text: /* crypto/srp/srp.h */
  /*
   * Written by Christophe Renou (christophe.renou@edelweb.fr) with the
   * precious help of Peter Sylvester (peter.sylvester@edelweb.fr) for the
   * EdelKey project and contributed to the OpenSSL project 2004.
   */
  /* ====================================================================
   * Copyright (c) 2004 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    licensing@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  #ifndef __SRP_H__
  # define __SRP_H__
  
  #include <openssl/opensslconf.h>
  
  # ifdef OPENSSL_NO_SRP
  #  error SRP is disabled.
  # endif
  
  # include <stdio.h>
  # include <string.h>
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  # include <openssl/safestack.h>
  # include <openssl/bn.h>
  # include <openssl/crypto.h>
  
  typedef struct SRP_gN_cache_st {
      char *b64_bn;
      BIGNUM *bn;
  } SRP_gN_cache;
  
  
  DEFINE_STACK_OF(SRP_gN_cache)
  
  typedef struct SRP_user_pwd_st {
      char *id;
      BIGNUM *s;
      BIGNUM *v;
      const BIGNUM *g;
      const BIGNUM *N;
      char *info;
  } SRP_user_pwd;
  
  DEFINE_STACK_OF(SRP_user_pwd)
  
  typedef struct SRP_VBASE_st {
      STACK_OF(SRP_user_pwd) *users_pwd;
      STACK_OF(SRP_gN_cache) *gN_cache;
  /* to simulate a user */
      char *seed_key;
      BIGNUM *default_g;
      BIGNUM *default_N;
  } SRP_VBASE;
  
  /*
   * Structure interne pour retenir les couples N et g
   */
  typedef struct SRP_gN_st {
      char *id;
      BIGNUM *g;
      BIGNUM *N;
  } SRP_gN;
  
  DEFINE_STACK_OF(SRP_gN)
  
  SRP_VBASE *SRP_VBASE_new(char *seed_key);
  void SRP_VBASE_free(SRP_VBASE *vb);
  int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file);
  SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username);
  char *SRP_create_verifier(const char *user, const char *pass, char **salt,
                            char **verifier, const char *N, const char *g);
  int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt,
                             BIGNUM **verifier, const BIGNUM *N,
                             const BIGNUM *g);
  
  # define SRP_NO_ERROR 0
  # define SRP_ERR_VBASE_INCOMPLETE_FILE 1
  # define SRP_ERR_VBASE_BN_LIB 2
  # define SRP_ERR_OPEN_FILE 3
  # define SRP_ERR_MEMORY 4
  
  # define DB_srptype      0
  # define DB_srpverifier  1
  # define DB_srpsalt      2
  # define DB_srpid        3
  # define DB_srpgN        4
  # define DB_srpinfo      5
  # undef  DB_NUMBER
  # define DB_NUMBER       6
  
  # define DB_SRP_INDEX    'I'
  # define DB_SRP_VALID    'V'
  # define DB_SRP_REVOKED  'R'
  # define DB_SRP_MODIF    'v'
  
  /* see srp.c */
  char *SRP_check_known_gN_param(BIGNUM *g, BIGNUM *N);
  SRP_gN *SRP_get_default_gN(const char *id);
  
  /* server side .... */
  BIGNUM *SRP_Calc_server_key(BIGNUM *A, BIGNUM *v, BIGNUM *u, BIGNUM *b,
                              BIGNUM *N);
  BIGNUM *SRP_Calc_B(BIGNUM *b, BIGNUM *N, BIGNUM *g, BIGNUM *v);
  int SRP_Verify_A_mod_N(BIGNUM *A, BIGNUM *N);
  BIGNUM *SRP_Calc_u(BIGNUM *A, BIGNUM *B, BIGNUM *N);
  
  /* client side .... */
  BIGNUM *SRP_Calc_x(BIGNUM *s, const char *user, const char *pass);
  BIGNUM *SRP_Calc_A(BIGNUM *a, BIGNUM *N, BIGNUM *g);
  BIGNUM *SRP_Calc_client_key(BIGNUM *N, BIGNUM *B, BIGNUM *g, BIGNUM *x,
                              BIGNUM *a, BIGNUM *u);
  int SRP_Verify_B_mod_N(BIGNUM *B, BIGNUM *N);
  
  # define SRP_MINIMAL_N 1024
  
  #ifdef  __cplusplus
  }
  #endif
  
  #endif
  