xref: /freebsd/crypto/openssl/include/internal/ktls.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright 2018 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 # ifndef OPENSSL_NO_KTLS
26 
27 #  if defined(__FreeBSD__)
28 #   include <sys/types.h>
29 #   include <sys/socket.h>
30 #   include <sys/ktls.h>
31 #   include <netinet/in.h>
32 #   include <netinet/tcp.h>
33 #   include "openssl/ssl3.h"
34 
35 #   ifndef TCP_RXTLS_ENABLE
36 #    define OPENSSL_NO_KTLS_RX
37 #   endif
38 #   define OPENSSL_KTLS_AES_GCM_128
39 #   define OPENSSL_KTLS_AES_GCM_256
40 #   define OPENSSL_KTLS_TLS13
41 
42 /*
43  * Only used by the tests in sslapitest.c.
44  */
45 #   define TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE             8
46 #   define TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE             8
47 
48 typedef struct tls_enable ktls_crypto_info_t;
49 
50 /*
51  * FreeBSD does not require any additional steps to enable KTLS before
52  * setting keys.
53  */
54 static ossl_inline int ktls_enable(int fd)
55 {
56     return 1;
57 }
58 
59 /*
60  * The TCP_TXTLS_ENABLE socket option marks the outgoing socket buffer
61  * as using TLS.  If successful, then data sent using this socket will
62  * be encrypted and encapsulated in TLS records using the tls_en
63  * provided here.
64  *
65  * The TCP_RXTLS_ENABLE socket option marks the incoming socket buffer
66  * as using TLS.  If successful, then data received for this socket will
67  * be authenticated and decrypted using the tls_en provided here.
68  */
69 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *tls_en, int is_tx)
70 {
71     if (is_tx)
72         return setsockopt(fd, IPPROTO_TCP, TCP_TXTLS_ENABLE,
73                           tls_en, sizeof(*tls_en)) ? 0 : 1;
74 #   ifndef OPENSSL_NO_KTLS_RX
75     return setsockopt(fd, IPPROTO_TCP, TCP_RXTLS_ENABLE, tls_en,
76                       sizeof(*tls_en)) ? 0 : 1;
77 #   else
78     return 0;
79 #   endif
80 }
81 
82 /*
83  * Send a TLS record using the tls_en provided in ktls_start and use
84  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
85  * When the socket is non-blocking, then this call either returns EAGAIN or
86  * the entire record is pushed to TCP. It is impossible to send a partial
87  * record using this control message.
88  */
89 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
90                                               const void *data, size_t length)
91 {
92     struct msghdr msg = { 0 };
93     int cmsg_len = sizeof(record_type);
94     struct cmsghdr *cmsg;
95     char buf[CMSG_SPACE(cmsg_len)];
96     struct iovec msg_iov;   /* Vector of data to send/receive into */
97 
98     msg.msg_control = buf;
99     msg.msg_controllen = sizeof(buf);
100     cmsg = CMSG_FIRSTHDR(&msg);
101     cmsg->cmsg_level = IPPROTO_TCP;
102     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
103     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
104     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
105     msg.msg_controllen = cmsg->cmsg_len;
106 
107     msg_iov.iov_base = (void *)data;
108     msg_iov.iov_len = length;
109     msg.msg_iov = &msg_iov;
110     msg.msg_iovlen = 1;
111 
112     return sendmsg(fd, &msg, 0);
113 }
114 
115 #   ifdef OPENSSL_NO_KTLS_RX
116 
117 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
118 {
119     return -1;
120 }
121 
122 #   else /* !defined(OPENSSL_NO_KTLS_RX) */
123 
124 /*
125  * Receive a TLS record using the tls_en provided in ktls_start.  The
126  * kernel strips any explicit IV and authentication tag, but provides
127  * the TLS record header via a control message.  If there is an error
128  * with the TLS record such as an invalid header, invalid padding, or
129  * authentication failure recvmsg() will fail with an error.
