tohexstr.c revision 8309:c32ddef7d3ad 
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 */
40void
41tohexstr(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 */
66int
67hexstr_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
115out:
116	if (b != NULL && ret != 0) {
117		free(b);
118		*blen = 0;
119	} else
120		*bytes = b;
121
122	return (ret);
123}
124