aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/ipsec/ipsec_sa.h
blob: 79971538646b5969b9cf0fc2de3ddac8d31d4fd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef __IPSEC_SPD_SA_H__
#define __IPSEC_SPD_SA_H__

#include <vlib/vlib.h>
#include <vnet/ip/ip.h>
#include <vnet/fib/fib_node.h>

#define foreach_ipsec_crypto_alg    \
  _ (0, NONE, "none")               \
  _ (1, AES_CBC_128, "aes-cbc-128") \
  _ (2, AES_CBC_192, "aes-cbc-192") \
  _ (3, AES_CBC_256, "aes-cbc-256") \
  _ (4, AES_CTR_128, "aes-ctr-128") \
  _ (5, AES_CTR_192, "aes-ctr-192") \
  _ (6, AES_CTR_256, "aes-ctr-256") \
  _ (7, AES_GCM_128, "aes-gcm-128") \
  _ (8, AES_GCM_192, "aes-gcm-192") \
  _ (9, AES_GCM_256, "aes-gcm-256") \
  _ (10, DES_CBC, "des-cbc")        \
  _ (11, 3DES_CBC, "3des-cbc")

typedef enum
{
#define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
  foreach_ipsec_crypto_alg
#undef _
    IPSEC_CRYPTO_N_ALG,
} ipsec_crypto_alg_t;

#define IPSEC_CRYPTO_ALG_IS_GCM(_alg)                     \
  (((_alg == IPSEC_CRYPTO_ALG_AES_GCM_128) ||             \
    (_alg == IPSEC_CRYPTO_ALG_AES_GCM_192) ||             \
    (_alg == IPSEC_CRYPTO_ALG_AES_GCM_256)))

#define foreach_ipsec_integ_alg                                            \
  _ (0, NONE, "none")                                                      \
  _ (1, MD5_96, "md5-96")           /* RFC2403 */                          \
  _ (2, SHA1_96, "sha1-96")         /* RFC2404 */                          \
  _ (3, SHA_256_96, "sha-256-96")   /* draft-ietf-ipsec-ciph-sha-256-00 */ \
  _ (4, SHA_256_128, "sha-256-128") /* RFC4868 */                          \
  _ (5, SHA_384_192, "sha-384-192") /* RFC4868 */                          \
  _ (6, SHA_512_256, "sha-512-256")	/* RFC4868 */

typedef enum
{
#define _(v, f, s) IPSEC_INTEG_ALG_##f = v,
  foreach_ipsec_integ_alg
#undef _
    IPSEC_INTEG_N_ALG,
} ipsec_integ_alg_t;

typedef enum
{
  IPSEC_PROTOCOL_AH = 0,
  IPSEC_PROTOCOL_ESP = 1
} ipsec_protocol_t;

#define IPSEC_KEY_MAX_LEN 128
typedef struct ipsec_key_t_
{
  u8 len;
  u8 data[IPSEC_KEY_MAX_LEN];
} ipsec_key_t;

/*
 * Enable extended sequence numbers
 * Enable Anti-replay
 * IPsec tunnel mode if non-zero, else transport mode
 * IPsec tunnel mode is IPv6 if non-zero,
 * else IPv4 tunnel only valid if is_tunnel is non-zero
 * enable UDP encapsulation for NAT traversal
 */
#define foreach_ipsec_sa_flags                            \
  _ (0, NONE, "none")                                     \
  _ (1, USE_ESN, "esn")                                   \
  _ (2, USE_ANTI_REPLAY, "anti-replay")                   \
  _ (4, IS_TUNNEL, "tunnel")                              \
  _ (8, IS_TUNNEL_V6, "tunnel-v6")                        \
  _ (16, UDP_ENCAP, "udp-encap")                          \
  _ (32, IS_PROTECT, "Protect")                           \
  _ (64, IS_INBOUND, "inbound")                           \
  _ (128, IS_AEAD, "aead")                                \

typedef enum ipsec_sad_flags_t_
{
#define _(v, f, s) IPSEC_SA_FLAG_##f = v,
  foreach_ipsec_sa_flags
#undef _
} __clib_packed ipsec_sa_flags_t;

STATIC_ASSERT (sizeof (ipsec_sa_flags_t) == 1, "IPSEC SA flags > 1 byte");

typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);

  /* flags */
  ipsec_sa_flags_t flags;

  u8 crypto_iv_size;
  u8 crypto_block_size;
  u8 integ_icv_size;
  u32 spi;
  u32 seq;
  u32 seq_hi;
  u32 last_seq;
  u32 last_seq_hi;
  u64 replay_window;
  dpo_id_t dpo;

  vnet_crypto_key_index_t crypto_key_index;
  vnet_crypto_key_index_t integ_key_index;
  vnet_crypto_op_id_t crypto_enc_op_id:16;
  vnet_crypto_op_id_t crypto_dec_op_id:16;
  vnet_crypto_op_id_t integ_op_id:16;

