src/mx/tls.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Generic TLS / S/MIME commands.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2020 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   6  * SPDX-License-Identifier: BSD-4-Clause TODO ISC (is taken from book!)
   7  */
   8 /*
   9  * Copyright (c) 2002
  10  * Gunnar Ritter.  All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  * This product includes software developed by Gunnar Ritter
  23  * and his contributors.
  24  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  */
  40 #undef su_FILE
  41 #define su_FILE tls
  42 #define mx_SOURCE
  43
  44 #ifndef mx_HAVE_AMALGAMATION
  45 # include "mx/nail.h"
  46 #endif
  47
  48 su_EMPTY_FILE()
  49 #ifdef mx_HAVE_TLS
  50 #include <su/cs.h>
  51 #include <su/mem.h>
  52
  53 #include "mx/cmd.h"
  54 #include "mx/file-streams.h"
  55 #include "mx/net-socket.h"
  56 #include "mx/tty.h"
  57 #include "mx/url.h"
  58
  59 /* TODO fake */
  60 #include "su/code-in.h"
  61
  62 struct a_tls_verify_levels{
  63    char const tv_name[8];
  64    enum n_tls_verify_level tv_level;
  65 };
  66
  67 /* Supported SSL/TLS verification methods: update manual on change! */
  68 static struct a_tls_verify_levels const a_tls_verify_levels[] = {
  69    {"strict", n_TLS_VERIFY_STRICT},
  70    {"ask", n_TLS_VERIFY_ASK},
  71    {"warn", n_TLS_VERIFY_WARN},
  72    {"ignore", n_TLS_VERIFY_IGNORE}
  73 };
  74
  75 FL void
  76 n_tls_set_verify_level(struct mx_url const *urlp){
  77    uz i;
  78    char const *cp;
  79    NYD2_IN;
  80
  81    n_tls_verify_level = n_TLS_VERIFY_ASK;
  82
  83    if((cp = xok_vlook(tls_verify, urlp, OXM_ALL)) != NULL ||
  84          (cp = xok_vlook(ssl_verify, urlp, OXM_ALL)) != NULL){
  85       for(i = 0;;)
  86          if(!su_cs_cmp_case(a_tls_verify_levels[i].tv_name, cp)){
  87             n_tls_verify_level = a_tls_verify_levels[i].tv_level;
  88             break;
  89          }else if(++i >= NELEM(a_tls_verify_levels)){
  90             n_err(_("Invalid value of *tls-verify*: %s\n"), cp);
  91             break;
  92          }
  93    }
  94    NYD2_OU;
  95 }
  96
  97 FL boole
  98 n_tls_verify_decide(void){
  99    boole rv;
 100    NYD2_IN;
 101
 102    switch(n_tls_verify_level){
 103    default:
 104    case n_TLS_VERIFY_STRICT:
 105       rv = FAL0;
 106       break;
 107    case n_TLS_VERIFY_ASK:
 108       rv = mx_tty_yesorno(NIL, FAL0);
 109       break;
 110    case n_TLS_VERIFY_WARN:
 111    case n_TLS_VERIFY_IGNORE:
 112       rv = TRU1;
 113       break;
 114    }
 115    NYD2_OU;
 116    return rv;
 117 }
 118
 119 FL boole
 120 mx_smime_split(FILE *ip, FILE **hp, FILE **bp, long xcount, boole keep){
 121    struct myline{
 122       struct myline *ml_next;
 123       uz ml_len;
 124       char ml_buf[VFIELD_SIZE(0)];
 125    } *head, *tail;
 126    int c;
 127    uz bufsize, buflen, cnt;
 128    char *buf;
 129    boole rv;
 130    NYD_IN;
 131
 132    rv = FAL0;
 133    mx_fs_linepool_aquire(&buf, &bufsize);
 134    *hp = *bp = NIL;
 135
 136    if((*hp = mx_fs_tmp_open("smimeh", (mx_FS_O_RDWR | mx_FS_O_UNLINK |
 137             mx_FS_O_REGISTER), NIL)) == NIL)
 138       goto jleave;
 139    if((*bp = mx_fs_tmp_open("smimeb", (mx_FS_O_RDWR | mx_FS_O_UNLINK |
 140             mx_FS_O_REGISTER), NIL)) == NIL)
 141       goto jleave;
