1/*
2 * Copyright 2018-2021 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
44typedef struct tls_enable ktls_crypto_info_t;
45
46/*
47 * FreeBSD does not require any additional steps to enable KTLS before
48 * setting keys.
49 */
50static ossl_inline int ktls_enable(int fd)
51{
52    return 1;
53}
54
55/*
56 * The TCP_TXTLS_ENABLE socket option marks the outgoing socket buffer
57 * as using TLS.  If successful, then data sent using this socket will
58 * be encrypted and encapsulated in TLS records using the tls_en
59 * provided here.
60 *
61 * The TCP_RXTLS_ENABLE socket option marks the incoming socket buffer
62 * as using TLS.  If successful, then data received for this socket will
63 * be authenticated and decrypted using the tls_en provided here.
64 */
65static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *tls_en, int is_tx)
66{
67    if (is_tx)
68        return setsockopt(fd, IPPROTO_TCP, TCP_TXTLS_ENABLE,
69                          tls_en, sizeof(*tls_en)) ? 0 : 1;
70#   ifndef OPENSSL_NO_KTLS_RX
71    return setsockopt(fd, IPPROTO_TCP, TCP_RXTLS_ENABLE, tls_en,
72                      sizeof(*tls_en)) ? 0 : 1;
73#   else
74    return 0;
75#   endif
76}
77
78/*
79 * Send a TLS record using the tls_en provided in ktls_start and use
80 * record_type instead of the default SSL3_RT_APPLICATION_DATA.
81 * When the socket is non-blocking, then this call either returns EAGAIN or
82 * the entire record is pushed to TCP. It is impossible to send a partial
83 * record using this control message.
84 */
85static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
86                                              const void *data, size_t length)
87{
88    struct msghdr msg = { 0 };
89    int cmsg_len = sizeof(record_type);
90    struct cmsghdr *cmsg;
91    char buf[CMSG_SPACE(cmsg_len)];
92    struct iovec msg_iov;   /* Vector of data to send/receive into */
93
94    msg.msg_control = buf;
95    msg.msg_controllen = sizeof(buf);
96    cmsg = CMSG_FIRSTHDR(&msg);
97    cmsg->cmsg_level = IPPROTO_TCP;
98    cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
99    cmsg->cmsg_len = CMSG_LEN(cmsg_len);
100    *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
101    msg.msg_controllen = cmsg->cmsg_len;
102
103    msg_iov.iov_base = (void *)data;
104    msg_iov.iov_len = length;
105    msg.msg_iov = &msg_iov;
106    msg.msg_iovlen = 1;
107
108    return sendmsg(fd, &msg, 0);
109}
110
111#   ifdef OPENSSL_NO_KTLS_RX
112
113static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
114{
115    return -1;
116}
117
118#   else /* !defined(OPENSSL_NO_KTLS_RX) */
119
120/*
121 * Receive a TLS record using the tls_en provided in ktls_start.  The
122 * kernel strips any explicit IV and authentication tag, but provides
123 * the TLS record header via a control message.  If there is an error
124 * with the TLS record such as an invalid header, invalid padding, or
125 * authentication failure recvmsg() will fail with an error.
126 */
127static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
128{
129    struct msghdr msg = { 0 };
130    int cmsg_len = sizeof(struct tls_get_record);
131    struct tls_get_record *tgr;
132    struct cmsghdr *cmsg;
133    char buf[CMSG_SPACE(cmsg_len)];
134    struct iovec msg_iov;   /* Vector of data to send/receive into */
135    int ret;
136    unsigned char *p = data;
137    const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
138
139    if (length <= prepend_length) {
140        errno = EINVAL;
141        return -1;
142    }
143
144    msg.msg_control = buf;
145    msg.msg_controllen = sizeof(buf);
146
147    msg_iov.iov_base = p + prepend_length;
148    msg_iov.iov_len = length - prepend_length;
149    msg.msg_iov = &msg_iov;
150    msg.msg_iovlen = 1;
151
152    ret = recvmsg(fd, &msg, 0);
153    if (ret <= 0)
154        return ret;
155
156    if ((msg.msg_flags & (MSG_EOR | MSG_CTRUNC)) != MSG_EOR) {
157        errno = EMSGSIZE;
158        return -1;
159    }
160
161    if (msg.msg_controllen == 0) {
162        errno = EBADMSG;
163        return -1;
164    }
165
166    cmsg = CMSG_FIRSTHDR(&msg);
167    if (cmsg->cmsg_level != IPPROTO_TCP || cmsg->cmsg_type != TLS_GET_RECORD
168        || cmsg->cmsg_len != CMSG_LEN(cmsg_len)) {
169        errno = EBADMSG;
170        return -1;
171    }
172
173    tgr = (struct tls_get_record *)CMSG_DATA(cmsg);
174    p[0] = tgr->tls_type;
175    p[1] = tgr->tls_vmajor;
176    p[2] = tgr->tls_vminor;
177    *(uint16_t *)(p + 3) = htons(ret);
178
179    return ret + prepend_length;
180}
181
182#   endif /* OPENSSL_NO_KTLS_RX */
183
184/*
185 * KTLS enables the sendfile system call to send data from a file over
186 * TLS.
