ssl.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Generic SSL / SMIME commands.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2013 Steffen "Daode" Nurpmeso <sdaoden@users.sf.net>.
   6  */
   7 /*
   8  * Copyright (c) 2002
   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 #include "config.h"
  41
  42 #ifndef HAVE_SSL
  43 typedef int avoid_empty_file_compiler_warning;
  44 #else
  45 #include "nail.h"
  46
  47 void
  48 ssl_set_vrfy_level(const char *uhp)
  49 {
  50         size_t l;
  51         char *cp, *vrvar;
  52
  53         ssl_vrfy_level = VRFY_ASK;
  54         l = strlen(uhp);
  55         vrvar = ac_alloc(l + 12);
  56         memcpy(vrvar, "ssl-verify-", 11);
  57         memcpy(vrvar + 11, uhp, l + 1);
  58
  59         if ((cp = value(vrvar)) == NULL)
  60                 cp = value("ssl-verify");
  61         ac_free(vrvar);
  62         if (cp != NULL) {
  63                 if (strcmp(cp, "strict") == 0)
  64                         ssl_vrfy_level = VRFY_STRICT;
  65                 else if (strcmp(cp, "ask") == 0)
  66                         ssl_vrfy_level = VRFY_ASK;
  67                 else if (strcmp(cp, "warn") == 0)
  68                         ssl_vrfy_level = VRFY_WARN;
  69                 else if (strcmp(cp, "ignore") == 0)
  70                         ssl_vrfy_level = VRFY_IGNORE;
  71                 else
  72                         fprintf(stderr, tr(265,
  73                                 "invalid value of ssl-verify: %s\n"), cp);
  74         }
  75 }
  76
  77 enum okay
  78 ssl_vrfy_decide(void)
  79 {
  80         enum okay ok = STOP;
  81
  82         switch (ssl_vrfy_level) {
  83         case VRFY_STRICT:
  84                 ok = STOP;
  85                 break;
  86         case VRFY_ASK:
  87                 {
  88                         char *line = NULL;
  89                         size_t linesize = 0;
  90
  91                         fprintf(stderr, tr(264, "Continue (y/n)? "));
  92                         if (readline_restart(stdin, &line, &linesize, 0) > 0 &&
  93                                         *line == 'y')
  94                                 ok = OKAY;
  95                         else
  96                                 ok = STOP;
  97                         if (line)
  98                                 free(line);
  99                 }
 100                 break;
 101         case VRFY_WARN:
 102         case VRFY_IGNORE:
 103                 ok = OKAY;
 104         }
 105         return ok;
 106 }
 107
 108 char *
 109 ssl_method_string(const char *uhp)
 110 {
 111         size_t l;
 112         char *cp, *mtvar;
 113
 114         l = strlen(uhp);
 115         mtvar = ac_alloc(l + 12);
 116         memcpy(mtvar, "ssl-method-", 11);
 117         memcpy(mtvar + 11, uhp, l + 1);
 118         if ((cp = value(mtvar)) == NULL)
 119                 cp = value("ssl-method");
 120         ac_free(mtvar);
 121         return cp;
 122 }
 123
 124 enum okay
 125 smime_split(FILE *ip, FILE **hp, FILE **bp, long xcount, int keep)
 126 {
 127         /* TODO like i said quite often now, the entire SSL stuff really needs
 128          * TODO a review ASAP; also in respect to correct resource release, and
 129          * TODO especially in case of errors; S-nail is a program that REALLY
 130          * TODO may run for a week or longer!!! */
 131         char    *buf, *hn, *bn;
 132         char    *savedfields = NULL;
 133         size_t  bufsize, buflen, cnt, savedsize = 0;
 134         int     c;
 135
 136         if ((*hp = Ftemp(&hn, "Rh", "w+", 0600, 1)) == NULL)
 137                 goto jetmp;
 138         rm(hn);
 139         Ftfree(&hn);
 140         if ((*bp = Ftemp(&bn, "Rb", "w+", 0600, 1)) == NULL) {
 141 jetmp:
 142                 perror("tempfile");
 143                 return STOP;
 144         }
 145         rm(bn);
 146         Ftfree(&bn);
 147
 148         buf = smalloc(bufsize = LINESIZE);
 149         savedfields = smalloc(savedsize = 1);
 150         *savedfields = '\0';
 151         if (xcount < 0)
 152                 cnt = fsize(ip);
 153         else
 154                 cnt = xcount;
 155
 156         while (fgetline(&buf, &bufsize, &cnt, &buflen, ip, 0) != NULL &&
 157                         *buf != '\n') {
 158                 if (ascncasecmp(buf, "content-", 8) == 0) {
 159                         if (keep)
 160                                 fputs("X-Encoded-", *hp);
 161                         for (;;) {
 162                                 savedsize += buflen;
 163                                 savedfields = srealloc(savedfields, savedsize);
