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https://github.com/OpenVPN/openvpn.git
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34cb9132ef
Suitable for mature project. root - administrative stuff doc - documents src - sources tests - tests distro - distro specific files sample - samples SIDE EFFECT: many changes to rpm spec. Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com> Acked-by: Adriaan de Jong <dejong@fox-it.com> Signed-off-by: David Sommerseth <davids@redhat.com>
76 lines
3.3 KiB
C
76 lines
3.3 KiB
C
/*
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* OpenVPN -- An application to securely tunnel IP networks
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* over a single TCP/UDP port, with support for SSL/TLS-based
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* session authentication and key exchange,
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* packet encryption, packet authentication, and
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* packet compression.
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*
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* Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program (see the file COPYING included with this
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* distribution); if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/**
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* @file
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* Data Channel Crypto module documentation file.
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*/
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/**
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* @addtogroup data_crypto Data Channel Crypto module
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*
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* The Data Channel Crypto Module performs cryptographic operations on
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* data channel packets.
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*
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* @par Security parameters
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* This module is merely the user of a VPN tunnel's security parameters.
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* It does not perform the negotiation and setup of the security
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* parameters, nor the %key generation involved. These actions are done
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* by the \link control_processor Control Channel Processor\endlink. This
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* module receives the appropriate security parameters from that module in
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* the form of a \c crypto_options structure when they are necessary for
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* processing a packet.
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*
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* @par Packet processing functions
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* This module receives data channel packets from the \link data_control
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* Data Channel Control module\endlink and processes them according to the
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* security parameters of the packet's VPN tunnel. The \link data_control
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* Data Channel Control module\endlink uses the following interface
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* functions:
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* - For packets which will be sent to a remote OpenVPN peer:
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* - \c tls_pre_encrypt()
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* - \c openvpn_encrypt()
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* - \c tls_post_encrypt()
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* - For packets which have been received from a remote OpenVPN peer:
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* - \c tls_pre_decrypt() (documented as part of the \link
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* external_multiplexer External Multiplexer\endlink)
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* - \c openvpn_decrypt()
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*
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* @par Settings that control this module's activity
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* Whether or not the Data Channel Crypto module is active depends on the
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* compile-time \c USE_CRYPTO and \c USE_SSL preprocessor macros. How it
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* processes packets received from the \link data_control Data Channel
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* Control module\endlink at runtime depends on the associated \c
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* crypto_options structure. To perform cryptographic operations, the \c
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* crypto_options.key_ctx_bi must contain the correct cipher and HMAC
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* security parameters for the direction the packet is traveling in.
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*
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* @par Crypto algorithms
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* This module uses the crypto algorithm implementations of the external
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* OpenSSL library. More precisely, it uses the OpenSSL library's \c
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* EVP_Cipher* and \c HMAC_* set of functions to perform cryptographic
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* operations on data channel packets.
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*/
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