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To: linux-kernel@xxxxxxxxxxxxxxx, netdev@xxxxxxxxxxx
Subject: [PATCH] USAGI IPsec
From: Mitsuru KANDA <mk@xxxxxxxxxxxxxx>
Date: Fri, 11 Oct 2002 17:05:59 +0900
Cc: cryptoapi-devel@xxxxxxxxxxx, design@xxxxxxxxxxxxxxxxxx, usagi@xxxxxxxxxxxxxx
Sender: netdev-bounce@xxxxxxxxxxx
Hello Linux kernel network maintainers,

I'm a member of USAGI project.

In IPv6 specifications, IPsec is mandatory.

We implemented IPsec for Linux IP stack.

At present, our implementation includes:
        PF_KEY V2 interface,
        Security Association Database and
        Security Policy Database for whole IP versions,
        IPsec for IPv6,(transport, tunnel mode),
        IPsec for IPv4 (transport mode),

Would you mind checking it ?

The patch is a little too big to send to the mailing list.

Please visit our ftp site <>
and retrieve it from
    (more patches are available)


=== For more details ===
##### USAGI IPsec #####

Table of Contents
        1. How to Apply Patches
        2. Cipher/Digest Algorithms
        3. PF_KEY v2 Implementation
        4. IPsec Implementation
        4.1 Supported Header Order
        4.2 IPsec Mode
        4.3 Packet Processing
        4.4 Conformance Test
        5. New and Changed Files
        6. References
        7. Acknowledgements
1. How to Apply Patches

        1. apply CryptoAPI patch (if you need to compile for test)
        2. apply ipsec-2.4.20-pre10-ALL.patch.gz 
           or ipsec-2.5.41-ALL.patch.gz

        We also prepared rough split patches.
        (for PF_KEY, IPv6 and IPv4 part)
        If you apply them instead of ipsec-*-ALL.patch.gz,
        please apply following order:
        (sorry we haven't prepared rough split patches for 2.5)

2. Cipher/Digest Algorithms

        Supported algorithms:
                Ciphers: DES, 3DES and AES
                Digests: MD5 and SHA1

        We use CryptoAPI as cipher/digest algorithm.
        - CryptoAPI

3. PF_KEY v2 Implementation

        We introduced struct sockaddr_storage{} to handle both IPv4 and
        IPv6 in Security Association Database (SADB) and Security
        Policy Database (SPD).

        We conform to RFC2367 (PF_KEY_V2).
        Many other implementations have extended PF_KEY_V2 protocol to
        process IPsec Security Policy. We have implemented FreeS/WAN's
        PF_KEY extension in order to be compatible with their
        IKEv1 daemon (Pluto).

4. IPsec Implementation

        RFC 2401  Security Architecture for IP
        RFC 2402  IP Authentication Header
        RFC 2406  IP Encapsulating Security Payload

4.1 Supported Header Order

        We support [AH], [ESP], and [AH][ESP].

4.2 IPsec Mode

        Transport Mode

                 We implemented inside IP stack.

        Tunnel Mode
                We implemented  IPsec Tunnel Mode by making use of IP
                over IP tunnel 

                 We realized it by making use of HUT(mipl) IPv6 over
                 IPv6 tunnel.

                 Not yet implemented.(Do we use net/ipv4/ipip.c ?)

4.3 Packet Processing

        Inbound Processing

        Our implementation parses AH and ESP in extension header
        parsing routine (ipv6_parse_exthdrs()). The kernel
        parses AH and ESP and keeps the information of SAs which are
        used during the processing in skb->cb as struct inet6_skb_parm{}.
        The kernel keeps the AH SA information as offset from a IPv6
        header  (the kernel doesn't remove AH header). 
        It also keeps ESP SA information as SPI value.

        If there is something wrong in processing AH and/or ESP, the
        kernel drops the packet. When processing completes successfully,
        the kernel compares SAs information and policy in
        ipsec6_input_check(), which is called from ip6_input_finish().

        When using tunnel mode, there are a couple of differences from
        transport mode. The AH and ESP parsing is same as transport
        mode. However, in tunnel mode the kernel uses the inner header's
        addresses as key to lookup IPsec Security Policy Database.

        Outbound Processing

        The kernel checks IPsec Security Policy Database using as a key
        the src/dst address pair. If it matches with the action applying
        IPsec, start IPsec processing (preparing AH calculation, ESP
        encryption, AH calculation).

