diplodocus.org Git - nmh/blob - sbr/ruserpass.c

   1 /*
   2  * Portions of this code are
   3  * Copyright (c) 1985 Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms are permitted
   7  * provided that the above copyright notice and this paragraph are
   8  * duplicated in all such forms and that any documentation,
   9  * advertising materials, and other materials related to such
  10  * distribution and use acknowledge that the software was developed
  11  * by the University of California, Berkeley.  The name of the
  12  * University may not be used to endorse or promote products derived
  13  * from this software without specific prior written permission.
  14  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  * Portions of this code are Copyright (c) 2013, by the authors of
  19  * nmh.  See the COPYRIGHT file in the root directory of the nmh
  20  * distribution for complete copyright information.
  21  */
  22
  23 #include <h/mh.h>
  24 #include <h/utils.h>
  25 #include <pwd.h>
  26
  27 static FILE *cfile;
  28
  29 #define DEFAULT 1
  30 #define LOGIN   2
  31 #define PASSWD  3
  32 #define ACCOUNT 4
  33 #define MACDEF  5
  34 #define ID      10
  35 #define MACH    11
  36
  37 #define MAX_TOKVAL_SIZE 1024
  38
  39 struct toktab {
  40     char *tokstr;
  41     int tval;
  42 };
  43
  44 static struct toktab toktabs[] = {
  45     { "default",  DEFAULT },
  46     { "login",    LOGIN },
  47     { "password", PASSWD },
  48     { "passwd",   PASSWD },
  49     { "account",  ACCOUNT },
  50     { "machine",  MACH },
  51     { "macdef",   MACDEF },
  52     { 0,          0 }
  53 };
  54
  55 /*
  56  * prototypes
  57  */
  58 static int token(char *);
  59
  60
  61 void
  62 ruserpass(const char *host, char **aname, char **apass, int flags)
  63 {
  64     int t, usedefault = 0;
  65     struct stat stb;
  66
  67     init_credentials_file ();
  68
  69     cfile = fopen (credentials_file, "r");
  70     if (cfile == NULL) {
  71         if (errno != ENOENT)
  72             perror (credentials_file);
  73     } else {
  74         char tokval[MAX_TOKVAL_SIZE];
  75         tokval[0] = '\0';
  76
  77         while ((t = token(tokval))) {
  78             switch(t) {
  79             case DEFAULT:
  80                 usedefault = 1;
  81                 /* FALL THROUGH */
  82
  83             case MACH:
  84                 if (!usedefault) {
  85                     if (token(tokval) != ID)
  86                         continue;
  87                     /*
  88                      * Allow match either for user's host name.
  89                      */
  90                     if (strcasecmp(host, tokval) == 0)
  91                         goto match;
  92                     continue;
  93                 }
  94             match:
  95                 while ((t = token(tokval)) && t != MACH && t != DEFAULT) {
  96                     switch(t) {
  97                     case LOGIN:
  98                         if (token(tokval) && *aname == 0)
  99                             *aname = mh_xstrdup(tokval);
 100                         break;
 101
 102                     case PASSWD:
 103                         if (!credentials_no_perm_check &&
 104                             fstat(fileno(cfile), &stb) >= 0 &&
 105                             (stb.st_mode & 077) != 0) {
 106                             /* We make this a fatal error to force the
 107                                user to correct it. */
 108                             advise(NULL, "Error - file %s must not be world or "
 109                                    "group readable.", credentials_file);
 110                             adios(NULL, "Remove password or correct file "
 111                                   "permissions.");
 112                         }
 113                         if (token(tokval) && *apass == 0)
 114                             *apass = mh_xstrdup(tokval);
 115                         break;
 116
 117                     case ACCOUNT:
 118                         break;
 119
 120                     case MACDEF:
 121                         fclose(cfile);
 122                         return;
 123
 124                     default:
 125                         fprintf(stderr,
 126                                 "Unknown keyword %s in credentials file %s\n",
 127                                 tokval, credentials_file);
 128                         break;
 129                     }
 130                 }
 131                 return;
 132             }
 133         }
 134     }
 135
 136     if (!*aname && ! (flags & RUSERPASS_NO_PROMPT_USER)) {
 137         char tmp[80];
 138         char *myname;
 139
 140         if ((myname = getlogin()) == NULL) {
 141             struct passwd *pp;
 142
 143             if ((pp = getpwuid (getuid())) != NULL)
 144                 myname = pp->pw_name;
 145         }
 146         printf("Name (%s:%s): ", host, myname);
 147
 148         if (fgets(tmp, sizeof(tmp) - 1, stdin) == NULL) {
 149             advise ("tmp", "fgets");
 150         }
 151         TrimSuffixC(tmp, '\n');
 152         if (*tmp != '\0' || myname == NULL) {
 153             myname = tmp;
 154         }
 155
 156         *aname = mh_xstrdup(myname);
 157     }
 158
 159     if (!*apass && ! (flags & RUSERPASS_NO_PROMPT_PASSWORD)) {
 160         char prompt[256];
 161         char *mypass;
 162
 163         snprintf(prompt, sizeof(prompt), "Password (%s:%s): ", host, *aname);
 164         mypass = nmh_getpass(prompt);
 165
 166         if (*mypass == '\0') {
 167             mypass = *aname;
 168         }
 169
 170         *aname = mh_xstrdup(mypass);
 171     }
 172
 173 }
 174
 175 static int
 176 token(char *tokval)
 177 {
 178     char *cp;
 179     int c;
 180     struct toktab *t;
 181
 182     if (feof(cfile))
 183         return (0);
 184     while ((c = getc(cfile)) != EOF &&
 185            (c == '\n' || c == '\t' || c == ' ' || c == ','))
 186         continue;
 187     if (c == EOF)
 188         return (0);
 189     cp = tokval;
 190     if (c == '"') {
 191         while ((c = getc(cfile)) != EOF && c != '"') {
 192             if (c == '\\')
 193                 c = getc(cfile);
 194             *cp++ = c;
 195             if (cp - tokval > MAX_TOKVAL_SIZE-1) {
 196                 adios(NULL, "credential tokens restricted to length %d",
 197                       MAX_TOKVAL_SIZE - 1);
 198             }
 199         }
 200     } else {
 201         *cp++ = c;
 202         while ((c = getc(cfile)) != EOF
 203                && c != '\n' && c != '\t' && c != ' ' && c != ',') {
 204             if (c == '\\')
 205                 c = getc(cfile);
 206             *cp++ = c;
 207             if (cp - tokval > MAX_TOKVAL_SIZE-1) {
 208                 adios(NULL, "credential tokens restricted to length %d",
 209                       MAX_TOKVAL_SIZE - 1);
 210             }
 211         }
 212     }
 213     *cp = 0;
 214     if (tokval[0] == 0)
 215         return (0);
 216     for (t = toktabs; t->tokstr; t++)
 217         if (!strcmp(t->tokstr, tokval))
 218             return (t->tval);
 219     return (ID);
 220 }