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/*
* Copyright (c) 2015 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __ESP_H__
#define __ESP_H__
#include <vnet/ip/ip.h>
#include <vnet/crypto/crypto.h>
#include <vnet/ipsec/ipsec.h>
typedef struct
{
u32 spi;
u32 seq;
u8 data[0];
} esp_header_t;
typedef struct
{
u8 pad_length;
u8 next_header;
} esp_footer_t;
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
ip4_header_t ip4;
esp_header_t esp;
}) ip4_and_esp_header_t;
/* *INDENT-ON* */
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
ip4_header_t ip4;
udp_header_t udp;
esp_header_t esp;
}) ip4_and_udp_and_esp_header_t;
/* *INDENT-ON* */
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
ip6_header_t ip6;
esp_header_t esp;
}) ip6_and_esp_header_t;
/* *INDENT-ON* */
#define ESP_WINDOW_SIZE (64)
#define ESP_SEQ_MAX (4294967295UL)
u8 *format_esp_header (u8 * s, va_list * args);
always_inline int
esp_replay_check (ipsec_sa_t * sa, u32 seq)
{
u32 diff;
if (PREDICT_TRUE (seq > sa->last_seq))
return 0;
diff = sa->last_seq - seq;
if (ESP_WINDOW_SIZE > diff)
return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
else
return 1;
return 0;
}
always_inline int
esp_replay_check_esn (ipsec_sa_t * sa, u32 seq)
{
u32 tl = sa->last_seq;
u32 th = sa->last_seq_hi;
u32 diff = tl - seq;
if (PREDICT_TRUE (tl >= (ESP_WINDOW_SIZE - 1)))
{
if (seq >= (tl - ESP_WINDOW_SIZE + 1))
{
sa->seq_hi = th;
if (seq <= tl)
return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
else
return 0;
}
else
{
sa->seq_hi = th + 1;
return 0;
}
}
else
{
if (seq >= (tl - ESP_WINDOW_SIZE + 1))
{
sa->seq_hi = th - 1;
return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
}
else
{
sa->seq_hi = th;
if (seq <= tl)
return (sa->replay_window & (1ULL << diff)) ? 1 : 0;
else
return 0;
}
}
return 0;
}
/* TODO seq increment should be atomic to be accessed by multiple workers */
always_inline void
esp_replay_advance (ipsec_sa_t * sa, u32 seq)
{
u32 pos;
if (seq > sa->last_seq)
{
pos = seq - sa->last_seq;
if (pos < ESP_WINDOW_SIZE)
sa->replay_window = ((sa->replay_window) << pos) | 1;
else
sa->replay_window = 1;
sa->last_seq = seq;
}
else
{
pos = sa->last_seq - seq;
sa->replay_window |= (1ULL << pos);
}
}
always_inline void
esp_replay_advance_esn (ipsec_sa_t * sa, u32 seq)
{
int wrap = sa->seq_hi - sa->last_seq_hi;
u32 pos;
if (wrap == 0 && seq > sa->last_seq)
{
pos = seq - sa->last_seq;
if (pos < ESP_WINDOW_SIZE)
sa->replay_window = ((sa->replay_window) << pos) | 1;
else
sa->replay_window = 1;
sa->last_seq = seq;
}
else if (wrap > 0)
{
pos = ~seq + sa->last_seq + 1;
if (pos < ESP_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;
}
else if (wrap < 0)
{
pos = ~seq + sa->last_seq + 1;
sa->replay_window |= (1ULL << pos);
}
else
{
pos = sa->last_seq - seq;
sa->replay_window |= (1ULL << pos);
}
}
always_inline int
esp_seq_advance (ipsec_sa_t * sa)
{
if (PREDICT_TRUE (sa->use_esn))
{
if (PREDICT_FALSE (sa->seq == ESP_SEQ_MAX))
{
if (PREDICT_FALSE
(sa->use_anti_replay && sa->seq_hi == ESP_SEQ_MAX))
return 1;
sa->seq_hi++;
}
sa->seq++;
}
else
{
if (PREDICT_FALSE (sa->use_anti_replay && sa->seq == ESP_SEQ_MAX))
return 1;
sa->seq++;
}
return 0;
}
always_inline unsigned int
hmac_calc (vlib_main_t * vm, ipsec_sa_t * sa, u8 * data, int data_len,
u8 * signature)
{
vnet_crypto_op_t _op, *op = &_op;
if (PREDICT_FALSE (sa->integ_op_type == 0))
return 0;
op->op = sa->integ_op_type;
op->key = sa->integ_key.data;
op->key_len = sa->integ_key.len;
op->src = data;
op->len = data_len;
op->dst = signature;
op->hmac_trunc_len = sa->integ_trunc_size;
#if 0
HMAC_Init_ex (ctx, key, key_len, md, NULL);
HMAC_Update (ctx, data, data_len);
if (PREDICT_TRUE (use_esn))
HMAC_Update (ctx, (u8 *) & seq_hi, sizeof (seq_hi));
HMAC_Final (ctx, signature, &len);
#endif
vnet_crypto_process_ops (vm, op, 1);
return sa->integ_trunc_size;
}
#endif /* __ESP_H__ */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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