transmission/libtransmission/crypto.h

124 lines
3.3 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2 (b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#ifndef TR_ENCRYPTION_H
#define TR_ENCRYPTION_H
#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif
#include <inttypes.h>
#include "utils.h" /* TR_GNUC_NULL_TERMINATED */
/**
*** @addtogroup peers
*** @{
**/
#include <openssl/dh.h> /* RC4_KEY */
#include <openssl/rc4.h> /* DH */
enum
{
KEY_LEN = 96
};
/** @brief Holds state information for encrypted peer communications */
typedef struct
{
RC4_KEY dec_key;
RC4_KEY enc_key;
DH * dh;
uint8_t myPublicKey[KEY_LEN];
uint8_t mySecret[KEY_LEN];
uint8_t torrentHash[SHA_DIGEST_LENGTH];
bool isIncoming;
bool torrentHashIsSet;
bool mySecretIsSet;
}
tr_crypto;
/** @brief construct a new tr_crypto object */
void tr_cryptoConstruct (tr_crypto * crypto, const uint8_t * torrentHash, bool isIncoming);
/** @brief destruct an existing tr_crypto object */
void tr_cryptoDestruct (tr_crypto * crypto);
void tr_cryptoSetTorrentHash (tr_crypto * crypto, const uint8_t * torrentHash);
const uint8_t* tr_cryptoGetTorrentHash (const tr_crypto * crypto);
int tr_cryptoHasTorrentHash (const tr_crypto * crypto);
const uint8_t* tr_cryptoComputeSecret (tr_crypto * crypto,
const uint8_t * peerPublicKey);
const uint8_t* tr_cryptoGetMyPublicKey (const tr_crypto * crypto,
int * setme_len);
void tr_cryptoDecryptInit (tr_crypto * crypto);
void tr_cryptoDecrypt (tr_crypto * crypto,
size_t buflen,
const void * buf_in,
void * buf_out);
void tr_cryptoEncryptInit (tr_crypto * crypto);
void tr_cryptoEncrypt (tr_crypto * crypto,
size_t buflen,
const void * buf_in,
void * buf_out);
/* @} */
/**
*** @addtogroup utils Utilities
*** @{
**/
/** @brief generate a SHA1 hash from one or more chunks of memory */
void tr_sha1 (uint8_t * setme,
const void * content1,
int content1_len,
...) TR_GNUC_NULL_TERMINATED;
/** @brief returns a random number in the range of [0...n) */
int tr_cryptoRandInt (int n);
/**
* @brief returns a pseudorandom number in the range of [0...n)
*
* This is faster, BUT WEAKER, than tr_cryptoRandInt () and never
* be used in sensitive cases.
* @see tr_cryptoRandInt ()
*/
int tr_cryptoWeakRandInt (int n);
/** @brief fill a buffer with random bytes */
void tr_cryptoRandBuf (void * buf, size_t len);
/** @brief generate a SSHA password from its plaintext source */
char* tr_ssha1 (const void * plaintext);
/** @brief Validate a test password against the a ssha1 password */
bool tr_ssha1_matches (const char * ssha1, const char * pass);
/* @} */
#endif