IPSec AH protocol enhancement in VPP native core

Change-Id: Iec5804d768485f4015bbf732d8d19ef2f24e6939
Signed-off-by: “mukeshyadav1984” <mukyadav@cisco.com>

13 files changed, 892 insertions, 55 deletions

diff --git a/src/vnet.am b/src/vnet.am
index 7dc4b7df55f..72e67dcb298 100644
--- a/src/vnet.am
+++ b/src/vnet.am
@@ -425,6 +425,8 @@ libvnet_la_SOURCES +=				\
  vnet/ipsec/esp_format.c			\
  vnet/ipsec/esp_encrypt.c			\
  vnet/ipsec/esp_decrypt.c			\
+ vnet/ipsec/ah_decrypt.c			\
+ vnet/ipsec/ah_encrypt.c			\
  vnet/ipsec/ikev2.c				\
  vnet/ipsec/ikev2_crypto.c			\
  vnet/ipsec/ikev2_cli.c				\
@@ -441,6 +443,7 @@ libvnet_la_SOURCES +=				\
 nobase_include_HEADERS +=			\
  vnet/ipsec/ipsec.h				\
  vnet/ipsec/esp.h				\
+ vnet/ipsec/ah.h				\
  vnet/ipsec/ikev2.h				\
  vnet/ipsec/ikev2_priv.h			\
  vnet/ipsec/ipsec.api.h
diff --git a/src/vnet/ipsec/ah.h b/src/vnet/ipsec/ah.h
new file mode 100644
index 00000000000..37fc29a1ced
--- /dev/null
+++ b/src/vnet/ipsec/ah.h
@@ -0,0 +1,60 @@
+/*
+ * 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 __AH_H__
+#define __AH_H__
+
+
+#include <vnet/ip/ip.h>
+#include <vnet/ipsec/ipsec.h>
+
+#include <openssl/hmac.h>
+#include <openssl/rand.h>
+#include <openssl/evp.h>
+
+
+typedef struct
+{
+  unsigned char nexthdr;
+  unsigned char hdrlen;
+  unsigned short reserved;
+  unsigned int spi;
+  unsigned int seq_no;
+  unsigned char auth_data[0];
+} ah_header_t;
+
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED (struct {
+  ip4_header_t ip4;
+  ah_header_t ah;
+}) ip4_and_ah_header_t;
+/* *INDENT-ON* */
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED (struct {
+  ip6_header_t ip6;
+  ah_header_t ah;
+}) ip6_and_ah_header_t;
+/* *INDENT-ON* */
+
+#endif /* __AH_H__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vnet/ipsec/ah_decrypt.c b/src/vnet/ipsec/ah_decrypt.c
new file mode 100644
index 00000000000..c487d82e34a
--- /dev/null
+++ b/src/vnet/ipsec/ah_decrypt.c
@@ -0,0 +1,343 @@
+/*
+ * ah_decrypt.c : IPSec AH decrypt node
+ *
+ * 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.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/api_errno.h>
+#include <vnet/ip/ip.h>
+
+#include <vnet/ipsec/ipsec.h>
+#include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ah.h>
+
+#define foreach_ah_decrypt_next                \
+_(DROP, "error-drop")                           \
+_(IP4_INPUT, "ip4-input")                       \
+_(IP6_INPUT, "ip6-input")                       \
+_(IPSEC_GRE_INPUT, "ipsec-gre-input")
+
+#define _(v, s) AH_DECRYPT_NEXT_##v,
+typedef enum
+{
+  foreach_ah_decrypt_next
+#undef _
+    AH_DECRYPT_N_NEXT,
+} ah_decrypt_next_t;
+
+
+#define foreach_ah_decrypt_error                   \
+ _(RX_PKTS, "AH pkts received")                    \
+ _(DECRYPTION_FAILED, "AH decryption failed")      \
+ _(INTEG_ERROR, "Integrity check failed")           \
+ _(REPLAY, "SA replayed packet")                    \
+ _(NOT_IP, "Not IP packet (dropped)")
+
+
+typedef enum
+{
+#define _(sym,str) AH_DECRYPT_ERROR_##sym,
+  foreach_ah_decrypt_error
+#undef _
+    AH_DECRYPT_N_ERROR,
+} ah_decrypt_error_t;
+
+static char *ah_decrypt_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ah_decrypt_error
+#undef _
+};
+
+typedef struct
+{
+  ipsec_integ_alg_t integ_alg;
+} ah_decrypt_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_ah_decrypt_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  ah_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);
+
+  s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg);
+  return s;
+}
+
+static uword
+ah_decrypt_node_fn (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  u32 n_left_from, *from, next_index, *to_next;
+  ipsec_main_t *im = &ipsec_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+  int icv_size = 0;
+
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 i_bi0;
+	  u32 next0;
+	  vlib_buffer_t *i_b0;
+	  ah_header_t *ah0;
+	  ipsec_sa_t *sa0;
+	  u32 sa_index0 = ~0;
+	  u32 seq;
+	  ip4_header_t *ih4 = 0, *oh4 = 0;
+	  ip6_header_t *ih6 = 0, *oh6 = 0;
+	  u8 tunnel_mode = 1;
+	  u8 transport_ip6 = 0;
+	  u8 ip_hdr_size = 0;
+	  u8 tos = 0;
+	  u8 ttl = 0;
+
+
+	  i_bi0 = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  next0 = AH_DECRYPT_NEXT_DROP;
+
+	  i_b0 = vlib_get_buffer (vm, i_bi0);
+	  to_next[0] = i_bi0;
+	  to_next += 1;
+	  ih4 = vlib_buffer_get_current (i_b0);
+	  ip_hdr_size = ip4_header_bytes (ih4);
+	  ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
+
+	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
+	  sa0 = pool_elt_at_index (im->sad, sa_index0);
+
+	  seq = clib_host_to_net_u32 (ah0->seq_no);
+	  /* anti-replay check */
+	  //TODO UT remaining
+	  if (sa0->use_anti_replay)
+	    {