130  */
131 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
132 {
133     struct msghdr msg = { 0 };
134     int cmsg_len = sizeof(struct tls_get_record);
135     struct tls_get_record *tgr;
136     struct cmsghdr *cmsg;
137     char buf[CMSG_SPACE(cmsg_len)];
138     struct iovec msg_iov;   /* Vector of data to send/receive into */
139     int ret;
140     unsigned char *p = data;
141     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
142 
143     if (length <= prepend_length) {
144         errno = EINVAL;
145         return -1;
146     }
147 
148     msg.msg_control = buf;
149     msg.msg_controllen = sizeof(buf);
150 
151     msg_iov.iov_base = p + prepend_length;
152     msg_iov.iov_len = length - prepend_length;
153     msg.msg_iov = &msg_iov;
154     msg.msg_iovlen = 1;
155 
156     ret = recvmsg(fd, &msg, 0);
157     if (ret <= 0)
158         return ret;
159 
160     if ((msg.msg_flags & (MSG_EOR | MSG_CTRUNC)) != MSG_EOR) {
161         errno = EMSGSIZE;
162         return -1;
163     }
164 
165     if (msg.msg_controllen == 0) {
166         errno = EBADMSG;
167         return -1;
168     }
169 
170     cmsg = CMSG_FIRSTHDR(&msg);
171     if (cmsg->cmsg_level != IPPROTO_TCP || cmsg->cmsg_type != TLS_GET_RECORD
172         || cmsg->cmsg_len != CMSG_LEN(cmsg_len)) {
173         errno = EBADMSG;
174         return -1;
175     }
176 
177     tgr = (struct tls_get_record *)CMSG_DATA(cmsg);
178     p[0] = tgr->tls_type;
179     p[1] = tgr->tls_vmajor;
180     p[2] = tgr->tls_vminor;
181     *(uint16_t *)(p + 3) = htons(ret);
182 
183     return ret + prepend_length;
184 }
185 
186 #   endif /* OPENSSL_NO_KTLS_RX */
187 
188 /*
189  * KTLS enables the sendfile system call to send data from a file over
190  * TLS.
191  */
192 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off,
193                                               size_t size, int flags)
194 {
195     off_t sbytes = 0;
196     int ret;
197 
198     ret = sendfile(fd, s, off, size, NULL, &sbytes, flags);
199     if (ret == -1 && sbytes == 0)
200         return -1;
201     return sbytes;
202 }
203 
204 #  endif                         /* __FreeBSD__ */
205 
206 #  if defined(OPENSSL_SYS_LINUX)
207 
208 #   include <linux/tls.h>
209 #   if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
210 #    define OPENSSL_NO_KTLS_RX
211 #    ifndef PEDANTIC
212 #     warning "KTLS requires Kernel Headers >= 4.17.0 for receiving"
213 #     warning "Skipping Compilation of KTLS receive data path"
214 #    endif
215 #   endif
216 #   define OPENSSL_KTLS_AES_GCM_128
217 #   if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
218 #    define OPENSSL_KTLS_AES_GCM_256
219 #    define OPENSSL_KTLS_TLS13
220 #    if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
221 #     define OPENSSL_KTLS_AES_CCM_128
222 #    endif
223 #   endif
224 
225 #   include <sys/sendfile.h>
226 #   include <netinet/tcp.h>
227 #   include <linux/socket.h>
228 #   include "openssl/ssl3.h"
229 #   include "openssl/tls1.h"
230 #   include "openssl/evp.h"
231 
232 #   ifndef SOL_TLS
233 #    define SOL_TLS 282
234 #   endif
235 
236 #   ifndef TCP_ULP
237 #    define TCP_ULP 31
238 #   endif
239 
240 #   ifndef TLS_RX
241 #    define TLS_RX                  2
242 #   endif
243 
244 struct tls_crypto_info_all {
245     union {
246 #   ifdef OPENSSL_KTLS_AES_GCM_128
247         struct tls12_crypto_info_aes_gcm_128 gcm128;
248 #   endif
249 #   ifdef OPENSSL_KTLS_AES_GCM_256
250         struct tls12_crypto_info_aes_gcm_256 gcm256;
251 #   endif
252 #   ifdef OPENSSL_KTLS_AES_CCM_128
253         struct tls12_crypto_info_aes_ccm_128 ccm128;
254 #   endif
255     };
256     size_t tls_crypto_info_len;
257 };
258 
259 typedef struct tls_crypto_info_all ktls_crypto_info_t;
260 
261 /*
262  * When successful, this socket option doesn't change the behaviour of the
263  * TCP socket, except changing the TCP setsockopt handler to enable the
264  * processing of SOL_TLS socket options. All other functionality remains the
265  * same.
266  */
267 static ossl_inline int ktls_enable(int fd)
268 {
269     return setsockopt(fd, SOL_TCP, TCP_ULP, "tls", sizeof("tls")) ? 0 : 1;
270 }
271 
272 /*
273  * The TLS_TX socket option changes the send/sendmsg handlers of the TCP socket.
274  * If successful, then data sent using this socket will be encrypted and
275  * encapsulated in TLS records using the crypto_info provided here.
276  * The TLS_RX socket option changes the recv/recvmsg handlers of the TCP socket.
