2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
15 #ifndef __IPSEC_SPD_SA_H__
16 #define __IPSEC_SPD_SA_H__
18 #include <vlib/vlib.h>
19 #include <vnet/crypto/crypto.h>
20 #include <vnet/ip/ip.h>
21 #include <vnet/fib/fib_node.h>
22 #include <vnet/tunnel/tunnel.h>
24 #define foreach_ipsec_crypto_alg \
26 _ (1, AES_CBC_128, "aes-cbc-128") \
27 _ (2, AES_CBC_192, "aes-cbc-192") \
28 _ (3, AES_CBC_256, "aes-cbc-256") \
29 _ (4, AES_CTR_128, "aes-ctr-128") \
30 _ (5, AES_CTR_192, "aes-ctr-192") \
31 _ (6, AES_CTR_256, "aes-ctr-256") \
32 _ (7, AES_GCM_128, "aes-gcm-128") \
33 _ (8, AES_GCM_192, "aes-gcm-192") \
34 _ (9, AES_GCM_256, "aes-gcm-256") \
35 _ (10, DES_CBC, "des-cbc") \
36 _ (11, 3DES_CBC, "3des-cbc")
40 #define _(v, f, s) IPSEC_CRYPTO_ALG_##f = v,
41 foreach_ipsec_crypto_alg
44 } __clib_packed ipsec_crypto_alg_t;
46 #define IPSEC_CRYPTO_ALG_IS_GCM(_alg) \
47 (((_alg == IPSEC_CRYPTO_ALG_AES_GCM_128) || \
48 (_alg == IPSEC_CRYPTO_ALG_AES_GCM_192) || \
49 (_alg == IPSEC_CRYPTO_ALG_AES_GCM_256)))
51 #define IPSEC_CRYPTO_ALG_IS_CTR(_alg) \
52 (((_alg == IPSEC_CRYPTO_ALG_AES_CTR_128) || \
53 (_alg == IPSEC_CRYPTO_ALG_AES_CTR_192) || \
54 (_alg == IPSEC_CRYPTO_ALG_AES_CTR_256)))
56 #define foreach_ipsec_integ_alg \
58 _ (1, MD5_96, "md5-96") /* RFC2403 */ \
59 _ (2, SHA1_96, "sha1-96") /* RFC2404 */ \
60 _ (3, SHA_256_96, "sha-256-96") /* draft-ietf-ipsec-ciph-sha-256-00 */ \
61 _ (4, SHA_256_128, "sha-256-128") /* RFC4868 */ \
62 _ (5, SHA_384_192, "sha-384-192") /* RFC4868 */ \
63 _ (6, SHA_512_256, "sha-512-256") /* RFC4868 */
67 #define _(v, f, s) IPSEC_INTEG_ALG_##f = v,
68 foreach_ipsec_integ_alg
71 } __clib_packed ipsec_integ_alg_t;
75 IPSEC_PROTOCOL_AH = 0,
76 IPSEC_PROTOCOL_ESP = 1
77 } __clib_packed ipsec_protocol_t;
79 #define IPSEC_KEY_MAX_LEN 128
80 typedef struct ipsec_key_t_
83 u8 data[IPSEC_KEY_MAX_LEN];
87 * Enable extended sequence numbers
89 * IPsec tunnel mode if non-zero, else transport mode
90 * IPsec tunnel mode is IPv6 if non-zero,
91 * else IPv4 tunnel only valid if is_tunnel is non-zero
92 * enable UDP encapsulation for NAT traversal
94 #define foreach_ipsec_sa_flags \
96 _ (1, USE_ESN, "esn") \
97 _ (2, USE_ANTI_REPLAY, "anti-replay") \
98 _ (4, IS_TUNNEL, "tunnel") \
99 _ (8, IS_TUNNEL_V6, "tunnel-v6") \
100 _ (16, UDP_ENCAP, "udp-encap") \
101 _ (32, IS_PROTECT, "Protect") \
102 _ (64, IS_INBOUND, "inbound") \
103 _ (128, IS_AEAD, "aead") \
104 _ (256, IS_CTR, "ctr") \
105 _ (512, IS_ASYNC, "async")
107 typedef enum ipsec_sad_flags_t_
109 #define _(v, f, s) IPSEC_SA_FLAG_##f = v,
110 foreach_ipsec_sa_flags
112 } __clib_packed ipsec_sa_flags_t;
114 STATIC_ASSERT (sizeof (ipsec_sa_flags_t) == 2, "IPSEC SA flags != 2 byte");
118 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
121 ipsec_sa_flags_t flags;
138 vnet_crypto_key_index_t crypto_key_index;
139 vnet_crypto_key_index_t integ_key_index;
141 /* Union data shared by sync and async ops, updated when mode is
147 vnet_crypto_op_id_t crypto_enc_op_id:16;
148 vnet_crypto_op_id_t crypto_dec_op_id:16;
149 vnet_crypto_op_id_t integ_op_id:16;
154 vnet_crypto_async_op_id_t crypto_async_enc_op_id:16;
155 vnet_crypto_async_op_id_t crypto_async_dec_op_id:16;
156 vnet_crypto_key_index_t linked_key_index;
162 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
166 ip4_header_t ip4_hdr;
167 ip6_header_t ip6_hdr;
169 udp_header_t udp_hdr;