+	      int rv = 0;
+
+	      if (PREDICT_TRUE (sa0->use_esn))
+		rv = esp_replay_check_esn (sa0, seq);
+	      else
+		rv = esp_replay_check (sa0, seq);
+
+	      if (PREDICT_FALSE (rv))
+		{
+		  clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_REPLAY, 1);
+		  to_next[0] = i_bi0;
+		  to_next += 1;
+		  goto trace;
+		}
+	    }
+
+
+	  sa0->total_data_size += i_b0->current_length;
+	  icv_size =
+	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
+	  if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
+	    {
+	      u8 sig[64];
+	      u8 digest[64];
+	      memset (sig, 0, sizeof (sig));
+	      memset (digest, 0, sizeof (digest));
+	      u8 *icv =
+		vlib_buffer_get_current (i_b0) + ip_hdr_size +
+		sizeof (ah_header_t);
+	      memcpy (digest, icv, icv_size);
+	      memset (icv, 0, icv_size);
+
+	      if ((ih4->ip_version_and_header_length & 0xF0) == 0x40)
+		{
+		  tos = ih4->tos;
+		  ttl = ih4->ttl;
+		  ih4->tos = 0;
+		  ih4->ttl = 0;
+		  ih4->checksum = 0;
+		  ih4->flags_and_fragment_offset = 0;
+		}		//TODO else part for IPv6
+	      hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
+			 (u8 *) ih4, i_b0->current_length, sig, sa0->use_esn,
+			 sa0->seq_hi);
+
+	      if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
+		{
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_INTEG_ERROR,
+					       1);
+		  to_next[0] = i_bi0;
+		  to_next += 1;
+		  goto trace;
+		}
+
+	      //TODO UT remaining
+	      if (PREDICT_TRUE (sa0->use_anti_replay))
+		{
+		  if (PREDICT_TRUE (sa0->use_esn))
+		    esp_replay_advance_esn (sa0, seq);
+		  else
+		    esp_replay_advance (sa0, seq);
+		}
+
+	    }
+
+
+	  vlib_buffer_advance (i_b0,
+			       ip_hdr_size + sizeof (ah_header_t) + icv_size);
+	  i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+
+	  /* transport mode */
+	  if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
+	    {
+	      tunnel_mode = 0;
+
+	      if (PREDICT_TRUE
+		  ((ih4->ip_version_and_header_length & 0xF0) != 0x40))
+		{
+		  if (PREDICT_TRUE
+		      ((ih4->ip_version_and_header_length & 0xF0) == 0x60))
+		    transport_ip6 = 1;
+		  else
+		    {
+		      clib_warning ("next header: 0x%x", ah0->nexthdr);
+		      vlib_node_increment_counter (vm, ah_decrypt_node.index,
+						   AH_DECRYPT_ERROR_NOT_IP,
+						   1);
+		      goto trace;
+		    }
+		}
+	    }
+
+	  if (PREDICT_TRUE (tunnel_mode))
+	    {
+	      if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
+		next0 = AH_DECRYPT_NEXT_IP4_INPUT;
+	      else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
+		next0 = AH_DECRYPT_NEXT_IP6_INPUT;
+	      else
+		{
+		  clib_warning ("next header: 0x%x", ah0->nexthdr);
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_DECRYPTION_FAILED,
+					       1);
+		  goto trace;
+		}
+	    }
+	  /* transport mode */
+	  else
+	    {
+	      if (PREDICT_FALSE (transport_ip6))
+		{
+		  ih6 =
+		    (ip6_header_t *) (i_b0->data +
+				      sizeof (ethernet_header_t));
+		  vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
+		  oh6 = vlib_buffer_get_current (i_b0);
+		  memmove (oh6, ih6, sizeof (ip6_header_t));
+
+		  next0 = AH_DECRYPT_NEXT_IP6_INPUT;
+		  oh6->protocol = ah0->nexthdr;
+		  oh6->payload_length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (vm, i_b0) - sizeof (ip6_header_t));
+		}
+	      else
+		{
+		  vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
+		  oh4 = vlib_buffer_get_current (i_b0);
+		  memmove (oh4, ih4, sizeof (ip4_header_t));
+
+		  next0 = AH_DECRYPT_NEXT_IP4_INPUT;
+		  oh4->ip_version_and_header_length = 0x45;
+		  oh4->fragment_id = 0;
+		  oh4->flags_and_fragment_offset = 0;
+		  oh4->protocol = ah0->nexthdr;
+		  oh4->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (vm, i_b0));
+		  oh4->ttl = ttl;
+		  oh4->tos = tos;
+		  oh4->checksum = ip4_header_checksum (oh4);
+		}
+	    }
+
+	  /* for IPSec-GRE tunnel next node is ipsec-gre-input */
+	  if (PREDICT_FALSE
+	      ((vnet_buffer (i_b0)->ipsec.flags) &
+	       IPSEC_FLAG_IPSEC_GRE_TUNNEL))
+	    next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;
+
+
+	  vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	trace:
+	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      i_b0->flags |= VLIB_BUFFER_IS_TRACED;
+	      ah_decrypt_trace_t *tr =
+		vlib_add_trace (vm, node, i_b0, sizeof (*tr));
+	      tr->integ_alg = sa0->integ_alg;
+	    }
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, i_bi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+			       AH_DECRYPT_ERROR_RX_PKTS,
+			       from_frame->n_vectors);
+
+  return from_frame->n_vectors;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ah_decrypt_node) = {
+  .function = ah_decrypt_node_fn,
