17 | ssize_t ss; | |
18 | ||
19 | assert(stream); | |
20 | assert(stream->encrypted); | |
21 | ||
22 | if (stream->dnstls_data.write_buffer->length > 0) { | |
23 | assert(stream->dnstls_data.write_buffer->data); | |
24 | ||
25 | struct iovec iov[1]; | |
26 | iov[0].iov_base = stream->dnstls_data.write_buffer->data; | |
27 | iov[0].iov_len = stream->dnstls_data.write_buffer->length; | |
28 | ss = dns_stream_writev(stream, iov, 1, DNS_STREAM_WRITE_TLS_DATA); | |
29 | if (ss < 0) { | |
30 | if (ss == -EAGAIN) | |
31 | stream->dnstls_events |= EPOLLOUT; | |
32 | ||
33 | return ss; | |
34 | } else { | |
35 | stream->dnstls_data.write_buffer->length -= ss; | |
36 | stream->dnstls_data.write_buffer->data += ss; | |
37 | ||
38 | if (stream->dnstls_data.write_buffer->length > 0) { | |
39 | stream->dnstls_events |= EPOLLOUT; | |
40 | return -EAGAIN; | |
41 | } | |
42 | } | |
43 | } | |
44 | ||
45 | return 0; | |
46 | } | |
47 | ||
096cbdce | 48 | int dnstls_stream_connect_tls(DnsStream *stream, DnsServer *server) { |
36f1946c | 49 | _cleanup_(BIO_freep) BIO *rb = NULL, *wb = NULL; |
096cbdce | 50 | _cleanup_(SSL_freep) SSL *s = NULL; |
36f1946c | 51 | int error, r; |
096cbdce IT |
52 | |
53 | assert(stream); | |
54 | assert(server); | |
55 | ||
04c4d919 IT |
56 | rb = BIO_new_socket(stream->fd, 0); |
57 | if (!rb) | |
58 | return -ENOMEM; | |
59 | ||
60 | wb = BIO_new(BIO_s_mem()); | |
61 | if (!wb) | |
096cbdce IT |
62 | return -ENOMEM; |
63 | ||
04c4d919 IT |
64 | BIO_get_mem_ptr(wb, &stream->dnstls_data.write_buffer); |
65 | ||
096cbdce IT |
66 | s = SSL_new(server->dnstls_data.ctx); |
67 | if (!s) | |
68 | return -ENOMEM; | |
69 | ||
70 | SSL_set_connect_state(s); | |
04c4d919 IT |
71 | SSL_set_session(s, server->dnstls_data.session); |
72 | SSL_set_bio(s, TAKE_PTR(rb), TAKE_PTR(wb)); | |
73 | ||
59c3fee2 | 74 | ERR_clear_error(); |
04c4d919 IT |
75 | stream->dnstls_data.handshake = SSL_do_handshake(s); |
76 | if (stream->dnstls_data.handshake <= 0) { | |
77 | error = SSL_get_error(s, stream->dnstls_data.handshake); | |
78 | if (!IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
79 | char errbuf[256]; | |
096cbdce | 80 | |
04c4d919 IT |
81 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); |
82 | log_debug("Failed to invoke SSL_do_handshake: %s", errbuf); | |
83 | return -ECONNREFUSED; | |
84 | } | |
85 | } | |
096cbdce IT |
86 | |
87 | stream->encrypted = true; | |
04c4d919 IT |
88 | |
89 | r = dnstls_flush_write_buffer(stream); | |
90 | if (r < 0 && r != -EAGAIN) | |
91 | return r; | |
92 | ||
096cbdce IT |
93 | stream->dnstls_data.ssl = TAKE_PTR(s); |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | void dnstls_stream_free(DnsStream *stream) { | |
99 | assert(stream); | |
100 | assert(stream->encrypted); | |
101 | ||
102 | if (stream->dnstls_data.ssl) | |
103 | SSL_free(stream->dnstls_data.ssl); | |
104 | } | |
105 | ||
04c4d919 | 106 | int dnstls_stream_on_io(DnsStream *stream, uint32_t revents) { |
36f1946c | 107 | int error, r; |
096cbdce IT |
108 | |
109 | assert(stream); | |
110 | assert(stream->encrypted); | |
111 | assert(stream->dnstls_data.ssl); | |
112 | ||
36f1946c | 113 | /* Flush write buffer when requested by OpenSSL */ |
04c4d919 IT |
114 | if ((revents & EPOLLOUT) && (stream->dnstls_events & EPOLLOUT)) { |
115 | r = dnstls_flush_write_buffer(stream); | |
116 | if (r < 0) | |
117 | return r; | |
118 | } | |
119 | ||
096cbdce | 120 | if (stream->dnstls_data.shutdown) { |
59c3fee2 | 121 | ERR_clear_error(); |
096cbdce | 122 | r = SSL_shutdown(stream->dnstls_data.ssl); |
8eadd291 YW |
123 | if (r == 0) { |
124 | stream->dnstls_events = 0; | |
125 | ||
126 | r = dnstls_flush_write_buffer(stream); | |
127 | if (r < 0) | |
128 | return r; | |
129 | ||
130 | return -EAGAIN; | |
131 | } else if (r < 0) { | |
096cbdce | 132 | error = SSL_get_error(stream->dnstls_data.ssl, r); |
8eadd291 YW |