 142
 143    head = tail = NIL;
 144    cnt = (xcount < 0) ? fsize(ip) : xcount;
 145
 146    for(;;){
 147       if(fgetline(&buf, &bufsize, &cnt, &buflen, ip, FAL0) == NIL){
 148          if(ferror(ip))
 149             goto jleave;
 150          break;
 151       }
 152       if(*buf == '\n')
 153          break;
 154
 155       if(!su_cs_cmp_case_n(buf, "content-", 8)){
 156          if(keep && fputs("X-Encoded-", *hp) == EOF)
 157             goto jleave;
 158          for(;;){
 159             struct myline *ml;
 160
 161             ml = n_lofi_alloc(VSTRUCT_SIZEOF(struct myline, ml_buf) +
 162                   buflen +1);
 163             if(tail != NIL)
 164                tail->ml_next = ml;
 165             else
 166                head = ml;
 167             tail = ml;
 168             ml->ml_next = NIL;
 169             ml->ml_len = buflen;
 170             su_mem_copy(ml->ml_buf, buf, buflen +1);
 171             if(keep && fwrite(buf, sizeof *buf, buflen, *hp) != buflen)
 172                goto jleave;
 173             if((c = getc(ip)) == EOF || ungetc(c, ip) == EOF)
 174                goto jleave;
 175             if(!su_cs_is_blank(c))
 176                break;
 177             if(fgetline(&buf, &bufsize, &cnt, &buflen, ip, FAL0) == NIL &&
 178                   ferror(ip))
 179                goto jleave;
 180          }
 181          continue;
 182       }
 183
 184       if(fwrite(buf, sizeof *buf, buflen, *hp) != buflen)
 185          goto jleave;
 186    }
 187    fflush_rewind(*hp);
 188
 189    while(head != NIL){
 190       if(fwrite(head->ml_buf, sizeof *head->ml_buf, head->ml_len, *bp
 191             ) != head->ml_len)
 192          goto jleave;
 193       tail = head;
 194       head = head->ml_next;
 195       n_lofi_free(tail);
 196    }
 197
 198    if(putc('\n', *bp) == EOF)
 199       goto jleave;
 200    while(fgetline(&buf, &bufsize, &cnt, &buflen, ip, FAL0) != NIL){
 201       if(fwrite(buf, sizeof *buf, buflen, *bp) != buflen)
 202          goto jleave;
 203    }
 204    fflush_rewind(*bp);
 205    if(ferror(ip))
 206       goto jleave;
 207
 208    rv = OKAY;
 209 jleave:
 210    if(rv != OKAY){
 211       if(*bp != NIL){
 212          mx_fs_close(*bp);
 213          *bp = NIL;
 214       }
 215       if(*hp != NIL){
 216          mx_fs_close(*hp);
 217          *hp = NIL;
 218       }
 219    }
 220
 221    mx_fs_linepool_release(buf, bufsize);
 222
 223    NYD_OU;
 224    return rv;
 225 }
 226
 227 FL FILE *
 228 smime_sign_assemble(FILE *hp, FILE *bp, FILE *tsp, char const *message_digest)
 229 {
 230    char *boundary;
 231    int c, lastc = EOF;
 232    FILE *op;
 233    NYD_IN;
 234
 235    if((op = mx_fs_tmp_open("smimea", (mx_FS_O_RDWR | mx_FS_O_UNLINK |
 236             mx_FS_O_REGISTER), NIL)) == NIL){
 237       n_perr(_("tempfile"), 0);
 238       goto jleave;
 239    }
 240
 241    while ((c = getc(hp)) != EOF) {
 242       if (c == '\n' && lastc == '\n')
 243          break;
 244       putc(c, op);
 245       lastc = c;
 246    }
 247
 248    boundary = mime_param_boundary_create();
 249    fprintf(op, "Content-Type: multipart/signed;\n"
 250       " protocol=\"application/pkcs7-signature\"; micalg=%s;\n"
 251       " boundary=\"%s\"\n\n", message_digest, boundary);
 252    fprintf(op, "This is a S/MIME signed message.\n\n--%s\n", boundary);
