1 files changed, 320 insertions, 0 deletions

diff --git a/src/vnet/ipsec/esp.h b/src/vnet/ipsec/esp.h
new file mode 100644
index 00000000000..50cac806d14
--- /dev/null
+++ b/src/vnet/ipsec/esp.h
@@ -0,0 +1,320 @@
+/*
+ * 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 <openssl/hmac.h>
+#include <openssl/rand.h>
+#include <openssl/evp.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 {
+  ip6_header_t ip6;
+  esp_header_t esp;
+}) ip6_and_esp_header_t;
+/* *INDENT-ON* */
+
+typedef struct
+{
+  const EVP_CIPHER *type;
+} esp_crypto_alg_t;
+
+typedef struct
+{
+  const EVP_MD *md;
+  u8 trunc_size;
+} esp_integ_alg_t;
+
+typedef struct
+{
+  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
+  EVP_CIPHER_CTX encrypt_ctx;
+    CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
+  EVP_CIPHER_CTX decrypt_ctx;
+    CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
+  HMAC_CTX hmac_ctx;
+  ipsec_crypto_alg_t last_encrypt_alg;
+  ipsec_crypto_alg_t last_decrypt_alg;
+  ipsec_integ_alg_t last_integ_alg;
+} esp_main_per_thread_data_t;
+
+typedef struct
+{
+  esp_crypto_alg_t *esp_crypto_algs;
+  esp_integ_alg_t *esp_integ_algs;
+  esp_main_per_thread_data_t *per_thread_data;
+} esp_main_t;
+
+esp_main_t esp_main;
+
+#define ESP_WINDOW_SIZE		(64)
+#define ESP_SEQ_MAX 		(4294967295UL)
+
+
+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 void
+esp_init ()
+{
+  esp_main_t *em = &esp_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+
+  memset (em, 0, sizeof (em[0]));
+
+  vec_validate (em->esp_crypto_algs, IPSEC_CRYPTO_N_ALG - 1);
+  em->esp_crypto_algs[IPSEC_CRYPTO_ALG_AES_CBC_128].type = EVP_aes_128_cbc ();
+  em->esp_crypto_algs[IPSEC_CRYPTO_ALG_AES_CBC_192].type = EVP_aes_192_cbc ();
+  em->esp_crypto_algs[IPSEC_CRYPTO_ALG_AES_CBC_256].type = EVP_aes_256_cbc ();
+
+  vec_validate (em->esp_integ_algs, IPSEC_INTEG_N_ALG - 1);
+  esp_integ_alg_t *i;
+
+  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA1_96];
+  i->md = EVP_sha1 ();
+  i->trunc_size = 12;
+
+  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA_256_96];
+  i->md = EVP_sha256 ();
+  i->trunc_size = 12;
+
+  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA_256_128];
+  i->md = EVP_sha256 ();
+  i->trunc_size = 16;
+
+  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA_384_192];
+  i->md = EVP_sha384 ();
+  i->trunc_size = 24;
+
+  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA_512_256];
+  i->md = EVP_sha512 ();
+  i->trunc_size = 32;
+
+  vec_validate_aligned (em->per_thread_data, tm->n_vlib_mains - 1,
+			CLIB_CACHE_LINE_BYTES);
+  int thread_id;
+
+  for (thread_id = 0; thread_id < tm->n_vlib_mains - 1; thread_id++)
+    {
+      EVP_CIPHER_CTX_init (&(em->per_thread_data[thread_id].encrypt_ctx));
+      EVP_CIPHER_CTX_init (&(em->per_thread_data[thread_id].decrypt_ctx));
+      HMAC_CTX_init (&(em->per_thread_data[thread_id].hmac_ctx));
+    }
+}
+
+always_inline unsigned int
+hmac_calc (ipsec_integ_alg_t alg,
+	   u8 * key,
+	   int key_len,
+	   u8 * data, int data_len, u8 * signature, u8 use_esn, u32 seq_hi)
+{
+  esp_main_t *em = &esp_main;
+  u32 cpu_index = os_get_cpu_number ();
+  HMAC_CTX *ctx = &(em->per_thread_data[cpu_index].hmac_ctx);
+  const EVP_MD *md = NULL;
+  unsigned int len;
+
+  ASSERT (alg < IPSEC_INTEG_N_ALG);
+
+  if (PREDICT_FALSE (em->esp_integ_algs[alg].md == 0))
+    return 0;
+
+  if (PREDICT_FALSE (alg != em->per_thread_data[cpu_index].last_integ_alg))
+    {
+      md = em->esp_integ_algs[alg].md;
+      em->per_thread_data[cpu_index].last_integ_alg = alg;
+    }
+
+  HMAC_Init (ctx, key, key_len, md);
+
+  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);
+
+  return em->esp_integ_algs[alg].trunc_size;
+}
+
+#endif /* __ESP_H__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */