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-rw-r--r--src/vnet/crypto/crypto.h4
-rw-r--r--src/vnet/ipsec/esp_encrypt.c88
-rw-r--r--src/vnet/ipsec/ipsec_sa.h2
3 files changed, 72 insertions, 22 deletions
diff --git a/src/vnet/crypto/crypto.h b/src/vnet/crypto/crypto.h
index b0a83e08be3..1bb6a04c0ee 100644
--- a/src/vnet/crypto/crypto.h
+++ b/src/vnet/crypto/crypto.h
@@ -304,7 +304,7 @@ typedef struct
i16 integ_start_offset;
u32 crypto_total_length;
/* adj total_length for integ, e.g.4 bytes for IPSec ESN */
- u16 integ_length_adj;
+ i16 integ_length_adj;
u8 *iv;
union
{
@@ -573,7 +573,7 @@ vnet_crypto_async_add_to_frame (vlib_main_t * vm,
u32 key_index,
u32 crypto_len, i16 integ_len_adj,
i16 crypto_start_offset,
- u16 integ_start_offset,
+ i16 integ_start_offset,
u32 buffer_index,
u16 next_node,
u8 * iv, u8 * tag, u8 * aad, u8 flags)
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 8b722ef541f..c7030d313a2 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -234,6 +234,24 @@ esp_get_ip6_hdr_len (ip6_header_t * ip6, ip6_ext_header_t ** ext_hdr)
return len;
}
+/* IPsec IV generation: IVs requirements differ depending of the
+ * encryption mode: IVs must be unpredictable for AES-CBC whereas it can
+ * be predictable but should never be reused with the same key material
+ * for CTR and GCM.
+ * We use a packet counter as the IV for CTR and GCM, and to ensure the
+ * IV is unpredictable for CBC, it is then encrypted using the same key
+ * as the message. You can refer to NIST SP800-38a and NIST SP800-38d
+ * for more details. */
+static_always_inline void *
+esp_generate_iv (ipsec_sa_t * sa, void *payload, int iv_sz)
+{
+ ASSERT (iv_sz >= sizeof (u64));
+ u64 *iv = (u64 *) (payload - iv_sz);
+ clib_memset_u8 (iv, 0, iv_sz);
+ *iv = sa->iv_counter++;
+ return iv;
+}
+
static_always_inline void
esp_process_chained_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
vnet_crypto_op_t * ops, vlib_buffer_t * b[],
@@ -396,10 +414,16 @@ esp_prepare_sync_op (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
vnet_crypto_op_t *op;
vec_add2_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
vnet_crypto_op_init (op, sa0->crypto_enc_op_id);
+ u8 *crypto_start = payload;
+ /* esp_add_footer_and_icv() in esp_encrypt_inline() makes sure we always
+ * have enough space for ESP header and footer which includes ICV */
+ ASSERT (payload_len > icv_sz);
+ u16 crypto_len = payload_len - icv_sz;
+
+ /* generate the IV in front of the payload */
+ void *pkt_iv = esp_generate_iv (sa0, payload, iv_sz);
- op->src = op->dst = payload;
op->key_index = sa0->crypto_key_index;
- op->len = payload_len - icv_sz;
op->user_data = b - bufs;
if (ipsec_sa_is_set_IS_AEAD (sa0))
@@ -411,18 +435,21 @@ esp_prepare_sync_op (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
op->aad = payload - hdr_len - sizeof (esp_aead_t);
op->aad_len = esp_aad_fill (op->aad, esp, sa0);
- op->tag = payload + op->len;
+ op->tag = payload + crypto_len;
op->tag_len = 16;
- u64 *iv = (u64 *) (payload - iv_sz);
nonce->salt = sa0->salt;
- nonce->iv = *iv = clib_host_to_net_u64 (sa0->gcm_iv_counter++);
+ nonce->iv = *(u64 *) pkt_iv;
op->iv = (u8 *) nonce;
}
else
{
- op->iv = payload - iv_sz;
- op->flags = VNET_CRYPTO_OP_FLAG_INIT_IV;
+ /* construct zero iv in front of the IP header */
+ op->iv = pkt_iv - hdr_len - iv_sz;
+ clib_memset_u8 (op->iv, 0, iv_sz);
+ /* include iv field in crypto */
+ crypto_start -= iv_sz;
+ crypto_len += iv_sz;
}
if (lb != b[0])
@@ -431,8 +458,15 @@ esp_prepare_sync_op (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
op->chunk_index = vec_len (ptd->chunks);
op->tag = vlib_buffer_get_tail (lb) - icv_sz;
- esp_encrypt_chain_crypto (vm, ptd, sa0, b[0], lb, icv_sz, payload,
- payload_len, &op->n_chunks);
+ esp_encrypt_chain_crypto (vm, ptd, sa0, b[0], lb, icv_sz,
+ crypto_start, crypto_len + icv_sz,
+ &op->n_chunks);
+ }
+ else
+ {
+ /* not chained */
+ op->src = op->dst = crypto_start;
+ op->len = crypto_len;
}
}
@@ -482,17 +516,20 @@ esp_prepare_async_frame (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
u8 *tag, *iv, *aad = 0;
u8 flag = 0;
u32 key_index;
- i16 crypto_start_offset, integ_start_offset = 0;
+ i16 crypto_start_offset, integ_start_offset;
u16 crypto_total_len, integ_total_len;
post->next_index = next[0];
next[0] = ESP_ENCRYPT_NEXT_PENDING;
/* crypto */
- crypto_start_offset = payload - b->data;
+ crypto_start_offset = integ_start_offset = payload - b->data;
crypto_total_len = integ_total_len = payload_len - icv_sz;
tag = payload + crypto_total_len;
+ /* generate the IV in front of the payload */
+ void *pkt_iv = esp_generate_iv (sa, payload, iv_sz);
+
/* aead */
if (ipsec_sa_is_set_IS_AEAD (sa))
{
@@ -503,7 +540,7 @@ esp_prepare_async_frame (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
esp_aad_fill (aad, esp, sa);
nonce = (esp_gcm_nonce_t *) (aad - sizeof (*nonce));
nonce->salt = sa->salt;
- nonce->iv = *pkt_iv = clib_host_to_net_u64 (sa->gcm_iv_counter++);
+ nonce->iv = *(u64 *) pkt_iv;
iv = (u8 *) nonce;
key_index = sa->crypto_key_index;
@@ -513,25 +550,38 @@ esp_prepare_async_frame (vlib_main_t * vm, ipsec_per_thread_data_t * ptd,
flag |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
tag = vlib_buffer_get_tail (lb) - icv_sz;
crypto_total_len = esp_encrypt_chain_crypto (vm, ptd, sa, b, lb,
- icv_sz, payload,
- payload_len, 0);
+ icv_sz,
+ b->data +
+ crypto_start_offset,
+ crypto_total_len +
+ icv_sz, 0);
}
goto out;
}
+ else
+ {
+ /* construct zero iv in front of the IP header */
+ iv = pkt_iv - hdr_len - iv_sz;
+ clib_memset_u8 (iv, 0, iv_sz);
+ /* include iv field in crypto */
+ crypto_start_offset -= iv_sz;
+ crypto_total_len += iv_sz;
+ }
/* cipher then hash */
- iv = payload - iv_sz;
- integ_start_offset = crypto_start_offset - iv_sz - sizeof (esp_header_t);
+ integ_start_offset -= iv_sz + sizeof (esp_header_t);
integ_total_len += iv_sz + sizeof (esp_header_t);
- flag |= VNET_CRYPTO_OP_FLAG_INIT_IV;
key_index = sa->linked_key_index;
if (b != lb)
{
flag |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
crypto_total_len = esp_encrypt_chain_crypto (vm, ptd, sa, b, lb,
- icv_sz, payload,
- payload_len, 0);
+ icv_sz,
+ b->data +
+ crypto_start_offset,
+ crypto_total_len + icv_sz,
+ 0);
tag = vlib_buffer_get_tail (lb) - icv_sz;
integ_total_len = esp_encrypt_chain_integ (vm, ptd, sa, b, lb, icv_sz,
payload - iv_sz -
diff --git a/src/vnet/ipsec/ipsec_sa.h b/src/vnet/ipsec/ipsec_sa.h
index 5950d6f53b3..72636368977 100644
--- a/src/vnet/ipsec/ipsec_sa.h
+++ b/src/vnet/ipsec/ipsec_sa.h
@@ -182,7 +182,7 @@ typedef struct
/* Salt used in GCM modes - stored in network byte order */
u32 salt;
- u64 gcm_iv_counter;
+ u64 iv_counter;
union
{