_(RUNT, "undersized packet") \
_(CHAINED_BUFFER, "chained buffers (packet dropped)") \
_(OVERSIZED_HEADER, "buffer with oversized header (dropped)") \
- _(NO_TAIL_SPACE, "no enough buffer tail space (dropped)")
+ _(NO_TAIL_SPACE, "no enough buffer tail space (dropped)") \
+ _(TUN_NO_PROTO, "no tunnel protocol") \
typedef enum
typedef struct
{
u32 seq;
+ u32 sa_seq;
+ u32 sa_seq_hi;
ipsec_crypto_alg_t crypto_alg;
ipsec_integ_alg_t integ_alg;
} esp_decrypt_trace_t;
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 seq %u",
- format_ipsec_crypto_alg, t->crypto_alg,
- format_ipsec_integ_alg, t->integ_alg, t->seq);
+ 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);
return s;
}
u64 sa_data;
};
+ u32 seq;
i16 current_data;
i16 current_length;
u16 hdr_sz;
} esp_decrypt_packet_data_t;
-STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 2 * sizeof (u64));
+STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 3 * sizeof (u64));
#define ESP_ENCRYPT_PD_F_FD_TRANSPORT (1 << 2)
pd->current_length = b[0]->current_length;
pd->hdr_sz = pd->current_data - vnet_buffer (b[0])->l3_hdr_offset;
payload = b[0]->data + pd->current_data;
+ pd->seq = clib_host_to_net_u32 (((esp_header_t *) payload)->seq);
/* we need 4 extra bytes for HMAC calculation when ESN are used */
if (ipsec_sa_is_set_USE_ESN (sa0) && pd->icv_sz &&
}
/* anti-reply check */
- if (ipsec_sa_anti_replay_check (sa0, &((esp_header_t *) payload)->seq))
+ if (ipsec_sa_anti_replay_check (sa0, pd->seq))
{
b[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY];
next[0] = ESP_DECRYPT_NEXT_DROP;
op->len = len;
if (ipsec_sa_is_set_USE_ESN (sa0))
{
- /* shift ICV for 4 bytes to insert ESN */
+ /* shift ICV by 4 bytes to insert ESN */
+ u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi);
u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa0->seq_hi);
clib_memcpy_fast (tmp, payload + len, ESP_MAX_ICV_SIZE);
- clib_memcpy_fast (payload + len, &sa0->seq_hi, sz);
+ clib_memcpy_fast (payload + len, &seq_hi, sz);
clib_memcpy_fast (payload + len + sz, tmp, ESP_MAX_ICV_SIZE);
op->len += sz;
op->digest += sz;
goto trace;
sa0 = vec_elt_at_index (im->sad, pd->sa_index);
- u8 *payload = b[0]->data + pd->current_data;
- ipsec_sa_anti_replay_advance (sa0, ((esp_header_t *) payload)->seq);
+ /*
+ * redo the anti-reply check
+ * in this frame say we have sequence numbers, s, s+1, s+1, s+1
+ * and s and s+1 are in the window. When we did the anti-replay
+ * check above we did so against the state of the window (W),
+ * after packet s-1. So each of the packets in the sequence will be
+ * accepted.
+ * This time s will be cheked against Ws-1, s+1 chceked against Ws
+ * (i.e. the window state is updated/advnaced)
+ * so this time the successive s+! packet will be dropped.
+ * This is a consequence of batching the decrypts. If the
+ * check-dcrypt-advance process was done for each packet it would
+ * be fine. But we batch the decrypts because it's much more efficient
+ * to do so in SW and if we offload to HW and the process is async.
+ *
+ * You're probably thinking, but this means an attacker can send the
+ * above sequence and cause VPP to perform decrpyts that will fail,
+ * and that's true. But if the attacker can determine s (a valid
+ * sequence number in the window) which is non-trivial, it can generate
+ * 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))
+ {
+ b[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY];
+ next[0] = ESP_DECRYPT_NEXT_DROP;
+ goto trace;
+ }
+
+ ipsec_sa_anti_replay_advance (sa0, pd->seq);
esp_footer_t *f = (esp_footer_t *) (b[0]->data + pd->current_data +
pd->current_length - sizeof (*f) -
&ip4->dst_address) ||
!ip46_address_is_equal_v4 (&itp->itp_tun.dst,
&ip4->src_address))
- next[0] = ESP_DECRYPT_NEXT_DROP;
-
+ {
+ next[0] = ESP_DECRYPT_NEXT_DROP;
+ b[0]->error =
+ node->errors[ESP_DECRYPT_ERROR_TUN_NO_PROTO];
+ }
}
else if (f->next_header == IP_PROTOCOL_IPV6)
{
&ip6->dst_address) ||
!ip46_address_is_equal_v6 (&itp->itp_tun.dst,
&ip6->src_address))
- next[0] = ESP_DECRYPT_NEXT_DROP;
+ {
+ next[0] = ESP_DECRYPT_NEXT_DROP;
+ b[0]->error =
+ node->errors[ESP_DECRYPT_ERROR_TUN_NO_PROTO];
+ }
}
}
}
if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
{
esp_decrypt_trace_t *tr;
- u8 *payload = b[0]->data + pd->current_data;
tr = vlib_add_trace (vm, node, b[0], sizeof (*tr));
sa0 = pool_elt_at_index (im->sad,
vnet_buffer (b[0])->ipsec.sad_index);
tr->crypto_alg = sa0->crypto_alg;
tr->integ_alg = sa0->integ_alg;
- tr->seq = clib_host_to_net_u32 (((esp_header_t *) payload)->seq);
+ tr->seq = pd->seq;
+ tr->sa_seq = sa0->last_seq;
+ tr->sa_seq_hi = sa0->seq_hi;
}
/* next */
.vector_size = sizeof (u32),
.format_trace = format_esp_decrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
-
.n_errors = ARRAY_LEN(esp_decrypt_error_strings),
.error_strings = esp_decrypt_error_strings,
-
- .n_next_nodes = ESP_DECRYPT_N_NEXT,
- .next_nodes = {
-#define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
- foreach_esp_decrypt_next
-#undef _
- },
+ .sibling_of = "esp4-decrypt",
};
VLIB_REGISTER_NODE (esp6_decrypt_tun_node) = {
.vector_size = sizeof (u32),
.format_trace = format_esp_decrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
-
.n_errors = ARRAY_LEN(esp_decrypt_error_strings),
.error_strings = esp_decrypt_error_strings,
-
- .n_next_nodes = ESP_DECRYPT_N_NEXT,
- .next_nodes = {
-#define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
- foreach_esp_decrypt_next
-#undef _
- },
+ .sibling_of = "esp6-decrypt",
};
/* *INDENT-ON* */