usr/src/lib/libcryptoutil/common/tohexstr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/types.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29
  30 #include <cryptoutil.h>
  31
  32 /*
  33  * tohexstr
  34  * IN   bytes
  35  *      blen
  36  *      hexlen should be 2 * blen + 1
  37  * OUT
  38  *      hexstr
  39  */
  40 void
  41 tohexstr(uchar_t *bytes, size_t blen, char *hexstr, size_t hexlen)
  42 {
  43         size_t i;
  44         char hexlist[] = "0123456789abcdef";
  45
  46         for (i = 0; i < blen; i++) {
  47                 if (hexlen < (2 * i + 1))
  48                         break;
  49                 hexstr[2 * i] = hexlist[(bytes[i] >> 4) & 0xf];
  50                 hexstr[2 * i + 1] = hexlist[bytes[i] & 0xf];
  51         }
  52         hexstr[2 * blen] = '\0';
  53 }
  54
  55 /*
  56  * This function takes a char[] and length of hexadecimal values and
  57  * returns a malloc'ed byte array with the length of that new byte array.
  58  * The caller needs to provide a pointer to where this new malloc'ed byte array
  59  * will be passed back; as well as, a pointer for the length of the new
  60  * byte array.
  61  *
  62  * The caller is responsible for freeing the malloc'ed array when done
  63  *
  64  * The return code is 0 if successful, otherwise the errno value is returned.
  65  */
  66 int
  67 hexstr_to_bytes(char *hexstr, size_t hexlen, uchar_t **bytes, size_t *blen)
  68 {
  69         int i, ret = 0;
  70         unsigned char ch;
  71         uchar_t *b = NULL;
  72
  73         *bytes = NULL;
  74         *blen = 0;
  75
  76         if (hexstr == NULL || (hexlen % 2 == 1))
  77                 return (EINVAL);
  78
  79         if (hexstr[0] == '0' && ((hexstr[1] == 'x') || (hexstr[1] == 'X'))) {
  80                 hexstr += 2;
  81                 hexlen -= 2;
  82         }
  83
  84         *blen = (hexlen / 2);
  85
  86         b = malloc(*blen);
  87         if (b == NULL) {
  88                 *blen = 0;
  89                 return (errno);
  90         }
  91
  92         for (i = 0; i < hexlen; i++) {
  93                 ch = (unsigned char) *hexstr;
  94
  95                 if (!isxdigit(ch)) {
  96                         ret = EINVAL;
  97                         goto out;
  98                 }
  99
 100                 hexstr++;
 101
 102                 if ((ch >= '0') && (ch <= '9'))
 103                         ch -= '0';
 104                 else if ((ch >= 'A') && (ch <= 'F'))
 105                         ch = ch - 'A' + 10;
 106                 else if ((ch >= 'a') && (ch <= 'f'))
 107                         ch = ch - 'a' + 10;
 108
 109                 if (i & 1)
 110                         b[i/2] |= ch;
 111                 else
 112                         b[i/2] = (ch << 4);
 113         }
 114
 115 out:
 116         if (b != NULL && ret != 0) {
 117                 free(b);
 118                 *blen = 0;
 119         } else
 120                 *bytes = b;
 121
 122         return (ret);
 123 }