ssl.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Generic SSL / S/MIME commands.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   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 #undef n_FILE
  40 #define n_FILE ssl
  41
  42 #ifndef HAVE_AMALGAMATION
  43 # include "nail.h"
  44 #endif
  45
  46 EMPTY_FILE()
  47 #ifdef HAVE_SSL
  48 struct ssl_verify_levels {
  49    char const              sv_name[8];
  50    enum ssl_verify_level   sv_level;
  51 };
  52
  53 /* Supported SSL/TLS verification methods: update manual on change! */
  54 static struct ssl_verify_levels const  _ssl_verify_levels[] = {
  55    {"strict", SSL_VERIFY_STRICT},
  56    {"ask", SSL_VERIFY_ASK},
  57    {"warn", SSL_VERIFY_WARN},
  58    {"ignore", SSL_VERIFY_IGNORE}
  59 };
  60
  61 FL void
  62 ssl_set_verify_level(struct url const *urlp)
  63 {
  64    size_t i;
  65    char *cp;
  66    NYD_ENTER;
  67
  68    ssl_verify_level = SSL_VERIFY_ASK;
  69    cp = xok_vlook(ssl_verify, urlp, OXM_ALL);
  70
  71    if (cp != NULL) {
  72       for (i = 0; i < n_NELEM(_ssl_verify_levels); ++i)
  73          if (!asccasecmp(_ssl_verify_levels[i].sv_name, cp)) {
  74             ssl_verify_level = _ssl_verify_levels[i].sv_level;
  75             goto jleave;
  76          }
  77       n_err(_("Invalid value of *ssl-verify*: %s\n"), cp);
  78    }
  79 jleave:
  80    NYD_LEAVE;
  81 }
  82
  83 FL enum okay
  84 ssl_verify_decide(void)
  85 {
  86    enum okay rv = STOP;
  87    NYD_ENTER;
  88
  89    switch (ssl_verify_level) {
  90    case SSL_VERIFY_STRICT:
  91       rv = STOP;
  92       break;
  93    case SSL_VERIFY_ASK:
  94       rv = getapproval(NULL, FAL0) ? OKAY : STOP;
  95       break;
  96    case SSL_VERIFY_WARN:
  97    case SSL_VERIFY_IGNORE:
  98       rv = OKAY;
  99       break;
 100    }
 101    NYD_LEAVE;
 102    return rv;
 103 }
 104
 105 FL enum okay
 106 smime_split(FILE *ip, FILE **hp, FILE **bp, long xcount, int keep)
 107 {
 108    struct myline {
 109       struct myline  *ml_next;
 110       size_t         ml_len;
 111       char           ml_buf[n_VFIELD_SIZE(0)];
 112    } *head, *tail;
 113    char *buf;
 114    size_t bufsize, buflen, cnt;
 115    int c;
 116    enum okay rv = STOP;
 117    NYD_ENTER;
 118
 119    if ((*hp = Ftmp(NULL, "smimeh", OF_RDWR | OF_UNLINK | OF_REGISTER)) == NULL)
 120       goto jetmp;
 121    if ((*bp = Ftmp(NULL, "smimeb", OF_RDWR | OF_UNLINK | OF_REGISTER)) ==NULL) {
 122       Fclose(*hp);
 123 jetmp:
 124       n_perr(_("tempfile"), 0);
 125       goto jleave;
 126    }
 127
 128    head = tail = NULL;
 129    buf = smalloc(bufsize = LINESIZE);
 130    cnt = (xcount < 0) ? fsize(ip) : xcount;
 131
 132    while (fgetline(&buf, &bufsize, &cnt, &buflen, ip, 0) != NULL &&
 133          *buf != '\n') {
 134       if (!ascncasecmp(buf, "content-", 8)) {
 135          if (keep)
 136             fputs("X-Encoded-", *hp);
 137          for (;;) {
 138             struct myline *ml = smalloc(n_VSTRUCT_SIZEOF(struct myline, ml_buf
 139                   ) + buflen +1);
 140             if (tail != NULL)
 141                tail->ml_next = ml;
 142             else
 143                head = ml;
 144             tail = ml;
 145             ml->ml_next = NULL;
 146             ml->ml_len = buflen;
 147             memcpy(ml->ml_buf, buf, buflen +1);
 148             if (keep)
 149                fwrite(buf, sizeof *buf, buflen, *hp);
 150             c = getc(ip);
 151             ungetc(c, ip);
 152             if (!blankchar(c))
 153                break;
 154             fgetline(&buf, &bufsize, &cnt, &buflen, ip, 0);
 155          }
 156          continue;
 157       }
 158       fwrite(buf, sizeof *buf, buflen, *hp);
 159    }
 160    fflush_rewind(*hp);
 161
