smtp.c

   1 /*
   2  * Heirloom mailx - a mail user agent derived from Berkeley Mail.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  */
   6 /*
   7  * Copyright (c) 2000
   8  *      Gunnar Ritter.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by Gunnar Ritter
  21  *      and his contributors.
  22  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #ifndef lint
  40 #ifdef  DOSCCS
  41 static char sccsid[] = "@(#)smtp.c      2.43 (gritter) 8/4/07";
  42 #endif
  43 #endif /* not lint */
  44
  45 #include "rcv.h"
  46
  47 #include <sys/utsname.h>
  48 #ifdef  HAVE_SOCKETS
  49 #include <sys/socket.h>
  50 #include <netdb.h>
  51 #include <netinet/in.h>
  52 #ifdef  HAVE_ARPA_INET_H
  53 #include <arpa/inet.h>
  54 #endif  /* HAVE_ARPA_INET_H */
  55 #endif  /* HAVE_SOCKETS */
  56 #include <unistd.h>
  57 #include <setjmp.h>
  58
  59 #include "extern.h"
  60 #include "md5.h"
  61
  62 /*
  63  * Mail -- a mail program
  64  *
  65  * SMTP client and other internet related functions.
  66  */
  67
  68 #ifdef  HAVE_SOCKETS
  69 static int verbose;
  70 static int _debug;
  71 #endif
  72
  73 /*
  74  * Return our hostname.
  75  */
  76 char *
  77 nodename(int mayoverride)
  78 {
  79         static char *hostname;
  80         char *hn;
  81         struct utsname ut;
  82 #ifdef  HAVE_SOCKETS
  83 #ifdef  HAVE_IPv6_FUNCS
  84         struct addrinfo hints, *res;
  85 #else   /* !HAVE_IPv6_FUNCS */
  86         struct hostent *hent;
  87 #endif  /* !HAVE_IPv6_FUNCS */
  88 #endif  /* HAVE_SOCKETS */
  89
  90         if (mayoverride && (hn = value("hostname")) != NULL && *hn) {
  91                 free(hostname);
  92                 hostname = sstrdup(hn);
  93         }
  94         if (hostname == NULL) {
  95                 uname(&ut);
  96                 hn = ut.nodename;
  97 #ifdef  HAVE_SOCKETS
  98 #ifdef  HAVE_IPv6_FUNCS
  99                 memset(&hints, 0, sizeof hints);
 100                 hints.ai_socktype = SOCK_DGRAM; /* dummy */
 101                 hints.ai_flags = AI_CANONNAME;
 102                 if (getaddrinfo(hn, "0", &hints, &res) == 0) {
 103                         if (res->ai_canonname) {
 104                                 hn = salloc(strlen(res->ai_canonname) + 1);
 105                                 strcpy(hn, res->ai_canonname);
 106                         }
 107                         freeaddrinfo(res);
 108                 }
 109 #else   /* !HAVE_IPv6_FUNCS */
 110                 hent = gethostbyname(hn);
 111                 if (hent != NULL) {
 112                         hn = hent->h_name;
 113                 }
 114 #endif  /* !HAVE_IPv6_FUNCS */
 115 #endif  /* HAVE_SOCKETS */
 116                 hostname = smalloc(strlen(hn) + 1);
 117                 strcpy(hostname, hn);
 118         }
 119         return hostname;
 120 }
 121
 122 /*
 123  * Return the user's From: address(es).
 124  */
 125 char *
 126 myaddrs(struct header *hp)
 127 {
 128         char *cp, *hn;
 129         static char *addr;
 130         size_t sz;
 131
 132         if (hp != NULL && hp->h_from != NULL) {
 133                 if (hp->h_from->n_fullname)
 134                         return savestr(hp->h_from->n_fullname);
 135                 if (hp->h_from->n_name)
 136                         return savestr(hp->h_from->n_name);
 137         }
 138         if ((cp = value("from")) != NULL)
 139                 return cp;
 140         /*
 141          * When invoking sendmail directly, it's its task
 142          * to generate a From: address.