+  .name = "ah-decrypt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ah_decrypt_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
+  .error_strings = ah_decrypt_error_strings,
+
+  .n_next_nodes = AH_DECRYPT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
+    foreach_ah_decrypt_next
+#undef _
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (ah_decrypt_node, ah_decrypt_node_fn)
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vnet/ipsec/ah_encrypt.c b/src/vnet/ipsec/ah_encrypt.c
new file mode 100644
index 00000000000..6619d872013
--- /dev/null
+++ b/src/vnet/ipsec/ah_encrypt.c
@@ -0,0 +1,344 @@
+/*
+ * ah_encrypt.c : IPSec AH encrypt node
+ *
+ * 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.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/api_errno.h>
+#include <vnet/ip/ip.h>
+
+#include <vnet/ipsec/ipsec.h>
+#include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ah.h>
+
+#define foreach_ah_encrypt_next                   \
+_(DROP, "error-drop")                              \
+_(IP4_LOOKUP, "ip4-lookup")                        \
+_(IP6_LOOKUP, "ip6-lookup")                        \
+_(INTERFACE_OUTPUT, "interface-output")
+
+#define _(v, s) AH_ENCRYPT_NEXT_##v,
+typedef enum
+{
+  foreach_ah_encrypt_next
+#undef _
+    AH_ENCRYPT_N_NEXT,
+} ah_encrypt_next_t;
+
+#define foreach_ah_encrypt_error                   \
+ _(RX_PKTS, "AH pkts received")                    \
+ _(SEQ_CYCLED, "sequence number cycled")
+
+
+typedef enum
+{
+#define _(sym,str) AH_ENCRYPT_ERROR_##sym,
+  foreach_ah_encrypt_error
+#undef _
+    AH_ENCRYPT_N_ERROR,
+} ah_encrypt_error_t;
+
+static char *ah_encrypt_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ah_encrypt_error
+#undef _
+};
+
+vlib_node_registration_t ah_encrypt_node;
+
+typedef struct
+{
+  u32 spi;
+  u32 seq;
+  ipsec_integ_alg_t integ_alg;
+} ah_encrypt_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_ah_encrypt_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  ah_encrypt_trace_t *t = va_arg (*args, ah_encrypt_trace_t *);
+
+  s = format (s, "ah: spi %u seq %u integrity %U",
+	      t->spi, t->seq, format_ipsec_integ_alg, t->integ_alg);
+  return s;
+}
+
+static uword
+ah_encrypt_node_fn (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  u32 n_left_from, *from, *to_next = 0, next_index;
+  int icv_size = 0;
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+  ipsec_main_t *im = &ipsec_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 i_bi0, next0;
+	  vlib_buffer_t *i_b0 = 0;
+	  u32 sa_index0;
+	  ipsec_sa_t *sa0;
+	  ip4_and_ah_header_t *ih0, *oh0 = 0;
+	  ip6_and_ah_header_t *ih6_0, *oh6_0 = 0;
+	  u8 is_ipv6;
+	  u8 ip_hdr_size;
+	  u8 next_hdr_type;
+	  u8 transport_mode = 0;
+	  u8 tos = 0;
+	  u8 ttl = 0;
+
+	  i_bi0 = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+	  next0 = AH_ENCRYPT_NEXT_DROP;
+
+	  i_b0 = vlib_get_buffer (vm, i_bi0);
+	  to_next[0] = i_bi0;
+	  to_next += 1;
+	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
+	  sa0 = pool_elt_at_index (im->sad, sa_index0);
+
+	  if (PREDICT_FALSE (esp_seq_advance (sa0)))
+	    {
+	      clib_warning ("sequence number counter has cycled SPI %u",
+			    sa0->spi);
+	      vlib_node_increment_counter (vm, ah_encrypt_node.index,
+					   AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
+	      //TODO need to confirm if below is needed
+	      to_next[0] = i_bi0;
+	      to_next += 1;
+	      goto trace;
+	    }
+
+
+	  sa0->total_data_size += i_b0->current_length;
+
+	  ssize_t adv;
+	  ih0 = vlib_buffer_get_current (i_b0);
+	  ttl = ih0->ip4.ttl;
+	  tos = ih0->ip4.tos;
+
+	  is_ipv6 = (ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60;
+	  /* is ipv6 */
+	  if (PREDICT_TRUE (sa0->is_tunnel))
+	    {
+	      if (PREDICT_TRUE (!is_ipv6))
+		adv = -sizeof (ip4_and_ah_header_t);
+	      else
+		adv = -sizeof (ip6_and_ah_header_t);
+	    }
+	  else
+	    {
+	      adv = -sizeof (ah_header_t);
+	    }
+
+	  icv_size =
+	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
+	  /*transport mode save the eth header before it is overwritten */
+	  if (PREDICT_FALSE (!sa0->is_tunnel))
+	    {
+	      ethernet_header_t *ieh0 = (ethernet_header_t *)
+		((u8 *) vlib_buffer_get_current (i_b0) -
+		 sizeof (ethernet_header_t));
+	      ethernet_header_t *oeh0 =
+		(ethernet_header_t *) ((u8 *) ieh0 + (adv - icv_size));
+	      clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
+	    }
+
+	  vlib_buffer_advance (i_b0, adv - icv_size);
+
+	  /* is ipv6 */
+	  if (PREDICT_FALSE (is_ipv6))
+	    {
+	      ih6_0 = (ip6_and_ah_header_t *) ih0;
+	      ip_hdr_size = sizeof (ip6_header_t);
+	      oh6_0 = vlib_buffer_get_current (i_b0);
+
+	      if (PREDICT_TRUE (sa0->is_tunnel))