187 */
188static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off,
189                                              size_t size, int flags)
190{
191    off_t sbytes = 0;
192    int ret;
193
194    ret = sendfile(fd, s, off, size, NULL, &sbytes, flags);
195    if (ret == -1 && sbytes == 0)
196        return -1;
197    return sbytes;
198}
199
200#  endif                         /* __FreeBSD__ */
201
202#  if defined(OPENSSL_SYS_LINUX)
203
204#   include <linux/tls.h>
205#   if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
206#    define OPENSSL_NO_KTLS_RX
207#    ifndef PEDANTIC
208#     warning "KTLS requires Kernel Headers >= 4.17.0 for receiving"
209#     warning "Skipping Compilation of KTLS receive data path"
210#    endif
211#   endif
212#   define OPENSSL_KTLS_AES_GCM_128
213#   if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
214#    define OPENSSL_KTLS_AES_GCM_256
215#    define OPENSSL_KTLS_TLS13
216#    if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
217#     define OPENSSL_KTLS_AES_CCM_128
218#     if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 11, 0)
219#      ifndef OPENSSL_NO_CHACHA
220#       define OPENSSL_KTLS_CHACHA20_POLY1305
221#      endif
222#     endif
223#    endif
224#   endif
225
226#   include <sys/sendfile.h>
227#   include <netinet/tcp.h>
228#   include <linux/socket.h>
229#   include <openssl/ssl3.h>
230#   include <openssl/tls1.h>
231#   include <openssl/evp.h>
232
233#   ifndef SOL_TLS
234#    define SOL_TLS 282
235#   endif
236
237#   ifndef TCP_ULP
238#    define TCP_ULP 31
239#   endif
240
241#   ifndef TLS_RX
242#    define TLS_RX                  2
243#   endif
244
245struct tls_crypto_info_all {
246    union {
247#   ifdef OPENSSL_KTLS_AES_GCM_128
248        struct tls12_crypto_info_aes_gcm_128 gcm128;
249#   endif
250#   ifdef OPENSSL_KTLS_AES_GCM_256
251        struct tls12_crypto_info_aes_gcm_256 gcm256;
252#   endif
253#   ifdef OPENSSL_KTLS_AES_CCM_128
254        struct tls12_crypto_info_aes_ccm_128 ccm128;
255#   endif
256#   ifdef OPENSSL_KTLS_CHACHA20_POLY1305
257        struct tls12_crypto_info_chacha20_poly1305 chacha20poly1305;
258#   endif
259    };
260    size_t tls_crypto_info_len;
261};
262
263typedef struct tls_crypto_info_all ktls_crypto_info_t;
264
265/*
266 * When successful, this socket option doesn't change the behaviour of the
267 * TCP socket, except changing the TCP setsockopt handler to enable the
268 * processing of SOL_TLS socket options. All other functionality remains the
269 * same.
270 */
271static ossl_inline int ktls_enable(int fd)
272{
273    return setsockopt(fd, SOL_TCP, TCP_ULP, "tls", sizeof("tls")) ? 0 : 1;
274}
275
276/*
277 * The TLS_TX socket option changes the send/sendmsg handlers of the TCP socket.
278 * If successful, then data sent using this socket will be encrypted and
279 * encapsulated in TLS records using the crypto_info provided here.
280 * The TLS_RX socket option changes the recv/recvmsg handlers of the TCP socket.
281 * If successful, then data received using this socket will be decrypted,
282 * authenticated and decapsulated using the crypto_info provided here.
283 */
284static ossl_inline int ktls_start(int fd, ktls_crypto_info_t *crypto_info,
285                                  int is_tx)
286{
287    return setsockopt(fd, SOL_TLS, is_tx ? TLS_TX : TLS_RX,
288                      crypto_info, crypto_info->tls_crypto_info_len) ? 0 : 1;
289}
290
291/*
292 * Send a TLS record using the crypto_info provided in ktls_start and use
293 * record_type instead of the default SSL3_RT_APPLICATION_DATA.
