crypto/x509v3/v3_utl.c

   1 /*
   2  * Copyright 1999-2017 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /* X509 v3 extension utilities */
  11
  12 #include "e_os.h"
  13 #include "internal/cryptlib.h"
  14 #include <stdio.h>
  15 #include "internal/ctype.h"
  16 #include <openssl/conf.h>
  17 #include <openssl/crypto.h>
  18 #include <openssl/x509v3.h>
  19 #include "internal/x509_int.h"
  20 #include <openssl/bn.h>
  21 #include "ext_dat.h"
  22
  23 static char *strip_spaces(char *name);
  24 static int sk_strcmp(const char *const *a, const char *const *b);
  25 static STACK_OF(OPENSSL_STRING) *get_email(X509_NAME *name,
  26                                            GENERAL_NAMES *gens);
  27 static void str_free(OPENSSL_STRING str);
  28 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk, const ASN1_IA5STRING *email);
  29
  30 static int ipv4_from_asc(unsigned char *v4, const char *in);
  31 static int ipv6_from_asc(unsigned char *v6, const char *in);
  32 static int ipv6_cb(const char *elem, int len, void *usr);
  33 static int ipv6_hex(unsigned char *out, const char *in, int inlen);
  34
  35 /* Add a CONF_VALUE name value pair to stack */
  36
  37 int X509V3_add_value(const char *name, const char *value,
  38                      STACK_OF(CONF_VALUE) **extlist)
  39 {
  40     CONF_VALUE *vtmp = NULL;
  41     char *tname = NULL, *tvalue = NULL;
  42     int sk_allocated = (*extlist == NULL);
  43
  44     if (name && (tname = OPENSSL_strdup(name)) == NULL)
  45         goto err;
  46     if (value && (tvalue = OPENSSL_strdup(value)) == NULL)
  47         goto err;
  48     if ((vtmp = OPENSSL_malloc(sizeof(*vtmp))) == NULL)
  49         goto err;
  50     if (sk_allocated && (*extlist = sk_CONF_VALUE_new_null()) == NULL)
  51         goto err;
  52     vtmp->section = NULL;
  53     vtmp->name = tname;
  54     vtmp->value = tvalue;
  55     if (!sk_CONF_VALUE_push(*extlist, vtmp))
  56         goto err;
  57     return 1;
  58  err:
  59     X509V3err(X509V3_F_X509V3_ADD_VALUE, ERR_R_MALLOC_FAILURE);
  60     if (sk_allocated) {
  61         sk_CONF_VALUE_free(*extlist);
  62         *extlist = NULL;
  63     }
  64     OPENSSL_free(vtmp);
  65     OPENSSL_free(tname);
  66     OPENSSL_free(tvalue);
  67     return 0;
  68 }
  69
  70 int X509V3_add_value_uchar(const char *name, const unsigned char *value,
  71                            STACK_OF(CONF_VALUE) **extlist)
  72 {
  73     return X509V3_add_value(name, (const char *)value, extlist);
  74 }
  75
  76 /* Free function for STACK_OF(CONF_VALUE) */
  77
  78 void X509V3_conf_free(CONF_VALUE *conf)
  79 {
  80     if (!conf)
  81         return;
  82     OPENSSL_free(conf->name);
  83     OPENSSL_free(conf->value);
  84     OPENSSL_free(conf->section);
  85     OPENSSL_free(conf);
  86 }
  87
  88 int X509V3_add_value_bool(const char *name, int asn1_bool,
  89                           STACK_OF(CONF_VALUE) **extlist)
  90 {
  91     if (asn1_bool)
  92         return X509V3_add_value(name, "TRUE", extlist);
  93     return X509V3_add_value(name, "FALSE", extlist);
  94 }
  95
  96 int X509V3_add_value_bool_nf(const char *name, int asn1_bool,
  97                              STACK_OF(CONF_VALUE) **extlist)
  98 {
  99     if (asn1_bool)
 100         return X509V3_add_value(name, "TRUE", extlist);
 101     return 1;
 102 }
 103
 104 static char *bignum_to_string(const BIGNUM *bn)
 105 {
 106     char *tmp, *ret;
 107     size_t len;
 108
 109     /*
 110      * Display large numbers in hex and small numbers in decimal. Converting to
 111      * decimal takes quadratic time and is no more useful than hex for large
 112      * numbers.
