xref: /openbmc/linux/include/net/tls.h (revision 1c5af5cf)
1 /*
2  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
3  * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #ifndef _TLS_OFFLOAD_H
35 #define _TLS_OFFLOAD_H
36 
37 #include <linux/types.h>
38 #include <asm/byteorder.h>
39 #include <linux/crypto.h>
40 #include <linux/socket.h>
41 #include <linux/tcp.h>
42 #include <net/tcp.h>
43 #include <net/strparser.h>
44 
45 #include <uapi/linux/tls.h>
46 
47 
48 /* Maximum data size carried in a TLS record */
49 #define TLS_MAX_PAYLOAD_SIZE		((size_t)1 << 14)
50 
51 #define TLS_HEADER_SIZE			5
52 #define TLS_NONCE_OFFSET		TLS_HEADER_SIZE
53 
54 #define TLS_CRYPTO_INFO_READY(info)	((info)->cipher_type)
55 
56 #define TLS_RECORD_TYPE_DATA		0x17
57 
58 #define TLS_AAD_SPACE_SIZE		13
59 #define TLS_DEVICE_NAME_MAX		32
60 
61 /*
62  * This structure defines the routines for Inline TLS driver.
63  * The following routines are optional and filled with a
64  * null pointer if not defined.
65  *
66  * @name: Its the name of registered Inline tls device
67  * @dev_list: Inline tls device list
68  * int (*feature)(struct tls_device *device);
69  *     Called to return Inline TLS driver capability
70  *
71  * int (*hash)(struct tls_device *device, struct sock *sk);
72  *     This function sets Inline driver for listen and program
73  *     device specific functioanlity as required
74  *
75  * void (*unhash)(struct tls_device *device, struct sock *sk);
76  *     This function cleans listen state set by Inline TLS driver
77  */
78 struct tls_device {
79 	char name[TLS_DEVICE_NAME_MAX];
80 	struct list_head dev_list;
81 	int  (*feature)(struct tls_device *device);
82 	int  (*hash)(struct tls_device *device, struct sock *sk);
83 	void (*unhash)(struct tls_device *device, struct sock *sk);
84 };
85 
86 struct tls_sw_context {
87 	struct crypto_aead *aead_send;
88 	struct crypto_aead *aead_recv;
89 	struct crypto_wait async_wait;
90 
91 	/* Receive context */
92 	struct strparser strp;
93 	void (*saved_data_ready)(struct sock *sk);
94 	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
95 				struct poll_table_struct *wait);
96 	struct sk_buff *recv_pkt;
97 	u8 control;
98 	bool decrypted;
99 
100 	char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
101 	char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];
102 
103 	/* Sending context */
104 	char aad_space[TLS_AAD_SPACE_SIZE];
105 
106 	unsigned int sg_plaintext_size;
107 	int sg_plaintext_num_elem;
108 	struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
109 
110 	unsigned int sg_encrypted_size;
111 	int sg_encrypted_num_elem;
112 	struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
113 
114 	/* AAD | sg_plaintext_data | sg_tag */
115 	struct scatterlist sg_aead_in[2];
116 	/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
117 	struct scatterlist sg_aead_out[2];
118 };
119 
120 enum {
121 	TLS_PENDING_CLOSED_RECORD
122 };
123 
124 struct cipher_context {
125 	u16 prepend_size;
126 	u16 tag_size;
127 	u16 overhead_size;
128 	u16 iv_size;
129 	char *iv;
130 	u16 rec_seq_size;
131 	char *rec_seq;
132 };
133 
134 struct tls_context {
135 	union {
136 		struct tls_crypto_info crypto_send;
137 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
138 	};
139 	union {
140 		struct tls_crypto_info crypto_recv;
141 		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
142 	};
143 
144 	void *priv_ctx;
145 
146 	u8 conf:3;
147 
148 	struct cipher_context tx;
149 	struct cipher_context rx;
150 
151 	struct scatterlist *partially_sent_record;
152 	u16 partially_sent_offset;
153 	unsigned long flags;
154 	bool in_tcp_sendpages;
155 
156 	u16 pending_open_record_frags;
157 	int (*push_pending_record)(struct sock *sk, int flags);
158 
159 	void (*sk_write_space)(struct sock *sk);
160 	void (*sk_proto_close)(struct sock *sk, long timeout);
161 
162 	int  (*setsockopt)(struct sock *sk, int level,
163 			   int optname, char __user *optval,
164 			   unsigned int optlen);
165 	int  (*getsockopt)(struct sock *sk, int level,
166 			   int optname, char __user *optval,
167 			   int __user *optlen);
168 	int  (*hash)(struct sock *sk);
169 	void (*unhash)(struct sock *sk);
170 };
171 
172 int wait_on_pending_writer(struct sock *sk, long *timeo);
173 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
174 		int __user *optlen);
175 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
176 		  unsigned int optlen);