171 /* Salt used in CTR modes (incl. GCM) - stored in network byte order */
174 ipsec_protocol_t protocol;
175 tunnel_encap_decap_flags_t tunnel_flags;
178 /* data accessed by dataplane code should be above this comment */
179 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
181 /* Elements with u64 size multiples */
186 vnet_crypto_op_id_t crypto_enc_op_id:16;
187 vnet_crypto_op_id_t crypto_dec_op_id:16;
188 vnet_crypto_op_id_t integ_op_id:16;
197 vnet_crypto_async_op_id_t crypto_async_enc_op_id:16;
198 vnet_crypto_async_op_id_t crypto_async_dec_op_id:16;
199 vnet_crypto_key_index_t linked_key_index;
208 /* elements with u32 size */
211 vnet_crypto_alg_t integ_calg;
212 vnet_crypto_alg_t crypto_calg;
215 ipsec_crypto_alg_t crypto_alg;
216 ipsec_integ_alg_t integ_alg;
218 ipsec_key_t integ_key;
219 ipsec_key_t crypto_key;
222 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);
223 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline2, 2 * CLIB_CACHE_LINE_BYTES);
228 extern ipsec_sa_t *ipsec_sa_pool;
231 * Ensure that the IPsec data does not overlap with the IP data in
232 * the buffer meta data
234 STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ipsec.sad_index) ==
235 STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_protocol),
236 "IPSec data is overlapping with IP data");
240 ipsec_sa_is_set_##v (const ipsec_sa_t *sa) { \
241 return (sa->flags & IPSEC_SA_FLAG_##v); \
243 foreach_ipsec_sa_flags
247 ipsec_sa_set_##v (ipsec_sa_t *sa) { \
248 return (sa->flags |= IPSEC_SA_FLAG_##v); \
250 foreach_ipsec_sa_flags
254 ipsec_sa_unset_##v (ipsec_sa_t *sa) { \
255 return (sa->flags &= ~IPSEC_SA_FLAG_##v); \
257 foreach_ipsec_sa_flags
261 * SA packet & bytes counters
263 extern vlib_combined_counter_main_t ipsec_sa_counters;
264 extern vlib_simple_counter_main_t ipsec_sa_lost_counters;
266 extern void ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len);
269 ipsec_sa_add_and_lock (u32 id, u32 spi, ipsec_protocol_t proto,
270 ipsec_crypto_alg_t crypto_alg, const ipsec_key_t *ck,
271 ipsec_integ_alg_t integ_alg, const ipsec_key_t *ik,
272 ipsec_sa_flags_t flags, u32 salt, u16 src_port,
273 u16 dst_port, const tunnel_t *tun, u32 *sa_out_index);
274 extern index_t ipsec_sa_find_and_lock (u32 id);
275 extern int ipsec_sa_unlock_id (u32 id);
276 extern void ipsec_sa_unlock (index_t sai);
277 extern void ipsec_sa_lock (index_t sai);
278 extern void ipsec_sa_clear (index_t sai);
279 extern void ipsec_sa_set_crypto_alg (ipsec_sa_t * sa,
280 ipsec_crypto_alg_t crypto_alg);
281 extern void ipsec_sa_set_integ_alg (ipsec_sa_t * sa,
282 ipsec_integ_alg_t integ_alg);
284 typedef walk_rc_t (*ipsec_sa_walk_cb_t) (ipsec_sa_t * sa, void *ctx);
285 extern void ipsec_sa_walk (ipsec_sa_walk_cb_t cd, void *ctx);
287 extern u8 *format_ipsec_replay_window (u8 *s, va_list *args);
288 extern u8 *format_ipsec_crypto_alg (u8 * s, va_list * args);
289 extern u8 *format_ipsec_integ_alg (u8 * s, va_list * args);
290 extern u8 *format_ipsec_sa (u8 * s, va_list * args);
291 extern u8 *format_ipsec_key (u8 * s, va_list * args);
292 extern uword unformat_ipsec_crypto_alg (unformat_input_t * input,
294 extern uword unformat_ipsec_integ_alg (unformat_input_t * input,
296 extern uword unformat_ipsec_key (unformat_input_t * input, va_list * args);
298 #define IPSEC_UDP_PORT_NONE ((u16)~0)
301 * Anti Replay definitions