 164                                 memcpy(savedfields + strlen(savedfields),
 165                                         buf, strlen(buf));
 166                                 if (keep)
 167                                         fwrite(buf, sizeof *buf, buflen, *hp);
 168                                 c = getc(ip);
 169                                 ungetc(c, ip);
 170                                 if (!blankchar(c))
 171                                         break;
 172                                 fgetline(&buf, &bufsize, &cnt, &buflen,
 173                                                 ip, 0);
 174                         }
 175                         continue;
 176                 }
 177                 fwrite(buf, sizeof *buf, buflen, *hp);
 178         }
 179         fflush(*hp);
 180         rewind(*hp);
 181
 182         fputs(savedfields, *bp);
 183         putc('\n', *bp);
 184         while (fgetline(&buf, &bufsize, &cnt, &buflen, ip, 0) != NULL)
 185                 fwrite(buf, sizeof *buf, buflen, *bp);
 186         fflush(*bp);
 187         rewind(*bp);
 188
 189         free(savedfields);
 190         free(buf);
 191         return OKAY;
 192 }
 193
 194 FILE *
 195 smime_sign_assemble(FILE *hp, FILE *bp, FILE *sp)
 196 {
 197         char    *boundary, *cp;
 198         FILE    *op;
 199         int     c, lastc = EOF;
 200
 201         if ((op = Ftemp(&cp, "Rs", "w+", 0600, 1)) == NULL) {
 202                 perror("tempfile");
 203                 return NULL;
 204         }
 205         rm(cp);
 206         Ftfree(&cp);
 207         boundary = mime_create_boundary();
 208         while ((c = getc(hp)) != EOF) {
 209                 if (c == '\n' && lastc == '\n')
 210                         break;
 211                 putc(c, op);
 212                 lastc = c;
 213         }
 214         fprintf(op, "Content-Type: multipart/signed;\n"
 215                 " protocol=\"application/x-pkcs7-signature\"; micalg=sha1;\n"
 216                 " boundary=\"%s\"\n\n", boundary);
 217         fprintf(op, "This is an S/MIME signed message.\n\n--%s\n",
 218                         boundary);
 219         while ((c = getc(bp)) != EOF)
 220                 putc(c, op);
 221         fprintf(op, "\n--%s\n", boundary);
 222         fputs("Content-Type: application/x-pkcs7-signature; "
 223                         "name=\"smime.p7s\"\n"
 224                 "Content-Transfer-Encoding: base64\n"
 225                 "Content-Disposition: attachment; filename=\"smime.p7s\"\n\n",
 226                 op);
 227         while ((c = getc(sp)) != EOF) {
 228                 if (c == '-') {
 229                         while ((c = getc(sp)) != EOF && c != '\n');
 230                         continue;
 231                 }
 232                 putc(c, op);
 233         }
 234         fprintf(op, "\n--%s--\n", boundary);
 235         Fclose(hp);
 236         Fclose(bp);
 237         Fclose(sp);
 238         fflush(op);
 239         if (ferror(op)) {
 240                 perror("signed output data");
 241                 Fclose(op);
 242                 return NULL;
 243         }
 244         rewind(op);
 245         return op;
 246 }
 247
 248 FILE *
 249 smime_encrypt_assemble(FILE *hp, FILE *yp)
 250 {
 251         char    *cp;
 252         FILE    *op;
 253         int     c, lastc = EOF;
 254
 255         if ((op = Ftemp(&cp, "Rs", "w+", 0600, 1)) == NULL) {
 256                 perror("tempfile");
 257                 return NULL;
 258         }
 259         rm(cp);
 260         Ftfree(&cp);
 261         while ((c = getc(hp)) != EOF) {
 262                 if (c == '\n' && lastc == '\n')
 263                         break;
 264                 putc(c, op);
 265                 lastc = c;
 266         }
 267         fprintf(op, "Content-Type: application/x-pkcs7-mime; "
 268                         "name=\"smime.p7m\"\n"
 269                 "Content-Transfer-Encoding: base64\n"
 270                 "Content-Disposition: attachment; "
 271                         "filename=\"smime.p7m\"\n\n");
 272         while ((c = getc(yp)) != EOF) {
 273                 if (c == '-') {
 274                         while ((c = getc(yp)) != EOF && c != '\n');
 275                         continue;
 276                 }
 277                 putc(c, op);
 278         }
 279         Fclose(hp);
 280         Fclose(yp);
 281         fflush(op);
 282         if (ferror(op)) {
 283                 perror("encrypted output data");
 284                 Fclose(op);
