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  * Copyright (c) 2012 Steffen "Daode" Nurpmeso.
   6  */
   7 /*
   8  * Copyright (c) 2000
   9  *      Gunnar Ritter.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by Gunnar Ritter
  22  *      and his contributors.
  23  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 #ifndef lint
  41 #ifdef  DOSCCS
  42 static char sccsid[] = "@(#)smtp.c      2.43 (gritter) 8/4/07";
  43 #endif
  44 #endif /* not lint */
  45
  46 #include "rcv.h"
  47
  48 #include <sys/utsname.h>
  49 #ifdef HAVE_SOCKETS
  50 # include <sys/socket.h>
  51 # include <netdb.h>
  52 # include <netinet/in.h>
  53 # ifdef HAVE_ARPA_INET_H
  54 #  include <arpa/inet.h>
  55 # endif
  56 #endif
  57 #include <unistd.h>
  58 #include <setjmp.h>
  59
  60 #include "extern.h"
  61 #include "md5.h"
  62
  63 /*
  64  * Mail -- a mail program
  65  *
  66  * SMTP client and other internet related functions.
  67  */
  68
  69 /* TODO longjmp() globbering as in cmd1.c and cmd3.c (see there)
  70  * TODO Problem: Popen doesn't encapsulate all cases of open failures,
  71  * TODO may leave child running if fdopen() fails! */
  72
  73 #ifdef HAVE_SOCKETS
  74 static int verbose;
  75 static int _debug;
  76 #endif
  77
  78 /*
  79  * Return our hostname.
  80  */
  81 char *
  82 nodename(int mayoverride)
  83 {
  84         static char *hostname;
  85         char *hn;
  86         struct utsname ut;
  87 #ifdef  HAVE_SOCKETS
  88 #ifdef  HAVE_IPv6_FUNCS
  89         struct addrinfo hints, *res;
  90 #else   /* !HAVE_IPv6_FUNCS */
  91         struct hostent *hent;
  92 #endif  /* !HAVE_IPv6_FUNCS */
  93 #endif  /* HAVE_SOCKETS */
  94
  95         if (mayoverride && (hn = value("hostname")) != NULL && *hn) {
  96                 free(hostname);
  97                 hostname = sstrdup(hn);
  98         }
  99         if (hostname == NULL) {
 100                 uname(&ut);
 101                 hn = ut.nodename;
 102 #ifdef  HAVE_SOCKETS
 103 #ifdef  HAVE_IPv6_FUNCS
 104                 memset(&hints, 0, sizeof hints);
 105                 hints.ai_socktype = SOCK_DGRAM; /* dummy */
 106                 hints.ai_flags = AI_CANONNAME;
 107                 if (getaddrinfo(hn, "0", &hints, &res) == 0) {
 108                         if (res->ai_canonname) {
 109                                 hn = salloc(strlen(res->ai_canonname) + 1);
 110                                 strcpy(hn, res->ai_canonname);
 111                         }
 112                         freeaddrinfo(res);
 113                 }
 114 #else   /* !HAVE_IPv6_FUNCS */
 115                 hent = gethostbyname(hn);
 116                 if (hent != NULL) {
 117                         hn = hent->h_name;
 118                 }
 119 #endif  /* !HAVE_IPv6_FUNCS */
 120 #endif  /* HAVE_SOCKETS */
 121                 hostname = smalloc(strlen(hn) + 1);
 122                 strcpy(hostname, hn);
 123         }
 124         return hostname;
 125 }
 126
 127 /*
 128  * Return the user's From: address(es).
 129  */
 130 char *
 131 myaddrs(struct header *hp)
 132 {
 133         char *cp, *hn;
 134         static char *addr;
 135         size_t sz;
 136
 137         if (hp != NULL && hp->h_from != NULL) {
 138                 if (hp->h_from->n_fullname)
 139                         return savestr(hp->h_from->n_fullname);
 140                 if (hp->h_from->n_name)
 141                         return savestr(hp->h_from->n_name);
 142         }
 143         if ((cp = value("from")) != NULL)
 144                 return cp;
 145         /*
 146          * When invoking sendmail directly, it's its task
 147          * to generate a From: address.
 148          */
 149         if (value("smtp") == NULL)
 150                 return NULL;
 151         if (addr == NULL) {
 152                 hn = nodename(1);
 153                 sz = strlen(myname) + strlen(hn) + 2;
 154                 addr = smalloc(sz);
 155                 snprintf(addr, sz, "%s@%s", myname, hn);
 156         }
 157         return addr;
 158 }
 159
 160 char *
 161 myorigin(struct header *hp)
 162 {
 163         char    *cp;
 164         struct name     *np;
 165
 166         if ((cp = myaddrs(hp)) == NULL ||
 167                         (np = sextract(cp, GEXTRA|GFULL)) == NULL)
 168                 return NULL;
 169         return np->n_flink != NULL ? value("sender") : cp;
 170 }
 171
 172 #ifdef USE_SMTP
 173
 174 static int read_smtp(struct sock *sp, int value, int ign_eof);
 175 static int talk_smtp(struct name *to, FILE *fi, struct sock *sp,
 176                 char *server, char *uhp, struct header *hp,
 177                 const char *user, const char *password, const char *skinned);
 178
 179 char *
 180 smtp_auth_var(const char *type, const char *addr)
 181 {
 182         char    *var, *cp;
 183         int     len;
 184
 185         var = ac_alloc(len = strlen(type) + strlen(addr) + 7);
 186         snprintf(var, len, "smtp-auth%s-%s", type, addr);
 187         if ((cp = value(var)) != NULL)
 188                 cp = savestr(cp);
 189         else {
 190                 snprintf(var, len, "smtp-auth%s", type);
 191                 if ((cp = value(var)) != NULL)
 192                         cp = savestr(cp);
 193         }
 194         ac_free(var);
 195         return cp;
 196 }
 197
 198 static char     *smtpbuf;
 199 static size_t   smtpbufsize;
 200
 201 /*
 202  * Get the SMTP server's answer, expecting value.
 203  */
 204 static int
 205 read_smtp(struct sock *sp, int value, int ign_eof)
 206 {
 207         int ret;
 208         int len;
 209
 210         do {
 211                 if ((len = sgetline(&smtpbuf, &smtpbufsize, NULL, sp)) < 6) {
 212                         if (len >= 0 && !ign_eof)
 213                                 fprintf(stderr, catgets(catd, CATSET, 241,
 214                                         "Unexpected EOF on SMTP connection\n"));
 215                         return -1;
 216                 }
 217                 if (verbose || debug || _debug)
 218                         fputs(smtpbuf, stderr);
 219                 switch (*smtpbuf) {
 220                 case '1': ret = 1; break;
 221                 case '2': ret = 2; break;
 222                 case '3': ret = 3; break;
 223                 case '4': ret = 4; break;
 224                 default: ret = 5;
 225                 }
 226                 if (value != ret)
 227                         fprintf(stderr, catgets(catd, CATSET, 191,
 228                                         "smtp-server: %s"), smtpbuf);
 229         } while (smtpbuf[3] == '-');
 230         return ret;
 231 }
 232
 233 /*
 234  * Macros for talk_smtp.
 235  */
 236 #define _SMTP_ANSWER(x, ign_eof)        \
 237                         if (!debug && !_debug) { \
 238                                 int     y; \
 239                                 if ((y = read_smtp(sp, x, ign_eof)) != (x) && \
 240                                         (!(ign_eof) || y != -1)) { \
 241                                         if (b != NULL) \
 242                                                 free(b); \
 243                                         return 1; \
 244                                 } \
 245                         }
 246
 247 #define SMTP_ANSWER(x)  _SMTP_ANSWER(x, 0)
 248
 249 #define SMTP_OUT(x)     if (verbose || debug || _debug) \
 250                                 fprintf(stderr, ">>> %s", x); \
 251                         if (!debug && !_debug) \
 252                                 swrite(sp, x);
 253
 254 /*
 255  * Talk to a SMTP server.
