crypto/openssl/crypto/asn1/x_long.c

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