+		{
+		  next_hdr_type = IP_PROTOCOL_IPV6;
+		  oh6_0->ip6.ip_version_traffic_class_and_flow_label =
+		    ih6_0->ip6.ip_version_traffic_class_and_flow_label;
+		}
+	      else
+		{
+		  next_hdr_type = ih6_0->ip6.protocol;
+		  memmove (oh6_0, ih6_0, sizeof (ip6_header_t));
+		}
+
+	      oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_AH;
+	      oh6_0->ip6.hop_limit = 254;
+	      oh6_0->ah.spi = clib_net_to_host_u32 (sa0->spi);
+	      oh6_0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
+	      oh6_0->ip6.payload_length =
+		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0) -
+				      sizeof (ip6_header_t));
+	    }
+	  else
+	    {
+	      ip_hdr_size = sizeof (ip4_header_t);
+	      oh0 = vlib_buffer_get_current (i_b0);
+	      memset (oh0, 0, sizeof (ip4_and_ah_header_t));
+
+	      if (PREDICT_TRUE (sa0->is_tunnel))
+		{
+		  next_hdr_type = IP_PROTOCOL_IP_IN_IP;
+		}
+	      else
+		{
+		  next_hdr_type = ih0->ip4.protocol;
+		  memmove (oh0, ih0, sizeof (ip4_header_t));
+		}
+
+	      oh0->ip4.length =
+		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0));
+	      oh0->ip4.ip_version_and_header_length = 0x45;
+	      oh0->ip4.fragment_id = 0;
+	      oh0->ip4.flags_and_fragment_offset = 0;
+	      oh0->ip4.ttl = 0;
+	      oh0->ip4.tos = 0;
+	      oh0->ip4.protocol = IP_PROTOCOL_IPSEC_AH;
+	      oh0->ah.spi = clib_net_to_host_u32 (sa0->spi);
+	      oh0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
+	      oh0->ip4.checksum = 0;
+	      oh0->ah.nexthdr = next_hdr_type;
+	      oh0->ah.hdrlen = 4;
+	    }
+
+
+
+	  if (PREDICT_TRUE
+	      (!is_ipv6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
+	    {
+	      oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
+	      oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
+
+	      next0 = AH_ENCRYPT_NEXT_IP4_LOOKUP;
+	      vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	    }
+	  else if (is_ipv6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
+	    {
+	      oh6_0->ip6.src_address.as_u64[0] =
+		sa0->tunnel_src_addr.ip6.as_u64[0];
+	      oh6_0->ip6.src_address.as_u64[1] =
+		sa0->tunnel_src_addr.ip6.as_u64[1];
+	      oh6_0->ip6.dst_address.as_u64[0] =
+		sa0->tunnel_dst_addr.ip6.as_u64[0];
+	      oh6_0->ip6.dst_address.as_u64[1] =
+		sa0->tunnel_dst_addr.ip6.as_u64[1];
+
+	      next0 = AH_ENCRYPT_NEXT_IP6_LOOKUP;
+	      vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	    }
+	  else
+	    {
+	      transport_mode = 1;
+	      next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
+	    }
+
+	  u8 sig[64];
+	  memset (sig, 0, sizeof (sig));
+	  u8 *digest = NULL;
+	  {
+	    digest = vlib_buffer_get_current (i_b0) + ip_hdr_size + icv_size;
+	    memset (digest, 0, icv_size);
+	  }
+
+	  hmac_calc (sa0->integ_alg, sa0->integ_key,
+		     sa0->integ_key_len,
+		     (u8 *) vlib_buffer_get_current (i_b0),
+		     i_b0->current_length, sig, sa0->use_esn, sa0->seq_hi);
+
+	  memcpy (digest, (char *) &sig[0], 12);
+
+	  if (PREDICT_FALSE (is_ipv6))
+	    {
+	    }
+	  else
+	    {
+	      oh0->ip4.ttl = ttl;
+	      oh0->ip4.tos = tos;
+	      oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
+	    }
+
+	  if (transport_mode)
+	    vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));;
+
+	trace:
+	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      i_b0->flags |= VLIB_BUFFER_IS_TRACED;
+	      ah_encrypt_trace_t *tr =
+		vlib_add_trace (vm, node, i_b0, sizeof (*tr));
+	      tr->spi = sa0->spi;
+	      tr->seq = sa0->seq - 1;
+	      tr->integ_alg = sa0->integ_alg;
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next, i_bi0,
+					   next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, ah_encrypt_node.index,
+			       AH_ENCRYPT_ERROR_RX_PKTS,
+			       from_frame->n_vectors);
+
+  return from_frame->n_vectors;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ah_encrypt_node) = {
+  .function = ah_encrypt_node_fn,
+  .name = "ah-encrypt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ah_encrypt_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(ah_encrypt_error_strings),
+  .error_strings = ah_encrypt_error_strings,
+
+  .n_next_nodes = AH_ENCRYPT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [AH_ENCRYPT_NEXT_##s] = n,
+    foreach_ah_encrypt_next
+#undef _
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (ah_encrypt_node, ah_encrypt_node_fn)
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vnet/ipsec/esp.h b/src/vnet/ipsec/esp.h
index d9ab1d855a8..82e3c961e1a 100644
--- a/src/vnet/ipsec/esp.h
+++ b/src/vnet/ipsec/esp.h
@@ -52,13 +52,13 @@ typedef CLIB_PACKED (struct {
 typedef struct
 {
   const EVP_CIPHER *type;
-} esp_crypto_alg_t;
+} ipsec_proto_main_crypto_alg_t;
 