 143          */
 144         if (value("smtp") == NULL)
 145                 return NULL;
 146         if (addr == NULL) {
 147                 hn = nodename(1);
 148                 sz = strlen(myname) + strlen(hn) + 2;
 149                 addr = smalloc(sz);
 150                 snprintf(addr, sz, "%s@%s", myname, hn);
 151         }
 152         return addr;
 153 }
 154
 155 char *
 156 myorigin(struct header *hp)
 157 {
 158         char    *cp;
 159         struct name     *np;
 160
 161         if ((cp = myaddrs(hp)) == NULL ||
 162                         (np = sextract(cp, GEXTRA|GFULL)) == NULL)
 163                 return NULL;
 164         return np->n_flink != NULL ? value("sender") : cp;
 165 }
 166
 167 #ifdef  HAVE_SOCKETS
 168
 169 static int read_smtp(struct sock *sp, int value, int ign_eof);
 170 static int talk_smtp(struct name *to, FILE *fi, struct sock *sp,
 171                 char *server, char *uhp, struct header *hp,
 172                 const char *user, const char *password, const char *skinned);
 173
 174 char *
 175 smtp_auth_var(const char *type, const char *addr)
 176 {
 177         char    *var, *cp;
 178         int     len;
 179
 180         var = ac_alloc(len = strlen(type) + strlen(addr) + 7);
 181         snprintf(var, len, "smtp-auth%s-%s", type, addr);
 182         if ((cp = value(var)) != NULL)
 183                 cp = savestr(cp);
 184         else {
 185                 snprintf(var, len, "smtp-auth%s", type);
 186                 if ((cp = value(var)) != NULL)
 187                         cp = savestr(cp);
 188         }
 189         ac_free(var);
 190         return cp;
 191 }
 192
 193 static char     *smtpbuf;
 194 static size_t   smtpbufsize;
 195
 196 /*
 197  * Get the SMTP server's answer, expecting value.
 198  */
 199 static int
 200 read_smtp(struct sock *sp, int value, int ign_eof)
 201 {
 202         int ret;
 203         int len;
 204
 205         do {
 206                 if ((len = sgetline(&smtpbuf, &smtpbufsize, NULL, sp)) < 6) {
 207                         if (len >= 0 && !ign_eof)
 208                                 fprintf(stderr, catgets(catd, CATSET, 241,
 209                                         "Unexpected EOF on SMTP connection\n"));
 210                         return -1;
 211                 }
 212                 if (verbose || debug || _debug)
 213                         fputs(smtpbuf, stderr);
 214                 switch (*smtpbuf) {
 215                 case '1': ret = 1; break;
 216                 case '2': ret = 2; break;
 217                 case '3': ret = 3; break;
 218                 case '4': ret = 4; break;
 219                 default: ret = 5;
 220                 }
 221                 if (value != ret)
 222                         fprintf(stderr, catgets(catd, CATSET, 191,
 223                                         "smtp-server: %s"), smtpbuf);
 224         } while (smtpbuf[3] == '-');
 225         return ret;
 226 }
 227
 228 /*
 229  * Macros for talk_smtp.
 230  */
 231 #define _SMTP_ANSWER(x, ign_eof)        \
 232                         if (!debug && !_debug) { \
 233                                 int     y; \
 234                                 if ((y = read_smtp(sp, x, ign_eof)) != (x) && \
 235                                         (!(ign_eof) || y != -1)) { \
 236                                         if (b != NULL) \
 237                                                 free(b); \
 238                                         return 1; \
 239                                 } \
 240                         }
 241
 242 #define SMTP_ANSWER(x)  _SMTP_ANSWER(x, 0)
 243
 244 #define SMTP_OUT(x)     if (verbose || debug || _debug) \
 245                                 fprintf(stderr, ">>> %s", x); \
 246                         if (!debug && !_debug) \
 247                                 swrite(sp, x);
 248
 249 /*
 250  * Talk to a SMTP server.
