xref: /linux/net/tls/tls.h (revision ccde82e909467abdf098a8ee6f63e1ecf9a47ce5)
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 	struct aead_request aead_req;
132 	u8 aead_req_ctx[];
133 };
134 
135 int __net_init tls_proc_init(struct net *net);
136 void __net_exit tls_proc_fini(struct net *net);
137 
138 struct tls_context *tls_ctx_create(struct sock *sk);
139 void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
140 void update_sk_prot(struct sock *sk, struct tls_context *ctx);
141 
142 int wait_on_pending_writer(struct sock *sk, long *timeo);
143 void tls_err_abort(struct sock *sk, int err);
144 void tls_strp_abort_strp(struct tls_strparser *strp, int err);
145 
146 int init_prot_info(struct tls_prot_info *prot,
147 		   const struct tls_crypto_info *crypto_info,
148 		   const struct tls_cipher_desc *cipher_desc);
149 int tls_set_sw_offload(struct sock *sk, int tx,
150 		       struct tls_crypto_info *new_crypto_info);
151 void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
152 void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
153 void tls_sw_strparser_done(struct tls_context *tls_ctx);
154 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
155 void tls_sw_splice_eof(struct socket *sock);
156 void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
157 void tls_sw_release_resources_tx(struct sock *sk);
158 void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
159 void tls_sw_free_resources_rx(struct sock *sk);
160 void tls_sw_release_resources_rx(struct sock *sk);
161 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
162 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
163 		   int flags, int *addr_len);
164 bool tls_sw_sock_is_readable(struct sock *sk);
165 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
166 			   struct pipe_inode_info *pipe,
167 			   size_t len, unsigned int flags);
168 int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
169 		     sk_read_actor_t read_actor);
170 
171 int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
172 void tls_device_splice_eof(struct socket *sock);
173 int tls_tx_records(struct sock *sk, int flags);
174 
175 void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
176 void tls_device_write_space(struct sock *sk, struct tls_context *ctx);
177 
178 int tls_process_cmsg(struct sock *sk, struct msghdr *msg,
179 		     unsigned char *record_type);
180 int decrypt_skb(struct sock *sk, struct scatterlist *sgout);
181 
182 int tls_sw_fallback_init(struct sock *sk,
183 			 struct tls_offload_context_tx *offload_ctx,
184 			 struct tls_crypto_info *crypto_info);
185 
186 int tls_strp_dev_init(void);
187 void tls_strp_dev_exit(void);
188 
189 void tls_strp_done(struct tls_strparser *strp);
190 void tls_strp_stop(struct tls_strparser *strp);
191 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
192 void tls_strp_data_ready(struct tls_strparser *strp);
193 
194 void tls_strp_check_rcv(struct tls_strparser *strp);
195 void tls_strp_msg_done(struct tls_strparser *strp);
196 
197 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
198 void tls_rx_msg_ready(struct tls_strparser *strp);
199 
200 bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
201 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
202 struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
203 int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
204 
205 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
206 {
207 	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
208 
209 	return &scb->tls;
210 }
211 
212 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
213 {
214 	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
215 	return ctx->strp.anchor;
216 }
217 
218 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
219 {
220 	return READ_ONCE(ctx->strp.msg_ready);
221 }
222 
223 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)
224 {
225 	return ctx->strp.mixed_decrypted;
226 }
227 
228 #ifdef CONFIG_TLS_DEVICE
229 int tls_device_init(void);
230 void tls_device_cleanup(void);
231 int tls_set_device_offload(struct sock *sk);
232 void tls_device_free_resources_tx(struct sock *sk);
233 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
