xref: /src/crypto/openssl/include/internal/ktls.h (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #if defined(OPENSSL_SYS_LINUX)
11 #ifndef OPENSSL_NO_KTLS
12 #include <linux/version.h>
13 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0)
14 #define OPENSSL_NO_KTLS
15 #ifndef PEDANTIC
16 #warning "KTLS requires Kernel Headers >= 4.13.0"
17 #warning "Skipping Compilation of KTLS"
18 #endif
19 #endif
20 #endif
21 #endif
22 
23 #ifndef HEADER_INTERNAL_KTLS
24 #define HEADER_INTERNAL_KTLS
25 #pragma once
26 
27 #ifndef OPENSSL_NO_KTLS
28 
29 #if defined(__FreeBSD__)
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/ktls.h>
33 #include <netinet/in.h>
34 #include <netinet/tcp.h>
35 #include <openssl/ssl3.h>
36 
37 #ifndef TCP_RXTLS_ENABLE
38 #define OPENSSL_NO_KTLS_RX
39 #endif
40 #define OPENSSL_KTLS_AES_GCM_128
41 #define OPENSSL_KTLS_AES_GCM_256
42 #define OPENSSL_KTLS_TLS13
43 #ifdef TLS_CHACHA20_IV_LEN
44 #ifndef OPENSSL_NO_CHACHA
45 #define OPENSSL_KTLS_CHACHA20_POLY1305
46 #endif
47 #endif
48 
49 typedef struct tls_enable ktls_crypto_info_t;
50 
51 /*
52  * FreeBSD does not require any additional steps to enable KTLS before
53  * setting keys.
54  */
ktls_enable(int fd)55 static ossl_inline int ktls_enable(int fd)
56 {
57     return 1;
58 }
59 
60 /*
61  * The TCP_TXTLS_ENABLE socket option marks the outgoing socket buffer
62  * as using TLS.  If successful, then data sent using this socket will
63  * be encrypted and encapsulated in TLS records using the tls_en
64  * provided here.
65  *
66  * The TCP_RXTLS_ENABLE socket option marks the incoming socket buffer
67  * as using TLS.  If successful, then data received for this socket will
68  * be authenticated and decrypted using the tls_en provided here.
69  */
ktls_start(int fd,ktls_crypto_info_t * tls_en,int is_tx)70 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *tls_en, int is_tx)
71 {
72     if (is_tx)
73         return setsockopt(fd, IPPROTO_TCP, TCP_TXTLS_ENABLE,
74                    tls_en, sizeof(*tls_en))
75             ? 0
76             : 1;
77 #ifndef OPENSSL_NO_KTLS_RX
78     return setsockopt(fd, IPPROTO_TCP, TCP_RXTLS_ENABLE, tls_en,
79                sizeof(*tls_en))
80         ? 0
81         : 1;
82 #else
83     return 0;
84 #endif
85 }
86 
87 /* Not supported on FreeBSD */
ktls_enable_tx_zerocopy_sendfile(int fd)88 static ossl_inline int ktls_enable_tx_zerocopy_sendfile(int fd)
89 {
90     return 0;
91 }
92 
93 /*
94  * Send a TLS record using the tls_en provided in ktls_start and use
95  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
96  * When the socket is non-blocking, then this call either returns EAGAIN or
97  * the entire record is pushed to TCP. It is impossible to send a partial
98  * record using this control message.