304 #define IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE (64)
305 #define IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE-1)
308 * sequence number less than the lower bound are outside of the window
309 * From RFC4303 Appendix A:
312 #define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND(_tl) (_tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1)
315 ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq)
317 if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) &&
318 sa->replay_window & (1ULL << (sa->seq - seq)))
326 * inputs need to be in host byte order.
328 * The function runs in two contexts. pre and post decrypt.
330 * 1 - determines if a packet is a replay - a simple check in the window
331 * 2 - returns the hi-seq number that should be used to decrypt.
333 * Checks whether the packet is a replay or falls out of window
335 * This funcion should be called even without anti-replay enabled to ensure
336 * the high sequence number is set.
339 ipsec_sa_anti_replay_and_sn_advance (const ipsec_sa_t *sa, u32 seq,
340 u32 hi_seq_used, bool post_decrypt,
343 ASSERT ((post_decrypt == false) == (hi_seq_req != 0));
345 if (!ipsec_sa_is_set_USE_ESN (sa))
348 /* no ESN, therefore the hi-seq is always 0 */
351 if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
354 if (PREDICT_TRUE (seq > sa->seq))
357 u32 diff = sa->seq - seq;
359 if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff)
360 return ((sa->replay_window & (1ULL << diff)) ? 1 : 0);
367 if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa))
369 /* there's no AR configured for this SA, but in order
370 * to know whether a packet has wrapped the hi ESN we need
371 * to know whether it is out of window. if we use the default
372 * lower bound then we are effectively forcing AR because
373 * out of window packets will get the increased hi seq number
374 * and will thus fail to decrypt. IOW we need a window to know
375 * if the SN has wrapped, but we don't want a window to check for
376 * anti replay. to resolve the contradiction we use a huge window.
377 * if the packet is not within 2^30 of the current SN, we'll consider
383 /* The packet's sequence number is larger that the SA's.
384 * that can't be a warp - unless we lost more than
385 * 2^32 packets ... how could we know? */
386 *hi_seq_req = sa->seq_hi;
389 /* The packet's SN is less than the SAs, so either the SN has
390 * wrapped or the SN is just old. */
391 if (sa->seq - seq > (1 << 30))
392 /* It's really really really old => it wrapped */
393 *hi_seq_req = sa->seq_hi + 1;
395 *hi_seq_req = sa->seq_hi;
400 * this is post-decrpyt and since it decrypted we accept it
404 if (PREDICT_TRUE (sa->seq >= (IPSEC_SA_ANTI_REPLAY_WINDOW_MAX_INDEX)))
407 * the last sequence number VPP recieved is more than one
408 * window size greater than zero.
409 * Case A from RFC4303 Appendix A.
411 if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (sa->seq))
414 * the received sequence number is lower than the lower bound
415 * of the window, this could mean either a replay packet or that
416 * the high sequence number has wrapped. if it decrypts corrently
417 * then it's the latter.
421 if (hi_seq_used == sa->seq_hi)
422 /* the high sequence number used to succesfully decrypt this
423 * packet is the same as the last-sequnence number of the SA.
424 * that means this packet did not cause a wrap.