 113      */
 114     if (BN_num_bits(bn) < 128)
 115         return BN_bn2dec(bn);
 116
 117     tmp = BN_bn2hex(bn);
 118     if (tmp == NULL)
 119         return NULL;
 120
 121     len = strlen(tmp) + 3;
 122     ret = OPENSSL_malloc(len);
 123     if (ret == NULL) {
 124         X509V3err(X509V3_F_BIGNUM_TO_STRING, ERR_R_MALLOC_FAILURE);
 125         OPENSSL_free(tmp);
 126         return NULL;
 127     }
 128
 129     /* Prepend "0x", but place it after the "-" if negative. */
 130     if (tmp[0] == '-') {
 131         OPENSSL_strlcpy(ret, "-0x", len);
 132         OPENSSL_strlcat(ret, tmp + 1, len);
 133     } else {
 134         OPENSSL_strlcpy(ret, "0x", len);
 135         OPENSSL_strlcat(ret, tmp, len);
 136     }
 137     OPENSSL_free(tmp);
 138     return ret;
 139 }
 140
 141 char *i2s_ASN1_ENUMERATED(X509V3_EXT_METHOD *method, const ASN1_ENUMERATED *a)
 142 {
 143     BIGNUM *bntmp = NULL;
 144     char *strtmp = NULL;
 145
 146     if (!a)
 147         return NULL;
 148     if ((bntmp = ASN1_ENUMERATED_to_BN(a, NULL)) == NULL
 149         || (strtmp = bignum_to_string(bntmp)) == NULL)
 150         X509V3err(X509V3_F_I2S_ASN1_ENUMERATED, ERR_R_MALLOC_FAILURE);
 151     BN_free(bntmp);
 152     return strtmp;
 153 }
 154
 155 char *i2s_ASN1_INTEGER(X509V3_EXT_METHOD *method, const ASN1_INTEGER *a)
 156 {
 157     BIGNUM *bntmp = NULL;
 158     char *strtmp = NULL;
 159
 160     if (!a)
 161         return NULL;
 162     if ((bntmp = ASN1_INTEGER_to_BN(a, NULL)) == NULL
 163         || (strtmp = bignum_to_string(bntmp)) == NULL)
 164         X509V3err(X509V3_F_I2S_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
 165     BN_free(bntmp);
 166     return strtmp;
 167 }
 168
 169 ASN1_INTEGER *s2i_ASN1_INTEGER(X509V3_EXT_METHOD *method, const char *value)
 170 {
 171     BIGNUM *bn = NULL;
 172     ASN1_INTEGER *aint;
 173     int isneg, ishex;
 174     int ret;
 175     if (value == NULL) {
 176         X509V3err(X509V3_F_S2I_ASN1_INTEGER, X509V3_R_INVALID_NULL_VALUE);
 177         return NULL;
 178     }
 179     bn = BN_new();
 180     if (bn == NULL) {
 181         X509V3err(X509V3_F_S2I_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
 182         return NULL;
 183     }
 184     if (value[0] == '-') {
 185         value++;
 186         isneg = 1;
 187     } else
 188         isneg = 0;
 189
 190     if (value[0] == '0' && ((value[1] == 'x') || (value[1] == 'X'))) {
 191         value += 2;
 192         ishex = 1;
 193     } else
 194         ishex = 0;
 195
 196     if (ishex)
 197         ret = BN_hex2bn(&bn, value);
 198     else
 199         ret = BN_dec2bn(&bn, value);
 200
 201     if (!ret || value[ret]) {
 202         BN_free(bn);
 203         X509V3err(X509V3_F_S2I_ASN1_INTEGER, X509V3_R_BN_DEC2BN_ERROR);
 204         return NULL;
 205     }
 206
 207     if (isneg && BN_is_zero(bn))
 208         isneg = 0;
 209
 210     aint = BN_to_ASN1_INTEGER(bn, NULL);
 211     BN_free(bn);