 162    while (head != NULL) {
 163       fwrite(head->ml_buf, sizeof *head->ml_buf, head->ml_len, *bp);
 164       tail = head;
 165       head = head->ml_next;
 166       free(tail);
 167    }
 168    putc('\n', *bp);
 169    while (fgetline(&buf, &bufsize, &cnt, &buflen, ip, 0) != NULL)
 170       fwrite(buf, sizeof *buf, buflen, *bp);
 171    fflush_rewind(*bp);
 172
 173    free(buf);
 174    rv = OKAY;
 175 jleave:
 176    NYD_LEAVE;
 177    return rv;
 178 }
 179
 180 FL FILE *
 181 smime_sign_assemble(FILE *hp, FILE *bp, FILE *sp, char const *message_digest)
 182 {
 183    char *boundary;
 184    int c, lastc = EOF;
 185    FILE *op;
 186    NYD_ENTER;
 187
 188    if ((op = Ftmp(NULL, "smimea", OF_RDWR | OF_UNLINK | OF_REGISTER)) == NULL) {
 189       n_perr(_("tempfile"), 0);
 190       goto jleave;
 191    }
 192
 193    while ((c = getc(hp)) != EOF) {
 194       if (c == '\n' && lastc == '\n')
 195          break;
 196       putc(c, op);
 197       lastc = c;
 198    }
 199
 200    boundary = mime_param_boundary_create();
 201    fprintf(op, "Content-Type: multipart/signed;\n"
 202       " protocol=\"application/pkcs7-signature\"; micalg=%s;\n"
 203       " boundary=\"%s\"\n\n", message_digest, boundary);
 204    fprintf(op, "This is a S/MIME signed message.\n\n--%s\n", boundary);
 205    while ((c = getc(bp)) != EOF)
 206       putc(c, op);
 207
 208    fprintf(op, "\n--%s\n", boundary);
 209    fputs("Content-Type: application/pkcs7-signature; name=\"smime.p7s\"\n"
 210       "Content-Transfer-Encoding: base64\n"
 211       "Content-Disposition: attachment; filename=\"smime.p7s\"\n"
 212       "Content-Description: S/MIME digital signature\n\n", op);
 213    while ((c = getc(sp)) != EOF) {
 214       if (c == '-') {
 215          while ((c = getc(sp)) != EOF && c != '\n');
 216          continue;
 217       }
 218       putc(c, op);
 219    }
 220
 221    fprintf(op, "\n--%s--\n", boundary);
 222
 223    Fclose(hp);
 224    Fclose(bp);
 225    Fclose(sp);
 226
 227    fflush(op);
 228    if (ferror(op)) {
 229       n_perr(_("signed output data"), 0);
 230       Fclose(op);
 231       op = NULL;
 232       goto jleave;
 233    }
 234    rewind(op);
 235 jleave:
 236    NYD_LEAVE;
 237    return op;
 238 }
 239
 240 FL FILE *
 241 smime_encrypt_assemble(FILE *hp, FILE *yp)
 242 {
 243    FILE *op;
 244    int c, lastc = EOF;
 245    NYD_ENTER;
 246
 247    if ((op = Ftmp(NULL, "smimee", OF_RDWR | OF_UNLINK | OF_REGISTER)) == NULL) {
 248       n_perr(_("tempfile"), 0);
 249       goto jleave;
 250    }
 251
 252    while ((c = getc(hp)) != EOF) {
 253       if (c == '\n' && lastc == '\n')
 254          break;
 255       putc(c, op);
 256       lastc = c;
 257    }
 258
 259    fputs("Content-Type: application/pkcs7-mime; name=\"smime.p7m\"\n"
 260       "Content-Transfer-Encoding: base64\n"
 261       "Content-Disposition: attachment; filename=\"smime.p7m\"\n"
 262       "Content-Description: S/MIME encrypted message\n\n", op);
 263    while ((c = getc(yp)) != EOF) {
 264       if (c == '-') {
 265          while ((c = getc(yp)) != EOF && c != '\n');
 266          continue;
 267       }
 268       putc(c, op);
 269    }
 270
 271    Fclose(hp);
 272    Fclose(yp);
 273
 274    fflush(op);
 275    if (ferror(op)) {
 276       n_perr(_("encrypted output data"), 0);
 277       Fclose(op);
 278       op = NULL;
 279       goto jleave;
 280    }
 281    rewind(op);
 282 jleave:
 283    NYD_LEAVE;
 284    return op;
 285 }
 286
 287 FL struct message *
 288 smime_decrypt_assemble(struct message *m, FILE *hp, FILE *bp)
 289 {
 290    ui32_t lastnl = 0;
 291    int binary = 0;
 292    char *buf = NULL;
 293    size_t bufsize = 0, buflen, cnt;
 294    long lines = 0, octets = 0;
 295    struct message *x;