 251  */
 252 static int
 253 talk_smtp(struct name *to, FILE *fi, struct sock *sp,
 254                 char *xserver, char *uhp, struct header *hp,
 255                 const char *user, const char *password, const char *skinned)
 256 {
 257         struct name *n;
 258         char *b = NULL, o[LINESIZE];
 259         size_t blen, bsize = 0, count;
 260         char    *b64, *authstr, *cp;
 261         enum    { AUTH_NONE, AUTH_PLAIN, AUTH_LOGIN, AUTH_CRAM_MD5 } auth;
 262         int     inhdr = 1, inbcc = 0;
 263
 264         if ((authstr = smtp_auth_var("", skinned)) == NULL)
 265                 auth = user && password ? AUTH_LOGIN : AUTH_NONE;
 266         else if (strcmp(authstr, "plain") == 0)
 267                 auth = AUTH_PLAIN;
 268         else if (strcmp(authstr, "login") == 0)
 269                 auth = AUTH_LOGIN;
 270         else if (strcmp(authstr, "cram-md5") == 0)
 271                 auth = AUTH_CRAM_MD5;
 272         else {
 273                 fprintf(stderr, "Unknown SMTP authentication "
 274                                 "method: \"%s\"\n", authstr);
 275                 return 1;
 276         }
 277         if (auth != AUTH_NONE && (user == NULL || password == NULL)) {
 278                 fprintf(stderr, "User and password are necessary "
 279                                 "for SMTP authentication.\n");
 280                 return 1;
 281         }
 282         SMTP_ANSWER(2);
 283 #ifdef  USE_SSL
 284         if (value("smtp-use-starttls") ||
 285                         value("smtp-use-tls") /* v11.0 compatibility */) {
 286                 char    *server;
 287                 if ((cp = strchr(xserver, ':')) != NULL) {
 288                         server = salloc(cp - xserver + 1);
 289                         memcpy(server, xserver, cp - xserver);
 290                         server[cp - xserver] = '\0';
 291                 } else
 292                         server = xserver;
 293                 snprintf(o, sizeof o, "EHLO %s\r\n", nodename(1));
 294                 SMTP_OUT(o);
 295                 SMTP_ANSWER(2);
 296                 SMTP_OUT("STARTTLS\r\n");
 297                 SMTP_ANSWER(2);
 298                 if (!debug && !_debug && ssl_open(server, sp, uhp) != OKAY)
 299                         return 1;
 300         }
 301 #else   /* !USE_SSL */
 302         if (value("smtp-use-starttls") || value("smtp-use-tls")) {
 303                 fprintf(stderr, "No SSL support compiled in.\n");
 304                 return 1;
 305         }
 306 #endif  /* !USE_SSL */
 307         if (auth != AUTH_NONE) {
 308                 snprintf(o, sizeof o, "EHLO %s\r\n", nodename(1));
 309                 SMTP_OUT(o);
 310                 SMTP_ANSWER(2);
 311                 switch (auth) {
 312                 default:
 313                 case AUTH_LOGIN:
 314                         SMTP_OUT("AUTH LOGIN\r\n");
 315                         SMTP_ANSWER(3);
 316                         b64 = strtob64(user);
 317                         snprintf(o, sizeof o, "%s\r\n", b64);
 318                         free(b64);
 319                         SMTP_OUT(o);
 320                         SMTP_ANSWER(3);
 321                         b64 = strtob64(password);
 322                         snprintf(o, sizeof o, "%s\r\n", b64);
 323                         free(b64);
 324                         SMTP_OUT(o);
 325                         SMTP_ANSWER(2);
 326                         break;
 327                 case AUTH_PLAIN:
 328                         SMTP_OUT("AUTH PLAIN\r\n");
 329                         SMTP_ANSWER(3);
 330                         snprintf(o, sizeof o, "%c%s%c%s", '\0', user, '\0',
 331                                                           password);
 332                         b64 = memtob64(o, strlen(user)+strlen(password)+2);
 333                         snprintf(o, sizeof o, "%s\r\n", b64);
 334                         SMTP_OUT(o);
 335                         SMTP_ANSWER(2);
 336                         break;
 337                 case AUTH_CRAM_MD5:
 338                         SMTP_OUT("AUTH CRAM-MD5\r\n");
 339                         SMTP_ANSWER(3);
 340                         for (cp = smtpbuf; digitchar(*cp&0377); cp++);
 341                         while (blankchar(*cp&0377)) cp++;
 342                         cp = cram_md5_string(user, password, cp);
 343                         SMTP_OUT(cp);
 344                         SMTP_ANSWER(2);
 345                         break;
 346                 }
 347         } else {
 348                 snprintf(o, sizeof o, "HELO %s\r\n", nodename(1));
 349                 SMTP_OUT(o);
 350                 SMTP_ANSWER(2);
 351         }
 352         snprintf(o, sizeof o, "MAIL FROM:<%s>\r\n", skinned);
 353         SMTP_OUT(o);
 354         SMTP_ANSWER(2);
 355         for (n = to; n != NULL; n = n->n_flink) {
 356                 if ((n->n_type & GDEL) == 0) {
 357                         snprintf(o, sizeof o, "RCPT TO:<%s>\r\n",
 358                                         skin(n->n_name));
 359                         SMTP_OUT(o);
 360                         SMTP_ANSWER(2);
 361                 }
 362         }
 363         SMTP_OUT("DATA\r\n");
 364         SMTP_ANSWER(3);
 365         fflush(fi);
 366         rewind(fi);
 367         count = fsize(fi);
 368         while (fgetline(&b, &bsize, &count, &blen, fi, 1) != NULL) {
 369                 if (inhdr) {
 370                         if (*b == '\n') {
 371                                 inhdr = 0;
 372                                 inbcc = 0;
 373                         } else if (inbcc && blankchar(*b & 0377))
 374                                 continue;
 375                         /*
 376                          * We know what we have generated first, so
 377                          * do not look for whitespace before the ':'.