 typedef struct
 {
   const EVP_MD *md;
   u8 trunc_size;
-} esp_integ_alg_t;
+} ipsec_proto_main_integ_alg_t;
 
 typedef struct
 {
@@ -83,16 +83,16 @@ typedef struct
   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;
+} ipsec_proto_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;
+  ipsec_proto_main_crypto_alg_t *ipsec_proto_main_crypto_algs;
+  ipsec_proto_main_integ_alg_t *ipsec_proto_main_integ_algs;
+  ipsec_proto_main_per_thread_data_t *per_thread_data;
+} ipsec_proto_main_t;
 
-extern esp_main_t esp_main;
+extern ipsec_proto_main_t ipsec_proto_main;
 
 #define ESP_WINDOW_SIZE		(64)
 #define ESP_SEQ_MAX 		(4294967295UL)
@@ -244,38 +244,41 @@ esp_seq_advance (ipsec_sa_t * sa)
 }
 
 always_inline void
-esp_init ()
+ipsec_proto_init ()
 {
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_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->ipsec_proto_main_crypto_algs, IPSEC_CRYPTO_N_ALG - 1);
+  em->ipsec_proto_main_crypto_algs[IPSEC_CRYPTO_ALG_AES_CBC_128].type =
+    EVP_aes_128_cbc ();
+  em->ipsec_proto_main_crypto_algs[IPSEC_CRYPTO_ALG_AES_CBC_192].type =
+    EVP_aes_192_cbc ();
+  em->ipsec_proto_main_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;
+  vec_validate (em->ipsec_proto_main_integ_algs, IPSEC_INTEG_N_ALG - 1);
+  ipsec_proto_main_integ_alg_t *i;
 
-  i = &em->esp_integ_algs[IPSEC_INTEG_ALG_SHA1_96];
+  i = &em->ipsec_proto_main_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 = &em->ipsec_proto_main_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 = &em->ipsec_proto_main_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 = &em->ipsec_proto_main_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 = &em->ipsec_proto_main_integ_algs[IPSEC_INTEG_ALG_SHA_512_256];
   i->md = EVP_sha512 ();
   i->trunc_size = 32;
 
@@ -303,7 +306,7 @@ hmac_calc (ipsec_integ_alg_t alg,
 	   int key_len,
 	   u8 * data, int data_len, u8 * signature, u8 use_esn, u32 seq_hi)
 {
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
   u32 thread_index = vlib_get_thread_index ();
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
   HMAC_CTX *ctx = em->per_thread_data[thread_index].hmac_ctx;
@@ -315,12 +318,12 @@ hmac_calc (ipsec_integ_alg_t alg,
 
   ASSERT (alg < IPSEC_INTEG_N_ALG);
 
-  if (PREDICT_FALSE (em->esp_integ_algs[alg].md == 0))
+  if (PREDICT_FALSE (em->ipsec_proto_main_integ_algs[alg].md == 0))
     return 0;
 
   if (PREDICT_FALSE (alg != em->per_thread_data[thread_index].last_integ_alg))
     {
-      md = em->esp_integ_algs[alg].md;
+      md = em->ipsec_proto_main_integ_algs[alg].md;
       em->per_thread_data[thread_index].last_integ_alg = alg;
     }
 
