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

   1 /* -*-c-*-
   2  *
   3  * $Id$
   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 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <errno.h>
  33 #include <stddef.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37
  38 #include <sys/types.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <termios.h>
  42 #include <pwd.h>
  43
  44 #include <sys/socket.h>
  45 #include <sys/un.h>
  46
  47 #include <mLib/alloc.h>
  48 #include <mLib/dstr.h>
  49 #include <mLib/str.h>
  50
  51 #include "pixie.h"
  52
  53 /*----- Main code ---------------------------------------------------------*/
  54
  55 /* --- @pixie_address@ --- *
  56  *
  57  * Arguments:   @const char *sock@ = pointer to socket name
  58  *              @size_t *psz@ = where to write the address size
  59  *
  60  * Returns:     Pointer to filled-in Unix-domain socket address.
  61  *
  62  * Use:         Returns a Unix-domain socket address to use to find the
  63  *              passphrase pixie.
  64  */
  65
  66 struct sockaddr_un *pixie_address(const char *sock, size_t *psz)
  67 {
  68   dstr d = DSTR_INIT;
  69
  70   /* --- Get the default socket path if none specified --- */
  71
  72   if (!sock)
  73     sock = getenv("CATACOMB_PIXIE_SOCKET");
  74   if (!sock)
  75     sock = "%h/.catacomb/pixie";
  76
  77   /* --- Substitute interesting sequences in the path --- */
  78
  79   {
  80     const char *q, *qq;
  81
  82     q = sock;
  83     for (;;) {
  84       qq = strchr(q, '%');
  85       if (!qq || !qq[1]) {
  86         DPUTS(&d, q);
  87         break;
  88       }
  89       DPUTM(&d, q, qq - q);
  90       q = qq + 1;
  91       switch (*q) {
  92         case 'u':
  93           qq = getenv("USER");
  94           if (!qq)
  95             qq = getenv("LOGNAME");
  96           if (!qq) {
  97             struct passwd *pw = getpwuid(getuid());
  98             if (pw)
  99               qq = pw->pw_name;
 100             else
 101               qq = "<unknown>";
 102           }
 103           DPUTS(&d, qq);
 104           break;
 105         case 'h':
 106           qq = getenv("HOME");
 107           if (!qq) {
 108             struct passwd *pw = getpwuid(getuid());
 109             if (pw)
 110               qq = pw->pw_dir;
 111             else
 112               qq = "<unknown>";
 113           }
 114           DPUTS(&d, qq);
 115           break;
 116         default:
 117           DPUTC(&d, '%');
 118           DPUTC(&d, *q);
 119           break;
 120       }
 121       q++;
 122     }
 123     DPUTZ(&d);
 124   }
 125
 126   /* --- Allocate and initialize the socket address --- */
 127
 128   {
 129     struct sockaddr_un *sun;
 130     size_t bsz = offsetof(struct sockaddr_un, sun_path);
 131     *psz = bsz + d.len + 1;
 132     sun = xmalloc(bsz + d.len + 1);
 133     memset(sun, 0, bsz);
 134     sun->sun_family = AF_UNIX;
 135     memcpy(sun->sun_path, d.buf, d.len + 1);
 136     dstr_destroy(&d);
 137     return (sun);
 138   }
 139 }
 140
 141 /* --- @pixie_fdline@ --- *
 142  *
 143  * Arguments:   @int fd@ = file descriptor to read from
 144  *              @char *buf@ = pointer to buffer
 145  *              @size_t sz@ = size of buffer
 146  *
 147  * Returns:     ---
 148  *
 149  * Use:         Reads a line from a file descriptor.  The read is done one
 150  *              character at a time.  If the entire line won't fit, the end
 151  *              is truncated.  The line is null terminated.
 152  */
 153
 154 void pixie_fdline(int fd, char *buf, size_t sz)
 155 {
 156   char *p = buf;
 157   char *q = p + sz - 1;
 158
 159   for (;;) {
 160     char c;
 161     if (read(fd, &c, 1) < 1)
 162       break;
 163     if (c == '\n')
 164       break;
 165     if (p < q)
 166       *p++ = c;
 167   }
 168   *p = 0;
 169 }
 170
 171 /* --- @pixie_getpass@ --- *
 172  *
 173  * Arguments:   @const char *prompt@ = pointer to prompt string
 174  *              @char *buf@ = pointer to buffer
 175  *              @size_t sz@ = size of buffer
 176  *
 177  * Returns:     Zero if it worked OK, nonzero otherwise.
 178  *
 179  * Use:         Reads a passphrase from the terminal or some other requested
 180  *              source.
 181  */
 182
 183 int pixie_getpass(const char *prompt, char *buf, size_t sz)
 184 {
 185   const char *pfd = getenv("CATACOMB_PASSPHRASE_FD");
 186   int fd = 0;
 187
 188   /* --- See whether a terminal is what's wanted --- */
 189
 190   if (pfd) {
 191     fd = atoi(pfd);
 192     pixie_fdline(fd, buf, sz);
 193   } else {
 194     struct termios ta;
 195     struct termios ota;
 196     char nl = '\n';
 197
 198     if ((fd = open("/dev/tty", O_RDWR)) < 0)
 199       goto fail_0;
 200     if (tcgetattr(fd, &ta) < 0)
 201       goto fail_1;
 202     ota = ta;
 203     ta.c_lflag &= ~(ECHO | ISIG);
 204     if (tcsetattr(fd, TCSAFLUSH, &ta))
 205       goto fail_1;
 206     write(fd, prompt, strlen(prompt));
 207     pixie_fdline(fd, buf, sz);
 208     tcsetattr(fd, TCSAFLUSH, &ota);
 209     write(fd, &nl, 1);
 210     close(fd);
 211   }
 212   return (0);
 213
 214   /* --- Tidy up if things went wrong --- */
 215
 216 fail_1:
 217   close(fd);
 218 fail_0:
 219   return (-1);
 220 }
 221
 222 /* --- @pixie_open@ --- *
 223  *
 224  * Arguments:   @const char *sock@ = path to pixie socket
 225  *
 226  * Returns:     Less than zero if it failed, or file descriptor.
