diff options
Diffstat (limited to '')
| -rw-r--r-- | third_party/heimdal/kadmin/random_password.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/third_party/heimdal/kadmin/random_password.c b/third_party/heimdal/kadmin/random_password.c new file mode 100644 index 0000000..bf8bf8b --- /dev/null +++ b/third_party/heimdal/kadmin/random_password.c @@ -0,0 +1,162 @@ +/* + * Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "kadmin_locl.h" + +/* This file defines some a function that generates a random password, + that can be used when creating a large amount of principals (such + as for a batch of students). Since this is a political matter, you + should think about how secure generated passwords has to be. + + Both methods defined here will give you at least 55 bits of + entropy. + */ + +/* If you want OTP-style passwords, define OTP_STYLE */ + +#ifdef OTP_STYLE +#include <otp.h> +#else +static void generate_password(char **pw, int num_classes, ...); +#endif + +void +random_password(char *pw, size_t len) +{ +#ifdef OTP_STYLE + { + OtpKey newkey; + + krb5_generate_random_block(&newkey, sizeof(newkey)); + otp_print_stddict (newkey, pw, len); + strlwr(pw); + } +#else + char *pass; + generate_password(&pass, 3, + "abcdefghijklmnopqrstuvwxyz", 7, + "ABCDEFGHIJKLMNOPQRSTUVWXYZ", 2, + "@$%&*()-+=:,/<>1234567890", 1); + strlcpy(pw, pass, len); + len = strlen(pass); + memset_s(pass, len, 0, len); + free(pass); +#endif +} + +/* some helper functions */ + +#ifndef OTP_STYLE +/* return a random value in range 0-127 */ +static int +RND(unsigned char *key, int keylen, int *left) +{ + if(*left == 0){ + krb5_generate_random_block(key, keylen); + *left = keylen; + } + (*left)--; + return ((unsigned char*)key)[*left]; +} + +/* This a helper function that generates a random password with a + number of characters from a set of character classes. + + If there are n classes, and the size of each class is Pi, and the + number of characters from each class is Ni, the number of possible + passwords are (given that the character classes are disjoint): + + n n + ----- / ---- \ + | | Ni | \ | + | | Pi | \ Ni| ! + | | ---- * | / | + | | Ni! | /___ | + i=1 \ i=1 / + + Since it uses the RND function above, neither the size of each + class, nor the total length of the generated password should be + larger than 127 (without fixing RND). + + */ +static void +generate_password(char **pw, int num_classes, ...) +{ + struct { + const char *str; + int len; + int freq; + } *classes; + va_list ap; + int len, i; + unsigned char rbuf[8]; /* random buffer */ + int rleft = 0; + + *pw = NULL; + + classes = malloc(num_classes * sizeof(*classes)); + if(classes == NULL) + return; + va_start(ap, num_classes); + len = 0; + for(i = 0; i < num_classes; i++){ + classes[i].str = va_arg(ap, const char*); + classes[i].len = strlen(classes[i].str); + classes[i].freq = va_arg(ap, int); + len += classes[i].freq; + } + va_end(ap); + *pw = malloc(len + 1); + if(*pw == NULL) { + free(classes); + return; + } + for(i = 0; i < len; i++) { + int j; + int x = RND(rbuf, sizeof(rbuf), &rleft) % (len - i); + int t = 0; + for(j = 0; j < num_classes; j++) { + if(x < t + classes[j].freq) { + (*pw)[i] = classes[j].str[RND(rbuf, sizeof(rbuf), &rleft) + % classes[j].len]; + classes[j].freq--; + break; + } + t += classes[j].freq; + } + } + (*pw)[len] = '\0'; + memset_s(rbuf, sizeof(rbuf), 0, sizeof(rbuf)); + free(classes); +} +#endif |