1 /* vi: set sw=4 ts=4: */
2 /*
3 * Utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9 #if !ENABLE_USE_BB_CRYPT
10 # if !defined(__FreeBSD__)
11 # include <crypt.h>
12 # endif
13 #endif
14 #include "libbb.h"
15
16 /* static const uint8_t ascii64[] ALIGN1 =
17 * "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
18 */
19
i64c(int i)20 static int i64c(int i)
21 {
22 i &= 0x3f;
23 if (i == 0)
24 return '.';
25 if (i == 1)
26 return '/';
27 if (i < 12)
28 return ('0' - 2 + i);
29 if (i < 38)
30 return ('A' - 12 + i);
31 return ('a' - 38 + i);
32 }
33
crypt_make_salt(char * p,int cnt)34 int FAST_FUNC crypt_make_salt(char *p, int cnt /*, int x */)
35 {
36 /* was: x += ... */
37 unsigned x = getpid() + monotonic_us();
38 do {
39 /* x = (x*1664525 + 1013904223) % 2^32 generator is lame
40 * (low-order bit is not "random", etc...),
41 * but for our purposes it is good enough */
42 x = x*1664525 + 1013904223;
43 /* BTW, Park and Miller's "minimal standard generator" is
44 * x = x*16807 % ((2^31)-1)
45 * It has no problem with visibly alternating lowest bit
46 * but is also weak in cryptographic sense + needs div,
47 * which needs more code (and slower) on many CPUs */
48 *p++ = i64c(x >> 16);
49 *p++ = i64c(x >> 22);
50 } while (--cnt);
51 *p = '\0';
52 return x;
53 }
54
crypt_make_pw_salt(char salt[MAX_PW_SALT_LEN],const char * algo)55 char* FAST_FUNC crypt_make_pw_salt(char salt[MAX_PW_SALT_LEN], const char *algo)
56 {
57 int len = 2/2;
58 char *salt_ptr = salt;
59
60 /* Standard chpasswd uses uppercase algos ("MD5", not "md5").
61 * Need to be case-insensitive in the code below.
62 */
63 if ((algo[0]|0x20) != 'd') { /* not des */
64 len = 8/2; /* so far assuming md5 */
65 *salt_ptr++ = '$';
66 *salt_ptr++ = '1';
67 *salt_ptr++ = '$';
68 #if !ENABLE_USE_BB_CRYPT || ENABLE_USE_BB_CRYPT_SHA
69 if ((algo[0]|0x20) == 's') { /* sha */
70 salt[1] = '5' + (strcasecmp(algo, "sha512") == 0);
71 len = 16/2;
72 }
73 #endif
74 }
75 crypt_make_salt(salt_ptr, len);
76 return salt_ptr;
77 }
78
79 #if ENABLE_USE_BB_CRYPT
80
81 static char*
to64(char * s,unsigned v,int n)82 to64(char *s, unsigned v, int n)
83 {
84 while (--n >= 0) {
85 /* *s++ = ascii64[v & 0x3f]; */
86 *s++ = i64c(v);
87 v >>= 6;
88 }
89 return s;
90 }
91
92 /*
93 * DES and MD5 crypt implementations are taken from uclibc.
94 * They were modified to not use static buffers.
95 */
96
97 #include "pw_encrypt_des.c"
98 #include "pw_encrypt_md5.c"
99 #if ENABLE_USE_BB_CRYPT_SHA
100 #include "pw_encrypt_sha.c"
101 #endif
102
103 /* Other advanced crypt ids (TODO?): */
104 /* $2$ or $2a$: Blowfish */
105
106 static struct const_des_ctx *des_cctx;
107 static struct des_ctx *des_ctx;
108
109 /* my_crypt returns malloc'ed data */
my_crypt(const char * key,const char * salt)110 static char *my_crypt(const char *key, const char *salt)
111 {
112 /* MD5 or SHA? */
113 if (salt[0] == '$' && salt[1] && salt[2] == '$') {
114 if (salt[1] == '1')
115 return md5_crypt(xzalloc(MD5_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt);
116 #if ENABLE_USE_BB_CRYPT_SHA
117 if (salt[1] == '5' || salt[1] == '6')
118 return sha_crypt((char*)key, (char*)salt);
119 #endif
120 }
121
122 if (!des_cctx)
123 des_cctx = const_des_init();
124 des_ctx = des_init(des_ctx, des_cctx);
125 /* Can return NULL if salt is bad ("" or "<one_char>") */
126 return des_crypt(des_ctx, xzalloc(DES_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt);
127 }
128
129 /* So far nobody wants to have it public */
my_crypt_cleanup(void)130 static void my_crypt_cleanup(void)
131 {
132 free(des_cctx);
133 free(des_ctx);
134 des_cctx = NULL;
135 des_ctx = NULL;
136 }
137
pw_encrypt(const char * clear,const char * salt,int cleanup)138 char* FAST_FUNC pw_encrypt(const char *clear, const char *salt, int cleanup)
139 {
140 char *encrypted;
141
142 encrypted = my_crypt(clear, salt);
143 if (!encrypted)
144 bb_simple_error_msg_and_die("bad salt");
145
146 if (cleanup)
147 my_crypt_cleanup();
148
149 return encrypted;
150 }
151
152 #else /* if !ENABLE_USE_BB_CRYPT */
153
pw_encrypt(const char * clear,const char * salt,int cleanup)154 char* FAST_FUNC pw_encrypt(const char *clear, const char *salt, int cleanup)
155 {
156 char *encrypted;
157
158 encrypted = crypt(clear, salt);
159 /*
160 * glibc used to return "" on malformed salts (for example, ""),
161 * but since 2.17 it returns NULL.
162 */
163 if (!encrypted || !encrypted[0])
164 bb_simple_error_msg_and_die("bad salt");
165 return xstrdup(encrypted);
166 }
167
168 #endif
169