 227  *
 228  * Use:         Opens a connection to a passphrase pixie.
 229  */
 230
 231 int pixie_open(const char *sock)
 232 {
 233   struct sockaddr_un *sun;
 234   size_t sz;
 235   int fd;
 236
 237   /* --- Open the connection --- */
 238
 239   if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 240     goto fail_0;
 241   sun = pixie_address(sock, &sz);
 242   if (connect(fd, (struct sockaddr *)sun, sz))
 243     goto fail_1;
 244   xfree(sun);
 245   return (fd);
 246
 247   /* --- Tidy up if things went wrong --- */
 248
 249 fail_1:
 250   xfree(sun);
 251   close(fd);
 252 fail_0:
 253   return (-1);
 254 }
 255
 256 /* --- @pixie_read@ --- *
 257  *
 258  * Arguments:   @int fd@ = connection to passphrase pixie
 259  *              @const char *tag@ = pointer to tag string
 260  *              @unsigned mode@ = reading mode
 261  *              @char *buf@ = pointer to destination buffer
 262  *              @size_t sz@ = size of the buffer
 263  *
 264  * Returns:     Zero if all went well, @-1@ if the read fails, @+1@ to
 265  *              request the passphrase from the user.
 266  *
 267  * Use:         Reads a passphrase from the pixie.
 268  */
 269
 270 int pixie_read(int fd, const char *tag, unsigned mode, char *buf, size_t sz)
 271 {
 272   dstr d = DSTR_INIT;
 273   char *p, *q;
 274
 275   /* --- Send the request --- */
 276
 277   dstr_putf(&d, "%s %s\n", mode == PMODE_READ ? "PASS" : "VERIFY", tag);
 278   write(fd, d.buf, d.len);
 279   dstr_destroy(&d);
 280
 281   /* --- Sort out the result --- */
 282
 283 again:
 284   pixie_fdline(fd, buf, sz);
 285   p = buf;
 286   if ((q = str_getword(&p)) == 0)
 287     return (-1);
 288   if (strcmp(q, "INFO") == 0)
 289     goto again;
 290   else if (strcmp(q, "MISSING") == 0)
 291     return (+1);
 292   else if (strcmp(q, "OK") != 0)
 293     return (-1);
 294
 295   /* --- Return the final answer --- */
 296
 297   if (p)
 298     memmove(buf, p, strlen(p) + 1);
 299   else
 300     *buf = 0;
 301   return (0);
 302 }
 303
 304 /* --- @pixie_set@ --- *
 305  *
 306  * Arguments:   @int fd@ = pixie file descriptor
 307  *              @const char *tag@ = pointer to tag string
 308  *              @const char *phrase@ = pointer to passphrase string
 309  *
 310  * Returns:     ---
 311  *
 312  * Use:         Sends a passphrase to the passphrase pixie.
 313  */
 314
 315 void pixie_set(int fd, const char *tag, const char *phrase)
 316 {
 317   dstr d = DSTR_INIT;
 318   char buf[16];
 319   size_t sz = strlen(phrase);
 320   char nl = '\n';
 321   char *p, *q;
 322
 323   /* --- Send the request --- *
 324    *
 325    * I didn't want to copy it out of the caller's buffer.  @writev@ may
 326    * produce a copy, too, so I didn't do that either.
 327    */
 328
 329   dstr_putf(&d, "SET %s -- ", tag);
 330   write(fd, d.buf, d.len);
 331   write(fd, phrase, sz);
 332   write(fd, &nl, 1);
 333   dstr_destroy(&d);
 334
 335   /* --- Pick up the pieces --- */
 336
 337 again:
 338   pixie_fdline(fd, buf, sizeof(buf));
 339   p = buf;
 340   if ((q = str_getword(&p)) != 0 && strcmp(q, "INFO") == 0)
 341     goto again;
 342 }
 343
 344 /* --- @pixie_cancel@ --- *
 345  *
 346  * Arguments:   @int fd@ = pixie file descriptor
 347  *              @const char *tag@ = pointer to tag string
 348  *
 349  * Returns:     ---
 350  *
 351  * Use:         Cancels a passphrase if it turns out to be bogus.
 352  */
 353
 354 void pixie_cancel(int fd, const char *tag)
 355 {
 356   dstr d = DSTR_INIT;
 357   char buf[16];
 358   char *p, *q;
 359
 360   /* --- Send the request --- */
 361
 362   dstr_putf(&d, "FLUSH %s\n", tag);
 363   write(fd, d.buf, d.len);
 364   dstr_destroy(&d);
 365
 366   /* --- Sort out the result --- */
 367
 368 again:
 369   pixie_fdline(fd, buf, sizeof(buf));
 370   p = buf;
 371   if ((q = str_getword(&p)) != 0 && strcmp(q, "INFO") == 0)
 372     goto again;
 373 }
 374
 375 /*----- That's all, folks -------------------------------------------------*/
 376