99  */
ktls_send_ctrl_message(int fd,unsigned char record_type,const void * data,size_t length)100 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
101     const void *data, size_t length)
102 {
103     struct msghdr msg = { 0 };
104     int cmsg_len = sizeof(record_type);
105     struct cmsghdr *cmsg;
106     char buf[CMSG_SPACE(cmsg_len)];
107     struct iovec msg_iov; /* Vector of data to send/receive into */
108 
109     msg.msg_control = buf;
110     msg.msg_controllen = sizeof(buf);
111     cmsg = CMSG_FIRSTHDR(&msg);
112     cmsg->cmsg_level = IPPROTO_TCP;
113     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
114     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
115     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
116     msg.msg_controllen = cmsg->cmsg_len;
117 
118     msg_iov.iov_base = (void *)data;
119     msg_iov.iov_len = length;
120     msg.msg_iov = &msg_iov;
121     msg.msg_iovlen = 1;
122 
123     return sendmsg(fd, &msg, 0);
124 }
125 
126 #ifdef OPENSSL_NO_KTLS_RX
127 
ktls_read_record(int fd,void * data,size_t length)128 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
129 {
130     return -1;
131 }
132 
133 #else /* !defined(OPENSSL_NO_KTLS_RX) */
134 
135 /*
136  * Receive a TLS record using the tls_en provided in ktls_start.  The
137  * kernel strips any explicit IV and authentication tag, but provides
138  * the TLS record header via a control message.  If there is an error
139  * with the TLS record such as an invalid header, invalid padding, or
140  * authentication failure recvmsg() will fail with an error.
141  */
ktls_read_record(int fd,void * data,size_t length)142 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
143 {
144     struct msghdr msg = { 0 };
145     int cmsg_len = sizeof(struct tls_get_record);
146     struct tls_get_record *tgr;
147     struct cmsghdr *cmsg;
148     char buf[CMSG_SPACE(cmsg_len)];
149     struct iovec msg_iov; /* Vector of data to send/receive into */
150     int ret;
151     unsigned char *p = data;
152     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
153 
154     if (length <= prepend_length) {
155         errno = EINVAL;
156         return -1;
157     }
158 
159     msg.msg_control = buf;
160     msg.msg_controllen = sizeof(buf);
161 
162     msg_iov.iov_base = p + prepend_length;
163     msg_iov.iov_len = length - prepend_length;
164     msg.msg_iov = &msg_iov;
165     msg.msg_iovlen = 1;
166 
167     ret = recvmsg(fd, &msg, 0);
168     if (ret <= 0)
169         return ret;
170 
171     if ((msg.msg_flags & (MSG_EOR | MSG_CTRUNC)) != MSG_EOR) {
172         errno = EMSGSIZE;
173         return -1;
174     }
175 
176     if (msg.msg_controllen == 0) {
177         errno = EBADMSG;
178         return -1;
179     }
180 
181     cmsg = CMSG_FIRSTHDR(&msg);
182     if (cmsg->cmsg_level != IPPROTO_TCP || cmsg->cmsg_type != TLS_GET_RECORD
183         || cmsg->cmsg_len != CMSG_LEN(cmsg_len)) {
184         errno = EBADMSG;
185         return -1;
186     }
187 
188     tgr = (struct tls_get_record *)CMSG_DATA(cmsg);
189     p[0] = tgr->tls_type;
190     p[1] = tgr->tls_vmajor;
191     p[2] = tgr->tls_vminor;
192     p[3] = (ret >> 8) & 0xff;
193     p[4] = ret & 0xff;
194 
195     return ret + prepend_length;
196 }
197 
198 #endif /* OPENSSL_NO_KTLS_RX */
199 
200 /*
201  * KTLS enables the sendfile system call to send data from a file over
202  * TLS.
