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/*
* Copyright (c) 1997-1999 The Stanford SRP Authentication Project
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF
* THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* In addition, the following conditions apply:
*
* 1. Any software that incorporates the SRP authentication technology
* must display the following acknowlegment:
* "This product uses the 'Secure Remote Password' cryptographic
* authentication system developed by Tom Wu (tjw@CS.Stanford.EDU)."
*
* 2. Any software that incorporates all or part of the SRP distribution
* itself must also display the following acknowledgment:
* "This product includes software developed by Tom Wu and Eugene
* Jhong for the SRP Distribution (http://srp.stanford.edu/srp/)."
*
* 3. Redistributions in source or binary form must retain an intact copy
* of this copyright notice and list of conditions.
*/
#ifndef T_CLIENT_H
#define T_CLIENT_H
#include "t_sha.h"
#if !defined(P)
#ifdef __STDC__
#define P(x) x
#else
#define P(x) ()
#endif
#endif
/* For building dynamic link libraries under windows, windows NT
* using MSVC1.5 or MSVC2.0
*/
#ifndef _DLLDECL
#define _DLLDECL
#ifdef MSVC15 /* MSVC1.5 support for 16 bit apps */
#define _MSVC15EXPORT _export
#define _MSVC20EXPORT
#define _DLLAPI _export _pascal
#define _TYPE(a) a _MSVC15EXPORT
#define DLLEXPORT 1
#elif MSVC20
#define _MSVC15EXPORT
#define _MSVC20EXPORT _declspec(dllexport)
#define _DLLAPI
#define _TYPE(a) _MSVC20EXPORT a
#define DLLEXPORT 1
#else /* Default, non-dll. Use this for Unix or DOS */
#define _MSVC15DEXPORT
#define _MSVC20EXPORT
#define _DLLAPI
#define _TYPE(a) a
#endif
#endif
#define ALEN 32
#define MIN_MOD_BYTES 64 /* 512 bits */
struct t_client {
struct t_num n;
struct t_num g;
struct t_num s;
struct t_num a;
struct t_num A;
struct t_num p;
struct t_num v;
SHA1_CTX hash, ckhash;
char username[MAXUSERLEN];
unsigned char session_key[SESSION_KEY_LEN];
unsigned char session_response[RESPONSE_LEN];
unsigned char nbuf[MAXPARAMLEN], gbuf[MAXPARAMLEN], sbuf[MAXSALTLEN];
unsigned char pbuf[MAXPARAMLEN], vbuf[MAXPARAMLEN];
unsigned char abuf[ALEN], Abuf[MAXPARAMLEN];
};
/*
* SRP client-side negotiation
*
* This code negotiates the client side of an SRP exchange.
* "t_clientopen" accepts a username, and N, g, and s parameters,
* which are usually sent by the server in the first round.
* The client should then call...
* "t_clientgenexp" will generate a random 256-bit exponent and
* raise g to that power, returning the result. This result
* should be sent to the server as w(p).
* "t_clientpasswd" accepts the user's password, which should be
* entered locally and updates the client's state.
* "t_clientgetkey" accepts the exponential y(p), which should
* be sent by the server in the next round and computes the
* 256-bit session key. This data should be saved before the
* session is closed.
* "t_clientresponse" computes the session key proof as SHA(y(p), K).
* "t_clientclose" closes the session and frees its memory.
*
* Note that authentication is not performed per se; it is up
* to either/both sides of the protocol to now verify securely
* that their session keys agree in order to establish authenticity.
* One possible way is through "oracle hashing"; one side sends
* r, the other replies with H(r,K), where H() is a hash function.
*
* t_clientresponse and t_clientverify now implement a version of
* the session-key verification described above.
*/
_TYPE( struct t_client * )
t_clientopen P((const char *, struct t_num *, struct t_num *,
struct t_num *));
_TYPE( struct t_num * ) t_clientgenexp P((struct t_client *));
_TYPE( void ) t_clientpasswd P((struct t_client *, char *));
_TYPE( unsigned char * )
t_clientgetkey P((struct t_client *, struct t_num *));
_TYPE( int ) t_clientverify P((struct t_client *, unsigned char *));
_TYPE( unsigned char * ) t_clientresponse P((struct t_client *));
_TYPE( void ) t_clientclose P((struct t_client *));
#endif
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