git.distorted.org.uk Git - u/mdw/catacomb/blob - pixie-common.c

   1 /* -*-c-*-
   2  *
   3  * $Id: pixie-common.c,v 1.1 1999/12/22 15:58:41 mdw Exp $
   4  *
   5  * Common code for Pixie client and server (Unix-specific)
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: pixie-common.c,v $
  33  * Revision 1.1  1999/12/22 15:58:41  mdw
  34  * Passphrase pixie support.
  35  *
  36  */
  37
  38 /*----- Header files ------------------------------------------------------*/
  39
  40 #include <errno.h>
  41 #include <stddef.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #include <sys/types.h>
  47 #include <unistd.h>
  48 #include <fcntl.h>
  49 #include <termios.h>
  50 #include <pwd.h>
  51
  52 #include <sys/socket.h>
  53 #include <sys/un.h>
  54
  55 #include <mLib/alloc.h>
  56 #include <mLib/dstr.h>
  57
  58 #include "pixie.h"
  59
  60 /*----- Main code ---------------------------------------------------------*/
  61
  62 /* --- @pixie_address@ --- *
  63  *
  64  * Arguments:   @const char *sock@ = pointer to socket name
  65  *              @size_t *psz@ = where to write the address size
  66  *
  67  * Returns:     Pointer to filled-in Unix-domain socket address.
  68  *
  69  * Use:         Returns a Unix-domain socket address to use to find the
  70  *              passphrase pixie.
  71  */
  72
  73 struct sockaddr_un *pixie_address(const char *sock, size_t *psz)
  74 {
  75   dstr d = DSTR_INIT;
  76
  77   /* --- Get the default socket path if none specified --- */
  78
  79   if (!sock)
  80     sock = getenv("CATACOMB_PIXIE_SOCKET");
  81   if (!sock)
  82     sock = "%h/.catacomb/pixie";
  83
  84   /* --- Substitute interesting sequences in the path --- */
  85
  86   {
  87     const char *q, *qq;
  88
  89     q = sock;
  90     for (;;) {
  91       qq = strchr(q, '%');
  92       if (!qq || !qq[1]) {
  93         DPUTS(&d, q);
  94         break;
  95       }
  96       DPUTM(&d, q, qq - q);
  97       q = qq + 1;
  98       switch (*q) {
  99         case 'u':
 100           qq = getenv("USER");
 101           if (!qq)
 102             qq = getenv("LOGNAME");
 103           if (!qq) {
 104             struct passwd *pw = getpwuid(getuid());
 105             if (pw)
 106               qq = pw->pw_name;
 107             else
 108               qq = "<unknown>";
 109           }
 110           DPUTS(&d, qq);
 111           break;
 112         case 'h':
 113           qq = getenv("HOME");
 114           if (!qq) {
 115             struct passwd *pw = getpwuid(getuid());
 116             if (pw)
 117               qq = pw->pw_dir;
 118             else
 119               qq = "<unknown>";
 120           }
 121           DPUTS(&d, qq);
 122           break;
 123         default:
 124           DPUTC(&d, '%');
 125           DPUTC(&d, *q);
 126           break;
 127       }
 128       q++;
 129     }
 130     DPUTZ(&d);
 131   }
 132
 133   /* --- Allocate and initialize the socket address --- */
 134
 135   {
 136     struct sockaddr_un *sun;
 137     size_t bsz = offsetof(struct sockaddr_un, sun_path);
 138     *psz = bsz + d.len + 1;
 139     sun = xmalloc(bsz + d.len + 1);
 140     memset(sun, 0, bsz);
 141     sun->sun_family = AF_UNIX;
 142     memcpy(sun->sun_path, d.buf, d.len + 1);
 143     dstr_destroy(&d);
 144     return (sun);
 145   }
 146 }
 147
 148 /* --- @pixie_fdline@ --- *
 149  *
 150  * Arguments:   @int fd@ = file descriptor to read from
 151  *              @char *buf@ = pointer to buffer
 152  *              @size_t sz@ = size of buffer
 153  *
 154  * Returns:     ---
 155  *
 156  * Use:         Reads a line from a file descriptor.  The read is done one
 157  *              character at a time.  If the entire line won't fit, the end
 158  *              is truncated.  The line is null terminated.
 159  */
 160
 161 void pixie_fdline(int fd, char *buf, size_t sz)
 162 {
 163   char *p = buf;
 164   char *q = p + sz - 1;
 165
 166   for (;;) {
 167     char c;
 168     if (read(fd, &c, 1) < 1)
 169       break;
 170     if (c == '\n')
 171       break;
 172     if (p < q)
 173       *p++ = c;
 174   }
 175   *p = 0;
 176 }
 177
 178 /* --- @pixie_getpass@ --- *
 179  *
 180  * Arguments:   @const char *prompt@ = pointer to prompt string
 181  *              @char *buf@ = pointer to buffer
 182  *              @size_t sz@ = size of buffer
 183  *
 184  * Returns:     Zero if it worked OK, nonzero otherwise.
 185  *
 186  * Use:         Reads a passphrase from the terminal or some other requested
 187  *              source.
 188  */
 189
 190 int pixie_getpass(const char *prompt, char *buf, size_t sz)
 191 {
 192   const char *pfd = getenv("CATACOMB_PASSPHRASE_FD");
 193   int fd = 0;
 194
 195   /* --- See whether a terminal is what's wanted --- */
 196
 197   if (pfd) {
 198     fd = atoi(pfd);
 199     pixie_fdline(fd, buf, sz);
 200   } else {
 201     struct termios ta;
 202     struct termios ota;
 203     char nl = '\n';
 204
 205     if ((fd = open("/dev/tty", O_RDWR)) < 0)
 206       goto fail_0;
 207     if (tcgetattr(fd, &ta) < 0)
 208       goto fail_1;
 209     ota = ta;
 210     ta.c_lflag &= ~(ECHO | ISIG);
 211     if (tcsetattr(fd, TCSAFLUSH, &ta))
 212       goto fail_1;
 213     write(fd, prompt, strlen(prompt));
 214     pixie_fdline(fd, buf, sz);
 215     tcsetattr(fd, TCSAFLUSH, &ota);
 216     write(fd, &nl, 1);
 217     close(fd);
 218   }
 219   return (0);
 220
 221   /* --- Tidy up if things went wrong --- */
 222
 223 fail_1:
 224   close(fd);
 225 fail_0:
 226   return (-1);
 227 }
 228
 229
 230 /*----- That's all, folks -------------------------------------------------*/
 231