xref: /linux/net/tls/tls.h (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 /*
2  * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
3  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
4  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #ifndef _TLS_INT_H
36 #define _TLS_INT_H
37 
38 #include <asm/byteorder.h>
39 #include <linux/types.h>
40 #include <linux/skmsg.h>
41 #include <net/tls.h>
42 #include <net/tls_prot.h>
43 
44 #define TLS_PAGE_ORDER	(min_t(unsigned int, PAGE_ALLOC_COSTLY_ORDER,	\
45 			       TLS_MAX_PAYLOAD_SIZE >> PAGE_SHIFT))
46 
47 #define __TLS_INC_STATS(net, field)				\
48 	__SNMP_INC_STATS((net)->mib.tls_statistics, field)
49 #define TLS_INC_STATS(net, field)				\
50 	SNMP_INC_STATS((net)->mib.tls_statistics, field)
51 #define TLS_DEC_STATS(net, field)				\
52 	SNMP_DEC_STATS((net)->mib.tls_statistics, field)
53 
54 struct tls_cipher_desc {
55 	unsigned int nonce;
56 	unsigned int iv;
57 	unsigned int key;
58 	unsigned int salt;
59 	unsigned int tag;
60 	unsigned int rec_seq;
61 	unsigned int iv_offset;
62 	unsigned int key_offset;
63 	unsigned int salt_offset;
64 	unsigned int rec_seq_offset;
65 	char *cipher_name;
66 	bool offloadable;
67 	size_t crypto_info;
68 };
69 
70 #define TLS_CIPHER_MIN TLS_CIPHER_AES_GCM_128
71 #define TLS_CIPHER_MAX TLS_CIPHER_ARIA_GCM_256
72 extern const struct tls_cipher_desc tls_cipher_desc[TLS_CIPHER_MAX + 1 - TLS_CIPHER_MIN];
73 
74 static inline const struct tls_cipher_desc *get_cipher_desc(u16 cipher_type)
75 {
76 	if (cipher_type < TLS_CIPHER_MIN || cipher_type > TLS_CIPHER_MAX)
77 		return NULL;
78 
79 	return &tls_cipher_desc[cipher_type - TLS_CIPHER_MIN];
80 }
81 
82 static inline char *crypto_info_iv(struct tls_crypto_info *crypto_info,
83 				   const struct tls_cipher_desc *cipher_desc)
84 {
85 	return (char *)crypto_info + cipher_desc->iv_offset;
86 }
87 
88 static inline char *crypto_info_key(struct tls_crypto_info *crypto_info,
89 				    const struct tls_cipher_desc *cipher_desc)
90 {
91 	return (char *)crypto_info + cipher_desc->key_offset;
92 }
93 
94 static inline char *crypto_info_salt(struct tls_crypto_info *crypto_info,
95 				     const struct tls_cipher_desc *cipher_desc)
96 {
97 	return (char *)crypto_info + cipher_desc->salt_offset;
98 }
99 
100 static inline char *crypto_info_rec_seq(struct tls_crypto_info *crypto_info,
101 					const struct tls_cipher_desc *cipher_desc)
102 {
103 	return (char *)crypto_info + cipher_desc->rec_seq_offset;
104 }
105 
106 
107 /* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
108  * allocated or mapped for each TLS record. After encryption, the records are
109  * stores in a linked list.
110  */
111 struct tls_rec {
112 	struct list_head list;
113 	int tx_ready;
114 	int tx_flags;
115 
116 	struct sk_msg msg_plaintext;
117 	struct sk_msg msg_encrypted;
118 
119 	/* AAD | msg_plaintext.sg.data | sg_tag */
120 	struct scatterlist sg_aead_in[2];
121 	/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
122 	struct scatterlist sg_aead_out[2];
123 
124 	char content_type;
125 	struct scatterlist sg_content_type;
126 
127 	struct sock *sk;
128 
129 	char aad_space[TLS_AAD_SPACE_SIZE];
130 	u8 iv_data[TLS_MAX_IV_SIZE];
131 
132 	/* Must be last --ends in a flexible-array member. */
133 	struct aead_request aead_req;
134 };
135 
136 int __net_init tls_proc_init(struct net *net);
137 void __net_exit tls_proc_fini(struct net *net);
138 
139 struct tls_context *tls_ctx_create(struct sock *sk);
140 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
141 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
142 
143 int wait_on_pending_writer(struct sock *sk, long *timeo);
144 void tls_err_abort(struct sock *sk, int err);
145 void tls_strp_abort_strp(struct tls_strparser *strp, int err);
146 
147 int init_prot_info(struct tls_prot_info *prot,
148 		   const struct tls_crypto_info *crypto_info,
149 		   const struct tls_cipher_desc *cipher_desc);
150 int tls_set_sw_offload(struct sock *sk, int tx,
151 		       struct tls_crypto_info *new_crypto_info);
152 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
153 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
154 void tls_sw_strparser_done(struct tls_context *tls_ctx);
155 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
156 void tls_sw_splice_eof(struct socket *sock);
157 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
158 void tls_sw_release_resources_tx(struct sock *sk);
159 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
160 void tls_sw_free_resources_rx(struct sock *sk);
161 void tls_sw_release_resources_rx(struct sock *sk);
162 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
163 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
164 		   int flags, int *addr_len);
165 bool tls_sw_sock_is_readable(struct sock *sk);
166 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
167 			   struct pipe_inode_info *pipe,
168 			   size_t len, unsigned int flags);
169 int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
170 		     sk_read_actor_t read_actor);
171 
172 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
173 void tls_device_splice_eof(struct socket *sock);
174 int tls_tx_records(struct sock *sk, int flags);
175 
176 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
177 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
178 
179 int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
180 		     unsigned char *record_type);
181 int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
182 
183 int tls_sw_fallback_init(struct sock *sk,
184 			 struct tls_offload_context_tx *offload_ctx,
185 			 struct tls_crypto_info *crypto_info);
186 
187 int tls_strp_dev_init(void);