@@ -332,7 +335,7 @@ hmac_calc (ipsec_integ_alg_t alg,
     HMAC_Update (ctx, (u8 *) & seq_hi, sizeof (seq_hi));
   HMAC_Final (ctx, signature, &len);
 
-  return em->esp_integ_algs[alg].trunc_size;
+  return em->ipsec_proto_main_integ_algs[alg].trunc_size;
 }
 
 #endif /* __ESP_H__ */
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 81ebbe55301..fac40358f16 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -84,7 +84,7 @@ always_inline void
 esp_decrypt_aes_cbc (ipsec_crypto_alg_t alg,
 		     u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
 {
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
   u32 thread_index = vlib_get_thread_index ();
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
   EVP_CIPHER_CTX *ctx = em->per_thread_data[thread_index].decrypt_ctx;
@@ -96,13 +96,13 @@ esp_decrypt_aes_cbc (ipsec_crypto_alg_t alg,
 
   ASSERT (alg < IPSEC_CRYPTO_N_ALG);
 
-  if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == 0))
+  if (PREDICT_FALSE (em->ipsec_proto_main_crypto_algs[alg].type == 0))
     return;
 
   if (PREDICT_FALSE
       (alg != em->per_thread_data[thread_index].last_decrypt_alg))
     {
-      cipher = em->esp_crypto_algs[alg].type;
+      cipher = em->ipsec_proto_main_crypto_algs[alg].type;
       em->per_thread_data[thread_index].last_decrypt_alg = alg;
     }
 
@@ -118,7 +118,7 @@ esp_decrypt_node_fn (vlib_main_t * vm,
 {
   u32 n_left_from, *from, next_index, *to_next;
   ipsec_main_t *im = &ipsec_main;
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
   u32 *recycle = 0;
   from = vlib_frame_vector_args (from_frame);
   n_left_from = from_frame->n_vectors;
@@ -200,7 +200,8 @@ esp_decrypt_node_fn (vlib_main_t * vm,
 	  if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
 	    {
 	      u8 sig[64];
-	      int icv_size = em->esp_integ_algs[sa0->integ_alg].trunc_size;
+	      int icv_size =
+		em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 	      memset (sig, 0, sizeof (sig));
 	      u8 *icv =
 		vlib_buffer_get_current (i_b0) + i_b0->current_length -
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 7bf1256acca..3e196b34869 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -22,7 +22,7 @@
 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
 
-esp_main_t esp_main;
+ipsec_proto_main_t ipsec_proto_main;
 
 #define foreach_esp_encrypt_next                   \
 _(DROP, "error-drop")                              \
@@ -88,7 +88,7 @@ always_inline void
 esp_encrypt_aes_cbc (ipsec_crypto_alg_t alg,
 		     u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
 {
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
   u32 thread_index = vlib_get_thread_index ();
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
   EVP_CIPHER_CTX *ctx = em->per_thread_data[thread_index].encrypt_ctx;
@@ -100,13 +100,14 @@ esp_encrypt_aes_cbc (ipsec_crypto_alg_t alg,
 
   ASSERT (alg < IPSEC_CRYPTO_N_ALG);
 
-  if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
+  if (PREDICT_FALSE
+      (em->ipsec_proto_main_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
     return;
 
   if (PREDICT_FALSE
       (alg != em->per_thread_data[thread_index].last_encrypt_alg))
     {
-      cipher = em->esp_crypto_algs[alg].type;
+      cipher = em->ipsec_proto_main_crypto_algs[alg].type;
       em->per_thread_data[thread_index].last_encrypt_alg = alg;
     }
 
diff --git a/src/vnet/ipsec/ipsec.c b/src/vnet/ipsec/ipsec.c
index cd05c1bb9bf..ab3c83b02f5 100644
--- a/src/vnet/ipsec/ipsec.c
+++ b/src/vnet/ipsec/ipsec.c
@@ -23,6 +23,7 @@
 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/ikev2.h>
 #include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ah.h>
 
 ipsec_main_t ipsec_main;
 
@@ -567,8 +568,18 @@ ipsec_init (vlib_main_t * vm)
   ASSERT (node);
   im->esp_decrypt_node_index = node->index;
 
+  node = vlib_get_node_by_name (vm, (u8 *) "ah-encrypt");
+  ASSERT (node);
+  im->ah_encrypt_node_index = node->index;
+
+  node = vlib_get_node_by_name (vm, (u8 *) "ah-decrypt");
+  ASSERT (node);
+  im->ah_decrypt_node_index = node->index;
+
   im->esp_encrypt_next_index = IPSEC_OUTPUT_NEXT_ESP_ENCRYPT;
   im->esp_decrypt_next_index = IPSEC_INPUT_NEXT_ESP_DECRYPT;
+  im->ah_encrypt_next_index = IPSEC_OUTPUT_NEXT_AH_ENCRYPT;
+  im->ah_decrypt_next_index = IPSEC_INPUT_NEXT_AH_DECRYPT;
 
   im->cb.check_support_cb = ipsec_check_support;
 
@@ -578,7 +589,7 @@ ipsec_init (vlib_main_t * vm)
   if ((error = vlib_call_init_function (vm, ipsec_tunnel_if_init)))
     return error;
 
