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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); |
04c4d919 | 123 | if (r <= 0) { |
096cbdce | 124 | error = SSL_get_error(stream->dnstls_data.ssl, r); |
04c4d919 IT |
125 | if (r == 0 || IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { |
126 | if (r < 0) | |
127 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
128 | ||
129 | r = dnstls_flush_write_buffer(stream); | |
130 | if (r < 0) | |
131 | return r; | |
132 | ||
096cbdce IT |
133 | return -EAGAIN; |
134 | } else { | |
135 | char errbuf[256]; | |
136 | ||
137 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
138 | log_debug("Failed to invoke SSL_shutdown: %s", errbuf); | |
139 | } | |
140 | } | |
141 | ||
04c4d919 IT |
142 | r = dnstls_flush_write_buffer(stream); |
143 | if (r < 0) | |
144 | return r; | |
145 | ||
096cbdce IT |
146 | stream->dnstls_events = 0; |
147 | stream->dnstls_data.shutdown = false; | |
148 | dns_stream_unref(stream); | |
149 | return DNSTLS_STREAM_CLOSED; | |
150 | } else if (stream->dnstls_data.handshake <= 0) { | |
59c3fee2 | 151 | ERR_clear_error(); |
096cbdce IT |
152 | stream->dnstls_data.handshake = SSL_do_handshake(stream->dnstls_data.ssl); |
153 | if (stream->dnstls_data.handshake <= 0) { | |
154 | error = SSL_get_error(stream->dnstls_data.ssl, stream->dnstls_data.handshake); | |
155 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
156 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
157 | r = dnstls_flush_write_buffer(stream); |
158 | if (r < 0) | |
159 | return r; | |
160 | ||
096cbdce IT |
161 | return -EAGAIN; |
162 | } else { | |
163 | char errbuf[256]; | |
164 | ||
165 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
166 | log_debug("Failed to invoke SSL_do_handshake: %s", errbuf); | |
167 | return -ECONNREFUSED; | |
168 | } | |
169 | } | |
170 | ||
171 | stream->dnstls_events = 0; | |
04c4d919 IT |
172 | r = dnstls_flush_write_buffer(stream); |
173 | if (r < 0) | |
174 | return r; | |
096cbdce IT |
175 | } |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
180 | int dnstls_stream_shutdown(DnsStream *stream, int error) { | |
36f1946c | 181 | int ssl_error, r; |
096cbdce IT |
182 | SSL_SESSION *s; |
183 | ||
184 | assert(stream); | |
185 | assert(stream->encrypted); | |
186 | assert(stream->dnstls_data.ssl); | |
187 | ||
04c4d919 IT |
188 | if (stream->server) { |
189 | s = SSL_get1_session(stream->dnstls_data.ssl); | |
190 | if (s) { | |
191 | if (stream->server->dnstls_data.session) | |
192 | SSL_SESSION_free(stream->server->dnstls_data.session); | |
193 | ||
194 | stream->server->dnstls_data.session = s; | |
195 | } | |
196 | } | |
197 | ||
096cbdce | 198 | if (error == ETIMEDOUT) { |
59c3fee2 | 199 | ERR_clear_error(); |
096cbdce IT |
200 | r = SSL_shutdown(stream->dnstls_data.ssl); |
201 | if (r == 0) { | |
202 | if (!stream->dnstls_data.shutdown) { | |
203 | stream->dnstls_data.shutdown = true; | |
204 | dns_stream_ref(stream); | |
205 | } | |
04c4d919 IT |
206 | |
207 | r = dnstls_flush_write_buffer(stream); | |
208 | if (r < 0) | |
209 | return r; | |
210 | ||
096cbdce IT |
211 | return -EAGAIN; |
212 | } else if (r < 0) { | |
213 | ssl_error = SSL_get_error(stream->dnstls_data.ssl, r); | |
214 | if (IN_SET(ssl_error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
215 | stream->dnstls_events = ssl_error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
216 | r = dnstls_flush_write_buffer(stream); |
217 | if (r < 0 && r != -EAGAIN) | |
218 | return r; | |
219 | ||
096cbdce IT |
220 | if (!stream->dnstls_data.shutdown) { |
221 | stream->dnstls_data.shutdown = true; | |
222 | dns_stream_ref(stream); | |
223 | } | |
224 | return -EAGAIN; | |
225 | } else { | |
226 | char errbuf[256]; | |
227 | ||
228 | ERR_error_string_n(ssl_error, errbuf, sizeof(errbuf)); | |
229 | log_debug("Failed to invoke SSL_shutdown: %s", errbuf); | |
230 | } | |
231 | } | |
04c4d919 IT |
232 | |
233 | stream->dnstls_events = 0; | |
234 | r = dnstls_flush_write_buffer(stream); | |
235 | if (r < 0) | |
236 | return r; | |
096cbdce IT |
237 | } |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | ssize_t dnstls_stream_write(DnsStream *stream, const char *buf, size_t count) { | |
36f1946c | 243 | int error, r; |
096cbdce IT |
244 | ssize_t ss; |
245 | ||
246 | assert(stream); | |
247 | assert(stream->encrypted); | |
248 | assert(stream->dnstls_data.ssl); | |
249 | assert(buf); | |
250 | ||
59c3fee2 | 251 | ERR_clear_error(); |
096cbdce IT |
252 | ss = r = SSL_write(stream->dnstls_data.ssl, buf, count); |
253 | if (r <= 0) { | |
254 | error = SSL_get_error(stream->dnstls_data.ssl, ss); | |
255 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
256 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
257 | r = dnstls_flush_write_buffer(stream); |
258 | if (r < 0) | |
259 | return r; | |
260 | ||
096cbdce IT |
261 | ss = -EAGAIN; |
262 | } else { | |
263 | char errbuf[256]; | |
264 | ||
265 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
36f1946c | 266 | log_debug("Failed to invoke SSL_write: %s", errbuf); |
096cbdce IT |
267 | ss = -EPIPE; |
268 | } | |
269 | } | |
270 | ||
271 | stream->dnstls_events = 0; | |
04c4d919 IT |
272 | r = dnstls_flush_write_buffer(stream); |
273 | if (r < 0) | |
274 | return r; | |
275 | ||
096cbdce IT |
276 | return ss; |
277 | } | |
278 | ||
279 | ssize_t dnstls_stream_read(DnsStream *stream, void *buf, size_t count) { | |
36f1946c | 280 | int error, r; |
096cbdce IT |
281 | ssize_t ss; |
282 | ||
283 | assert(stream); | |
284 | assert(stream->encrypted); | |
285 | assert(stream->dnstls_data.ssl); | |
286 | assert(buf); | |
287 | ||
59c3fee2 | 288 | ERR_clear_error(); |
096cbdce IT |
289 | ss = r = SSL_read(stream->dnstls_data.ssl, buf, count); |
290 | if (r <= 0) { | |
291 | error = SSL_get_error(stream->dnstls_data.ssl, ss); | |
292 | if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) { | |
293 | stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT; | |
04c4d919 IT |
294 | |
295 | /* flush write buffer in cache of renegotiation */ | |
296 | r = dnstls_flush_write_buffer(stream); | |
297 | if (r < 0) | |
298 | return r; | |
299 | ||
096cbdce IT |
300 | ss = -EAGAIN; |
301 | } else { | |
302 | char errbuf[256]; | |
303 | ||
304 | ERR_error_string_n(error, errbuf, sizeof(errbuf)); | |
305 | log_debug("Failed to invoke SSL_read: %s", errbuf); | |
306 | ss = -EPIPE; | |
307 | } | |
308 | } | |
309 | ||
310 | stream->dnstls_events = 0; | |
04c4d919 IT |
311 | |
312 | /* flush write buffer in cache of renegotiation */ | |
313 | r = dnstls_flush_write_buffer(stream); | |
314 | if (r < 0) | |
315 | return r; | |
316 | ||
096cbdce IT |
317 | return ss; |
318 | } | |
319 | ||
320 | void dnstls_server_init(DnsServer *server) { | |
321 | assert(server); | |
322 | ||
323 | server->dnstls_data.ctx = SSL_CTX_new(TLS_client_method()); | |
324 | if (server->dnstls_data.ctx) { | |
325 | SSL_CTX_set_min_proto_version(server->dnstls_data.ctx, TLS1_2_VERSION); | |
326 | SSL_CTX_set_options(server->dnstls_data.ctx, SSL_OP_NO_COMPRESSION); | |
327 | } | |
328 | } | |
329 | ||
330 | void dnstls_server_free(DnsServer *server) { | |
331 | assert(server); | |
332 | ||
333 | if (server->dnstls_data.ctx) | |
334 | SSL_CTX_free(server->dnstls_data.ctx); | |
04c4d919 IT |
335 | |
336 | if (server->dnstls_data.session) | |
337 | SSL_SESSION_free(server->dnstls_data.session); | |
096cbdce | 338 | } |