 212     if (!aint) {
 213         X509V3err(X509V3_F_S2I_ASN1_INTEGER,
 214                   X509V3_R_BN_TO_ASN1_INTEGER_ERROR);
 215         return NULL;
 216     }
 217     if (isneg)
 218         aint->type |= V_ASN1_NEG;
 219     return aint;
 220 }
 221
 222 int X509V3_add_value_int(const char *name, const ASN1_INTEGER *aint,
 223                          STACK_OF(CONF_VALUE) **extlist)
 224 {
 225     char *strtmp;
 226     int ret;
 227
 228     if (!aint)
 229         return 1;
 230     if ((strtmp = i2s_ASN1_INTEGER(NULL, aint)) == NULL)
 231         return 0;
 232     ret = X509V3_add_value(name, strtmp, extlist);
 233     OPENSSL_free(strtmp);
 234     return ret;
 235 }
 236
 237 int X509V3_get_value_bool(const CONF_VALUE *value, int *asn1_bool)
 238 {
 239     const char *btmp;
 240
 241     if ((btmp = value->value) == NULL)
 242         goto err;
 243     if (strcmp(btmp, "TRUE") == 0
 244         || strcmp(btmp, "true") == 0
 245         || strcmp(btmp, "Y") == 0
 246         || strcmp(btmp, "y") == 0
 247         || strcmp(btmp, "YES") == 0
 248         || strcmp(btmp, "yes") == 0) {
 249         *asn1_bool = 0xff;
 250         return 1;
 251     }
 252     if (strcmp(btmp, "FALSE") == 0
 253         || strcmp(btmp, "false") == 0
 254         || strcmp(btmp, "N") == 0
 255         || strcmp(btmp, "n") == 0
 256         || strcmp(btmp, "NO") == 0
 257         || strcmp(btmp, "no") == 0) {
 258         *asn1_bool = 0;
 259         return 1;
 260     }
 261  err:
 262     X509V3err(X509V3_F_X509V3_GET_VALUE_BOOL,
 263               X509V3_R_INVALID_BOOLEAN_STRING);
 264     X509V3_conf_err(value);
 265     return 0;
 266 }
 267
 268 int X509V3_get_value_int(const CONF_VALUE *value, ASN1_INTEGER **aint)
 269 {
 270     ASN1_INTEGER *itmp;
 271
 272     if ((itmp = s2i_ASN1_INTEGER(NULL, value->value)) == NULL) {
 273         X509V3_conf_err(value);
 274         return 0;
 275     }
 276     *aint = itmp;
 277     return 1;
 278 }
 279
 280 #define HDR_NAME        1
 281 #define HDR_VALUE       2
 282
 283 /*
 284  * #define DEBUG
 285  */
 286
 287 STACK_OF(CONF_VALUE) *X509V3_parse_list(const char *line)
 288 {
 289     char *p, *q, c;
 290     char *ntmp, *vtmp;
 291     STACK_OF(CONF_VALUE) *values = NULL;
 292     char *linebuf;
 293     int state;
 294     /* We are going to modify the line so copy it first */
 295     linebuf = OPENSSL_strdup(line);
 296     if (linebuf == NULL) {
 297         X509V3err(X509V3_F_X509V3_PARSE_LIST, ERR_R_MALLOC_FAILURE);
 298         goto err;
 299     }
 300     state = HDR_NAME;
 301     ntmp = NULL;
 302     /* Go through all characters */
 303     for (p = linebuf, q = linebuf; (c = *p) && (c != '\r') && (c != '\n');
 304          p++) {
 305
 306         switch (state) {
 307         case HDR_NAME:
 308             if (c == ':') {
 309                 state = HDR_VALUE;
 310                 *p = 0;
 311                 ntmp = strip_spaces(q);
