1/*
2 * UFC-crypt: ultra fast crypt(3) implementation
3 *
4 * Copyright (C) 1991-2017 Free Software Foundation, Inc.
5 *
6 * The GNU C Library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * The GNU C Library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with the GNU C Library; if not, see
18 * <http://www.gnu.org/licenses/>.
19 *
20 * crypt entry points
21 *
22 * @(#)crypt-entry.c 1.2 12/20/96
23 *
24 */
25
26#ifdef DEBUG
27#include <stdio.h>
28#endif
29#include <string.h>
30#include <errno.h>
31#include <fips-private.h>
32
33#ifndef STATIC
34#define STATIC static
35#endif
36
37#include "crypt-private.h"
38
39/* Prototypes for local functions. */
40#ifndef __GNU_LIBRARY__
41void _ufc_clearmem (char *start, int cnt);
42#else
43#define _ufc_clearmem(start, cnt) memset(start, 0, cnt)
44#endif
45extern char *__md5_crypt_r (const char *key, const char *salt, char *buffer,
46 int buflen);
47extern char *__md5_crypt (const char *key, const char *salt);
48extern char *__sha256_crypt_r (const char *key, const char *salt,
49 char *buffer, int buflen);
50extern char *__sha256_crypt (const char *key, const char *salt);
51extern char *__sha512_crypt_r (const char *key, const char *salt,
52 char *buffer, int buflen);
53extern char *__sha512_crypt (const char *key, const char *salt);
54
55/* Define our magic string to mark salt for MD5 encryption
56 replacement. This is meant to be the same as for other MD5 based
57 encryption implementations. */
58static const char md5_salt_prefix[] = "$1$";
59
60/* Magic string for SHA256 encryption. */
61static const char sha256_salt_prefix[] = "$5$";
62
63/* Magic string for SHA512 encryption. */
64static const char sha512_salt_prefix[] = "$6$";
65
66/* For use by the old, non-reentrant routines (crypt/encrypt/setkey) */
67extern struct crypt_data _ufc_foobar;
68
69/*
70 * UNIX crypt function
71 */
72
73char *
74__crypt_r (const char *key, const char *salt,
75 struct crypt_data * __restrict data)
76{
77 ufc_long res[4];
78 char ktab[9];
79 ufc_long xx = 25; /* to cope with GCC long long compiler bugs */
80
81#ifdef _LIBC
82 /* Try to find out whether we have to use MD5 encryption replacement. */
83 if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0)
84 {
85 /* FIPS rules out MD5 password encryption. */
86 if (fips_enabled_p ())
87 {
88 __set_errno (EPERM);
89 return NULL;
90 }
91 return __md5_crypt_r (key, salt, (char *) data,
92 sizeof (struct crypt_data));
93 }
94
95 /* Try to find out whether we have to use SHA256 encryption replacement. */
96 if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
97 return __sha256_crypt_r (key, salt, (char *) data,
98 sizeof (struct crypt_data));
99
100 /* Try to find out whether we have to use SHA512 encryption replacement. */
101 if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
102 return __sha512_crypt_r (key, salt, (char *) data,
103 sizeof (struct crypt_data));
104#endif
105
106 /*
107 * Hack DES tables according to salt
108 */
109 if (!_ufc_setup_salt_r (salt, data))
110 {
111 __set_errno (EINVAL);
112 return NULL;
113 }
114
115 /* FIPS rules out DES password encryption. */
116 if (fips_enabled_p ())
117 {
118 __set_errno (EPERM);
119 return NULL;
120 }
121
122 /*
123 * Setup key schedule
124 */
125 _ufc_clearmem (ktab, (int) sizeof (ktab));
126 (void) strncpy (ktab, key, 8);
127 _ufc_mk_keytab_r (ktab, data);
128
129 /*
130 * Go for the 25 DES encryptions
131 */
132 _ufc_clearmem ((char*) res, (int) sizeof (res));
133 _ufc_doit_r (xx, data, &res[0]);
134
135 /*
136 * Do final permutations
137 */
138 _ufc_dofinalperm_r (res, data);
139
140 /*
141 * And convert back to 6 bit ASCII
142 */
143 _ufc_output_conversion_r (res[0], res[1], salt, data);
144
145 /*
146 * Erase key-dependent intermediate data. Data dependent only on
147 * the salt is not considered sensitive.
148 */
149 explicit_bzero (ktab, sizeof (ktab));
150 explicit_bzero (data->keysched, sizeof (data->keysched));
151 explicit_bzero (res, sizeof (res));
152
153 return data->crypt_3_buf;
154}
155weak_alias (__crypt_r, crypt_r)
156
157char *
158crypt (const char *key, const char *salt)
159{
160#ifdef _LIBC
161 /* Try to find out whether we have to use MD5 encryption replacement. */
162 if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0
163 /* Let __crypt_r deal with the error code if FIPS is enabled. */
164 && !fips_enabled_p ())
165 return __md5_crypt (key, salt);
166
167 /* Try to find out whether we have to use SHA256 encryption replacement. */
168 if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
169 return __sha256_crypt (key, salt);
170
171 /* Try to find out whether we have to use SHA512 encryption replacement. */
172 if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
173 return __sha512_crypt (key, salt);
174#endif
175
176 return __crypt_r (key, salt, &_ufc_foobar);
177}
178
179
180/*
181 * To make fcrypt users happy.
182 * They don't need to call init_des.
183 */
184#ifdef _LIBC
185weak_alias (crypt, fcrypt)
186#else
187char *
188__fcrypt (const char *key, const char *salt)
189{
190 return crypt (key, salt);
191}
192#endif
193