203  */
ktls_sendfile(int s,int fd,off_t off,size_t size,int flags)204 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off,
205     size_t size, int flags)
206 {
207     off_t sbytes = 0;
208     int ret;
209 
210     ret = sendfile(fd, s, off, size, NULL, &sbytes, flags);
211     if (ret == -1 && sbytes == 0)
212         return -1;
213     return sbytes;
214 }
215 
216 #endif /* __FreeBSD__ */
217 
218 #if defined(OPENSSL_SYS_LINUX)
219 
220 #include <linux/tls.h>
221 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
222 #define OPENSSL_NO_KTLS_RX
223 #ifndef PEDANTIC
224 #warning "KTLS requires Kernel Headers >= 4.17.0 for receiving"
225 #warning "Skipping Compilation of KTLS receive data path"
226 #endif
227 #endif
228 #if LINUX_VERSION_CODE < KERNEL_VERSION(5, 19, 0)
229 #define OPENSSL_NO_KTLS_ZC_TX
230 #ifndef PEDANTIC
231 #warning "KTLS requires Kernel Headers >= 5.19.0 for zerocopy sendfile"
232 #warning "Skipping Compilation of KTLS zerocopy sendfile"
233 #endif
234 #endif
235 #define OPENSSL_KTLS_AES_GCM_128
236 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
237 #define OPENSSL_KTLS_AES_GCM_256
238 #define OPENSSL_KTLS_TLS13
239 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
240 #define OPENSSL_KTLS_AES_CCM_128
241 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 11, 0)
242 #ifndef OPENSSL_NO_CHACHA
243 #define OPENSSL_KTLS_CHACHA20_POLY1305
244 #endif
245 #endif
246 #endif
247 #endif
248 
249 #include <sys/sendfile.h>
250 #include <netinet/tcp.h>
251 #include <linux/socket.h>
252 #include <openssl/ssl3.h>
253 #include <openssl/tls1.h>
254 #include <openssl/evp.h>
255 
256 #ifndef SOL_TLS
257 #define SOL_TLS 282
258 #endif
259 
260 #ifndef TCP_ULP
261 #define TCP_ULP 31
262 #endif
263 
264 #ifndef TLS_RX
265 #define TLS_RX 2
266 #endif
267 
268 struct tls_crypto_info_all {
269     union {
270 #ifdef OPENSSL_KTLS_AES_GCM_128
271         struct tls12_crypto_info_aes_gcm_128 gcm128;
272 #endif
273 #ifdef OPENSSL_KTLS_AES_GCM_256
274         struct tls12_crypto_info_aes_gcm_256 gcm256;
275 #endif
276 #ifdef OPENSSL_KTLS_AES_CCM_128
277         struct tls12_crypto_info_aes_ccm_128 ccm128;
278 #endif
279 #ifdef OPENSSL_KTLS_CHACHA20_POLY1305
280         struct tls12_crypto_info_chacha20_poly1305 chacha20poly1305;
281 #endif
282     };
283     size_t tls_crypto_info_len;
284 };
285 
286 typedef struct tls_crypto_info_all ktls_crypto_info_t;
287 
288 /*
289  * When successful, this socket option doesn't change the behaviour of the
290  * TCP socket, except changing the TCP setsockopt handler to enable the
291  * processing of SOL_TLS socket options. All other functionality remains the
292  * same.
293  */
ktls_enable(int fd)294 static ossl_inline int ktls_enable(int fd)
295 {
296     return setsockopt(fd, SOL_TCP, TCP_ULP, "tls", sizeof("tls")) ? 0 : 1;
297 }
298 
299 /*
300  * The TLS_TX socket option changes the send/sendmsg handlers of the TCP socket.
301  * If successful, then data sent using this socket will be encrypted and
302  * encapsulated in TLS records using the crypto_info provided here.
303  * The TLS_RX socket option changes the recv/recvmsg handlers of the TCP socket.
304  * If successful, then data received using this socket will be decrypted,
305  * authenticated and decapsulated using the crypto_info provided here.
306  */
ktls_start(int fd,ktls_crypto_info_t * crypto_info,int is_tx)307 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *crypto_info,
308     int is_tx)
309 {
310     /*
311      * Socket must be in TCP established state to enable KTLS.
312      * Further calls to enable ktls will return EEXIST
313      */
314     ktls_enable(fd);
315 
316     return setsockopt(fd, SOL_TLS, is_tx ? TLS_TX : TLS_RX,
317                crypto_info, crypto_info->tls_crypto_info_len)
318         ? 0
319         : 1;
320 }
321 
ktls_enable_tx_zerocopy_sendfile(int fd)322 static ossl_inline int ktls_enable_tx_zerocopy_sendfile(int fd)
323 {
324 #ifndef OPENSSL_NO_KTLS_ZC_TX
325     int enable = 1;
326 
327     return setsockopt(fd, SOL_TLS, TLS_TX_ZEROCOPY_RO,
328                &enable, sizeof(enable))
329         ? 0
330         : 1;
331 #else
332     return 0;
333 #endif
334 }
335 
336 /*
337  * Send a TLS record using the crypto_info provided in ktls_start and use
338  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
339  * When the socket is non-blocking, then this call either returns EAGAIN or
340  * the entire record is pushed to TCP. It is impossible to send a partial
341  * record using this control message.