 312                 if (!ntmp) {
 313                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 314                               X509V3_R_INVALID_NULL_NAME);
 315                     goto err;
 316                 }
 317                 q = p + 1;
 318             } else if (c == ',') {
 319                 *p = 0;
 320                 ntmp = strip_spaces(q);
 321                 q = p + 1;
 322                 if (!ntmp) {
 323                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 324                               X509V3_R_INVALID_NULL_NAME);
 325                     goto err;
 326                 }
 327                 X509V3_add_value(ntmp, NULL, &values);
 328             }
 329             break;
 330
 331         case HDR_VALUE:
 332             if (c == ',') {
 333                 state = HDR_NAME;
 334                 *p = 0;
 335                 vtmp = strip_spaces(q);
 336                 if (!vtmp) {
 337                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 338                               X509V3_R_INVALID_NULL_VALUE);
 339                     goto err;
 340                 }
 341                 X509V3_add_value(ntmp, vtmp, &values);
 342                 ntmp = NULL;
 343                 q = p + 1;
 344             }
 345
 346         }
 347     }
 348
 349     if (state == HDR_VALUE) {
 350         vtmp = strip_spaces(q);
 351         if (!vtmp) {
 352             X509V3err(X509V3_F_X509V3_PARSE_LIST,
 353                       X509V3_R_INVALID_NULL_VALUE);
 354             goto err;
 355         }
 356         X509V3_add_value(ntmp, vtmp, &values);
 357     } else {
 358         ntmp = strip_spaces(q);
 359         if (!ntmp) {
 360             X509V3err(X509V3_F_X509V3_PARSE_LIST, X509V3_R_INVALID_NULL_NAME);
 361             goto err;
 362         }
 363         X509V3_add_value(ntmp, NULL, &values);
 364     }
 365     OPENSSL_free(linebuf);
 366     return values;
 367
 368  err:
 369     OPENSSL_free(linebuf);
 370     sk_CONF_VALUE_pop_free(values, X509V3_conf_free);
 371     return NULL;
 372
 373 }
 374
 375 /* Delete leading and trailing spaces from a string */
 376 static char *strip_spaces(char *name)
 377 {
 378     char *p, *q;
 379     /* Skip over leading spaces */
 380     p = name;
 381     while (*p && ossl_isspace(*p))
 382         p++;
 383     if (!*p)
 384         return NULL;
 385     q = p + strlen(p) - 1;
 386     while ((q != p) && ossl_isspace(*q))
 387         q--;
 388     if (p != q)
 389         q[1] = 0;
 390     if (!*p)
 391         return NULL;
 392     return p;
 393 }
 394
 395
 396 /*
 397  * V2I name comparison function: returns zero if 'name' matches cmp or cmp.*
 398  */
 399
 400 int name_cmp(const char *name, const char *cmp)
 401 {
 402     int len, ret;
 403     char c;
 404     len = strlen(cmp);
 405     if ((ret = strncmp(name, cmp, len)))
 406         return ret;
 407     c = name[len];
 408     if (!c || (c == '.'))
