/* *  OpenVPN -- An application to securely tunnel IP networks *             over a single UDP port, with support for TLS-based *             session authentication and key exchange, *             packet encryption, packet authentication, and *             packet compression. * *  Copyright (C) 2002 James Yonan <jim@yonan.net> * *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, or *  (at your option) any later version. * *  This program is distributed in the hope that it will be useful, *  but WITHOUT ANY WARRANTY; without even the implied warranty of *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the *  GNU General Public License for more details. * *  You should have received a copy of the GNU General Public License *  along with this program (see the file COPYING included with this *  distribution); if not, write to the Free Software Foundation, Inc., *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */#ifndef CRYPTO_H#define CRYPTO_H#ifdef USE_CRYPTO#include <openssl/objects.h>#include <openssl/rand.h>#include <openssl/evp.h>#include <openssl/hmac.h>#include <openssl/des.h>#include "basic.h"#include "buffer.h"#include "packet_id.h"#include "mtu.h"/* * Workarounds for incompatibilites between OpenSSL libraries. * Right now we accept OpenSSL libraries from 0.9.5 to 0.9.7. */#if SSLEAY_VERSION_NUMBER < 0x00907000L/* Workaround: EVP_CIPHER_mode is defined wrong in OpenSSL 0.9.6 but is fixed in 0.9.7 */#undef EVP_CIPHER_mode#define EVP_CIPHER_mode(e)  (((e)->flags) & EVP_CIPH_MODE)#define DES_cblock              des_cblock#define DES_is_weak_key         des_is_weak_key#define DES_check_key_parity    des_check_key_parity#define DES_set_odd_parity      des_set_odd_parity#define HMAC_CTX_cleanup        HMAC_cleanup#define EVP_MD_CTX_cleanup(md)  CLEAR (*md)#define INFO_CALLBACK_SSL_CONST#endif#ifndef INFO_CALLBACK_SSL_CONST#define INFO_CALLBACK_SSL_CONST const#endif#if SSLEAY_VERSION_NUMBER < 0x00906000#undef EVP_CIPHER_mode#define EVP_CIPHER_mode(x) 1#define EVP_CIPHER_CTX_mode(x) 1#define EVP_CIPHER_flags(x) 0#define EVP_CIPH_CBC_MODE 1#define EVP_CIPH_CFB_MODE 0#define EVP_CIPH_OFB_MODE 0#define EVP_CIPH_VARIABLE_LENGTH 0#define OPENSSL_malloc(x) malloc(x)#define OPENSSL_free(x) free(x)static inline intEVP_CipherInit_ov (EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, uint8_t *key, uint8_t *iv, int enc){  EVP_CipherInit (ctx, type, key, iv, enc);  return 1;}static inline intEVP_CipherUpdate_ov (EVP_CIPHER_CTX *ctx, uint8_t *out, int *outl, uint8_t *in, int inl){  EVP_CipherUpdate (ctx, out, outl, in, inl);  return 1;}static inline boolcipher_ok (const char* name){  const int i = strlen (name) - 4;  if (i >= 0)    return !strcmp (name + i, "-CBC");  else    return false;}#elsestatic inline intEVP_CipherInit_ov (EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, uint8_t *key, uint8_t *iv, int enc){  return EVP_CipherInit (ctx, type, key, iv, enc);}static inline intEVP_CipherUpdate_ov (EVP_CIPHER_CTX *ctx, uint8_t *out, int *outl, uint8_t *in, int inl){  return EVP_CipherUpdate (ctx, out, outl, in, inl);}static inline boolcipher_ok (const char* name){  return true;}#endif#if SSLEAY_VERSION_NUMBER < 0x0090581f#undef DES_check_key_parity#define DES_check_key_parity(x) 1#endif/* * Max size in bytes of any cipher key that might conceivably be used. * * This value is checked at compile time in crypto.c to make sure * it is always at least EVP_MAX_KEY_LENGTH. * * We define our own value, since this parameter * is used to control the size of static key files. * If the OpenSSL library increases EVP_MAX_KEY_LENGTH, * we don't want our key files to be suddenly rendered * unusable. */#define MAX_CIPHER_KEY_LENGTH 64 /* * Max size in bytes of any HMAC key that might conceivably be used. * * This value is checked at compile time in crypto.c to make sure * it is always at least EVP_MAX_MD_SIZE.  We define our own value * for the same reason as above. */#define MAX_HMAC_KEY_LENGTH 64/* * Defines a key type and key length for both cipher and HMAC. */struct key_type{  uint8_t cipher_length;  uint8_t hmac_length;  const EVP_CIPHER *cipher;  const EVP_MD *digest;};/* * A random key. */struct key{  uint8_t cipher[MAX_CIPHER_KEY_LENGTH];  uint8_t hmac[MAX_HMAC_KEY_LENGTH];};/* * A key context for cipher and/or HMAC. */struct key_ctx{  EVP_CIPHER_CTX *cipher;  HMAC_CTX *hmac;};/* * Cipher/HMAC key context for both sending and receiving * directions. */struct key_ctx_bi{  struct key_ctx encrypt;  struct key_ctx decrypt;};/* * Options for encrypt/decrypt. */struct crypto_options{  struct key_ctx_bi *key_ctx_bi;  struct packet_id *packet_id;  bool packet_id_long_form;  uint8_t *iv;};void init_key_type (struct key_type *kt, const char *ciphername,		    bool ciphername_defined, const char *authname,		    bool authname_defined, int keysize,		    bool cfb_ofb_allowed);void read_key_file (struct key *key, const char *filename);void write_key_file (const struct key *key, const char *filename);void generate_key_random (struct key *key, const struct key_type *kt);void randomize_iv (uint8_t *iv);void check_replay_iv_consistency(const struct key_type *kt, bool packet_id, bool iv);bool check_key (struct key *key, const struct key_type *kt);void fixup_key (struct key *key, const struct key_type *kt);void write_key (const struct key *key, const struct key_type *kt,		struct buffer *buf);int read_key (struct key *key, const struct key_type *kt, struct buffer *buf);bool cfb_ofb_mode (const struct key_type* kt);/* enc parameter in init_key_ctx */#define DO_ENCRYPT 1#define DO_DECRYPT 0void init_key_ctx (struct key_ctx *ctx, struct key *key,		   const struct key_type *kt, int enc,		   const char *prefix);void free_key_ctx (struct key_ctx *ctx);void free_key_ctx_bi (struct key_ctx_bi *ctx);void openvpn_encrypt (struct buffer *buf, struct buffer work,		      const struct crypto_options *opt,		      const struct frame* frame,		      const time_t current);void openvpn_decrypt (struct buffer *buf, struct buffer work,		      const struct crypto_options *opt,		      const struct frame* frame,		      const time_t current);void crypto_adjust_frame_parameters (struct frame *frame,				     const struct key_type* kt,				     bool cipher_defined,				     bool iv,				     bool packet_id,				     bool packet_id_long_form);void test_crypto (const struct crypto_options *co, struct frame* f);void show_available_ciphers ();void show_available_digests ();void init_crypto_lib ();#ifdef USE_SSLvoid get_tls_handshake_key (const struct key_type *key_type,			    struct key_ctx_bi *ctx,			    const char *passphrase_file);#elsevoid init_ssl_lib ();void free_ssl_lib ();#endif /* USE_SSL *//* * Inline functions */static inline boolkey_ctx_bi_defined(const struct key_ctx_bi* key){  return key->encrypt.cipher || key->encrypt.hmac || key->decrypt.cipher || key->decrypt.hmac;}#endif /* USE_CRYPTO */#endif /* CRYPTO_H */