133 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { |
134 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
135 | |
136 | r = dnstls_flush_write_buffer(stream); | |
137 | if (r < 0) | |
138 | return r; | |
139 | ||
096cbdce | 140 | return -EAGAIN; |
8eadd291 YW |
141 | } else if (error == SSL_ERROR_SYSCALL) { |
142 | if (errno > 0) | |
143 | log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m"); | |
096cbdce IT |
144 | } else { |
145 | char errbuf[256]; | |
146 | ||
147 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
8eadd291 | 148 | log_debug("Failed to invoke SSL_shutdown, ignoring: %s", errbuf); |
096cbdce IT |
149 | } |
150 | } | |
151 | ||
8eadd291 YW |
152 | stream->dnstls_events = 0; |
153 | stream->dnstls_data.shutdown = false; | |
154 | ||
04c4d919 IT |
155 | r = dnstls_flush_write_buffer(stream); |
156 | if (r < 0) | |
157 | return r; | |
158 | ||
096cbdce IT |
159 | dns_stream_unref(stream); |
160 | return DNSTLS_STREAM_CLOSED; | |
161 | } else if (stream->dnstls_data.handshake <= 0) { | |
59c3fee2 | 162 | ERR_clear_error(); |
096cbdce IT |
163 | stream->dnstls_data.handshake = SSL_do_handshake(stream->dnstls_data.ssl); |
164 | if (stream->dnstls_data.handshake <= 0) { | |
165 | error = SSL_get_error(stream->dnstls_data.ssl, stream->dnstls_data.handshake); | |
166 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
167 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
168 | r = dnstls_flush_write_buffer(stream); |
169 | if (r < 0) | |
170 | return r; | |
171 | ||
096cbdce IT |
172 | return -EAGAIN; |
173 | } else { | |
174 | char errbuf[256]; | |
175 | ||
176 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
177 | log_debug("Failed to invoke SSL_do_handshake: %s", errbuf); | |
178 | return -ECONNREFUSED; | |
179 | } | |
180 | } | |
181 | ||
182 | stream->dnstls_events = 0; | |
04c4d919 IT |
183 | r = dnstls_flush_write_buffer(stream); |
184 | if (r < 0) | |
185 | return r; | |
096cbdce IT |
186 | } |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | int dnstls_stream_shutdown(DnsStream *stream, int error) { | |
36f1946c | 192 | int ssl_error, r; |
096cbdce IT |
193 | SSL_SESSION *s; |
194 | ||
195 | assert(stream); | |
196 | assert(stream->encrypted); | |
197 | assert(stream->dnstls_data.ssl); | |
198 | ||
04c4d919 IT |
199 | if (stream->server) { |
200 | s = SSL_get1_session(stream->dnstls_data.ssl); | |
201 | if (s) { | |
202 | if (stream->server->dnstls_data.session) | |
203 | SSL_SESSION_free(stream->server->dnstls_data.session); | |
204 | ||
205 | stream->server->dnstls_data.session = s; | |
206 | } | |
207 | } | |
208 | ||
096cbdce | 209 | if (error == ETIMEDOUT) { |
59c3fee2 | 210 | ERR_clear_error(); |
096cbdce IT |
211 | r = SSL_shutdown(stream->dnstls_data.ssl); |
212 | if (r == 0) { | |
213 | if (!stream->dnstls_data.shutdown) { | |
214 | stream->dnstls_data.shutdown = true; | |
215 | dns_stream_ref(stream); | |
216 | } | |
04c4d919 | 217 | |
8eadd291 YW |
218 | stream->dnstls_events = 0; |
219 | ||
04c4d919 IT |
220 | r = dnstls_flush_write_buffer(stream); |
221 | if (r < 0) | |
222 | return r; | |
223 | ||
096cbdce IT |
224 | return -EAGAIN; |
225 | } else if (r < 0) { | |
226 | ssl_error = SSL_get_error(stream->dnstls_data.ssl, r); | |
227 | if (IN_SET(ssl_error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
228 | stream->dnstls_events = ssl_error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
229 | r = dnstls_flush_write_buffer(stream); |
230 | if (r < 0 && r != -EAGAIN) | |
231 | return r; | |
232 | ||
096cbdce IT |
233 | if (!stream->dnstls_data.shutdown) { |
234 | stream->dnstls_data.shutdown = true; | |
235 | dns_stream_ref(stream); | |
236 | } | |
237 | return -EAGAIN; | |
8eadd291 YW |
238 | } else if (ssl_error == SSL_ERROR_SYSCALL) { |
239 | if (errno > 0) | |
240 | log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m"); | |
096cbdce IT |