 296    off_t offset;
 297    NYD_ENTER;
 298
 299    x = salloc(sizeof *x);
 300    *x = *m;
 301    fflush(mb.mb_otf);
 302    fseek(mb.mb_otf, 0L, SEEK_END);
 303    offset = ftell(mb.mb_otf);
 304
 305    cnt = fsize(hp);
 306    while (fgetline(&buf, &bufsize, &cnt, &buflen, hp, 0) != NULL) {
 307       char const *cp;
 308       if (buf[0] == '\n')
 309          break;
 310       if ((cp = thisfield(buf, "content-transfer-encoding")) != NULL)
 311          if (!ascncasecmp(cp, "binary", 7))
 312             binary = 1;
 313       fwrite(buf, sizeof *buf, buflen, mb.mb_otf);
 314       octets += buflen;
 315       ++lines;
 316    }
 317
 318    {  struct time_current save = time_current;
 319       time_current_update(&time_current, TRU1);
 320       octets += mkdate(mb.mb_otf, "X-Decoding-Date");
 321       time_current = save;
 322    }
 323    ++lines;
 324
 325    cnt = fsize(bp);
 326    while (fgetline(&buf, &bufsize, &cnt, &buflen, bp, 0) != NULL) {
 327       lines++;
 328       if (!binary && buf[buflen - 1] == '\n' && buf[buflen - 2] == '\r')
 329          buf[--buflen - 1] = '\n';
 330       fwrite(buf, sizeof *buf, buflen, mb.mb_otf);
 331       octets += buflen;
 332       if (buf[0] == '\n')
 333          ++lastnl;
 334       else if (buf[buflen - 1] == '\n')
 335          lastnl = 1;
 336       else
 337          lastnl = 0;
 338    }
 339
 340    while (!binary && lastnl < 2) {
 341       putc('\n', mb.mb_otf);
 342       ++lines;
 343       ++octets;
 344       ++lastnl;
 345    }
 346
 347    Fclose(hp);
 348    Fclose(bp);
 349    free(buf);
 350
 351    fflush(mb.mb_otf);
 352    if (ferror(mb.mb_otf)) {
 353       n_perr(_("decrypted output data"), 0);
 354       x = NULL;
 355       goto jleave;
 356    }
 357    x->m_size = x->m_xsize = octets;
 358    x->m_lines = x->m_xlines = lines;
 359    x->m_block = mailx_blockof(offset);
 360    x->m_offset = mailx_offsetof(offset);
 361 jleave:
 362    NYD_LEAVE;
 363    return x;
 364 }
 365
 366 FL int
 367 c_certsave(void *v)
 368 {
 369    int *ip, *msgvec, val;
 370    char *file = NULL, *str = v;
 371    FILE *fp;
 372    bool_t f;
 373    NYD_ENTER;
 374
 375    msgvec = salloc((msgCount + 2) * sizeof *msgvec);
 376    val = 1;
 377
 378    if ((file = laststring(str, &f, TRU1)) == NULL ||
 379          (file = fexpand(file, FEXP_LOCAL | FEXP_NOPROTO)) == NULL) {
 380       n_err(_("No file to save certificate given\n"));
 381       goto jleave;
 382    }
 383
 384    if (!f) {
 385       msgvec[1] = 0;
 386       *msgvec = first(0, MMNORM);
 387    } else if (getmsglist(str, msgvec, 0) < 0)
 388       goto jleave;
 389    if (*msgvec == 0) {
 390       if (n_pstate & (n_PS_HOOK_MASK | n_PS_ROBOT))
 391          val = 0;
 392       else
 393          n_err(_("No applicable messages\n"));
 394       goto jleave;
 395    }
 396
 397    if ((fp = Fopen(file, "a")) == NULL) {
 398       n_perr(file, 0);
 399       goto jleave;
 400    }
 401    for (val = 0, ip = msgvec;
 402          *ip != 0 && UICMP(z, PTR2SIZE(ip - msgvec), <, msgCount); ++ip)
 403       if (smime_certsave(&message[*ip - 1], *ip, fp) != OKAY)
 404          val = 1;
 405    Fclose(fp);
 406
 407    if (val == 0)
 408       fprintf(n_stdout, "Certificate(s) saved\n");
 409 jleave:
 410    NYD_LEAVE;
 411    return val;
 412 }
 413
 414 FL enum okay
 415 rfc2595_hostname_match(char const *host, char const *pattern)
 416 {
 417    enum okay rv;
 418    NYD_ENTER;
 419
 420    if (pattern[0] == '*' && pattern[1] == '.') {
 421       ++pattern;
 422       while (*host && *host != '.')
 423          ++host;
 424    }
 425    rv = !asccasecmp(host, pattern) ? OKAY : STOP;
 426    NYD_LEAVE;
 427    return rv;
 428 }
 429 #endif /* HAVE_SSL */
 430
 431 /* s-it-mode */