From 5b8911020ee5512d76c8daccaa199878ed7cbc01 Mon Sep 17 00:00:00 2001 From: Neale Ranns Date: Mon, 28 Jun 2021 13:31:28 +0000 Subject: ipsec: Fix setting the hi-sequence number for decrypt Type: fix two problems; 1 - just because anti-reply is not enabled doesn't mean the high sequence number should not be used. - fix, there needs to be some means to detect a wrapped packet, so we use a window size of 2^30. 2 - The SA object was used as a scratch pad for the high-sequence number used during decryption. That means that once the batch has been processed the high-sequence number used is lost. This means it is not possible to distinguish this case: if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl)) { ... if (post_decrypt) { if (hi_seq_used == sa->seq_hi) /* the high sequence number used to succesfully decrypt this * packet is the same as the last-sequnence number of the SA. * that means this packet did not cause a wrap. * this packet is thus out of window and should be dropped */ return 1; else /* The packet decrypted with a different high sequence number * to the SA, that means it is the wrap packet and should be * accepted */ return 0; } - fix: don't use the SA as a scratch pad, use the 'packet_data' - the same place that is used as the scratch pad for the low sequence number. other consequences: - An SA doesn't have seq and last_seq, it has only seq; the sequence numnber of the last packet tx'd or rx'd. - there's 64bits of space available on the SA's first cache line. move the AES CTR mode IV there. - test the ESN/AR combinations to catch the bugs this fixes. This doubles the amount of tests, but without AR on they only run for 2 seconds. In the AR tests, the time taken to wait for packets that won't arrive is dropped from 1 to 0.2 seconds thus reducing the runtime of these tests from 10-15 to about 5 sceonds. Signed-off-by: Neale Ranns Change-Id: Iaac78905289a272dc01930d70decd8109cf5e7a5 --- src/vnet/ipsec/ah_decrypt.c | 11 ++- src/vnet/ipsec/esp.h | 7 +- src/vnet/ipsec/esp_decrypt.c | 135 +++++++++++++++++--------------- src/vnet/ipsec/esp_encrypt.c | 16 ++-- src/vnet/ipsec/ipsec_api.c | 12 +-- src/vnet/ipsec/ipsec_format.c | 5 +- src/vnet/ipsec/ipsec_sa.h | 178 +++++++++++++++++++++++++++++++----------- 7 files changed, 229 insertions(+), 135 deletions(-) (limited to 'src') diff --git a/src/vnet/ipsec/ah_decrypt.c b/src/vnet/ipsec/ah_decrypt.c index d192fb6b80a..182ed3d231c 100644 --- a/src/vnet/ipsec/ah_decrypt.c +++ b/src/vnet/ipsec/ah_decrypt.c @@ -98,6 +98,7 @@ typedef struct }; u32 sa_index; u32 seq; + u32 seq_hi; u8 icv_padding_len; u8 icv_size; u8 ip_hdr_size; @@ -221,7 +222,8 @@ ah_decrypt_inline (vlib_main_t * vm, pd->seq = clib_host_to_net_u32 (ah0->seq_no); /* anti-replay check */ - if (ipsec_sa_anti_replay_check (sa0, pd->seq)) + if (ipsec_sa_anti_replay_and_sn_advance (sa0, pd->seq, ~0, false, + &pd->seq_hi)) { b[0]->error = node->errors[AH_DECRYPT_ERROR_REPLAY]; next[0] = AH_DECRYPT_NEXT_DROP; @@ -257,7 +259,7 @@ ah_decrypt_inline (vlib_main_t * vm, op->user_data = b - bufs; if (ipsec_sa_is_set_USE_ESN (sa0)) { - u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi); + u32 seq_hi = clib_host_to_net_u32 (pd->seq_hi); op->len += sizeof (seq_hi); clib_memcpy (op->src + b[0]->current_length, &seq_hi, @@ -322,13 +324,14 @@ ah_decrypt_inline (vlib_main_t * vm, if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE)) { /* redo the anit-reply check. see esp_decrypt for details */ - if (ipsec_sa_anti_replay_check (sa0, pd->seq)) + if (ipsec_sa_anti_replay_and_sn_advance (sa0, pd->seq, pd->seq_hi, + true, NULL)) { b[0]->error = node->errors[AH_DECRYPT_ERROR_REPLAY]; next[0] = AH_DECRYPT_NEXT_DROP; goto trace; } - ipsec_sa_anti_replay_advance (sa0, pd->seq); + ipsec_sa_anti_replay_advance (sa0, pd->seq, pd->seq_hi); } u16 ah_hdr_len = sizeof (ah_header_t) + pd->icv_size diff --git a/src/vnet/ipsec/esp.h b/src/vnet/ipsec/esp.h index a0643c3b939..d179233df49 100644 --- a/src/vnet/ipsec/esp.h +++ b/src/vnet/ipsec/esp.h @@ -118,7 +118,8 @@ esp_seq_advance (ipsec_sa_t * sa) } always_inline u16 -esp_aad_fill (u8 * data, const esp_header_t * esp, const ipsec_sa_t * sa) +esp_aad_fill (u8 *data, const esp_header_t *esp, const ipsec_sa_t *sa, + u32 seq_hi) { esp_aead_t *aad; @@ -128,7 +129,7 @@ esp_aad_fill (u8 * data, const esp_header_t * esp, const ipsec_sa_t * sa) if (ipsec_sa_is_set_USE_ESN (sa)) { /* SPI, seq-hi, seq-low */ - aad->data[1] = (u32) clib_host_to_net_u32 (sa->seq_hi); + aad->data[1] = (u32) clib_host_to_net_u32 (seq_hi); aad->data[2] = esp->seq; return 12; } @@ -199,7 +200,7 @@ typedef struct i16 current_length; u16 hdr_sz; u16 is_chain; - u32 protect_index; + u32 seq_hi; } esp_decrypt_packet_data_t; STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 3 * sizeof (u64)); diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c index ec6d9811806..b700f2c9935 100644 --- a/src/vnet/ipsec/esp_decrypt.c +++ b/src/vnet/ipsec/esp_decrypt.c @@ -92,10 +92,14 @@ typedef struct u32 seq; u32 sa_seq; u32 sa_seq_hi; + u32 pkt_seq_hi; ipsec_crypto_alg_t crypto_alg; ipsec_integ_alg_t integ_alg; } esp_decrypt_trace_t; +/* The number of byres in the hisequence number */ +#define N_HI_ESN_BYTES 4 + /* packet trace format function */ static u8 * format_esp_decrypt_trace (u8 * s, va_list * args) @@ -104,11 +108,11 @@ format_esp_decrypt_trace (u8 * s, va_list * args) CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *); - s = - format (s, - "esp: crypto %U integrity %U pkt-seq %d sa-seq %u sa-seq-hi %u", - format_ipsec_crypto_alg, t->crypto_alg, format_ipsec_integ_alg, - t->integ_alg, t->seq, t->sa_seq, t->sa_seq_hi); + s = format (s, + "esp: crypto %U integrity %U pkt-seq %d sa-seq %u sa-seq-hi %u " + "pkt-seq-hi %u", + format_ipsec_crypto_alg, t->crypto_alg, format_ipsec_integ_alg, + t->integ_alg, t->seq, t->sa_seq, t->sa_seq_hi, t->pkt_seq_hi); return s; } @@ -235,40 +239,41 @@ esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first, return lb_curr; } -static_always_inline i16 -esp_insert_esn (vlib_main_t * vm, ipsec_sa_t * sa, - esp_decrypt_packet_data2_t * pd2, u32 * data_len, - u8 ** digest, u16 * len, vlib_buffer_t * b, u8 * payload) +static_always_inline u16 +esp_insert_esn (vlib_main_t *vm, ipsec_sa_t *sa, esp_decrypt_packet_data_t *pd, + esp_decrypt_packet_data2_t *pd2, u32 *data_len, u8 **digest, + u16 *len, vlib_buffer_t *b, u8 *payload) { if (!ipsec_sa_is_set_USE_ESN (sa)) return 0; - /* shift ICV by 4 bytes to insert ESN */ - u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi); - u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa->seq_hi); + u32 seq_hi = clib_host_to_net_u32 (pd->seq_hi); + u8 tmp[ESP_MAX_ICV_SIZE]; if (pd2->icv_removed) { u16 space_left = vlib_buffer_space_left_at_end (vm, pd2->lb); - if (space_left >= sz) + if (space_left >= N_HI_ESN_BYTES) { - clib_memcpy_fast (vlib_buffer_get_tail (pd2->lb), &seq_hi, sz); - *data_len += sz; + clib_memcpy_fast (vlib_buffer_get_tail (pd2->lb), &seq_hi, + N_HI_ESN_BYTES); + *data_len += N_HI_ESN_BYTES; } else - return sz; + return N_HI_ESN_BYTES; len[0] = b->current_length; } else { clib_memcpy_fast (tmp, payload + len[0], ESP_MAX_ICV_SIZE); - clib_memcpy_fast (payload + len[0], &seq_hi, sz); - clib_memcpy_fast (payload + len[0] + sz, tmp, ESP_MAX_ICV_SIZE); - *data_len += sz; - *digest += sz; + clib_memcpy_fast (payload + len[0], &seq_hi, N_HI_ESN_BYTES); + clib_memcpy_fast (payload + len[0] + N_HI_ESN_BYTES, tmp, + ESP_MAX_ICV_SIZE); + *data_len += N_HI_ESN_BYTES; + *digest += N_HI_ESN_BYTES; } - return sz; + return N_HI_ESN_BYTES; } static_always_inline u8 * @@ -284,14 +289,14 @@ esp_move_icv_esn (vlib_main_t * vm, vlib_buffer_t * first, if (ipsec_sa_is_set_USE_ESN (sa)) { - u8 sz = sizeof (sa->seq_hi); - u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi); + u32 seq_hi = clib_host_to_net_u32 (pd->seq_hi); u16 space_left = vlib_buffer_space_left_at_end (vm, pd2->lb); - if (space_left >= sz) + if (space_left >= N_HI_ESN_BYTES) { - clib_memcpy_fast (vlib_buffer_get_tail (pd2->lb), &seq_hi, sz); - *len += sz; + clib_memcpy_fast (vlib_buffer_get_tail (pd2->lb), &seq_hi, + N_HI_ESN_BYTES); + *len += N_HI_ESN_BYTES; } else { @@ -299,7 +304,8 @@ esp_move_icv_esn (vlib_main_t * vm, vlib_buffer_t * first, * (with ICV data) */ ASSERT (pd2->icv_removed); vlib_buffer_t *tmp = vlib_get_buffer (vm, pd2->free_buffer_index); - clib_memcpy_fast (vlib_buffer_get_current (tmp) - sz, &seq_hi, sz); + clib_memcpy_fast (vlib_buffer_get_current (tmp) - N_HI_ESN_BYTES, + &seq_hi, N_HI_ESN_BYTES); extra_esn[0] = 1; } } @@ -307,11 +313,12 @@ esp_move_icv_esn (vlib_main_t * vm, vlib_buffer_t * first, } static_always_inline int -esp_decrypt_chain_integ (vlib_main_t * vm, ipsec_per_thread_data_t * ptd, - esp_decrypt_packet_data2_t * pd2, - ipsec_sa_t * sa0, vlib_buffer_t * b, u8 icv_sz, - u8 * start_src, u32 start_len, - u8 ** digest, u16 * n_ch, u32 * integ_total_len) +esp_decrypt_chain_integ (vlib_main_t *vm, ipsec_per_thread_data_t *ptd, + const esp_decrypt_packet_data_t *pd, + esp_decrypt_packet_data2_t *pd2, ipsec_sa_t *sa0, + vlib_buffer_t *b, u8 icv_sz, u8 *start_src, + u32 start_len, u8 **digest, u16 *n_ch, + u32 *integ_total_len) { vnet_crypto_op_chunk_t *ch; vlib_buffer_t *cb = vlib_get_buffer (vm, b->next_buffer); @@ -334,19 +341,19 @@ esp_decrypt_chain_integ (vlib_main_t * vm, ipsec_per_thread_data_t * ptd, ch->len = cb->current_length - icv_sz; if (ipsec_sa_is_set_USE_ESN (sa0)) { - u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi); - u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa0->seq_hi); + u32 seq_hi = clib_host_to_net_u32 (pd->seq_hi); + u8 tmp[ESP_MAX_ICV_SIZE]; u8 *esn; vlib_buffer_t *tmp_b; u16 space_left = vlib_buffer_space_left_at_end (vm, pd2->lb); - if (space_left < sz) + if (space_left < N_HI_ESN_BYTES) { if (pd2->icv_removed) { /* use pre-data area from the last bufer that was removed from the chain */ tmp_b = vlib_get_buffer (vm, pd2->free_buffer_index); - esn = tmp_b->data - sz; + esn = tmp_b->data - N_HI_ESN_BYTES; } else { @@ -358,28 +365,29 @@ esp_decrypt_chain_integ (vlib_main_t * vm, ipsec_per_thread_data_t * ptd, esn = tmp_b->data; pd2->free_buffer_index = tmp_bi; } - clib_memcpy_fast (esn, &seq_hi, sz); + clib_memcpy_fast (esn, &seq_hi, N_HI_ESN_BYTES); vec_add2 (ptd->chunks, ch, 1); n_chunks += 1; ch->src = esn; - ch->len = sz; + ch->len = N_HI_ESN_BYTES; } else { if (pd2->icv_removed) { - clib_memcpy_fast (vlib_buffer_get_tail - (pd2->lb), &seq_hi, sz); + clib_memcpy_fast (vlib_buffer_get_tail (pd2->lb), + &seq_hi, N_HI_ESN_BYTES); } else { clib_memcpy_fast (tmp, *digest, ESP_MAX_ICV_SIZE); - clib_memcpy_fast (*digest, &seq_hi, sz); - clib_memcpy_fast (*digest + sz, tmp, ESP_MAX_ICV_SIZE); - *digest += sz; + clib_memcpy_fast (*digest, &seq_hi, N_HI_ESN_BYTES); + clib_memcpy_fast (*digest + N_HI_ESN_BYTES, tmp, + ESP_MAX_ICV_SIZE); + *digest += N_HI_ESN_BYTES; } - ch->len += sz; + ch->len += N_HI_ESN_BYTES; } } total_len += ch->len; @@ -540,7 +548,7 @@ esp_decrypt_prepare_sync_op (vlib_main_t * vm, vlib_node_runtime_t * node, op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS; op->chunk_index = vec_len (ptd->chunks); - if (esp_decrypt_chain_integ (vm, ptd, pd2, sa0, b, icv_sz, + if (esp_decrypt_chain_integ (vm, ptd, pd, pd2, sa0, b, icv_sz, payload, pd->current_length, &op->digest, &op->n_chunks, 0) < 0) { @@ -550,7 +558,7 @@ esp_decrypt_prepare_sync_op (vlib_main_t * vm, vlib_node_runtime_t * node, } } else - esp_insert_esn (vm, sa0, pd2, &op->len, &op->digest, &len, b, + esp_insert_esn (vm, sa0, pd, pd2, &op->len, &op->digest, &len, b, payload); out: vec_add_aligned (*(integ_ops[0]), op, 1, CLIB_CACHE_LINE_BYTES); @@ -576,7 +584,7 @@ esp_decrypt_prepare_sync_op (vlib_main_t * vm, vlib_node_runtime_t * node, /* constuct aad in a scratch space in front of the nonce */ esp_header_t *esp0 = (esp_header_t *) (payload - esp_sz); op->aad = (u8 *) nonce - sizeof (esp_aead_t); - op->aad_len = esp_aad_fill (op->aad, esp0, sa0); + op->aad_len = esp_aad_fill (op->aad, esp0, sa0, pd->seq_hi); op->tag = payload + len; op->tag_len = 16; } @@ -617,7 +625,6 @@ esp_decrypt_prepare_async_frame (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_buffer_t *b, u16 *next, u16 async_next) { const u8 esp_sz = sizeof (esp_header_t); - u32 current_protect_index = vnet_buffer (b)->ipsec.protect_index; esp_decrypt_packet_data_t *async_pd = &(esp_post_data (b))->decrypt_data; esp_decrypt_packet_data2_t *async_pd2 = esp_post_data2 (b); u8 *tag = payload + len, *iv = payload + esp_sz, *aad = 0; @@ -671,16 +678,16 @@ esp_decrypt_prepare_async_frame (vlib_main_t *vm, vlib_node_runtime_t *node, tag = vlib_buffer_get_tail (pd2->lb) - icv_sz; flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS; - if (esp_decrypt_chain_integ (vm, ptd, pd2, sa0, b, icv_sz, payload, - pd->current_length, &tag, - 0, &integ_len) < 0) + if (esp_decrypt_chain_integ (vm, ptd, pd, pd2, sa0, b, icv_sz, + payload, pd->current_length, &tag, 0, + &integ_len) < 0) { /* allocate buffer failed, will not add to frame and drop */ return (ESP_DECRYPT_ERROR_NO_BUFFERS); } } else - esp_insert_esn (vm, sa0, pd2, &integ_len, &tag, &len, b, payload); + esp_insert_esn (vm, sa0, pd, pd2, &integ_len, &tag, &len, b, payload); } else key_index = sa0->crypto_key_index; @@ -701,7 +708,7 @@ out: /* constuct aad in a scratch space in front of the nonce */ esp_header_t *esp0 = (esp_header_t *) (payload - esp_sz); aad = (u8 *) nonce - sizeof (esp_aead_t); - esp_aad_fill (aad, esp0, sa0); + esp_aad_fill (aad, esp0, sa0, pd->seq_hi); tag = payload + len; } else @@ -730,7 +737,6 @@ out: *async_pd = *pd; *async_pd2 = *pd2; - pd->protect_index = current_protect_index; /* for AEAD integ_len - crypto_len will be negative, it is ok since it * is ignored by the engine. */ @@ -776,14 +782,15 @@ esp_decrypt_post_crypto (vlib_main_t * vm, vlib_node_runtime_t * node, * a sequence s, s+1, s+2, s+3, ... s+n and nothing will prevent any * implementation, sequential or batching, from decrypting these. */ - if (ipsec_sa_anti_replay_check (sa0, pd->seq)) + if (ipsec_sa_anti_replay_and_sn_advance (sa0, pd->seq, pd->seq_hi, true, + NULL)) { b->error = node->errors[ESP_DECRYPT_ERROR_REPLAY]; next[0] = ESP_DECRYPT_NEXT_DROP; return; } - ipsec_sa_anti_replay_advance (sa0, pd->seq); + ipsec_sa_anti_replay_advance (sa0, pd->seq, pd->seq_hi); if (pd->is_chain) { @@ -968,12 +975,8 @@ esp_decrypt_post_crypto (vlib_main_t * vm, vlib_node_runtime_t * node, */ const ipsec_tun_protect_t *itp; - if (is_async) - itp = ipsec_tun_protect_get (pd->protect_index); - else - itp = - ipsec_tun_protect_get (vnet_buffer (b)-> - ipsec.protect_index); + itp = + ipsec_tun_protect_get (vnet_buffer (b)->ipsec.protect_index); if (PREDICT_TRUE (next_header == IP_PROTOCOL_IP_IN_IP)) { @@ -1148,7 +1151,8 @@ esp_decrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, pd->current_length = b[0]->current_length; /* anti-reply check */ - if (ipsec_sa_anti_replay_check (sa0, pd->seq)) + if (ipsec_sa_anti_replay_and_sn_advance (sa0, pd->seq, ~0, false, + &pd->seq_hi)) { err = ESP_DECRYPT_ERROR_REPLAY; esp_set_next_index (b[0], node, err, n_noop, noop_nexts, @@ -1306,8 +1310,9 @@ esp_decrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, tr->crypto_alg = sa0->crypto_alg; tr->integ_alg = sa0->integ_alg; tr->seq = pd->seq; - tr->sa_seq = sa0->last_seq; + tr->sa_seq = sa0->seq; tr->sa_seq_hi = sa0->seq_hi; + tr->pkt_seq_hi = pd->seq_hi; } /* next */ @@ -1374,7 +1379,7 @@ esp_decrypt_post_inline (vlib_main_t * vm, tr->crypto_alg = sa0->crypto_alg; tr->integ_alg = sa0->integ_alg; tr->seq = pd->seq; - tr->sa_seq = sa0->last_seq; + tr->sa_seq = sa0->seq; tr->sa_seq_hi = sa0->seq_hi; } diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c index 68aeb60885c..da9c56a7e03 100644 --- a/src/vnet/ipsec/esp_encrypt.c +++ b/src/vnet/ipsec/esp_encrypt.c @@ -379,7 +379,7 @@ esp_encrypt_chain_integ (vlib_main_t * vm, ipsec_per_thread_data_t * ptd, always_inline void esp_prepare_sync_op (vlib_main_t *vm, ipsec_per_thread_data_t *ptd, vnet_crypto_op_t **crypto_ops, - vnet_crypto_op_t **integ_ops, ipsec_sa_t *sa0, + vnet_crypto_op_t **integ_ops, ipsec_sa_t *sa0, u32 seq_hi, u8 *payload, u16 payload_len, u8 iv_sz, u8 icv_sz, u32 bi, vlib_buffer_t **b, vlib_buffer_t *lb, u32 hdr_len, esp_header_t *esp) @@ -408,7 +408,7 @@ esp_prepare_sync_op (vlib_main_t *vm, ipsec_per_thread_data_t *ptd, { /* constuct aad in a scratch space in front of the nonce */ op->aad = (u8 *) nonce - sizeof (esp_aead_t); - op->aad_len = esp_aad_fill (op->aad, esp, sa0); + op->aad_len = esp_aad_fill (op->aad, esp, sa0, seq_hi); op->tag = payload + op->len; op->tag_len = 16; } @@ -465,8 +465,8 @@ esp_prepare_sync_op (vlib_main_t *vm, ipsec_per_thread_data_t *ptd, } else if (ipsec_sa_is_set_USE_ESN (sa0)) { - u32 seq_hi = clib_net_to_host_u32 (sa0->seq_hi); - clib_memcpy_fast (op->digest, &seq_hi, sizeof (seq_hi)); + u32 tmp = clib_net_to_host_u32 (seq_hi); + clib_memcpy_fast (op->digest, &tmp, sizeof (seq_hi)); op->len += sizeof (seq_hi); } } @@ -508,7 +508,7 @@ esp_prepare_async_frame (vlib_main_t *vm, ipsec_per_thread_data_t *ptd, { /* constuct aad in a scratch space in front of the nonce */ aad = (u8 *) nonce - sizeof (esp_aead_t); - esp_aad_fill (aad, esp, sa); + esp_aad_fill (aad, esp, sa, sa->seq_hi); key_index = sa->crypto_key_index; } else @@ -956,9 +956,9 @@ esp_encrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, async_next_node, lb); } else - esp_prepare_sync_op (vm, ptd, crypto_ops, integ_ops, sa0, payload, - payload_len, iv_sz, icv_sz, n_sync, b, lb, - hdr_len, esp); + esp_prepare_sync_op (vm, ptd, crypto_ops, integ_ops, sa0, sa0->seq_hi, + payload, payload_len, iv_sz, icv_sz, n_sync, b, + lb, hdr_len, esp); vlib_buffer_advance (b[0], 0LL - hdr_len); diff --git a/src/vnet/ipsec/ipsec_api.c