188 void tls_strp_dev_exit(void);
189 
190 void tls_strp_done(struct tls_strparser *strp);
191 void tls_strp_stop(struct tls_strparser *strp);
192 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
193 void tls_strp_data_ready(struct tls_strparser *strp);
194 
195 void tls_strp_check_rcv(struct tls_strparser *strp);
196 void tls_strp_msg_done(struct tls_strparser *strp);
197 
198 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
199 void tls_rx_msg_ready(struct tls_strparser *strp);
200 
201 bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
202 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
203 struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
204 int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
205 
206 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
207 {
208 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
209 
210 	return &scb->tls;
211 }
212 
213 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
214 {
215 	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
216 	return ctx->strp.anchor;
217 }
218 
219 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
220 {
221 	return READ_ONCE(ctx->strp.msg_ready);
222 }
223 
224 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
225 {
226 	return ctx->strp.mixed_decrypted;
227 }
228 
229 #ifdef CONFIG_TLS_DEVICE
230 int tls_device_init(void);
231 void tls_device_cleanup(void);
232 int tls_set_device_offload(struct sock *sk);
233 void tls_device_free_resources_tx(struct sock *sk);
234 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
235 void tls_device_offload_cleanup_rx(struct sock *sk);
236 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
237 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
238 #else
239 static inline int tls_device_init(void) { return 0; }
240 static inline void tls_device_cleanup(void) {}
241 
242 static inline int
243 tls_set_device_offload(struct sock *sk)
244 {
245 	return -EOPNOTSUPP;
246 }
247 
248 static inline void tls_device_free_resources_tx(struct sock *sk) {}
249 
250 static inline int
251 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
252 {
253 	return -EOPNOTSUPP;
254 }
255 
256 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
257 static inline void
258 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
259 
260 static inline int
261 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
262 {
263 	return 0;
264 }
265 #endif
266 
267 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
268 		struct scatterlist *sg, u16 first_offset,
269 		int flags);
270 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
271 			    int flags);
272 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
273 
274 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
275 {
276 	return !!ctx->partially_sent_record;
277 }
278 
279 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
280 {
281 	return tls_ctx->pending_open_record_frags;
282 }
283 
284 static inline bool tls_bigint_increment(unsigned char *seq, int len)
285 {
286 	int i;
287 
288 	for (i = len - 1; i >= 0; i--) {
289 		++seq[i];
290 		if (seq[i] != 0)
291 			break;
292 	}
293 
294 	return (i == -1);
295 }
296 
297 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
298 {
299 	u64 rcd_sn;
300 	__be64 *p;
301 
302 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
303 
304 	p = (__be64 *)seq;
305 	rcd_sn = be64_to_cpu(*p);
306 	*p = cpu_to_be64(rcd_sn - n);
307 }
308 
309 static inline void
310 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
311 		      struct cipher_context *ctx)
312 {
313 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
314 		tls_err_abort(sk, -EBADMSG);
315 
316 	if (prot->version != TLS_1_3_VERSION &&
317 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
318 		tls_bigint_increment(ctx->iv + prot->salt_size,
319 				     prot->iv_size);
320 }
321 
322 static inline void
323 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
324 {
325 	int i;
326 
327 	if (prot->version == TLS_1_3_VERSION ||
328 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
329 		for (i = 0; i < 8; i++)
330 			iv[i + 4] ^= seq[i];
331 	}
332 }
333 
334 static inline void
335 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
336 		 unsigned char record_type)
337 {
338 	struct tls_prot_info *prot = &ctx->prot_info;
339 	size_t pkt_len, iv_size = prot->iv_size;
340 
341 	pkt_len = plaintext_len + prot->tag_size;
342 	if (prot->version != TLS_1_3_VERSION &&
343 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
344 		pkt_len += iv_size;
345 
346 		memcpy(buf + TLS_NONCE_OFFSET,
347 		       ctx->tx.iv + prot->salt_size, iv_size);
348 	}
349 
350 	/* we cover nonce explicit here as well, so buf should be of
351 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
352 	 */
353 	buf[0] = prot->version == TLS_1_3_VERSION ?
354 		   TLS_RECORD_TYPE_DATA : record_type;
355 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
356 	buf[1] = TLS_1_2_VERSION_MINOR;
357 	buf[2] = TLS_1_2_VERSION_MAJOR;
358 	/* we can use IV for nonce explicit according to spec */
359 	buf[3] = pkt_len >> 8;
360 	buf[4] = pkt_len & 0xFF;
361 }
362 
363 static inline
364 void tls_make_aad(char *buf, size_t size, char *record_sequence,
365 		  unsigned char record_type, struct tls_prot_info *prot)
366 {
367 	if (prot->version != TLS_1_3_VERSION) {
368 		memcpy(buf, record_sequence, prot->rec_seq_size);
369 		buf += 8;
370 	} else {
371 		size += prot->tag_size;
372 	}
373 
374 	buf[0] = prot->version == TLS_1_3_VERSION ?
375 		  TLS_RECORD_TYPE_DATA : record_type;
376 	buf[1] = TLS_1_2_VERSION_MAJOR;
377 	buf[2] = TLS_1_2_VERSION_MINOR;
378 	buf[3] = size >> 8;
379 	buf[4] = size & 0xFF;
380 }
381 
382 #endif
383