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/esp_decrypt.c | 135 ++++++++++++++++++++++--------------------- 1 file changed, 70 insertions(+), 65 deletions(-) (limited to 'src/vnet/ipsec/esp_decrypt.c') 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; } -- cgit 1.2.3-korg