kdc/kstash.c

   1 /*
   2  * Copyright (c) 1997-2004 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "headers.h"
  35
  36 krb5_context context;
  37
  38 static char *keyfile;
  39 static int convert_flag;
  40 static int help_flag;
  41 static int version_flag;
  42
  43 static int master_key_fd = -1;
  44 static int random_key_flag;
  45
  46 static const char *enctype_str = "des3-cbc-sha1";
  47
  48 static struct getargs args[] = {
  49     { "enctype", 'e', arg_string, &enctype_str, "encryption type" },
  50     { "key-file", 'k', arg_string, &keyfile, "master key file", "file" },
  51     { "convert-file", 0, arg_flag, &convert_flag,
  52       "just convert keyfile to new format" },
  53     { "master-key-fd", 0, arg_integer, &master_key_fd,
  54       "filedescriptor to read passphrase from", "fd" },
  55     { "random-key", 0, arg_flag, &random_key_flag, "generate a random master key" },
  56     { "help", 'h', arg_flag, &help_flag },
  57     { "version", 0, arg_flag, &version_flag }
  58 };
  59
  60 int num_args = sizeof(args) / sizeof(args[0]);
  61
  62 int
  63 main(int argc, char **argv)
  64 {
  65     char buf[1024];
  66     krb5_error_code ret;
  67
  68     krb5_enctype enctype;
  69
  70     hdb_master_key mkey;
  71
  72     krb5_program_setup(&context, argc, argv, args, num_args, NULL);
  73
  74     if(help_flag)
  75         krb5_std_usage(0, args, num_args);
  76     if(version_flag){
  77         print_version(NULL);
  78         exit(0);
  79     }
  80
  81     if (master_key_fd != -1 && random_key_flag)
  82         krb5_errx(context, 1, "random-key and master-key-fd "
  83                   "is mutual exclusive");
  84
  85     if (keyfile == NULL)
  86         asprintf(&keyfile, "%s/m-key", hdb_db_dir(context));
  87
  88     ret = krb5_string_to_enctype(context, enctype_str, &enctype);
  89     if(ret)
  90         krb5_err(context, 1, ret, "krb5_string_to_enctype");
  91
  92     ret = hdb_read_master_key(context, keyfile, &mkey);
  93     if(ret && ret != ENOENT)
  94         krb5_err(context, 1, ret, "reading master key from %s", keyfile);
  95
  96     if (convert_flag) {
  97         if (ret)
  98             krb5_err(context, 1, ret, "reading master key from %s", keyfile);
  99     } else {
 100         krb5_keyblock key;
 101         krb5_salt salt;
 102         salt.salttype = KRB5_PW_SALT;
 103         /* XXX better value? */
 104         salt.saltvalue.data = NULL;
 105         salt.saltvalue.length = 0;
 106         if (random_key_flag) {
 107             ret = krb5_generate_random_keyblock(context, enctype, &key);
 108             if (ret)
 109                 krb5_err(context, 1, ret, "krb5_generate_random_keyblock");
 110
 111         } else {
 112             if(master_key_fd != -1) {
 113                 ssize_t n;
 114                 n = read(master_key_fd, buf, sizeof(buf));
 115                 if(n <= 0)
 116                     krb5_err(context, 1, errno, "failed to read passphrase");
 117                 buf[n] = '\0';
 118                 buf[strcspn(buf, "\r\n")] = '\0';
 119
 120             } else {
 121                 if(UI_UTIL_read_pw_string(buf, sizeof(buf), "Master key: ", 1))
 122                     exit(1);
 123             }
 124             krb5_string_to_key_salt(context, enctype, buf, salt, &key);
 125         }
 126         ret = hdb_add_master_key(context, &key, &mkey);
 127
 128         krb5_free_keyblock_contents(context, &key);
 129
 130     }
 131
 132     {
 133         char *new, *old;
 134         asprintf(&old, "%s.old", keyfile);
 135         asprintf(&new, "%s.new", keyfile);
 136         if(unlink(new) < 0 && errno != ENOENT) {
 137             ret = errno;
 138             goto out;
 139         }
 140         krb5_warnx(context, "writing key to `%s'", keyfile);
 141         ret = hdb_write_master_key(context, new, mkey);
 142         if(ret)
 143             unlink(new);
 144         else {
 145 #ifndef NO_POSIX_LINKS
 146             unlink(old);
 147             if(link(keyfile, old) < 0 && errno != ENOENT) {
 148                 ret = errno;
 149                 unlink(new);
 150             } else {
 151 #endif
 152                 if(rename(new, keyfile) < 0) {
 153                     ret = errno;
 154                 }
 155 #ifndef NO_POSIX_LINKS
 156             }
 157 #endif
 158         }
 159     out:
 160         free(old);
 161         free(new);
 162         if(ret)
 163             krb5_warn(context, errno, "writing master key file");
 164     }
 165
 166     hdb_free_master_key(context, mkey);
 167
 168     exit(ret != 0);
 169 }