package/ead/src/tinysrp/t_client.h

   1 /*
   2  * Copyright (c) 1997-1999  The Stanford SRP Authentication Project
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  18  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  19  *
  20  * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
  21  * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
  22  * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF
  23  * THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT
  24  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  25  *
  26  * In addition, the following conditions apply:
  27  *
  28  * 1. Any software that incorporates the SRP authentication technology
  29  *    must display the following acknowlegment:
  30  *    "This product uses the 'Secure Remote Password' cryptographic
  31  *     authentication system developed by Tom Wu (tjw@CS.Stanford.EDU)."
  32  *
  33  * 2. Any software that incorporates all or part of the SRP distribution
  34  *    itself must also display the following acknowledgment:
  35  *    "This product includes software developed by Tom Wu and Eugene
  36  *     Jhong for the SRP Distribution (http://srp.stanford.edu/srp/)."
  37  *
  38  * 3. Redistributions in source or binary form must retain an intact copy
  39  *    of this copyright notice and list of conditions.
  40  */
  41
  42 #ifndef T_CLIENT_H
  43 #define T_CLIENT_H
  44
  45 #include "t_sha.h"
  46
  47 #if     !defined(P)
  48 #ifdef  __STDC__
  49 #define P(x)    x
  50 #else
  51 #define P(x)    ()
  52 #endif
  53 #endif
  54
  55 /*      For building dynamic link libraries under windows, windows NT
  56  *      using MSVC1.5 or MSVC2.0
  57  */
  58
  59 #ifndef _DLLDECL
  60 #define _DLLDECL
  61
  62 #ifdef MSVC15   /* MSVC1.5 support for 16 bit apps */
  63 #define _MSVC15EXPORT _export
  64 #define _MSVC20EXPORT
  65 #define _DLLAPI _export _pascal
  66 #define _TYPE(a) a _MSVC15EXPORT
  67 #define DLLEXPORT 1
  68
  69 #elif MSVC20
  70 #define _MSVC15EXPORT
  71 #define _MSVC20EXPORT _declspec(dllexport)
  72 #define _DLLAPI
  73 #define _TYPE(a) _MSVC20EXPORT a
  74 #define DLLEXPORT 1
  75
  76 #else                   /* Default, non-dll.  Use this for Unix or DOS */
  77 #define _MSVC15DEXPORT
  78 #define _MSVC20EXPORT
  79 #define _DLLAPI
  80 #define _TYPE(a) a
  81 #endif
  82 #endif
  83
  84 #define ALEN 32
  85 #define MIN_MOD_BYTES 64        /* 512 bits */
  86
  87 struct t_client {
  88   struct t_num n;
  89   struct t_num g;
  90   struct t_num s;
  91
  92   struct t_num a;
  93   struct t_num A;
  94
  95   struct t_num p;
  96   struct t_num v;
  97
  98   SHA1_CTX hash, ckhash;
  99
 100   char username[MAXUSERLEN];
 101   unsigned char session_key[SESSION_KEY_LEN];
 102   unsigned char session_response[RESPONSE_LEN];
 103
 104   unsigned char nbuf[MAXPARAMLEN], gbuf[MAXPARAMLEN], sbuf[MAXSALTLEN];
 105   unsigned char pbuf[MAXPARAMLEN], vbuf[MAXPARAMLEN];
 106   unsigned char abuf[ALEN], Abuf[MAXPARAMLEN];
 107 };
 108
 109 /*
 110  * SRP client-side negotiation
 111  *
 112  * This code negotiates the client side of an SRP exchange.
 113  * "t_clientopen" accepts a username, and N, g, and s parameters,
 114  *   which are usually sent by the server in the first round.
 115  *   The client should then call...
 116  * "t_clientgenexp" will generate a random 256-bit exponent and
 117  *   raise g to that power, returning the result.  This result
 118  *   should be sent to the server as w(p).
 119  * "t_clientpasswd" accepts the user's password, which should be
 120  *   entered locally and updates the client's state.
 121  * "t_clientgetkey" accepts the exponential y(p), which should
 122  *   be sent by the server in the next round and computes the
 123  *   256-bit session key.  This data should be saved before the
 124  *   session is closed.
 125  * "t_clientresponse" computes the session key proof as SHA(y(p), K).
 126  * "t_clientclose" closes the session and frees its memory.
 127  *
 128  * Note that authentication is not performed per se; it is up
 129  * to either/both sides of the protocol to now verify securely
 130  * that their session keys agree in order to establish authenticity.
 131  * One possible way is through "oracle hashing"; one side sends
 132  * r, the other replies with H(r,K), where H() is a hash function.
 133  *
 134  * t_clientresponse and t_clientverify now implement a version of
 135  * the session-key verification described above.
 136  */
 137 _TYPE( struct t_client * )
 138   t_clientopen P((const char *, struct t_num *, struct t_num *,
 139                   struct t_num *));
 140 _TYPE( struct t_num * ) t_clientgenexp P((struct t_client *));
 141 _TYPE( void ) t_clientpasswd P((struct t_client *, char *));
 142 _TYPE( unsigned char * )
 143   t_clientgetkey P((struct t_client *, struct t_num *));
 144 _TYPE( int ) t_clientverify P((struct t_client *, unsigned char *));
 145 _TYPE( unsigned char * ) t_clientresponse P((struct t_client *));
 146 _TYPE( void ) t_clientclose P((struct t_client *));
 147
 148 #endif