 409         return 0;
 410     return 1;
 411 }
 412
 413 static int sk_strcmp(const char *const *a, const char *const *b)
 414 {
 415     return strcmp(*a, *b);
 416 }
 417
 418 STACK_OF(OPENSSL_STRING) *X509_get1_email(X509 *x)
 419 {
 420     GENERAL_NAMES *gens;
 421     STACK_OF(OPENSSL_STRING) *ret;
 422
 423     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 424     ret = get_email(X509_get_subject_name(x), gens);
 425     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 426     return ret;
 427 }
 428
 429 STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x)
 430 {
 431     AUTHORITY_INFO_ACCESS *info;
 432     STACK_OF(OPENSSL_STRING) *ret = NULL;
 433     int i;
 434
 435     info = X509_get_ext_d2i(x, NID_info_access, NULL, NULL);
 436     if (!info)
 437         return NULL;
 438     for (i = 0; i < sk_ACCESS_DESCRIPTION_num(info); i++) {
 439         ACCESS_DESCRIPTION *ad = sk_ACCESS_DESCRIPTION_value(info, i);
 440         if (OBJ_obj2nid(ad->method) == NID_ad_OCSP) {
 441             if (ad->location->type == GEN_URI) {
 442                 if (!append_ia5
 443                     (&ret, ad->location->d.uniformResourceIdentifier))
 444                     break;
 445             }
 446         }
 447     }
 448     AUTHORITY_INFO_ACCESS_free(info);
 449     return ret;
 450 }
 451
 452 STACK_OF(OPENSSL_STRING) *X509_REQ_get1_email(X509_REQ *x)
 453 {
 454     GENERAL_NAMES *gens;
 455     STACK_OF(X509_EXTENSION) *exts;
 456     STACK_OF(OPENSSL_STRING) *ret;
 457
 458     exts = X509_REQ_get_extensions(x);
 459     gens = X509V3_get_d2i(exts, NID_subject_alt_name, NULL, NULL);
 460     ret = get_email(X509_REQ_get_subject_name(x), gens);
 461     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 462     sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
 463     return ret;
 464 }
 465
 466 static STACK_OF(OPENSSL_STRING) *get_email(X509_NAME *name,
 467                                            GENERAL_NAMES *gens)
 468 {
 469     STACK_OF(OPENSSL_STRING) *ret = NULL;
 470     X509_NAME_ENTRY *ne;
 471     const ASN1_IA5STRING *email;
 472     GENERAL_NAME *gen;
 473     int i = -1;
 474
 475     /* Now add any email address(es) to STACK */
 476     /* First supplied X509_NAME */
 477     while ((i = X509_NAME_get_index_by_NID(name,
 478                                            NID_pkcs9_emailAddress, i)) >= 0) {
 479         ne = X509_NAME_get_entry(name, i);
 480         email = X509_NAME_ENTRY_get_data(ne);
 481         if (!append_ia5(&ret, email))
 482             return NULL;
 483     }
 484     for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 485         gen = sk_GENERAL_NAME_value(gens, i);
 486         if (gen->type != GEN_EMAIL)
 487             continue;
 488         if (!append_ia5(&ret, gen->d.ia5))
 489             return NULL;
 490     }
 491     return ret;
 492 }
 493
 494 static void str_free(OPENSSL_STRING str)
 495 {
 496     OPENSSL_free(str);
 497 }
 498
 499 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk, const ASN1_IA5STRING *email)
 500 {
 501     char *emtmp;
 502     /* First some sanity checks */
 503     if (email->type != V_ASN1_IA5STRING)
 504         return 1;
 505     if (!email->data || !email->length)
 506         return 1;
 507     if (*sk == NULL)
 508         *sk = sk_OPENSSL_STRING_new(sk_strcmp);
 509     if (*sk == NULL)
 510         return 0;
 511     /* Don't add duplicates */
 512     if (sk_OPENSSL_STRING_find(*sk, (char *)email->data) != -1)
 513         return 1;
 514     emtmp = OPENSSL_strdup((char *)email->data);
 515     if (emtmp == NULL || !sk_OPENSSL_STRING_push(*sk, emtmp)) {
 516         OPENSSL_free(emtmp);    /* free on push failure */
 517         X509_email_free(*sk);
 518         *sk = NULL;
 519         return 0;
 520     }
 521     return 1;
 522 }
 523
 524 void X509_email_free(STACK_OF(OPENSSL_STRING) *sk)
 525 {
 526     sk_OPENSSL_STRING_pop_free(sk, str_free);
 527 }
 528
 529 typedef int (*equal_fn) (const unsigned char *pattern, size_t pattern_len,
 530                          const unsigned char *subject, size_t subject_len,
 531                          unsigned int flags);
 532
 533 /* Skip pattern prefix to match "wildcard" subject */
 534 static void skip_prefix(const unsigned char **p, size_t *plen,
 535                         size_t subject_len,
 536                         unsigned int flags)
 537 {
 538     const unsigned char *pattern = *p;
 539     size_t pattern_len = *plen;
 540
 541     /*
 542      * If subject starts with a leading '.' followed by more octets, and
 543      * pattern is longer, compare just an equal-length suffix with the
 544      * full subject (starting at the '.'), provided the prefix contains
 545      * no NULs.