234 void tls_device_offload_cleanup_rx(struct sock *sk);
235 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
236 int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx);
237 #else
238 static inline int tls_device_init(void) { return 0; }
239 static inline void tls_device_cleanup(void) {}
240 
241 static inline int
242 tls_set_device_offload(struct sock *sk)
243 {
244 	return -EOPNOTSUPP;
245 }
246 
247 static inline void tls_device_free_resources_tx(struct sock *sk) {}
248 
249 static inline int
250 tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
251 {
252 	return -EOPNOTSUPP;
253 }
254 
255 static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
256 static inline void
257 tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
258 
259 static inline int
260 tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx)
261 {
262 	return 0;
263 }
264 #endif
265 
266 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
267 		struct scatterlist *sg, u16 first_offset,
268 		int flags);
269 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
270 			    int flags);
271 void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
272 
273 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
274 {
275 	return !!ctx->partially_sent_record;
276 }
277 
278 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
279 {
280 	return tls_ctx->pending_open_record_frags;
281 }
282 
283 static inline bool tls_bigint_increment(unsigned char *seq, int len)
284 {
285 	int i;
286 
287 	for (i = len - 1; i >= 0; i--) {
288 		++seq[i];
289 		if (seq[i] != 0)
290 			break;
291 	}
292 
293 	return (i == -1);
294 }
295 
296 static inline void tls_bigint_subtract(unsigned char *seq, int  n)
297 {
298 	u64 rcd_sn;
299 	__be64 *p;
300 
301 	BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);
302 
303 	p = (__be64 *)seq;
304 	rcd_sn = be64_to_cpu(*p);
305 	*p = cpu_to_be64(rcd_sn - n);
306 }
307 
308 static inline void
309 tls_advance_record_sn(struct sock *sk, struct tls_prot_info *prot,
310 		      struct cipher_context *ctx)
311 {
312 	if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
313 		tls_err_abort(sk, -EBADMSG);
314 
315 	if (prot->version != TLS_1_3_VERSION &&
316 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
317 		tls_bigint_increment(ctx->iv + prot->salt_size,
318 				     prot->iv_size);
319 }
320 
321 static inline void
322 tls_xor_iv_with_seq(struct tls_prot_info *prot, char *iv, char *seq)
323 {
324 	int i;
325 
326 	if (prot->version == TLS_1_3_VERSION ||
327 	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
328 		for (i = 0; i < 8; i++)
329 			iv[i + 4] ^= seq[i];
330 	}
331 }
332 
333 static inline void
334 tls_fill_prepend(struct tls_context *ctx, char *buf, size_t plaintext_len,
335 		 unsigned char record_type)
336 {
337 	struct tls_prot_info *prot = &ctx->prot_info;
338 	size_t pkt_len, iv_size = prot->iv_size;
339 
340 	pkt_len = plaintext_len + prot->tag_size;
341 	if (prot->version != TLS_1_3_VERSION &&
342 	    prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
343 		pkt_len += iv_size;
344 
345 		memcpy(buf + TLS_NONCE_OFFSET,
346 		       ctx->tx.iv + prot->salt_size, iv_size);
347 	}
348 
349 	/* we cover nonce explicit here as well, so buf should be of
350 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
351 	 */
352 	buf[0] = prot->version == TLS_1_3_VERSION ?
353 		   TLS_RECORD_TYPE_DATA : record_type;
354 	/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
355 	buf[1] = TLS_1_2_VERSION_MINOR;
356 	buf[2] = TLS_1_2_VERSION_MAJOR;
357 	/* we can use IV for nonce explicit according to spec */
358 	buf[3] = pkt_len >> 8;
359 	buf[4] = pkt_len & 0xFF;
360 }
361 
362 static inline
363 void tls_make_aad(char *buf, size_t size, char *record_sequence,
364 		  unsigned char record_type, struct tls_prot_info *prot)
365 {
366 	if (prot->version != TLS_1_3_VERSION) {
367 		memcpy(buf, record_sequence, prot->rec_seq_size);
368 		buf += 8;
369 	} else {
370 		size += prot->tag_size;
371 	}
372 
373 	buf[0] = prot->version == TLS_1_3_VERSION ?
374 		  TLS_RECORD_TYPE_DATA : record_type;
375 	buf[1] = TLS_1_2_VERSION_MAJOR;
376 	buf[2] = TLS_1_2_VERSION_MINOR;
377 	buf[3] = size >> 8;
378 	buf[4] = size & 0xFF;
379 }
380 
381 #endif
382