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 TOK_EOF 0
  30 #define DEFAULT 1
  31 #define LOGIN   2
  32 #define PASSWD  3
  33 #define ACCOUNT 4
  34 #define MACDEF  5
  35 #define ID      10
  36 #define MACH    11
  37
  38 #define MAX_TOKVAL_SIZE 1024 /* Including terminating NUL. */
  39
  40 struct toktab {
  41     char *tokstr;
  42     int tval;
  43 };
  44
  45 static struct toktab toktabs[] = {
  46     { "",         TOK_EOF },
  47     { "default",  DEFAULT },
  48     { "login",    LOGIN },
  49     { "password", PASSWD },
  50     { "passwd",   PASSWD },
  51     { "account",  ACCOUNT },
  52     { "machine",  MACH },
  53     { "macdef",   MACDEF },
  54     { 0,          0 }
  55 };
  56
  57 /*
  58  * prototypes
  59  */
  60 static int token(char *);
  61
  62
  63 void
  64 ruserpass(const char *host, char **aname, char **apass, int flags)
  65 {
  66     int t, usedefault = 0;
  67     struct stat stb;
  68
  69     init_credentials_file ();
  70
  71     cfile = fopen (credentials_file, "r");
  72     if (cfile == NULL) {
  73         if (errno != ENOENT)
  74             perror (credentials_file);
  75     } else {
  76         char tokval[MAX_TOKVAL_SIZE];
  77         tokval[0] = '\0';
  78
  79         while ((t = token(tokval))) {
  80             switch(t) {
  81             case DEFAULT:
  82                 usedefault = 1;
  83                 /* FALLTHRU */
  84
  85             case MACH:
  86                 if (!usedefault) {
  87                     if (token(tokval) != ID)
  88                         continue;
  89                     /*
  90                      * Allow match either for user's host name.
  91                      */
  92                     if (strcasecmp(host, tokval) == 0)
  93                         goto match;
  94                     continue;
  95                 }
  96             match:
  97                 while ((t = token(tokval)) && t != MACH && t != DEFAULT) {
  98                     switch(t) {
  99                     case LOGIN:
 100                         if (token(tokval) && *aname == 0)
 101                             *aname = mh_xstrdup(tokval);
 102                         break;
 103
 104                     case PASSWD:
 105                         if (!credentials_no_perm_check &&
 106                             fstat(fileno(cfile), &stb) >= 0 &&
 107                             (stb.st_mode & 077) != 0) {
 108                             /* We make this a fatal error to force the
 109                                user to correct it. */
 110                             advise(NULL, "group or other permissions, %#o, "
 111                                 "forbidden: %s", stb.st_mode, credentials_file);
 112                             adios(NULL, "Remove password or correct file "
 113                                   "permissions.");
 114                         }
 115                         if (token(tokval) && *apass == 0)
 116                             *apass = mh_xstrdup(tokval);
 117                         break;
 118
 119                     case ACCOUNT:
 120                         break;
 121
 122                     case MACDEF:
 123                         fclose(cfile);
 124                         return;
 125
 126                     default:
 127                         fprintf(stderr,
 128                                 "Unknown keyword %s in credentials file %s\n",
 129                                 tokval, credentials_file);
 130                         break;
 131                     }
 132                 }
 133                 return;
 134             }
 135         }
 136     }
 137
 138     if (!*aname && ! (flags & RUSERPASS_NO_PROMPT_USER)) {
 139         char tmp[80];
 140         char *myname;
 141
 142         if ((myname = getlogin()) == NULL) {
 143             struct passwd *pp;
 144
 145             if ((pp = getpwuid (getuid())) != NULL)
 146                 myname = pp->pw_name;
 147         }
 148         printf("Name (%s:%s): ", host, myname);
 149
 150         if (fgets(tmp, sizeof tmp, stdin) == NULL) {
 151             advise ("tmp", "fgets");
 152         }
 153         trim_suffix_c(tmp, '\n');
 154         if (*tmp != '\0' || myname == NULL) {
 155             myname = tmp;
 156         }
 157
 158         *aname = mh_xstrdup(myname);
 159     }
 160
 161     if (!*apass && ! (flags & RUSERPASS_NO_PROMPT_PASSWORD)) {
 162         char prompt[256];
 163         char *mypass;
 164
 165         snprintf(prompt, sizeof(prompt), "Password (%s:%s): ", host, *aname);
 166         mypass = nmh_getpass(prompt);
 167
 168         if (*mypass == '\0') {
 169             mypass = *aname;
 170         }
 171
 172         *aname = mh_xstrdup(mypass);
 173     }
 174
 175 }
 176
 177 static int
 178 token(char *tokval)
 179 {
 180     int c;
 181     const char normalStop[] = "\t\n ,"; /* Each breaks a word. */
 182     const char *stop;
 183     char *cp;
 184     struct toktab *t;
 185
 186     if (feof(cfile) || ferror(cfile))
 187         return TOK_EOF;
 188
 189     stop = normalStop;
 190     while ((c = getc(cfile)) != EOF && c && strchr(stop, c))
 191         ;
 192     if (c == EOF)
 193         return TOK_EOF;
 194
 195     cp = tokval;
 196     if (c == '"')
 197         /* FIXME: Where is the quoted-string syntax of netrc documented?
 198          * This code treats «"foo""bar"» as two tokens without further
 199          * separators. */
 200         stop = "\"";
 201     else
 202         /* Might be backslash.  Get it again later.  It's handled then. */
 203         if (ungetc(c, cfile) == EOF)
 204             return TOK_EOF;
 205
 206     while ((c = getc(cfile)) != EOF && c && !strchr(stop, c)) {
 207         if (c == '\\' && (c = getc(cfile)) == EOF)
 208             return TOK_EOF; /* Discard whole token. */
 209
 210         *cp++ = c;
 211         if (cp - tokval > MAX_TOKVAL_SIZE-1) {
 212             adios(NULL, "credential tokens restricted to length %d",
 213                   MAX_TOKVAL_SIZE - 1);
 214         }
 215     }
 216     *cp = '\0';
 217
 218     for (t = toktabs; t->tokstr; t++)
 219         if (!strcmp(t->tokstr, tokval))
 220             return (t->tval);
 221
 222     return (ID);
 223 }