 253    while ((c = getc(bp)) != EOF)
 254       putc(c, op);
 255
 256    fprintf(op, "\n--%s\n", boundary);
 257    fputs("Content-Type: application/pkcs7-signature; name=\"smime.p7s\"\n"
 258       "Content-Transfer-Encoding: base64\n"
 259       "Content-Disposition: attachment; filename=\"smime.p7s\"\n", op);
 260    /* C99 */{
 261       char const *cp;
 262
 263       if(*(cp = ok_vlook(content_description_smime_signature)) != '\0')
 264          fprintf(op, "Content-Description: %s\n", cp);
 265    }
 266    putc('\n', op);
 267
 268    while ((c = getc(tsp)) != EOF) {
 269       if (c == '-') {
 270          while ((c = getc(tsp)) != EOF && c != '\n');
 271          continue;
 272       }
 273       putc(c, op);
 274    }
 275
 276    fprintf(op, "\n--%s--\n", boundary);
 277
 278    mx_fs_close(hp);
 279    mx_fs_close(bp);
 280    mx_fs_close(tsp);
 281
 282    fflush(op);
 283    if (ferror(op)) {
 284       n_perr(_("signed output data"), 0);
 285       mx_fs_close(op);
 286       op = NULL;
 287       goto jleave;
 288    }
 289    rewind(op);
 290 jleave:
 291    NYD_OU;
 292    return op;
 293 }
 294
 295 FL FILE *
 296 smime_encrypt_assemble(FILE *hp, FILE *yp)
 297 {
 298    FILE *op;
 299    int c, lastc = EOF;
 300    NYD_IN;
 301
 302    if((op = mx_fs_tmp_open("smimee", (mx_FS_O_RDWR | mx_FS_O_UNLINK |
 303             mx_FS_O_REGISTER), NIL)) == NIL){
 304       n_perr(_("tempfile"), 0);
 305       goto jleave;
 306    }
 307
 308    while ((c = getc(hp)) != EOF) {
 309       if (c == '\n' && lastc == '\n')
 310          break;
 311       putc(c, op);
 312       lastc = c;
 313    }
 314
 315    fputs("Content-Type: application/pkcs7-mime; name=\"smime.p7m\"\n"
 316       "Content-Transfer-Encoding: base64\n"
 317       "Content-Disposition: attachment; filename=\"smime.p7m\"\n", op);
 318    /* C99 */{
 319       char const *cp;
 320
 321       if(*(cp = ok_vlook(content_description_smime_message)) != '\0')
 322          fprintf(op, "Content-Description: %s\n", cp);
 323    }
 324    putc('\n', op);
 325
 326    while ((c = getc(yp)) != EOF) {
 327       if (c == '-') {
 328          while ((c = getc(yp)) != EOF && c != '\n');
 329          continue;
 330       }
 331       putc(c, op);
 332    }
 333
 334    mx_fs_close(hp);
 335    mx_fs_close(yp);
 336
 337    fflush(op);
 338    if (ferror(op)) {
 339       n_perr(_("encrypted output data"), 0);
 340       mx_fs_close(op);
 341       op = NULL;
 342       goto jleave;
 343    }
 344    rewind(op);
 345 jleave:
 346    NYD_OU;
 347    return op;
 348 }
 349
 350 FL struct message *
 351 mx_smime_decrypt_assemble(struct message *mp, FILE *hp, FILE *bp){
 352    boole binary, lastnl;
 353    long lns, octets;
 354    off_t offset;
 355    uz bufsize, buflen, cnt;
 356    char *buf;
 357    struct message *xmp;
 358    NYD_IN;
 359
 360    xmp = NIL;
 361    mx_fs_linepool_aquire(&buf, &bufsize);
 362
 363    fflush(mb.mb_otf);
 364    fseek(mb.mb_otf, 0L, SEEK_END);
 365    offset = ftell(mb.mb_otf);
 366    lns = octets = 0;
 367    binary = FAL0;
 368
 369    cnt = fsize(hp);
 370    while(fgetline(&buf, &bufsize, &cnt, &buflen, hp, FAL0) != NIL){
 371       char const *cp;
 372
 373       if(buf[0] == '\n')
 374          break;
 375       if((cp = n_header_get_field(buf, "content-transfer-encoding", NIL)