342  */
ktls_send_ctrl_message(int fd,unsigned char record_type,const void * data,size_t length)343 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
344     const void *data, size_t length)
345 {
346     struct msghdr msg;
347     int cmsg_len = sizeof(record_type);
348     struct cmsghdr *cmsg;
349     union {
350         struct cmsghdr hdr;
351         char buf[CMSG_SPACE(sizeof(unsigned char))];
352     } cmsgbuf;
353     struct iovec msg_iov; /* Vector of data to send/receive into */
354 
355     memset(&msg, 0, sizeof(msg));
356     msg.msg_control = cmsgbuf.buf;
357     msg.msg_controllen = sizeof(cmsgbuf.buf);
358     cmsg = CMSG_FIRSTHDR(&msg);
359     cmsg->cmsg_level = SOL_TLS;
360     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
361     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
362     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
363     msg.msg_controllen = cmsg->cmsg_len;
364 
365     msg_iov.iov_base = (void *)data;
366     msg_iov.iov_len = length;
367     msg.msg_iov = &msg_iov;
368     msg.msg_iovlen = 1;
369 
370     return sendmsg(fd, &msg, 0);
371 }
372 
373 /*
374  * KTLS enables the sendfile system call to send data from a file over TLS.
375  * @flags are ignored on Linux. (placeholder for FreeBSD sendfile)
376  * */
ktls_sendfile(int s,int fd,off_t off,size_t size,int flags)377 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
378 {
379     return sendfile(s, fd, &off, size);
380 }
381 
382 #ifdef OPENSSL_NO_KTLS_RX
383 
ktls_read_record(int fd,void * data,size_t length)384 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
385 {
386     return -1;
387 }
388 
389 #else /* !defined(OPENSSL_NO_KTLS_RX) */
390 
391 /*
392  * Receive a TLS record using the crypto_info provided in ktls_start.
393  * The kernel strips the TLS record header, IV and authentication tag,
394  * returning only the plaintext data or an error on failure.
395  * We add the TLS record header here to satisfy routines in rec_layer_s3.c
396  */
ktls_read_record(int fd,void * data,size_t length)397 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
398 {
399     struct msghdr msg;
400     struct cmsghdr *cmsg;
401     union {
402         struct cmsghdr hdr;
403         char buf[CMSG_SPACE(sizeof(unsigned char))];
404     } cmsgbuf;
405     struct iovec msg_iov;
406     int ret;
407     unsigned char *p = data;
408     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
409 
410     if (length < prepend_length + EVP_GCM_TLS_TAG_LEN) {
411         errno = EINVAL;
412         return -1;
413     }
414 
415     memset(&msg, 0, sizeof(msg));
416     msg.msg_control = cmsgbuf.buf;
417     msg.msg_controllen = sizeof(cmsgbuf.buf);
418 
419     msg_iov.iov_base = p + prepend_length;
420     msg_iov.iov_len = length - prepend_length - EVP_GCM_TLS_TAG_LEN;
421     msg.msg_iov = &msg_iov;
422     msg.msg_iovlen = 1;
423 
424     ret = recvmsg(fd, &msg, 0);
425     if (ret < 0)
426         return ret;
427 
428     if (msg.msg_controllen > 0) {
429         cmsg = CMSG_FIRSTHDR(&msg);
430         if (cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
431             p[0] = *((unsigned char *)CMSG_DATA(cmsg));
432             p[1] = TLS1_2_VERSION_MAJOR;
433             p[2] = TLS1_2_VERSION_MINOR;
434             /* returned length is limited to msg_iov.iov_len above */
435             p[3] = (ret >> 8) & 0xff;
436             p[4] = ret & 0xff;
437             ret += prepend_length;
438         }
439     }
440 
441     return ret;
442 }
443 
444 #endif /* OPENSSL_NO_KTLS_RX */
445 
446 #endif /* OPENSSL_SYS_LINUX */
447 #endif /* OPENSSL_NO_KTLS */
448 #endif /* HEADER_INTERNAL_KTLS */
449