b/src/vnet/ipsec/ipsec_api.c index 73f4474a604..11bfa41b4f1 100644 --- a/src/vnet/ipsec/ipsec_api.c +++ b/src/vnet/ipsec/ipsec_api.c @@ -826,11 +826,11 @@ send_ipsec_sa_details (ipsec_sa_t * sa, void *arg) } mp->seq_outbound = clib_host_to_net_u64 (((u64) sa->seq)); - mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->last_seq)); + mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->seq)); if (ipsec_sa_is_set_USE_ESN (sa)) { mp->seq_outbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); - mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->last_seq_hi)); + mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); } if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) mp->replay_window = clib_host_to_net_u64 (sa->replay_window); @@ -913,11 +913,11 @@ send_ipsec_sa_v2_details (ipsec_sa_t * sa, void *arg) mp->entry.dscp = ip_dscp_encode (sa->tunnel.t_dscp); mp->seq_outbound = clib_host_to_net_u64 (((u64) sa->seq)); - mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->last_seq)); + mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->seq)); if (ipsec_sa_is_set_USE_ESN (sa)) { mp->seq_outbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); - mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->last_seq_hi)); + mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); } if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) mp->replay_window = clib_host_to_net_u64 (sa->replay_window); @@ -993,11 +993,11 @@ send_ipsec_sa_v3_details (ipsec_sa_t *sa, void *arg) } mp->seq_outbound = clib_host_to_net_u64 (((u64) sa->seq)); - mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->last_seq)); + mp->last_seq_inbound = clib_host_to_net_u64 (((u64) sa->seq)); if (ipsec_sa_is_set_USE_ESN (sa)) { mp->seq_outbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); - mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->last_seq_hi)); + mp->last_seq_inbound |= (u64) (clib_host_to_net_u32 (sa->seq_hi)); } if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) mp->replay_window = clib_host_to_net_u64 (sa->replay_window); diff --git a/src/vnet/ipsec/ipsec_format.c b/src/vnet/ipsec/ipsec_format.c index b67c11da1cd..5f7caab44e4 100644 --- a/src/vnet/ipsec/ipsec_format.c +++ b/src/vnet/ipsec/ipsec_format.c @@ -293,9 +293,8 @@ format_ipsec_sa (u8 * s, va_list * args) s = format (s, "\n salt 0x%x", clib_net_to_host_u32 (sa->salt)); s = format (s, "\n thread-index:%d", sa->thread_index); s = format (s, "\n seq %u seq-hi %u", sa->seq, sa->seq_hi); - s = format (s, "\n last-seq %u last-seq-hi %u window %U", - sa->last_seq, sa->last_seq_hi, - format_ipsec_replay_window, sa->replay_window); + s = format (s, "\n window %U", format_ipsec_replay_window, + sa->replay_window); s = format (s, "\n crypto alg %U", format_ipsec_crypto_alg, sa->crypto_alg); if (sa->crypto_alg && (flags & IPSEC_FORMAT_INSECURE)) diff --git a/src/vnet/ipsec/ipsec_sa.h b/src/vnet/ipsec/ipsec_sa.h index 7827ef18084..14461ad2cdd 100644 --- a/src/vnet/ipsec/ipsec_sa.h +++ b/src/vnet/ipsec/ipsec_sa.h @@ -131,9 +131,8 @@ typedef struct u32 spi; u32 seq; u32 seq_hi; - u32 last_seq; - u32 last_seq_hi; u64 replay_window; + u64 ctr_iv_counter; dpo_id_t dpo; vnet_crypto_key_index_t crypto_key_index; @@ -162,7 +161,6 @@ typedef struct CLIB_CACHE_LINE_ALIGN_MARK (cacheline1); - u64 ctr_iv_counter; union { ip4_header_t ip4_hdr; @@ -312,45 +310,104 @@ extern uword unformat_ipsec_key (unformat_input_t * input, va_list * args); */ #define IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND(_tl) (_tl - IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE + 1) +always_inline int +ipsec_sa_anti_replay_check (const ipsec_sa_t *sa, u32 seq) +{ + if (ipsec_sa_is_set_USE_ANTI_REPLAY (sa) && + sa->replay_window & (1ULL << (sa->seq - seq))) + return 1; + else + return 0; +} + /* * Anti replay check. * inputs need to be in host byte order. + * + * The function runs in two contexts. pre and post decrypt. + * Pre-decrypt it: + * 1 - determines if a packet is a replay - a simple check in the window + * 2 - returns the hi-seq number that should be used to decrypt. + * post-decrypt: + * Checks whether the packet is a replay or falls out of window + * + * This funcion should be called even without anti-replay enabled to ensure + * the high sequence number is set. */ always_inline int -ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) +ipsec_sa_anti_replay_and_sn_advance (const ipsec_sa_t *sa, u32 seq, + u32 hi_seq_used, bool post_decrypt, + u32 *hi_seq_req) { - u32 diff, tl, th; - - if ((sa->flags & IPSEC_SA_FLAG_USE_ANTI_REPLAY) == 0) - return 0; + ASSERT ((post_decrypt == false) == (hi_seq_req != 0)); if (!ipsec_sa_is_set_USE_ESN (sa)) { - if (PREDICT_TRUE (seq > sa->last_seq)) + if (hi_seq_req) + /* no ESN, therefore the hi-seq is always 0 */ + *hi_seq_req = 0; + + if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) return 0; - diff = sa->last_seq - seq; + if (PREDICT_TRUE (seq > sa->seq)) + return 0; + + u32 diff = sa->seq - seq; if (IPSEC_SA_ANTI_REPLAY_WINDOW_SIZE > diff) - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; + 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))) + if (!ipsec_sa_is_set_USE_ANTI_REPLAY (sa)) + { + /* there's no AR configured for this SA, but in order + * to know whether a packet has wrapped the hi ESN we need + * to know whether it is out of window. if we use the default + * lower bound then we are effectively forcing AR because + * out of window packets will get the increased hi seq number + * and will thus fail to decrypt. IOW we need a window to know + * if the SN has wrapped, but we don't want a window to check for + * anti replay. to resolve the contradiction we use a huge window. + * if the packet is not within 2^30 of the current SN, we'll consider + * it a wrap. + */ + if (hi_seq_req) + { + if (seq >= sa->seq) + /* The packet's sequence number is larger that the SA's. + * that can't be a warp - unless we lost more than + * 2^32 packets ... how could we know? */ + *hi_seq_req = sa->seq_hi; + else + { + /* The packet's SN is less than the SAs, so either the SN has + * wrapped or the SN is just old. */ + if (sa->seq - seq > (1 << 30)) + /* It's really really really old => it wrapped */ + *hi_seq_req = sa->seq_hi + 1; + else + *hi_seq_req = sa->seq_hi; + } + } + /* + * else + * this is post-decrpyt and since it decrypted we accept it + */ + return 0; + } + if (PREDICT_TRUE (sa->seq >= (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)) + if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (sa->seq)) { /* * the received sequence number is lower than the lower bound @@ -358,8 +415,28 @@ ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) * the high sequence number has wrapped. if it decrypts corrently * then it's the latter. */ - sa->seq_hi = th + 1; - return 0; + if (post_decrypt) + { + if (hi_seq_used == sa->seq_hi) + /* the high sequence number used to succesfully decrypt this + * packet is the same as the last-sequnence number of the SA. + * that means this packet did not cause a wrap. + * this packet is thus out of window and should be dropped */ + return 