 285                 return NULL;
 286         }
 287         rewind(op);
 288         return op;
 289 }
 290
 291 struct message *
 292 smime_decrypt_assemble(struct message *m, FILE *hp, FILE *bp)
 293 {
 294         ui32_t lastnl = 0;
 295         int     binary = 0;
 296         char    *buf = NULL;
 297         size_t  bufsize = 0, buflen, cnt;
 298         long    lines = 0, octets = 0;
 299         struct message  *x;
 300         off_t   offset;
 301
 302         x = salloc(sizeof *x);
 303         *x = *m;
 304         fflush(mb.mb_otf);
 305         fseek(mb.mb_otf, 0L, SEEK_END);
 306         offset = ftell(mb.mb_otf);
 307         cnt = fsize(hp);
 308         while (fgetline(&buf, &bufsize, &cnt, &buflen, hp, 0) != NULL) {
 309                 char const *cp;
 310                 if (buf[0] == '\n')
 311                         break;
 312                 if ((cp = thisfield(buf, "content-transfer-encoding")) != NULL)
 313                         if (ascncasecmp(cp, "binary", 7) == 0)
 314                                 binary = 1;
 315                 fwrite(buf, sizeof *buf, buflen, mb.mb_otf);
 316                 octets += buflen;
 317                 lines++;
 318         }
 319         octets += mkdate(mb.mb_otf, "X-Decoding-Date");
 320         lines++;
 321         cnt = fsize(bp);
 322         while (fgetline(&buf, &bufsize, &cnt, &buflen, bp, 0) != NULL) {
 323                 lines++;
 324                 if (!binary && buf[buflen-1] == '\n' && buf[buflen-2] == '\r')
 325                         buf[--buflen-1] = '\n';
 326                 fwrite(buf, sizeof *buf, buflen, mb.mb_otf);
 327                 octets += buflen;
 328                 if (buf[0] == '\n')
 329                         lastnl++;
 330                 else if (buf[buflen-1] == '\n')
 331                         lastnl = 1;
 332                 else
 333                         lastnl = 0;
 334         }
 335         while (!binary && lastnl < 2) {
 336                 putc('\n', mb.mb_otf);
 337                 lines++;
 338                 octets++;
 339                 lastnl++;
 340         }
 341         Fclose(hp);
 342         Fclose(bp);
 343         free(buf);
 344         fflush(mb.mb_otf);
 345         if (ferror(mb.mb_otf)) {
 346                 perror("decrypted output data");
 347                 return NULL;
 348         }
 349         x->m_size = x->m_xsize = octets;
 350         x->m_lines = x->m_xlines = lines;
 351         x->m_block = mailx_blockof(offset);
 352         x->m_offset = mailx_offsetof(offset);
 353         return x;
 354 }
 355
 356 int
 357 ccertsave(void *v)
 358 {
 359         int     *ip;
 360         int     f, *msgvec;
 361         char    *file = NULL, *str = v;
 362         int     val = 0;
 363         FILE    *fp;
 364
 365         msgvec = salloc((msgCount + 2) * sizeof *msgvec);
 366         if ((file = laststring(str, &f, 1)) == NULL) {
 367                 fprintf(stderr, "No file to save certificate given.\n");
 368                 return 1;
 369         }
 370         if (!f) {
 371                 *msgvec = first(0, MMNORM);
 372                 if (*msgvec == 0) {
 373                         if (inhook)
 374                                 return 0;
 375                         fprintf(stderr,
 376                                 "No messages to get certificates from.\n");
 377                         return 1;
 378                 }
 379                 msgvec[1] = 0;
 380         } else if (getmsglist(str, msgvec, 0) < 0)
 381                 return 1;
 382         if (*msgvec == 0) {
 383                 if (inhook)
 384                         return 0;
 385                 fprintf(stderr, "No applicable messages.\n");
 386                 return 1;
 387         }
 388         if ((fp = Fopen(file, "a")) == NULL) {
 389                 perror(file);
 390                 return 1;
 391         }
 392         for (ip = msgvec; *ip && ip-msgvec < msgCount; ip++)
 393                 if (smime_certsave(&message[*ip-1], *ip, fp) != OKAY)
 394                         val = 1;
 395         Fclose(fp);
 396         if (val == 0)
 397                 printf("Certificate(s) saved.\n");
 398         return val;
 399 }
 400
 401 enum okay
 402 rfc2595_hostname_match(const char *host, const char *pattern)
 403 {
 404         if (pattern[0] == '*' && pattern[1] == '.') {
 405                 pattern++;
 406                 while (*host && *host != '.')
 407                         host++;
 408         }
 409         return asccasecmp(host, pattern) == 0 ? OKAY : STOP;
 410 }
 411 #endif  /* HAVE_SSL */