425 * this packet is thus out of window and should be dropped */
428 /* The packet decrypted with a different high sequence number
429 * to the SA, that means it is the wrap packet and should be
435 /* pre-decrypt it might be the might that casues a wrap, we
436 * need to decrpyt to find out */
438 *hi_seq_req = sa->seq_hi + 1;
445 * the recieved sequence number greater than the low
449 *hi_seq_req = sa->seq_hi;
452 * The recieved seq number is within bounds of the window
453 * check if it's a duplicate
455 return (ipsec_sa_anti_replay_check (sa, seq));
458 * The received sequence number is greater than the window
459 * upper bound. this packet will move the window along, assuming
460 * it decrypts correctly.
468 * the last sequence number VPP recieved is within one window
469 * size of zero, i.e. 0 < TL < WINDOW_SIZE, the lower bound is thus a
470 * large sequence number.
471 * Note that the check below uses unsiged integer arthimetic, so the
472 * RHS will be a larger number.
473 * Case B from RFC4303 Appendix A.
475 if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (sa->seq))
478 * the sequence number is less than the lower bound.
483 * the packet is within the window upper bound.
484 * check for duplicates.
487 *hi_seq_req = sa->seq_hi;
488 return (ipsec_sa_anti_replay_check (sa, seq));
493 * the packet is less the window lower bound or greater than
494 * the higher bound, depending on how you look at it...
495 * We're assuming, given that the last sequence number received,
496 * TL < WINDOW_SIZE, that a largeer seq num is more likely to be
497 * a packet that moves the window forward, than a packet that has
498 * wrapped the high sequence again. If it were the latter then
499 * we've lost close to 2^32 packets.
502 *hi_seq_req = sa->seq_hi;
509 * the packet seq number is between the lower bound (a large nubmer)
510 * and MAX_SEQ_NUM. This is in the window since the window upper bound
512 * However, since TL is the other side of 0 to the received
513 * packet, the SA has moved on to a higher sequence number.
516 *hi_seq_req = sa->seq_hi - 1;
517 return (ipsec_sa_anti_replay_check (sa, seq));
527 ipsec_sa_anti_replay_window_shift (ipsec_sa_t *sa, u32 inc)
531 if (inc < IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
533 if (sa->seq > IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE)
536 * count how many holes there are in the portion
537 * of the window that we will right shift of the end
538 * as a result of this increments
540 u64 mask = (((u64) 1 << inc) - 1) << (BITS (u64) - inc);
541 u64 old = sa->replay_window & mask;
542 /* the number of packets we saw in this section of the window */
543 u64 seen = count_set_bits (old);
546 * the number we missed is the size of the window section
547 * minus the number we saw.
551 sa->replay_window = ((sa->replay_window) << inc) | 1;
555 /* holes in the replay window are lost packets */
556 n_lost = BITS (u64) - count_set_bits (sa->replay_window);
558 /* any sequence numbers that now fall outside the window
559 * are forever lost */
560 n_lost += inc - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE;
562 sa->replay_window = 1;
569 * Anti replay window advance
570 * inputs need to be in host byte order.
571 * This function both advances the anti-replay window and the sequence number
572 * We always need to move on the SN but the window updates are only needed
574 * However, updating the window is trivial, so we do it anyway to save
578 ipsec_sa_anti_replay_advance (ipsec_sa_t *sa, u32 thread_index, u32 seq,
584 if (ipsec_sa_is_set_USE_ESN (sa))
586 int wrap = hi_seq - sa->seq_hi;
588 if (wrap == 0 && seq > sa->seq)
591 n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
596 pos = ~seq + sa->seq + 1;
597 n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
603 pos = ~seq + sa->seq + 1;
604 sa->replay_window |= (1ULL << pos);
609 sa->replay_window |= (1ULL << pos);
617 n_lost = ipsec_sa_anti_replay_window_shift (sa, pos);
623 sa->replay_window |= (1ULL << pos);
632 * Makes choice for thread_id should be assigned.
633 * if input ~0, gets random worker_id based on unix_time_now_nsec
636 ipsec_sa_assign_thread (u32 thread_id)
638 return ((thread_id) ? thread_id
639 : (unix_time_now_nsec () % vlib_num_workers ()) + 1);
642 always_inline ipsec_sa_t *
643 ipsec_sa_get (u32 sa_index)
645 return (pool_elt_at_index (ipsec_sa_pool, sa_index));
648 #endif /* __IPSEC_SPD_SA_H__ */
651 * fd.io coding-style-patch-verification: ON
654 * eval: (c-set-style "gnu")