 256  */
 257 static int
 258 talk_smtp(struct name *to, FILE *fi, struct sock *sp,
 259                 char *xserver, char *uhp, struct header *hp,
 260                 const char *user, const char *password, const char *skinned)
 261 {
 262         struct name *n;
 263         char *b = NULL, o[LINESIZE];
 264         size_t blen, bsize = 0, count;
 265         char    *b64, *authstr, *cp;
 266         enum    { AUTH_NONE, AUTH_PLAIN, AUTH_LOGIN, AUTH_CRAM_MD5 } auth;
 267         int     inhdr = 1, inbcc = 0;
 268         (void)hp;
 269
 270         if ((authstr = smtp_auth_var("", skinned)) == NULL)
 271                 auth = user && password ? AUTH_LOGIN : AUTH_NONE;
 272         else if (strcmp(authstr, "plain") == 0)
 273                 auth = AUTH_PLAIN;
 274         else if (strcmp(authstr, "login") == 0)
 275                 auth = AUTH_LOGIN;
 276         else if (strcmp(authstr, "cram-md5") == 0)
 277                 auth = AUTH_CRAM_MD5;
 278         else {
 279                 fprintf(stderr, "Unknown SMTP authentication "
 280                                 "method: \"%s\"\n", authstr);
 281                 return 1;
 282         }
 283         if (auth != AUTH_NONE && (user == NULL || password == NULL)) {
 284                 fprintf(stderr, "User and password are necessary "
 285                                 "for SMTP authentication.\n");
 286                 return 1;
 287         }
 288         SMTP_ANSWER(2);
 289 #ifdef  USE_SSL
 290         if (value("smtp-use-starttls") ||
 291                         value("smtp-use-tls") /* v11.0 compatibility */) {
 292                 char    *server;
 293                 if ((cp = strchr(xserver, ':')) != NULL) {
 294                         server = salloc(cp - xserver + 1);
 295                         memcpy(server, xserver, cp - xserver);
 296                         server[cp - xserver] = '\0';
 297                 } else
 298                         server = xserver;
 299                 snprintf(o, sizeof o, "EHLO %s\r\n", nodename(1));
 300                 SMTP_OUT(o);
 301                 SMTP_ANSWER(2);
 302                 SMTP_OUT("STARTTLS\r\n");
 303                 SMTP_ANSWER(2);
 304                 if (!debug && !_debug && ssl_open(server, sp, uhp) != OKAY)
 305                         return 1;
 306         }
 307 #else   /* !USE_SSL */
 308         if (value("smtp-use-starttls") || value("smtp-use-tls")) {
 309                 fprintf(stderr, "No SSL support compiled in.\n");
 310                 return 1;
 311         }
 312 #endif  /* !USE_SSL */
 313         if (auth != AUTH_NONE) {
 314                 snprintf(o, sizeof o, "EHLO %s\r\n", nodename(1));
 315                 SMTP_OUT(o);
 316                 SMTP_ANSWER(2);
 317                 switch (auth) {
 318                 default:
 319                 case AUTH_LOGIN:
 320                         SMTP_OUT("AUTH LOGIN\r\n");
 321                         SMTP_ANSWER(3);
 322                         b64 = strtob64(user);
 323                         snprintf(o, sizeof o, "%s\r\n", b64);
 324                         free(b64);
 325                         SMTP_OUT(o);
 326                         SMTP_ANSWER(3);
 327                         b64 = strtob64(password);
 328                         snprintf(o, sizeof o, "%s\r\n", b64);
 329                         free(b64);
 330                         SMTP_OUT(o);
 331                         SMTP_ANSWER(2);
 332                         break;
 333                 case AUTH_PLAIN:
 334                         SMTP_OUT("AUTH PLAIN\r\n");
 335                         SMTP_ANSWER(3);
 336                         snprintf(o, sizeof o, "%c%s%c%s", '\0', user, '\0',
 337                                                           password);
 338                         b64 = memtob64(o, strlen(user)+strlen(password)+2);
 339                         snprintf(o, sizeof o, "%s\r\n", b64);
 340                         SMTP_OUT(o);
 341                         SMTP_ANSWER(2);
 342                         break;
 343                 case AUTH_CRAM_MD5:
 344                         SMTP_OUT("AUTH CRAM-MD5\r\n");
 345                         SMTP_ANSWER(3);
 346                         for (cp = smtpbuf; digitchar(*cp&0377); cp++);
 347                         while (blankchar(*cp&0377)) cp++;
 348                         cp = cram_md5_string(user, password, cp);
 349                         SMTP_OUT(cp);
 350                         SMTP_ANSWER(2);
 351                         break;
 352                 }
 353         } else {
 354                 snprintf(o, sizeof o, "HELO %s\r\n", nodename(1));
 355                 SMTP_OUT(o);
 356                 SMTP_ANSWER(2);
 357         }
 358         snprintf(o, sizeof o, "MAIL FROM:<%s>\r\n", skinned);
 359         SMTP_OUT(o);
 360         SMTP_ANSWER(2);
 361         for (n = to; n != NULL; n = n->n_flink) {
 362                 if ((n->n_type & GDEL) == 0) {
 363                         snprintf(o, sizeof o, "RCPT TO:<%s>\r\n",
 364                                         skin(n->n_name));
 365                         SMTP_OUT(o);
 366                         SMTP_ANSWER(2);
 367                 }
 368         }
 369         SMTP_OUT("DATA\r\n");
 370         SMTP_ANSWER(3);
 371         fflush(fi);
 372         rewind(fi);
 373         count = fsize(fi);
 374         while (fgetline(&b, &bsize, &count, &blen, fi, 1) != NULL) {
 375                 if (inhdr) {
 376                         if (*b == '\n') {
 377                                 inhdr = 0;
 378                                 inbcc = 0;
 379                         } else if (inbcc && blankchar(*b & 0377))
 380                                 continue;
 381                         /*
 382                          * We know what we have generated first, so
 383                          * do not look for whitespace before the ':'.