1; + else + /* The packet decrypted with a different high sequence number + * to the SA, that means it is the wrap packet and should be + * accepted */ + return 0; + } + else + { + /* pre-decrypt it might be the might that casues a wrap, we + * need to decrpyt to find out */ + if (hi_seq_req) + *hi_seq_req = sa->seq_hi + 1; + return 0; + } } else { @@ -367,13 +444,14 @@ ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) * the recieved sequence number greater than the low * end of the window. */ - sa->seq_hi = th; - if (seq <= tl) + if (hi_seq_req) + *hi_seq_req = sa->seq_hi; + if (seq <= sa->seq) /* * The recieved seq number is within bounds of the window * check if it's a duplicate */ - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; + return (ipsec_sa_anti_replay_check (sa, seq)); else /* * The received sequence number is greater than the window @@ -393,19 +471,20 @@ ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) * RHS will be a larger number. * Case B from RFC4303 Appendix A. */ - if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (tl)) + if (seq < IPSEC_SA_ANTI_REPLAY_WINDOW_LOWER_BOUND (sa->seq)) { /* * the sequence number is less than the lower bound. */ - if (seq <= tl) + if (seq <= sa->seq) { /* * the packet is within the window upper bound. * check for duplicates. */ - sa->seq_hi = th; - return (sa->replay_window & (1ULL << diff)) ? 1 : 0; + if (hi_seq_req) + *hi_seq_req = sa->seq_hi; + return (ipsec_sa_anti_replay_check (sa, seq)); } else { @@ -418,7 +497,8 @@ ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) * wrapped the high sequence again. If it were the latter then * we've lost close to 2^32 packets. */ - sa->seq_hi = th; + if (hi_seq_req) + *hi_seq_req = sa->seq_hi; return 0; } } @@ -431,73 +511,79 @@ ipsec_sa_anti_replay_check (ipsec_sa_t * sa, u32 seq) * 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; + if (hi_seq_req) + *hi_seq_req = sa->seq_hi - 1; + return (ipsec_sa_anti_replay_check (sa, seq)); } } + /* unhandled case */ + ASSERT (0); return 0; } /* * Anti replay window advance * inputs need to be in host byte order. + * This function both advances the anti-replay window and the sequence number + * We always need to move on the SN but the window updates are only needed + * if AR is on. + * However, updating the window is trivial, so we do it anyway to save + * the branch cost. */ always_inline void -ipsec_sa_anti_replay_advance (ipsec_sa_t * sa, u32 seq) +ipsec_sa_anti_replay_advance (ipsec_sa_t *sa, u32 seq, u32 hi_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)) + if (ipsec_sa_is_set_USE_ESN (sa)) { - int wrap = sa->seq_hi - sa->last_seq_hi; + int wrap = hi_seq - sa->seq_hi; - if (wrap == 0 && seq > sa->last_seq) + if (wrap == 0 && seq > sa->seq) { - pos = seq - sa->last_seq; + pos = seq - sa->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; + sa->seq = seq; } else if (wrap > 0) { - pos = ~seq + sa->last_seq + 1; + pos = ~seq + sa->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; + sa->seq = seq; + sa->seq_hi = hi_seq; } else if (wrap < 0) { - pos = ~seq + sa->last_seq + 1; + pos = ~seq + sa->seq + 1; sa->replay_window |= (1ULL << pos); } else { - pos = sa->last_seq - seq; + pos = sa->seq - seq; sa->replay_window |= (1ULL << pos); } } else { - if (seq > sa->last_seq) + if (seq > sa->seq) { - pos = seq - sa->last_seq; + pos = seq - sa->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; + sa->seq = seq; } else { - pos = sa->last_seq - seq; + pos = sa->seq - seq; sa->replay_window |= (1ULL << pos); } } -- cgit 1.2.3-korg