277  * If successful, then data received using this socket will be decrypted,
278  * authenticated and decapsulated using the crypto_info provided here.
279  */
280 static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *crypto_info,
281                                   int is_tx)
282 {
283     return setsockopt(fd, SOL_TLS, is_tx ? TLS_TX : TLS_RX,
284                       crypto_info, crypto_info->tls_crypto_info_len) ? 0 : 1;
285 }
286 
287 /*
288  * Send a TLS record using the crypto_info provided in ktls_start and use
289  * record_type instead of the default SSL3_RT_APPLICATION_DATA.
290  * When the socket is non-blocking, then this call either returns EAGAIN or
291  * the entire record is pushed to TCP. It is impossible to send a partial
292  * record using this control message.
293  */
294 static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
295                                               const void *data, size_t length)
296 {
297     struct msghdr msg;
298     int cmsg_len = sizeof(record_type);
299     struct cmsghdr *cmsg;
300     union {
301         struct cmsghdr hdr;
302         char buf[CMSG_SPACE(sizeof(unsigned char))];
303     } cmsgbuf;
304     struct iovec msg_iov;       /* Vector of data to send/receive into */
305 
306     memset(&msg, 0, sizeof(msg));
307     msg.msg_control = cmsgbuf.buf;
308     msg.msg_controllen = sizeof(cmsgbuf.buf);
309     cmsg = CMSG_FIRSTHDR(&msg);
310     cmsg->cmsg_level = SOL_TLS;
311     cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
312     cmsg->cmsg_len = CMSG_LEN(cmsg_len);
313     *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
314     msg.msg_controllen = cmsg->cmsg_len;
315 
316     msg_iov.iov_base = (void *)data;
317     msg_iov.iov_len = length;
318     msg.msg_iov = &msg_iov;
319     msg.msg_iovlen = 1;
320 
321     return sendmsg(fd, &msg, 0);
322 }
323 
324 /*
325  * KTLS enables the sendfile system call to send data from a file over TLS.
326  * @flags are ignored on Linux. (placeholder for FreeBSD sendfile)
327  * */
328 static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
329 {
330     return sendfile(s, fd, &off, size);
331 }
332 
333 #   ifdef OPENSSL_NO_KTLS_RX
334 
335 
336 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
337 {
338     return -1;
339 }
340 
341 #   else /* !defined(OPENSSL_NO_KTLS_RX) */
342 
343 /*
344  * Receive a TLS record using the crypto_info provided in ktls_start.
345  * The kernel strips the TLS record header, IV and authentication tag,
346  * returning only the plaintext data or an error on failure.
347  * We add the TLS record header here to satisfy routines in rec_layer_s3.c
348  */
349 static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
350 {
351     struct msghdr msg;
352     struct cmsghdr *cmsg;
353     union {
354         struct cmsghdr hdr;
355         char buf[CMSG_SPACE(sizeof(unsigned char))];
356     } cmsgbuf;
357     struct iovec msg_iov;
358     int ret;
359     unsigned char *p = data;
360     const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
361 
362     if (length < prepend_length + EVP_GCM_TLS_TAG_LEN) {
363         errno = EINVAL;
364         return -1;
365     }
366 
367     memset(&msg, 0, sizeof(msg));
368     msg.msg_control = cmsgbuf.buf;
369     msg.msg_controllen = sizeof(cmsgbuf.buf);
370 
371     msg_iov.iov_base = p + prepend_length;
372     msg_iov.iov_len = length - prepend_length - EVP_GCM_TLS_TAG_LEN;
373     msg.msg_iov = &msg_iov;
374     msg.msg_iovlen = 1;
375 
376     ret = recvmsg(fd, &msg, 0);
377     if (ret < 0)
378         return ret;
379 
380     if (msg.msg_controllen > 0) {
381         cmsg = CMSG_FIRSTHDR(&msg);
382         if (cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
383             p[0] = *((unsigned char *)CMSG_DATA(cmsg));
384             p[1] = TLS1_2_VERSION_MAJOR;
385             p[2] = TLS1_2_VERSION_MINOR;
386             /* returned length is limited to msg_iov.iov_len above */
387             p[3] = (ret >> 8) & 0xff;
388             p[4] = ret & 0xff;
389             ret += prepend_length;
390         }
391     }
392 
393     return ret;
394 }
395 
396 #   endif /* OPENSSL_NO_KTLS_RX */
397 
398 #  endif /* OPENSSL_SYS_LINUX */
399 # endif /* OPENSSL_NO_KTLS */
400 #endif /* HEADER_INTERNAL_KTLS */
401