 546      */
 547     if ((flags & _X509_CHECK_FLAG_DOT_SUBDOMAINS) == 0)
 548         return;
 549
 550     while (pattern_len > subject_len && *pattern) {
 551         if ((flags & X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS) &&
 552             *pattern == '.')
 553             break;
 554         ++pattern;
 555         --pattern_len;
 556     }
 557
 558     /* Skip if entire prefix acceptable */
 559     if (pattern_len == subject_len) {
 560         *p = pattern;
 561         *plen = pattern_len;
 562     }
 563 }
 564
 565 /* Compare while ASCII ignoring case. */
 566 static int equal_nocase(const unsigned char *pattern, size_t pattern_len,
 567                         const unsigned char *subject, size_t subject_len,
 568                         unsigned int flags)
 569 {
 570     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 571     if (pattern_len != subject_len)
 572         return 0;
 573     while (pattern_len) {
 574         unsigned char l = *pattern;
 575         unsigned char r = *subject;
 576         /* The pattern must not contain NUL characters. */
 577         if (l == 0)
 578             return 0;
 579         if (l != r) {
 580             if ('A' <= l && l <= 'Z')
 581                 l = (l - 'A') + 'a';
 582             if ('A' <= r && r <= 'Z')
 583                 r = (r - 'A') + 'a';
 584             if (l != r)
 585                 return 0;
 586         }
 587         ++pattern;
 588         ++subject;
 589         --pattern_len;
 590     }
 591     return 1;
 592 }
 593
 594 /* Compare using memcmp. */
 595 static int equal_case(const unsigned char *pattern, size_t pattern_len,
 596                       const unsigned char *subject, size_t subject_len,
 597                       unsigned int flags)
 598 {
 599     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 600     if (pattern_len != subject_len)
 601         return 0;
 602     return !memcmp(pattern, subject, pattern_len);
 603 }
 604
 605 /*
 606  * RFC 5280, section 7.5, requires that only the domain is compared in a
 607  * case-insensitive manner.
 608  */
 609 static int equal_email(const unsigned char *a, size_t a_len,
 610                        const unsigned char *b, size_t b_len,
 611                        unsigned int unused_flags)
 612 {
 613     size_t i = a_len;
 614     if (a_len != b_len)
 615         return 0;
 616     /*
 617      * We search backwards for the '@' character, so that we do not have to
 618      * deal with quoted local-parts.  The domain part is compared in a
 619      * case-insensitive manner.
 620      */
 621     while (i > 0) {
 622         --i;
 623         if (a[i] == '@' || b[i] == '@') {
 624             if (!equal_nocase(a + i, a_len - i, b + i, a_len - i, 0))
 625                 return 0;
 626             break;
 627         }
 628     }
 629     if (i == 0)
 630         i = a_len;
 631     return equal_case(a, i, b, i, 0);
 632 }
 633
 634 /*
 635  * Compare the prefix and suffix with the subject, and check that the
 636  * characters in-between are valid.
 637  */
 638 static int wildcard_match(const unsigned char *prefix, size_t prefix_len,
 639                           const unsigned char *suffix, size_t suffix_len,
 640                           const unsigned char *subject, size_t subject_len,
 641                           unsigned int flags)
 642 {
 643     const unsigned char *wildcard_start;
 644     const unsigned char *wildcard_end;
 645     const unsigned char *p;
 646     int allow_multi = 0;
 647     int allow_idna = 0;
 648
 649     if (subject_len < prefix_len + suffix_len)
 650         return 0;
 651     if (!equal_nocase(prefix, prefix_len, subject, prefix_len, flags))
 652         return 0;
 653     wildcard_start = subject + prefix_len;
 654     wildcard_end = subject + (subject_len - suffix_len);
 655     if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len, flags))
 656         return 0;
 657     /*
 658      * If the wildcard makes up the entire first label, it must match at
 659      * least one character.