 376             ) != NIL)
 377          if(!su_cs_cmp_case_n(cp, "binary", 7))
 378             binary = TRU1;
 379       if(fwrite(buf, sizeof *buf, buflen, mb.mb_otf) != buflen)
 380          goto jleave;
 381       octets += buflen;
 382       ++lns;
 383    }
 384    if(ferror(hp))
 385       goto jleave;
 386
 387    /* C99 */{
 388       struct time_current save;
 389       int w;
 390
 391       save = time_current;
 392       time_current_update(&time_current, TRU1);
 393       if((w = mkdate(mb.mb_otf, "X-Decoding-Date")) == -1)
 394          goto jleave;
 395       octets += w;
 396       time_current = save;
 397    }
 398    ++lns;
 399
 400    cnt = fsize(bp);
 401    lastnl = FAL0;
 402    while(fgetline(&buf, &bufsize, &cnt, &buflen, bp, FAL0) != NIL){
 403       lns++;
 404       if(!binary && buf[buflen - 1] == '\n' && buf[buflen - 2] == '\r')
 405          buf[--buflen - 1] = '\n';
 406       fwrite(buf, sizeof *buf, buflen, mb.mb_otf);
 407       octets += buflen;
 408       if(buf[0] == '\n')
 409          lastnl = lastnl ? TRUM1 : TRU1;
 410       else
 411          lastnl = (buf[buflen - 1] == '\n');
 412    }
 413    if(ferror(bp))
 414       goto jleave;
 415
 416    if(!binary && lastnl != TRUM1){
 417       for(;;){
 418          if(putc('\n', mb.mb_otf) == EOF)
 419             goto jleave;
 420          ++lns;
 421          ++octets;
 422          if(lastnl)
 423             break;
 424          lastnl = TRU1;
 425       }
 426    }
 427
 428    fflush(mb.mb_otf);
 429    if(!ferror(mb.mb_otf)){
 430       xmp = n_autorec_alloc(sizeof *xmp);
 431       *xmp = *mp;
 432       xmp->m_size = xmp->m_xsize = octets;
 433       xmp->m_lines = xmp->m_xlines = lns;
 434       xmp->m_block = mailx_blockof(offset);
 435       xmp->m_offset = mailx_offsetof(offset);
 436    }
 437
 438 jleave:
 439    mx_fs_linepool_release(buf, bufsize);
 440
 441    NYD_OU;
 442    return xmp;
 443 }
 444
 445 FL int
 446 c_certsave(void *vp){
 447    FILE *fp;
 448    int *msgvec, *ip;
 449    struct mx_cmd_arg_ctx *cacp;
 450    NYD_IN;
 451
 452    cacp = vp;
 453    ASSERT(cacp->cac_no == 2);
 454
 455    msgvec = cacp->cac_arg->ca_arg.ca_msglist;
 456    /* C99 */{
 457       char *file, *cp;
 458
 459       file = cacp->cac_arg->ca_next->ca_arg.ca_str.s;
 460       if((cp = fexpand(file, (FEXP_NOPROTO | FEXP_LOCAL_FILE | FEXP_NSHELL))
 461             ) == NIL || *cp == '\0'){
 462          n_err(_("certsave: file expansion failed: %s\n"),
 463             n_shexp_quote_cp(file, FAL0));
 464          vp = NULL;
 465          goto jleave;
 466       }
 467       file = cp;
 468
 469       if((fp = mx_fs_open(file, "a")) == NIL){
 470          n_perr(file, 0);
 471          vp = NULL;
 472          goto jleave;
 473       }
 474    }
 475
 476    for(ip = msgvec; *ip != 0; ++ip)
 477       if(smime_certsave(&message[*ip - 1], *ip, fp) != OKAY)
 478          vp = NULL;
 479
 480    mx_fs_close(fp);
 481
 482    if(vp != NULL)
 483       fprintf(n_stdout, "Certificate(s) saved\n");
 484 jleave:
 485    NYD_OU;
 486    return (vp != NULL);
 487 }
 488
 489 FL boole
 490 n_tls_rfc2595_hostname_match(char const *host, char const *pattern){
 491    boole rv;
 492    NYD_IN;
 493
 494    if(pattern[0] == '*' && pattern[1] == '.'){
 495       ++pattern;
 496       while(*host && *host != '.')