177 
178 
179 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
180 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
181 int tls_sw_sendpage(struct sock *sk, struct page *page,
182 		    int offset, size_t size, int flags);
183 void tls_sw_close(struct sock *sk, long timeout);
184 void tls_sw_free_resources(struct sock *sk);
185 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
186 		   int nonblock, int flags, int *addr_len);
187 unsigned int tls_sw_poll(struct file *file, struct socket *sock,
188 			 struct poll_table_struct *wait);
189 ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
190 			   struct pipe_inode_info *pipe,
191 			   size_t len, unsigned int flags);
192 
193 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
194 void tls_icsk_clean_acked(struct sock *sk);
195 
196 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
197 		struct scatterlist *sg, u16 first_offset,
198 		int flags);
199 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
200 				   int flags, long *timeo);
201 
202 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
203 {
204 	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
205 }
206 
207 static inline int tls_complete_pending_work(struct sock *sk,
208 					    struct tls_context *ctx,
209 					    int flags, long *timeo)
210 {
211 	int rc = 0;
212 
213 	if (unlikely(sk->sk_write_pending))
214 		rc = wait_on_pending_writer(sk, timeo);
215 
216 	if (!rc && tls_is_pending_closed_record(ctx))
217 		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
218 
219 	return rc;
220 }
221 
222 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
223 {
224 	return !!ctx->partially_sent_record;
225 }
226 
227 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
228 {
229 	return tls_ctx->pending_open_record_frags;
230 }
231 
232 static inline void tls_err_abort(struct sock *sk, int err)
233 {
234 	sk->sk_err = err;
235 	sk->sk_error_report(sk);
236 }
237 
238 static inline bool tls_bigint_increment(unsigned char *seq, int len)
239 {
240 	int i;
241 
242 	for (i = len - 1; i >= 0; i--) {
243 		++seq[i];
244 		if (seq[i] != 0)
245 			break;
246 	}
247 
248 	return (i == -1);
249 }
250 
251 static inline void tls_advance_record_sn(struct sock *sk,
252 					 struct cipher_context *ctx)
253 {
254 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
255 		tls_err_abort(sk, EBADMSG);
256 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
257 			     ctx->iv_size);
258 }
259 
260 static inline void tls_fill_prepend(struct tls_context *ctx,
261 			     char *buf,
262 			     size_t plaintext_len,
263 			     unsigned char record_type)
264 {
265 	size_t pkt_len, iv_size = ctx->tx.iv_size;
266 
267 	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
268 
269 	/* we cover nonce explicit here as well, so buf should be of
270 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
271 	 */
272 	buf[0] = record_type;
273 	buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
274 	buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
275 	/* we can use IV for nonce explicit according to spec */
276 	buf[3] = pkt_len >> 8;
277 	buf[4] = pkt_len & 0xFF;
278 	memcpy(buf + TLS_NONCE_OFFSET,
279 	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
280 }
281 
282 static inline void tls_make_aad(char *buf,
283 				size_t size,
284 				char *record_sequence,
285 				int record_sequence_size,
286 				unsigned char record_type)
287 {
288 	memcpy(buf, record_sequence, record_sequence_size);
289 
290 	buf[8] = record_type;
291 	buf[9] = TLS_1_2_VERSION_MAJOR;
292 	buf[10] = TLS_1_2_VERSION_MINOR;
293 	buf[11] = size >> 8;
294 	buf[12] = size & 0xFF;
295 }
296 
297 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
298 {
299 	struct inet_connection_sock *icsk = inet_csk(sk);
300 
301 	return icsk->icsk_ulp_data;
302 }
303 
304 static inline struct tls_sw_context *tls_sw_ctx(
305 		const struct tls_context *tls_ctx)
306 {
307 	return (struct tls_sw_context *)tls_ctx->priv_ctx;
308 }
309 
310 static inline struct tls_offload_context *tls_offload_ctx(
311 		const struct tls_context *tls_ctx)
312 {
313 	return (struct tls_offload_context *)tls_ctx->priv_ctx;
314 }
315 
316 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
317 		      unsigned char *record_type);
318 void tls_register_device(struct tls_device *device);
319 void tls_unregister_device(struct tls_device *device);
320 
321 #endif /* _TLS_OFFLOAD_H */
322