-  esp_init ();
+  ipsec_proto_init ();
 
   if ((error = ikev2_init (vm)))
     return error;
diff --git a/src/vnet/ipsec/ipsec.h b/src/vnet/ipsec/ipsec.h
index 1572e5501e2..e59cfcc4520 100644
--- a/src/vnet/ipsec/ipsec.h
+++ b/src/vnet/ipsec/ipsec.h
@@ -23,7 +23,8 @@
 
 #define foreach_ipsec_output_next                \
 _(DROP, "error-drop")                            \
-_(ESP_ENCRYPT, "esp-encrypt")
+_(ESP_ENCRYPT, "esp-encrypt")                    \
+_(AH_ENCRYPT, "ah-encrypt")
 
 #define _(v, s) IPSEC_OUTPUT_NEXT_##v,
 typedef enum
@@ -36,7 +37,8 @@ typedef enum
 
 #define foreach_ipsec_input_next                \
 _(DROP, "error-drop")                           \
-_(ESP_DECRYPT, "esp-decrypt")
+_(ESP_DECRYPT, "esp-decrypt")                   \
+_(AH_DECRYPT, "ah-decrypt")
 
 #define _(v, s) IPSEC_INPUT_NEXT_##v,
 typedef enum
@@ -278,9 +280,13 @@ typedef struct
   u32 error_drop_node_index;
   u32 esp_encrypt_node_index;
   u32 esp_decrypt_node_index;
+  u32 ah_encrypt_node_index;
+  u32 ah_decrypt_node_index;
   /* next node indeces */
   u32 esp_encrypt_next_index;
   u32 esp_decrypt_next_index;
+  u32 ah_encrypt_next_index;
+  u32 ah_decrypt_next_index;
 
   /* callbacks */
   ipsec_main_callbacks_t cb;
@@ -290,6 +296,8 @@ extern ipsec_main_t ipsec_main;
 
 extern vlib_node_registration_t esp_encrypt_node;
 extern vlib_node_registration_t esp_decrypt_node;
+extern vlib_node_registration_t ah_encrypt_node;
+extern vlib_node_registration_t ah_decrypt_node;
 extern vlib_node_registration_t ipsec_if_output_node;
 extern vlib_node_registration_t ipsec_if_input_node;
 
diff --git a/src/vnet/ipsec/ipsec_cli.c b/src/vnet/ipsec/ipsec_cli.c
index 0e034402b5c..711403ff81a 100644
--- a/src/vnet/ipsec/ipsec_cli.c
+++ b/src/vnet/ipsec/ipsec_cli.c
@@ -96,9 +96,7 @@ ipsec_sa_add_del_command_fn (vlib_main_t * vm,
 	sa.protocol = IPSEC_PROTOCOL_ESP;
       else if (unformat (line_input, "ah"))
 	{
-	  //sa.protocol = IPSEC_PROTOCOL_AH;
-	  error = clib_error_return (0, "unsupported security protocol 'AH'");
-	  goto done;
+	  sa.protocol = IPSEC_PROTOCOL_AH;
 	}
       else
 	if (unformat (line_input, "crypto-key %U", unformat_hex_string, &ck))
@@ -339,6 +337,21 @@ ipsec_policy_add_del_command_fn (vlib_main_t * vm,
 	}
     }
 
+  /* Check if SA is for IPv6/AH which is not supported. Return error if TRUE. */
+  if (p.sa_id)
+    {
+      uword *p1;
+      ipsec_main_t *im = &ipsec_main;
+      ipsec_sa_t *sa = 0;
+      p1 = hash_get (im->sa_index_by_sa_id, p.sa_id);
+      sa = pool_elt_at_index (im->sad, p1[0]);
+      if (sa && sa->protocol == IPSEC_PROTOCOL_AH && is_add && p.is_ipv6)
+	{
+	  error = clib_error_return (0, "AH not supported for IPV6: '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
   ipsec_add_del_policy (vm, &p, is_add);
   if (is_ip_any)
     {
diff --git a/src/vnet/ipsec/ipsec_if_in.c b/src/vnet/ipsec/ipsec_if_in.c
index b0761224fbb..2627e7c1ca6 100644
--- a/src/vnet/ipsec/ipsec_if_in.c
+++ b/src/vnet/ipsec/ipsec_if_in.c
@@ -65,7 +65,7 @@ ipsec_if_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   ipsec_main_t *im = &ipsec_main;
   vnet_main_t *vnm = im->vnet_main;
   vnet_interface_main_t *vim = &vnm->interface_main;
-  esp_main_t *em = &esp_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
   u32 *from, *to_next = 0, next_index;
   u32 n_left_from, last_sw_if_index = ~0;
   u32 thread_index = vlib_get_thread_index ();
@@ -130,7 +130,9 @@ ipsec_if_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 		  else
 		    {
 		      sa0 = pool_elt_at_index (im->sad, t->input_sa_index);
-		      icv_len = em->esp_integ_algs[sa0->integ_alg].trunc_size;
+		      icv_len =
+			em->ipsec_proto_main_integ_algs[sa0->
+							integ_alg].trunc_size;
 