4.4 Conformance Test

        We have tested TAHI <> conformance test.
        The results are fine.

5. New and Changed Files

net/key:               (NEW) - 
Makefile                (NEW) - 
af_key.c                (NEW) - PF_KEY_V2 socket interface 
                                (derived from FreeS/WAN 1.9
                                 pfkey_v2.c. changed a lot.)
pfkey_v2_build.c        (NEW) - building PF_KEY message 
                                (derived from FreeS/WAN 1.9
                                 changed a little.)
pfkey_v2_ext_bits.c     (NEW) - (derived from FreeS/WAN 1.9. 
                                 changed a little.)
pfkey_v2_msg.c          (NEW) - PF_KEY helper functions(SA lifetime,...)
pfkey_v2_msg.h          (NEW) - header file for pfkey_v2_msg.c
pfkey_v2_msg_add.c      (NEW) - processing SADB_ADD message 
pfkey_v2_msg_delete.c   (NEW) - processing SADB_DELETE message
pfkey_v2_msg_flow.c     (NEW) - processing SADB_X_ADDFLOW 
                                and SADB_X_DELFLOW messages
pfkey_v2_msg_get.c      (NEW) - processing SADB_GET message
pfkey_v2_msg_getspi.c   (NEW) - processing SADB_GETSPI message
pfkey_v2_msg_update.c   (NEW) - processing SADB_UPDATE message
sa_index.c              (NEW) - Security Association (SA) index 
                                (handle struct sa_index{})
sadb.c                  (NEW) - SA Database
sockaddr_utils.c        (NEW) - utilities
sockaddr_utils.h        (NEW) - utilities
spd.c                   (NEW) - Security Policy (SP) Database
sysctl_net_ipsec.c      (NEW) - sysctls (replay window and debug switch.)

net/ipv6:               (CHANGED)
Makefile                (CHANGED)
exthdrs.c               (CHANGED) - inserted ipsec processing functions
ip6_input.c             (CHANGED) - inserted ipsec processing functions
ip6_output.c            (CHANGED) - inserted ipsec processing functions
ipsec6_input.c          (NEW)     - IPsec processing for input packet
ipsec6_output.c         (NEW)     - IPsec processing for output packet
ipv6_sockglue.c         (CHANGED) - inserted IPsec processing functions.
ndisc.c                 (CHANGED) - inserted ipsec processing functions
                                    (for ND packets)
reassembly.c            (CHANGED) - inserted IPsec processing functions.
tcp_ipv6.c              (CHANGED) - inserted IPsec processing functions. 
                                    (based IABG IPv6 implementation)
net/ipv4:               (CHANGED) -
Makefile                (CHANGED) - 
ip_input.c              (CHANGED) - inserted ipsec processing functions
ip_output.c             (CHANGED) - inserted ipsec processing functions
ipsec4_input.c          (NEW)     - IPsec processing for input packet
ipsec4_output.c         (NEW)     - IPsec processing for output packet
tcp_ipv4.c              (CHANGED) - inserted ipsec processing functions

ip.h                    (CHANGED) - introduced struct ip_auth_hdr{} 
                                    and ip_esp_hdr{}.
ipsec.h                 (CHANGED) - added IPsec actions and 
                                    IPsec4 processing functions.
ipsec6.h                (NEW)     - added IPsec6 processing functions.
pfkey.h                 (NEW)     - PF_KEY related structs 
                                    (derived from FreeS/WAN 1.9)
pfkeyv2.h               (NEW)     - PF_KEY_V2 header file
ipv6.h                  (CHANGED) - introduced struct ipv6_auth_hdr{} 
                                    and ipv6_esp_hdr.
                                    added  'espspi' member 
                                    in struct inet6_skb_parm.
socket.h                (CHANGED) - introduced struct sockaddr_storage{} 
                                    to handle both IPv4 and IPv6
                                    sockaddr in SADB/SPD.
sysctl.h                (CHANGED) - added IPsec entry.

sadb.h                  (NEW)     - SA Database header file
spd.h                   (NEW)     - SP Database header file
ipv6.h                  (CHANGED) - changed ipv6_parse_exthdrs()

6. References

        USAGI Project

7. Acknowledgements

        Joy Latten <latten@xxxxxxxxxxxxxx>
        and IBM IPv6 team

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