294 * When the socket is non-blocking, then this call either returns EAGAIN or
295 * the entire record is pushed to TCP. It is impossible to send a partial
296 * record using this control message.
297 */
298static ossl_inline int ktls_send_ctrl_message(int fd, unsigned char record_type,
299                                              const void *data, size_t length)
300{
301    struct msghdr msg;
302    int cmsg_len = sizeof(record_type);
303    struct cmsghdr *cmsg;
304    union {
305        struct cmsghdr hdr;
306        char buf[CMSG_SPACE(sizeof(unsigned char))];
307    } cmsgbuf;
308    struct iovec msg_iov;       /* Vector of data to send/receive into */
309
310    memset(&msg, 0, sizeof(msg));
311    msg.msg_control = cmsgbuf.buf;
312    msg.msg_controllen = sizeof(cmsgbuf.buf);
313    cmsg = CMSG_FIRSTHDR(&msg);
314    cmsg->cmsg_level = SOL_TLS;
315    cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
316    cmsg->cmsg_len = CMSG_LEN(cmsg_len);
317    *((unsigned char *)CMSG_DATA(cmsg)) = record_type;
318    msg.msg_controllen = cmsg->cmsg_len;
319
320    msg_iov.iov_base = (void *)data;
321    msg_iov.iov_len = length;
322    msg.msg_iov = &msg_iov;
323    msg.msg_iovlen = 1;
324
325    return sendmsg(fd, &msg, 0);
326}
327
328/*
329 * KTLS enables the sendfile system call to send data from a file over TLS.
330 * @flags are ignored on Linux. (placeholder for FreeBSD sendfile)
331 * */
332static ossl_inline ossl_ssize_t ktls_sendfile(int s, int fd, off_t off, size_t size, int flags)
333{
334    return sendfile(s, fd, &off, size);
335}
336
337#   ifdef OPENSSL_NO_KTLS_RX
338
339
340static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
341{
342    return -1;
343}
344
345#   else /* !defined(OPENSSL_NO_KTLS_RX) */
346
347/*
348 * Receive a TLS record using the crypto_info provided in ktls_start.
349 * The kernel strips the TLS record header, IV and authentication tag,
350 * returning only the plaintext data or an error on failure.
351 * We add the TLS record header here to satisfy routines in rec_layer_s3.c
352 */
353static ossl_inline int ktls_read_record(int fd, void *data, size_t length)
354{
355    struct msghdr msg;
356    struct cmsghdr *cmsg;
357    union {
358        struct cmsghdr hdr;
359        char buf[CMSG_SPACE(sizeof(unsigned char))];
360    } cmsgbuf;
361    struct iovec msg_iov;
362    int ret;
363    unsigned char *p = data;
364    const size_t prepend_length = SSL3_RT_HEADER_LENGTH;
365
366    if (length < prepend_length + EVP_GCM_TLS_TAG_LEN) {
367        errno = EINVAL;
368        return -1;
369    }
370
371    memset(&msg, 0, sizeof(msg));
372    msg.msg_control = cmsgbuf.buf;
373    msg.msg_controllen = sizeof(cmsgbuf.buf);
374
375    msg_iov.iov_base = p + prepend_length;
376    msg_iov.iov_len = length - prepend_length - EVP_GCM_TLS_TAG_LEN;
377    msg.msg_iov = &msg_iov;
378    msg.msg_iovlen = 1;
379
380    ret = recvmsg(fd, &msg, 0);
381    if (ret < 0)
382        return ret;
383
384    if (msg.msg_controllen > 0) {
385        cmsg = CMSG_FIRSTHDR(&msg);
386        if (cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
387            p[0] = *((unsigned char *)CMSG_DATA(cmsg));
388            p[1] = TLS1_2_VERSION_MAJOR;
389            p[2] = TLS1_2_VERSION_MINOR;
390            /* returned length is limited to msg_iov.iov_len above */
391            p[3] = (ret >> 8) & 0xff;
392            p[4] = ret & 0xff;
393            ret += prepend_length;
394        }
395    }
396
397    return ret;
398}
399
400#   endif /* OPENSSL_NO_KTLS_RX */
401
402#  endif /* OPENSSL_SYS_LINUX */
403# endif /* OPENSSL_NO_KTLS */
404#endif /* HEADER_INTERNAL_KTLS */
405