crypto/asn1/i2d_dhp.c

   1 /* crypto/asn1/i2d_dhp.c */
   2 /* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include "bn.h"
  62 #include "asn1_mac.h"
  63 #include "dh.h"
  64
  65 /*
  66  * ASN1err(ASN1_F_D2I_DHPARAMS,ASN1_R_LENGTH_MISMATCH);
  67  * ASN1err(ASN1_F_X509_DHPARAMS_NEW,ASN1_R_LENGTH_MISMATCH);
  68  */
  69
  70 int i2d_DHparams(a,pp)
  71 DH *a;
  72 unsigned char **pp;
  73         {
  74         BIGNUM *num[3];
  75         ASN1_INTEGER bs;
  76         unsigned int j,i,tot=0,len,max=0;
  77         int t,ret= -1;
  78         unsigned char *p;
  79
  80         if (a == NULL) return(0);
  81         num[0]=a->p;
  82         num[1]=a->g;
  83         if (a->length != 0)
  84                 {
  85                 if ((num[2]=BN_new()) == NULL) goto err;
  86                 if (!BN_set_word(num[2],a->length)) goto err;
  87                 }
  88         else
  89                 num[2]=NULL;
  90
  91         for (i=0; i<3; i++)
  92                 {
  93                 if (num[i] == NULL) continue;
  94                 j=BN_num_bits(num[i]);
  95                 len=((j == 0)?0:((j/8)+1));
  96                 if (len > max) max=len;
  97                 len=ASN1_object_size(0,len,
  98                         (num[i]->neg)?V_ASN1_NEG_INTEGER:V_ASN1_INTEGER);
  99                 tot+=len;
 100                 }
 101
 102         t=ASN1_object_size(1,tot,V_ASN1_SEQUENCE);
 103         if (pp == NULL) return(t);
 104
 105         p= *pp;
 106         ASN1_put_object(&p,1,tot,V_ASN1_SEQUENCE,V_ASN1_UNIVERSAL);
 107
 108         bs.type=V_ASN1_INTEGER;
 109         bs.data=(unsigned char *)Malloc(max+4);
 110         if (bs.data == NULL)
 111                 {
 112                 ASN1err(ASN1_F_I2D_DHPARAMS,ERR_R_MALLOC_FAILURE);
 113                 goto err;
 114                 }
 115
 116         for (i=0; i<3; i++)
 117                 {
 118                 if (num[i] == NULL) continue;
 119                 bs.length=BN_bn2bin(num[i],bs.data);
 120                 i2d_ASN1_INTEGER(&bs,&p);
 121                 }
 122         Free((char *)bs.data);
 123         ret=t;
 124 err:
 125         if (num[2] != NULL) BN_free(num[2]);
 126         *pp=p;
 127         return(ret);
 128         }