 		      /* length = packet length - ESP/tunnel overhead */
 		      n_bytes -= n_packets * (sizeof (ip4_header_t) +
@@ -178,7 +180,7 @@ ipsec_if_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   if (last_t)
     {
       sa0 = pool_elt_at_index (im->sad, last_t->input_sa_index);
-      icv_len = em->esp_integ_algs[sa0->integ_alg].trunc_size;
+      icv_len = em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 
       n_bytes -= n_packets * (sizeof (ip4_header_t) + sizeof (esp_header_t) +
 			      sizeof (esp_footer_t) + 16 /* aes-cbc IV */  +
diff --git a/src/vnet/ipsec/ipsec_input.c b/src/vnet/ipsec/ipsec_input.c
index f27058bb778..9aa5654c9da 100644
--- a/src/vnet/ipsec/ipsec_input.c
+++ b/src/vnet/ipsec/ipsec_input.c
@@ -22,6 +22,7 @@
 
 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ah.h>
 
 #define foreach_ipsec_input_error                   \
  _(RX_PKTS, "IPSEC pkts received")                  \
@@ -194,6 +195,7 @@ ipsec_input_ip4_node_fn (vlib_main_t * vm,
 	  vlib_buffer_t *b0;
 	  ip4_header_t *ip0;
 	  esp_header_t *esp0;
+	  ah_header_t *ah0;
 	  ip4_ipsec_config_t *c0;
 	  ipsec_spd_t *spd0;
 	  ipsec_policy_t *p0 = 0;
@@ -213,7 +215,6 @@ ipsec_input_ip4_node_fn (vlib_main_t * vm,
 	  spd0 = pool_elt_at_index (im->spds, c0->spd_index);
 
 	  ip0 = vlib_buffer_get_current (b0);
-	  esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 
 	  if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
 	    {
@@ -226,6 +227,7 @@ ipsec_input_ip4_node_fn (vlib_main_t * vm,
 		 clib_net_to_host_u16 (ip0->length), spd0->id);
 #endif
 
+	      esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
 	      p0 = ipsec_input_protect_policy_match (spd0,
 						     clib_net_to_host_u32
 						     (ip0->src_address.
@@ -246,21 +248,60 @@ ipsec_input_ip4_node_fn (vlib_main_t * vm,
 		  vlib_buffer_advance (b0, ip4_header_bytes (ip0));
 		  goto trace0;
 		}
+
+	      /* FIXME bypass and discard */
+	    trace0:
+	      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+		{
+		  ipsec_input_trace_t *tr =
+		    vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
+		    {
+		      if (p0)
+			tr->sa_id = p0->sa_id;
+		      tr->spi = clib_host_to_net_u32 (esp0->spi);
+		      tr->seq = clib_host_to_net_u32 (esp0->seq);
+		    }
+		}
+
 	    }
 
-	  /* FIXME bypass and discard */
 
-	trace0:
-	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+	  if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_AH))
 	    {
-	      ipsec_input_trace_t *tr =
-		vlib_add_trace (vm, node, b0, sizeof (*tr));
-	      if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
+	      ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
+	      p0 = ipsec_input_protect_policy_match (spd0,
+						     clib_net_to_host_u32
+						     (ip0->src_address.
+						      as_u32),
+						     clib_net_to_host_u32
+						     (ip0->dst_address.
+						      as_u32),
+						     clib_net_to_host_u32
+						     (ah0->spi));
+
+	      if (PREDICT_TRUE (p0 != 0))
 		{
-		  if (p0)
-		    tr->sa_id = p0->sa_id;
-		  tr->spi = clib_host_to_net_u32 (esp0->spi);
-		  tr->seq = clib_host_to_net_u32 (esp0->seq);
+		  p0->counter.packets++;
+		  p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
+		  vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
+		  vnet_buffer (b0)->ipsec.flags = 0;
+		  next0 = im->ah_decrypt_next_index;
+		  goto trace1;
+		}
+	      /* FIXME bypass and discard */
+	    trace1:
+	      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+		{
+		  ipsec_input_trace_t *tr =
+		    vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
+		    {
+		      if (p0)
+			tr->sa_id = p0->sa_id;
+		      tr->spi = clib_host_to_net_u32 (ah0->spi);
+		      tr->seq = clib_host_to_net_u32 (ah0->seq_no);
+		    }
 		}
 	    }
 
diff --git a/src/vnet/ipsec/ipsec_output.c b/src/vnet/ipsec/ipsec_output.c
index 1b8070d651a..e86292c0d17 100644
--- a/src/vnet/ipsec/ipsec_output.c
+++ b/src/vnet/ipsec/ipsec_output.c
@@ -270,8 +270,15 @@ ipsec_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	{
 	  if (p0->policy == IPSEC_POLICY_ACTION_PROTECT)
 	    {
+	      u32 sa_index = 0;
+	      ipsec_sa_t *sa = 0;
 	      nc_protect++;
-	      next_node_index = im->esp_encrypt_node_index;
+	      sa_index = ipsec_get_sa_index_by_sa_id (p0->sa_id);
+	      sa = pool_elt_at_index (im->sad, sa_index);
+	      if (sa->protocol == IPSEC_PROTOCOL_ESP)
+		next_node_index = im->esp_encrypt_node_index;
+	      else
+		next_node_index = im->ah_encrypt_node_index;
 	      vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
 	      vlib_buffer_advance (b0, iph_offset);
 	      p0->counter.packets++;