  /* data accessed by dataplane code should be above this comment */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

  union
  {
    ip4_header_t ip4_hdr;
    ip6_header_t ip6_hdr;
  };
  udp_header_t udp_hdr;

  fib_node_t node;
  u32 id;
  u32 stat_index;
  ipsec_protocol_t protocol;

  ipsec_crypto_alg_t crypto_alg;
  ipsec_key_t crypto_key;
  vnet_crypto_alg_t crypto_calg;

  ipsec_integ_alg_t integ_alg;
  ipsec_key_t integ_key;
  vnet_crypto_alg_t integ_calg;

  ip46_address_t tunnel_src_addr;
  ip46_address_t tunnel_dst_addr;

  fib_node_index_t fib_entry_index;
  u32 sibling;

  u32 tx_fib_index;

  /* Salt used in GCM modes - stored in network byte order */
  u32 salt;
  u64 gcm_iv_counter;
} ipsec_sa_t;

STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);

#define _(a,v,s)                                                        \
  always_inline int                                                     \
  ipsec_sa_is_set_##v (const ipsec_sa_t *sa) {                          \
    return (sa->flags & IPSEC_SA_FLAG_##v);                             \
  }
foreach_ipsec_sa_flags
#undef _
#define _(a,v,s)                                                        \
  always_inline int                                                     \
  ipsec_sa_set_##v (ipsec_sa_t *sa) {                                   \
    return (sa->flags |= IPSEC_SA_FLAG_##v);                            \
  }
  foreach_ipsec_sa_flags
#undef _
#define _(a,v,s)                                                        \
  always_inline int                                                     \
  ipsec_sa_unset_##v (ipsec_sa_t *sa) {                                 \
    return (sa->flags &= ~IPSEC_SA_FLAG_##v);                           \
  }
  foreach_ipsec_sa_flags
#undef _
/**
 * @brief
 * SA packet & bytes counters
 */
extern vlib_combined_counter_main_t ipsec_sa_counters;

extern void ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len);

extern int ipsec_sa_add_and_lock (u32 id,
				  u32 spi,
				  ipsec_protocol_t proto,
				  ipsec_crypto_alg_t crypto_alg,
				  const ipsec_key_t * ck,
				  ipsec_integ_alg_t integ_alg,
				  const ipsec_key_t * ik,
				  ipsec_sa_flags_t flags,
				  u32 tx_table_id,
				  u32 salt,
				  const ip46_address_t * tunnel_src_addr,
				  const ip46_address_t * tunnel_dst_addr,
				  u32 * sa_index);
extern index_t ipsec_sa_find_and_lock (u32 id);
extern int ipsec_sa_unlock_id (u32 id);
extern void ipsec_sa_unlock (index_t sai);
extern void ipsec_sa_lock (index_t sai);
extern void ipsec_sa_clear (index_t sai);
extern void ipsec_sa_set_crypto_alg (ipsec_sa_t * sa,
				     ipsec_crypto_alg_t crypto_alg);
extern void ipsec_sa_set_integ_alg (ipsec_sa_t * sa,
				    ipsec_integ_alg_t integ_alg);

typedef walk_rc_t (*ipsec_sa_walk_cb_t) (ipsec_sa_t * sa, void *ctx);
extern void ipsec_sa_walk (ipsec_sa_walk_cb_t cd, void *ctx);

extern u8 *format_ipsec_crypto_alg (u8 * s, va_list * args);
extern u8 *format_ipsec_integ_alg (u8 * s, va_list * args);
extern u8 *format_ipsec_sa (u8 * s, va_list * args);
extern u8 *format_ipsec_key (u8 * s, va_list * args);
extern uword unformat_ipsec_crypto_alg (unformat_input_t * input,
					va_list * args);
extern uword unformat_ipsec_integ_alg (unformat_input_t * input,
				       va_list * args);
extern uword unformat_ipsec_key (unformat_input_t * input, va_list * args);

/*
 * Anti Replay definitions
 */

#define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (64)
#define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE-1)

/*
 * sequence number less than the lower bound are outside of the window
 * From RFC4303 Appendix A:
 *  Bl = Tl - W + 1
 */
#define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND(_tl) (_tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1)

/*
 * Anti replay check.
 *  inputs need to be in host byte order.
 */
always_inline int
ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq)
{
  u32 diff, tl, th;

  if ((sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
    return 0;

  if (!ipsec_sa_is_set_USE_ESN (sa))
    {
      if (PREDICT_TRUE (seq > sa->last_seq))
	return 0;

      diff = sa->last_seq - seq;

      if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff)
	return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
      else
	return 1;

      return 0;
    }

  tl = sa->last_seq;
  th = sa->last_seq_hi;
  diff = tl - seq;

  if (PREDICT_TRUE (tl >= (IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX)))
    {
      /*
       * the last sequence number VPP recieved is more than one
       * window size greater than zero.
       * Case A from RFC4303 Appendix A.
       */
      if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
	{
	  /*
	   * the received sequence number is lower than the lower bound
	   * of the window, this could mean either a replay packet or that
	   * the high sequence number has wrapped. if it decrypts corrently
	   * then it's the latter.
	   */
	  sa->seq_hi = th + 1;
	  return 0;
	}
      else
	{
	  /*
	   * the recieved sequence number greater than the low
	   * end of the window.
	   */
	  sa->seq_hi = th;
	  if (seq <= tl)
	    /*
	     * The recieved seq number is within bounds of the window
	     * check if it's a duplicate
	     */
	    return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	  else
	    /*
	     * The received sequence number is greater than the window
	     * upper bound. this packet will move the window along, assuming
	     * it decrypts correctly.
	     */
	    return 0;
	}
    }
  else
    {
      /*
       * the last sequence number VPP recieved is within one window
       * size of zero, i.e. 0 < TL < WINDOW_SIZE, the lower bound is thus a
       * large sequence number.
       * Note that the check below uses unsiged integer arthimetic, so the
       * RHS will be a larger number.
       * Case B from RFC4303 Appendix A.
       */
      if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl))
	{
	  /*
	   * the sequence number is less than the lower bound.
	   */
	  if (seq <= tl)
	    {
	      /*
	       * the packet is within the window upper bound.
	       * check for duplicates.
	       */
	      sa->seq_hi = th;
	      return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	    }
	  else
	    {
	      /*
	       * the packet is less the window lower bound or greater than
	       * the higher bound, depending on how you look at it...
	       * We're assuming, given that the last sequence number received,
	       * TL < WINDOW_SIZE, that a largeer seq num is more likely to be
	       * a packet that moves the window forward, than a packet that has
	       * wrapped the high sequence again. If it were the latter then
	       * we've lost close to 2^32 packets.
	       */
	      sa->seq_hi = th;
	      return 0;
	    }
	}
      else
	{
	  /*
	   * the packet seq number is between the lower bound (a large nubmer)
	   * and MAX_SEQ_NUM. This is in the window since the window upper bound
	   * tl > 0.
	   * However, since TL is the other side of 0 to the received
	   * packet, the SA has moved on to a higher sequence number.
	   */
	  sa->seq_hi = th - 1;
	  return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
	}
    }

  return 0;
}

/*
 * Anti replay window advance
 *  inputs need to be in host byte order.
 */
always_inline void
ipsec_sa_anti_replay_advance (ipsec_sa_t * sa, u32 seq)
{
  u32 pos;
  if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0)
    return;

  if (PREDICT_TRUE (sa->flags & IPSEC_SA_FLAG_USE_ESN))
    {
      int wrap = sa->seq_hi - sa->last_seq_hi;

      if (wrap == 0 && seq > sa->last_seq)
	{
	  pos = seq - sa->last_seq;
	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	    sa->replay_window = ((sa->replay_window) << pos) | 1;
	  else
	    sa->replay_window = 1;
	  sa->last_seq = seq;
	}
      else if (wrap > 0)
	{
	  pos = ~seq + sa->last_seq + 1;
	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	    sa->replay_window = ((sa->replay_window) << pos) | 1;
	  else
	    sa->replay_window = 1;
	  sa->last_seq = seq;
	  sa->last_seq_hi = sa->seq_hi;
	}
      else if (wrap < 0)
	{
	  pos = ~seq + sa->last_seq + 1;
	  sa->replay_window |= (1ULL << pos);
	}
      else
	{
	  pos = sa->last_seq - seq;
	  sa->replay_window |= (1ULL << pos);
	}
    }
  else
    {
      if (seq > sa->last_seq)
	{
	  pos = seq - sa->last_seq;
	  if (pos < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
	    sa->replay_window = ((sa->replay_window) << pos) | 1;
	  else
	    sa->replay_window = 1;
	  sa->last_seq = seq;
	}
      else
	{
	  pos = sa->last_seq - seq;
	  sa->replay_window |= (1ULL << pos);
	}
    }
}

#endif /* __IPSEC_SPD_SA_H__ */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */