1 /* $NetBSD: hex.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $ */ 2 3 /* 4 * Copyright (c) 2004-2005 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * 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 the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 37 #include <config.h> 38 #include <krb5/roken.h> 39 #include <ctype.h> 40 #include <krb5/hex.h> 41 42 const static char hexchar[] = "0123456789ABCDEF"; 43 44 static int 45 pos(char c) 46 { 47 const char *p; 48 c = toupper((unsigned char)c); 49 for (p = hexchar; *p; p++) 50 if (*p == c) 51 return p - hexchar; 52 return -1; 53 } 54 55 ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL 56 hex_encode(const void *data, size_t size, char **str) 57 { 58 const unsigned char *q = data; 59 size_t i; 60 char *p; 61 62 /* check for overflow */ 63 if (size * 2 < size) { 64 *str = NULL; 65 return -1; 66 } 67 68 p = malloc(size * 2 + 1); 69 if (p == NULL) { 70 *str = NULL; 71 return -1; 72 } 73 74 for (i = 0; i < size; i++) { 75 p[i * 2] = hexchar[(*q >> 4) & 0xf]; 76 p[i * 2 + 1] = hexchar[*q & 0xf]; 77 q++; 78 } 79 p[i * 2] = '\0'; 80 *str = p; 81 82 return i * 2; 83 } 84 85 ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL 86 hex_decode(const char *str, void *data, size_t len) 87 { 88 size_t l; 89 unsigned char *p = data; 90 size_t i; 91 92 l = strlen(str); 93 94 /* check for overflow, same as (l+1)/2 but overflow safe */ 95 if ((l/2) + (l&1) > len) 96 return -1; 97 98 i = 0; 99 if (l & 1) { 100 p[0] = pos(str[0]); 101 str++; 102 p++; 103 } 104 for (i = 0; i < l / 2; i++) 105 p[i] = pos(str[i * 2]) << 4 | pos(str[(i * 2) + 1]); 106 return i + (l & 1); 107 } 108