1 /* $NetBSD: random_password.c,v 1.1.1.1 2011/04/13 18:14:35 elric Exp $ */
4 * Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
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9 * modification, are permitted provided that the following conditions
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16 * notice, this list of conditions and the following disclaimer in the
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20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
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36 #include "kadmin_locl.h"
38 /* This file defines some a function that generates a random password,
39 that can be used when creating a large amount of principals (such
40 as for a batch of students). Since this is a political matter, you
41 should think about how secure generated passwords has to be.
43 Both methods defined here will give you at least 55 bits of
47 /* If you want OTP-style passwords, define OTP_STYLE */
52 static void generate_password(char **pw
, int num_classes
, ...);
56 random_password(char *pw
, size_t len
)
62 krb5_generate_random_block(&newkey
, sizeof(newkey
));
63 otp_print_stddict (newkey
, pw
, len
);
68 generate_password(&pass
, 3,
69 "abcdefghijklmnopqrstuvwxyz", 7,
70 "ABCDEFGHIJKLMNOPQRSTUVWXYZ", 2,
71 "@$%&*()-+=:,/<>1234567890", 1);
72 strlcpy(pw
, pass
, len
);
73 memset(pass
, 0, strlen(pass
));
78 /* some helper functions */
81 /* return a random value in range 0-127 */
83 RND(unsigned char *key
, int keylen
, int *left
)
86 krb5_generate_random_block(key
, keylen
);
90 return ((unsigned char*)key
)[*left
];
93 /* This a helper function that generates a random password with a
94 number of characters from a set of character classes.
96 If there are n classes, and the size of each class is Pi, and the
97 number of characters from each class is Ni, the number of possible
98 passwords are (given that the character classes are disjoint):
108 Since it uses the RND function above, neither the size of each
109 class, nor the total length of the generated password should be
110 larger than 127 (without fixing RND).
114 generate_password(char **pw
, int num_classes
, ...)
123 unsigned char rbuf
[8]; /* random buffer */
128 classes
= malloc(num_classes
* sizeof(*classes
));
131 va_start(ap
, num_classes
);
133 for(i
= 0; i
< num_classes
; i
++){
134 classes
[i
].str
= va_arg(ap
, const char*);
135 classes
[i
].len
= strlen(classes
[i
].str
);
136 classes
[i
].freq
= va_arg(ap
, int);
137 len
+= classes
[i
].freq
;
140 *pw
= malloc(len
+ 1);
145 for(i
= 0; i
< len
; i
++) {
147 int x
= RND(rbuf
, sizeof(rbuf
), &rleft
) % (len
- i
);
149 for(j
= 0; j
< num_classes
; j
++) {
150 if(x
< t
+ classes
[j
].freq
) {
151 (*pw
)[i
] = classes
[j
].str
[RND(rbuf
, sizeof(rbuf
), &rleft
)
156 t
+= classes
[j
].freq
;
160 memset(rbuf
, 0, sizeof(rbuf
));