 384                          */
 385                         else if (ascncasecmp(b, "bcc: ", 5) == 0) {
 386                                 inbcc = 1;
 387                                 continue;
 388                         } else
 389                                 inbcc = 0;
 390                 }
 391                 if (*b == '.') {
 392                         if (debug || _debug)
 393                                 putc('.', stderr);
 394                         else
 395                                 swrite1(sp, ".", 1, 1);
 396                 }
 397                 if (debug || _debug) {
 398                         fprintf(stderr, ">>> %s", b);
 399                         continue;
 400                 }
 401                 b[blen-1] = '\r';
 402                 b[blen] = '\n';
 403                 swrite1(sp, b, blen+1, 1);
 404         }
 405         SMTP_OUT(".\r\n");
 406         SMTP_ANSWER(2);
 407         SMTP_OUT("QUIT\r\n");
 408         _SMTP_ANSWER(2, 1);
 409         if (b != NULL)
 410                 free(b);
 411         return 0;
 412 }
 413
 414 static sigjmp_buf       smtpjmp;
 415
 416 static void
 417 onterm(int signo)
 418 {
 419         (void)signo;
 420         siglongjmp(smtpjmp, 1);
 421 }
 422
 423 /*
 424  * Connect to a SMTP server.
 425  */
 426 int
 427 smtp_mta(char *server, struct name *to, FILE *fi, struct header *hp,
 428                 const char *user, const char *password, const char *skinned)
 429 {
 430         struct sock     so;
 431         int     use_ssl, ret;
 432         sighandler_type saveterm;
 433
 434         memset(&so, 0, sizeof so);
 435         verbose = value("verbose") != NULL;
 436         _debug = value("debug") != NULL;
 437         saveterm = safe_signal(SIGTERM, SIG_IGN);
 438         if (sigsetjmp(smtpjmp, 1)) {
 439                 safe_signal(SIGTERM, saveterm);
 440                 return 1;
 441         }
 442         if (saveterm != SIG_IGN)
 443                 safe_signal(SIGTERM, onterm);
 444         if (strncmp(server, "smtp://", 7) == 0) {
 445                 use_ssl = 0;
 446                 server += 7;
 447 #ifdef  USE_SSL
 448         } else if (strncmp(server, "smtps://", 8) == 0) {
 449                 use_ssl = 1;
 450                 server += 8;
 451 #endif
 452         } else
 453                 use_ssl = 0;
 454         if (!debug && !_debug && sopen(server, &so, use_ssl, server,
 455                                 use_ssl ? "smtps" : "smtp", verbose) != OKAY) {
 456                 safe_signal(SIGTERM, saveterm);
 457                 return 1;
 458         }
 459         so.s_desc = "SMTP";
 460         ret = talk_smtp(to, fi, &so, server, server, hp,
 461                         user, password, skinned);
 462         if (!debug && !_debug)
 463                 sclose(&so);
 464         if (smtpbuf) {
 465                 free(smtpbuf);
 466                 smtpbuf = NULL;
 467                 smtpbufsize = 0;
 468         }
 469         safe_signal(SIGTERM, saveterm);
 470         return ret;
 471 }
 472 #else   /* !USE_SMTP */
 473 int
 474 smtp_mta(char *server, struct name *to, FILE *fi, struct header *hp,
 475                 const char *user, const char *password, const char *skinned)
 476 {
 477         (void)server;
 478         (void)to;
 479         (void)fi;
 480         (void)hp;
 481         (void)user;
 482         (void)password;
 483         (void)skinned;
 484         fputs(catgets(catd, CATSET, 194,
 485                         "No SMTP support compiled in.\n"), stderr);
 486         return 1;
 487 }
 488 #endif  /* USE_SMTP */