crypto/asn1/x_long.c

   1 /* x_long.c */
   2 /*
   3  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   4  * 2000.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    licensing@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59
  60 #include <stdio.h>
  61 #include "cryptlib.h"
  62 #include <openssl/asn1t.h>
  63 #include <openssl/bn.h>
  64
  65 /*
  66  * Custom primitive type for long handling. This converts between an
  67  * ASN1_INTEGER and a long directly.
  68  */
  69
  70 static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
  71 static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
  72
  73 static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
  74                     const ASN1_ITEM *it);
  75 static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
  76                     int utype, char *free_cont, const ASN1_ITEM *it);
  77
  78 static ASN1_PRIMITIVE_FUNCS long_pf = {
  79     NULL, 0,
  80     long_new,
  81     long_free,
  82     long_free,                  /* Clear should set to initial value */
  83     long_c2i,
  84     long_i2c
  85 };
  86
  87 ASN1_ITEM_start(LONG)
  88         ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, ASN1_LONG_UNDEF, "LONG"
  89 ASN1_ITEM_end(LONG)
  90
  91 ASN1_ITEM_start(ZLONG)
  92         ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, 0, "ZLONG"
  93 ASN1_ITEM_end(ZLONG)
  94
  95 static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
  96 {
  97     *(long *)pval = it->size;
  98     return 1;
  99 }
 100
 101 static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
 102 {
 103     *(long *)pval = it->size;
 104 }
 105
 106 static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
 107                     const ASN1_ITEM *it)
 108 {
 109     long ltmp;
 110     unsigned long utmp;
 111     int clen, pad, i;
 112     /* this exists to bypass broken gcc optimization */
 113     char *cp = (char *)pval;
 114
 115     /* use memcpy, because we may not be long aligned */
 116     memcpy(&ltmp, cp, sizeof(long));
 117
 118     if (ltmp == it->size)
 119         return -1;
 120     /*
 121      * Convert the long to positive: we subtract one if negative so we can
 122      * cleanly handle the padding if only the MSB of the leading octet is
 123      * set.
 124      */
 125     if (ltmp < 0)
 126         utmp = -ltmp - 1;
 127     else
 128         utmp = ltmp;
 129     clen = BN_num_bits_word(utmp);
 130     /* If MSB of leading octet set we need to pad */
 131     if (!(clen & 0x7))
 132         pad = 1;
 133     else
 134         pad = 0;
 135
 136     /* Convert number of bits to number of octets */
 137     clen = (clen + 7) >> 3;
 138
 139     if (cont) {
 140         if (pad)
 141             *cont++ = (ltmp < 0) ? 0xff : 0;
 142         for (i = clen - 1; i >= 0; i--) {
 143             cont[i] = (unsigned char)(utmp & 0xff);
 144             if (ltmp < 0)
 145                 cont[i] ^= 0xff;
 146             utmp >>= 8;
 147         }
 148     }
 149     return clen + pad;
 150 }
 151
 152 static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
 153                     int utype, char *free_cont, const ASN1_ITEM *it)
 154 {
 155     int neg, i;
 156     long ltmp;
 157     unsigned long utmp = 0;
 158     char *cp = (char *)pval;
 159     if (len > (int)sizeof(long)) {
 160         ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
 161         return 0;
 162     }
 163     /* Is it negative? */
 164     if (len && (cont[0] & 0x80))
 165         neg = 1;
 166     else
 167         neg = 0;
 168     utmp = 0;
 169     for (i = 0; i < len; i++) {
 170         utmp <<= 8;
 171         if (neg)
 172             utmp |= cont[i] ^ 0xff;
 173         else
 174             utmp |= cont[i];
 175     }
 176     ltmp = (long)utmp;
 177     if (neg) {
 178         ltmp++;
 179         ltmp = -ltmp;
 180     }
 181     if (ltmp == it->size) {
 182         ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
 183         return 0;
 184     }
 185     memcpy(cp, &ltmp, sizeof(long));
 186     return 1;
 187 }