 378                          */
 379                         else if (ascncasecmp(b, "bcc: ", 5) == 0) {
 380                                 inbcc = 1;
 381                                 continue;
 382                         } else
 383                                 inbcc = 0;
 384                 }
 385                 if (*b == '.') {
 386                         if (debug || _debug)
 387                                 putc('.', stderr);
 388                         else
 389                                 swrite1(sp, ".", 1, 1);
 390                 }
 391                 if (debug || _debug) {
 392                         fprintf(stderr, ">>> %s", b);
 393                         continue;
 394                 }
 395                 b[blen-1] = '\r';
 396                 b[blen] = '\n';
 397                 swrite1(sp, b, blen+1, 1);
 398         }
 399         SMTP_OUT(".\r\n");
 400         SMTP_ANSWER(2);
 401         SMTP_OUT("QUIT\r\n");
 402         _SMTP_ANSWER(2, 1);
 403         if (b != NULL)
 404                 free(b);
 405         return 0;
 406 }
 407
 408 static sigjmp_buf       smtpjmp;
 409
 410 static void
 411 onterm(int signo)
 412 {
 413         siglongjmp(smtpjmp, 1);
 414 }
 415
 416 /*
 417  * Connect to a SMTP server.
 418  */
 419 int
 420 smtp_mta(char *server, struct name *to, FILE *fi, struct header *hp,
 421                 const char *user, const char *password, const char *skinned)
 422 {
 423         struct sock     so;
 424         int     use_ssl, ret;
 425         sighandler_type saveterm;
 426
 427         memset(&so, 0, sizeof so);
 428         verbose = value("verbose") != NULL;
 429         _debug = value("debug") != NULL;
 430         saveterm = safe_signal(SIGTERM, SIG_IGN);
 431         if (sigsetjmp(smtpjmp, 1)) {
 432                 safe_signal(SIGTERM, saveterm);
 433                 return 1;
 434         }
 435         if (saveterm != SIG_IGN)
 436                 safe_signal(SIGTERM, onterm);
 437         if (strncmp(server, "smtp://", 7) == 0) {
 438                 use_ssl = 0;
 439                 server += 7;
 440 #ifdef  USE_SSL
 441         } else if (strncmp(server, "smtps://", 8) == 0) {
 442                 use_ssl = 1;
 443                 server += 8;
 444 #endif
 445         } else
 446                 use_ssl = 0;
 447         if (!debug && !_debug && sopen(server, &so, use_ssl, server,
 448                                 use_ssl ? "smtps" : "smtp", verbose) != OKAY) {
 449                 safe_signal(SIGTERM, saveterm);
 450                 return 1;
 451         }
 452         so.s_desc = "SMTP";
 453         ret = talk_smtp(to, fi, &so, server, server, hp,
 454                         user, password, skinned);
 455         if (!debug && !_debug)
 456                 sclose(&so);
 457         if (smtpbuf) {
 458                 free(smtpbuf);
 459                 smtpbuf = NULL;
 460                 smtpbufsize = 0;
 461         }
 462         safe_signal(SIGTERM, saveterm);
 463         return ret;
 464 }
 465 #else   /* !HAVE_SOCKETS */
 466 int
 467 smtp_mta(char *server, struct name *to, FILE *fi, struct header *hp,
 468                 const char *user, const char *password, const char *skinned)
 469 {
 470         fputs(catgets(catd, CATSET, 194,
 471                         "No SMTP support compiled in.\n"), stderr);
 472         return 1;
 473 }
 474 #endif  /* !HAVE_SOCKETS */