 497          ++host;
 498    }
 499    rv = (su_cs_cmp_case(host, pattern) == 0);
 500    NYD_OU;
 501    return rv;
 502 }
 503
 504 FL int
 505 c_tls(void *vp){
 506 #ifdef mx_HAVE_NET
 507    struct mx_socket so;
 508    struct mx_url url;
 509 #endif
 510    uz i;
 511    enum {a_FPRINT, a_CERTIFICATE, a_CERTCHAIN} mode;
 512    char const **argv, *varname, *varres, *cp;
 513    NYD_IN;
 514
 515    argv = vp;
 516    vp = NULL; /* -> return value (boolean) */
 517    varname = (n_pstate & n_PS_ARGMOD_VPUT) ? *argv++ : NULL;
 518    varres = n_empty;
 519
 520    if((cp = argv[0])[0] == '\0')
 521       goto jesubcmd;
 522    else if(su_cs_starts_with_case("fingerprint", cp))
 523       mode = a_FPRINT;
 524    else if(su_cs_starts_with_case("certificate", cp))
 525       mode = a_CERTIFICATE;
 526    else if(su_cs_starts_with_case("certchain", cp))
 527       mode = a_CERTCHAIN;
 528    else
 529       goto jesubcmd;
 530
 531 #ifndef mx_HAVE_NET
 532    n_err(_("tls: fingerprint: no +sockets in *features*\n"));
 533    n_pstate_err_no = su_ERR_OPNOTSUPP;
 534    goto jleave;
 535 #else
 536    if(argv[1] == NULL || argv[2] != NULL)
 537       goto jesynopsis;
 538    if((i = su_cs_len(*++argv)) >= U32_MAX)
 539       goto jeoverflow; /* TODO generic for ALL commands!! */
 540    if(!mx_url_parse(&url, CPROTO_CERTINFO, *argv))
 541       goto jeinval;
 542
 543    if(!mx_socket_open(&so, &url)){
 544       n_pstate_err_no = su_err_no();
 545       goto jleave;
 546    }
 547    mx_socket_close(&so);
 548
 549    switch(mode){
 550    case a_FPRINT:
 551       if(so.s_tls_finger == NIL)
 552          goto jeinval;
 553       varres = so.s_tls_finger;
 554       break;
 555    case a_CERTIFICATE:
 556       if(so.s_tls_certificate == NIL)
 557          goto jeinval;
 558       varres = so.s_tls_certificate;
 559       break;
 560    case a_CERTCHAIN:
 561       if(so.s_tls_certchain == NIL)
 562          goto jeinval;
 563       varres = so.s_tls_certchain;
 564       break;
 565    }
 566 #endif /* mx_HAVE_NET */
 567
 568    n_pstate_err_no = su_ERR_NONE;
 569    vp = (char*)-1;
 570 jleave:
 571    if(varname == NULL){
 572       if(fprintf(n_stdout, "%s\n", varres) < 0){
 573          n_pstate_err_no = su_err_no();
 574          vp = NULL;
 575       }
 576    }else if(!n_var_vset(varname, (up)varres)){
 577       n_pstate_err_no = su_ERR_NOTSUP;
 578       vp = NULL;
 579    }
 580    NYD_OU;
 581    return (vp == NULL);
 582
 583 jeoverflow:
 584    n_err(_("tls: string length or offset overflows datatype\n"));
 585    n_pstate_err_no = su_ERR_OVERFLOW;
 586    goto jleave;
 587
 588 jesubcmd:
 589    n_err(_("tls: invalid subcommand: %s\n"),
 590       n_shexp_quote_cp(*argv, FAL0));
 591 jesynopsis:
 592    mx_cmd_print_synopsis(mx_cmd_firstfit("tls"), NIL);
 593 jeinval:
 594    n_pstate_err_no = su_ERR_INVAL;
 595    goto jleave;
 596 }
 597
 598 #include "su/code-ou.h"
 599 #endif /* mx_HAVE_TLS */
 600 /* s-it-mode */