 660      */
 661     if (prefix_len == 0 && *suffix == '.') {
 662         if (wildcard_start == wildcard_end)
 663             return 0;
 664         allow_idna = 1;
 665         if (flags & X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS)
 666             allow_multi = 1;
 667     }
 668     /* IDNA labels cannot match partial wildcards */
 669     if (!allow_idna &&
 670         subject_len >= 4 && strncasecmp((char *)subject, "xn--", 4) == 0)
 671         return 0;
 672     /* The wildcard may match a literal '*' */
 673     if (wildcard_end == wildcard_start + 1 && *wildcard_start == '*')
 674         return 1;
 675     /*
 676      * Check that the part matched by the wildcard contains only
 677      * permitted characters and only matches a single label unless
 678      * allow_multi is set.
 679      */
 680     for (p = wildcard_start; p != wildcard_end; ++p)
 681         if (!(('0' <= *p && *p <= '9') ||
 682               ('A' <= *p && *p <= 'Z') ||
 683               ('a' <= *p && *p <= 'z') ||
 684               *p == '-' || (allow_multi && *p == '.')))
 685             return 0;
 686     return 1;
 687 }
 688
 689 #define LABEL_START     (1 << 0)
 690 #define LABEL_END       (1 << 1)
 691 #define LABEL_HYPHEN    (1 << 2)
 692 #define LABEL_IDNA      (1 << 3)
 693
 694 static const unsigned char *valid_star(const unsigned char *p, size_t len,
 695                                        unsigned int flags)
 696 {
 697     const unsigned char *star = 0;
 698     size_t i;
 699     int state = LABEL_START;
 700     int dots = 0;
 701     for (i = 0; i < len; ++i) {
 702         /*
 703          * Locate first and only legal wildcard, either at the start
 704          * or end of a non-IDNA first and not final label.
 705          */
 706         if (p[i] == '*') {
 707             int atstart = (state & LABEL_START);
 708             int atend = (i == len - 1 || p[i + 1] == '.');
 709             /*-
 710              * At most one wildcard per pattern.
 711              * No wildcards in IDNA labels.
 712              * No wildcards after the first label.
 713              */
 714             if (star != NULL || (state & LABEL_IDNA) != 0 || dots)
 715                 return NULL;
 716             /* Only full-label '*.example.com' wildcards? */
 717             if ((flags & X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)
 718                 && (!atstart || !atend))
 719                 return NULL;
 720             /* No 'foo*bar' wildcards */
 721             if (!atstart && !atend)
 722                 return NULL;
 723             star = &p[i];
 724             state &= ~LABEL_START;
 725         } else if (('a' <= p[i] && p[i] <= 'z')
 726                    || ('A' <= p[i] && p[i] <= 'Z')
 727                    || ('0' <= p[i] && p[i] <= '9')) {
 728             if ((state & LABEL_START) != 0
 729                 && len - i >= 4 && strncasecmp((char *)&p[i], "xn--", 4) == 0)
 730                 state |= LABEL_IDNA;
 731             state &= ~(LABEL_HYPHEN | LABEL_START);
 732         } else if (p[i] == '.') {
 733             if ((state & (LABEL_HYPHEN | LABEL_START)) != 0)
 734                 return NULL;
 735             state = LABEL_START;
 736             ++dots;
 737         } else if (p[i] == '-') {
 738             /* no domain/subdomain starts with '-' */
 739             if ((state & LABEL_START) != 0)
 740                 return NULL;
 741             state |= LABEL_HYPHEN;
 742         } else
 743             return NULL;
 744     }
 745
 746     /*
 747      * The final label must not end in a hyphen or ".", and
 748      * there must be at least two dots after the star.