241 | } else { |
242 | char errbuf[256]; | |
243 | ||
244 | ERR_error_string_n(ssl_error, errbuf, sizeof(errbuf)); | |
8eadd291 | 245 | log_debug("Failed to invoke SSL_shutdown, ignoring: %s", errbuf); |
096cbdce IT |
246 | } |
247 | } | |
04c4d919 IT |
248 | |
249 | stream->dnstls_events = 0; | |
250 | r = dnstls_flush_write_buffer(stream); | |
251 | if (r < 0) | |
252 | return r; | |
096cbdce IT |
253 | } |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | ssize_t dnstls_stream_write(DnsStream *stream, const char *buf, size_t count) { | |
36f1946c | 259 | int error, r; |
096cbdce IT |
260 | ssize_t ss; |
261 | ||
262 | assert(stream); | |
263 | assert(stream->encrypted); | |
264 | assert(stream->dnstls_data.ssl); | |
265 | assert(buf); | |
266 | ||
59c3fee2 | 267 | ERR_clear_error(); |
096cbdce IT |
268 | ss = r = SSL_write(stream->dnstls_data.ssl, buf, count); |
269 | if (r <= 0) { | |
8e740110 | 270 | error = SSL_get_error(stream->dnstls_data.ssl, r); |
096cbdce IT |
271 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { |
272 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
273 | ss = -EAGAIN; | |
8e740110 YW |
274 | } else if (error == SSL_ERROR_ZERO_RETURN) { |
275 | stream->dnstls_events = 0; | |
276 | ss = 0; | |
096cbdce IT |
277 | } else { |
278 | char errbuf[256]; | |
279 | ||
280 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
36f1946c | 281 | log_debug("Failed to invoke SSL_write: %s", errbuf); |
8e740110 | 282 | stream->dnstls_events = 0; |
096cbdce IT |
283 | ss = -EPIPE; |
284 | } | |
8e740110 YW |
285 | } else |
286 | stream->dnstls_events = 0; | |
096cbdce | 287 | |
04c4d919 IT |
288 | r = dnstls_flush_write_buffer(stream); |
289 | if (r < 0) | |
290 | return r; | |
291 | ||
096cbdce IT |
292 | return ss; |
293 | } | |
294 | ||
295 | ssize_t dnstls_stream_read(DnsStream *stream, void *buf, size_t count) { | |
36f1946c | 296 | int error, r; |
096cbdce IT |
297 | ssize_t ss; |
298 | ||
299 | assert(stream); | |
300 | assert(stream->encrypted); | |
301 | assert(stream->dnstls_data.ssl); | |
302 | assert(buf); | |
303 | ||
59c3fee2 | 304 | ERR_clear_error(); |
096cbdce IT |
305 | ss = r = SSL_read(stream->dnstls_data.ssl, buf, count); |
306 | if (r <= 0) { | |
8e740110 | 307 | error = SSL_get_error(stream->dnstls_data.ssl, r); |
096cbdce IT |
308 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { |
309 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
310 | ss = -EAGAIN; | |
8e740110 YW |
311 | } else if (error == SSL_ERROR_ZERO_RETURN) { |
312 | stream->dnstls_events = 0; | |
313 | ss = 0; | |
096cbdce IT |
314 | } else { |
315 | char errbuf[256]; | |
316 | ||
317 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
318 | log_debug("Failed to invoke SSL_read: %s", errbuf); | |
8e740110 | 319 | stream->dnstls_events = 0; |
096cbdce IT |
320 | ss = -EPIPE; |
321 | } | |
8e740110 YW |
322 | } else |
323 | stream->dnstls_events = 0; | |
04c4d919 IT |
324 | |
325 | /* flush write buffer in cache of renegotiation */ | |
326 | r = dnstls_flush_write_buffer(stream); | |
327 | if (r < 0) | |
328 | return r; | |
329 | ||
096cbdce IT |
330 | return ss; |
331 | } | |
332 | ||
333 | void dnstls_server_init(DnsServer *server) { | |
334 | assert(server); | |
335 | ||
336 | server->dnstls_data.ctx = SSL_CTX_new(TLS_client_method()); | |
337 | if (server->dnstls_data.ctx) { | |
338 | SSL_CTX_set_min_proto_version(server->dnstls_data.ctx, TLS1_2_VERSION); | |
339 | SSL_CTX_set_options(server->dnstls_data.ctx, SSL_OP_NO_COMPRESSION); | |
340 | } | |
341 | } | |
342 | ||
343 | void dnstls_server_free(DnsServer *server) { | |
344 | assert(server); | |
345 | ||
346 | if (server->dnstls_data.ctx) | |
347 | SSL_CTX_free(server->dnstls_data.ctx); | |
04c4d919 IT |
348 | |
349 | if (server->dnstls_data.session) | |
350 | SSL_SESSION_free(server->dnstls_data.session); | |
096cbdce | 351 | } |