 749      */
 750     if ((state & (LABEL_START | LABEL_HYPHEN)) != 0 || dots < 2)
 751         return NULL;
 752     return star;
 753 }
 754
 755 /* Compare using wildcards. */
 756 static int equal_wildcard(const unsigned char *pattern, size_t pattern_len,
 757                           const unsigned char *subject, size_t subject_len,
 758                           unsigned int flags)
 759 {
 760     const unsigned char *star = NULL;
 761
 762     /*
 763      * Subject names starting with '.' can only match a wildcard pattern
 764      * via a subject sub-domain pattern suffix match.
 765      */
 766     if (!(subject_len > 1 && subject[0] == '.'))
 767         star = valid_star(pattern, pattern_len, flags);
 768     if (star == NULL)
 769         return equal_nocase(pattern, pattern_len,
 770                             subject, subject_len, flags);
 771     return wildcard_match(pattern, star - pattern,
 772                           star + 1, (pattern + pattern_len) - star - 1,
 773                           subject, subject_len, flags);
 774 }
 775
 776 /*
 777  * Compare an ASN1_STRING to a supplied string. If they match return 1. If
 778  * cmp_type > 0 only compare if string matches the type, otherwise convert it
 779  * to UTF8.
 780  */
 781
 782 static int do_check_string(const ASN1_STRING *a, int cmp_type, equal_fn equal,
 783                            unsigned int flags, const char *b, size_t blen,
 784                            char **peername)
 785 {
 786     int rv = 0;
 787
 788     if (!a->data || !a->length)
 789         return 0;
 790     if (cmp_type > 0) {
 791         if (cmp_type != a->type)
 792             return 0;
 793         if (cmp_type == V_ASN1_IA5STRING)
 794             rv = equal(a->data, a->length, (unsigned char *)b, blen, flags);
 795         else if (a->length == (int)blen && !memcmp(a->data, b, blen))
 796             rv = 1;
 797         if (rv > 0 && peername)
 798             *peername = OPENSSL_strndup((char *)a->data, a->length);
 799     } else {
 800         int astrlen;
 801         unsigned char *astr;
 802         astrlen = ASN1_STRING_to_UTF8(&astr, a);
 803         if (astrlen < 0) {
 804             /*
 805              * -1 could be an internal malloc failure or a decoding error from
 806              * malformed input; we can't distinguish.
 807              */
 808             return -1;
 809         }
 810         rv = equal(astr, astrlen, (unsigned char *)b, blen, flags);
 811         if (rv > 0 && peername)
 812             *peername = OPENSSL_strndup((char *)astr, astrlen);
 813         OPENSSL_free(astr);
 814     }
 815     return rv;
 816 }
 817
 818 static int do_x509_check(X509 *x, const char *chk, size_t chklen,
 819                          unsigned int flags, int check_type, char **peername)
 820 {
 821     GENERAL_NAMES *gens = NULL;
 822     X509_NAME *name = NULL;
 823     int i;
 824     int cnid = NID_undef;
 825     int alt_type;
 826     int san_present = 0;
 827     int rv = 0;
 828     equal_fn equal;
 829
 830     /* See below, this flag is internal-only */
 831     flags &= ~_X509_CHECK_FLAG_DOT_SUBDOMAINS;
 832     if (check_type == GEN_EMAIL) {
 833         cnid = NID_pkcs9_emailAddress;
 834         alt_type = V_ASN1_IA5STRING;
 835         equal = equal_email;
 836     } else if (check_type == GEN_DNS) {
 837         cnid = NID_commonName;
 838         /* Implicit client-side DNS sub-domain pattern */
 839         if (chklen > 1 && chk[0] == '.')
 840             flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;
 841         alt_type = V_ASN1_IA5STRING;
 842         if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
 843             equal = equal_nocase;
 844         else
 845             equal = equal_wildcard;
 846     } else {
 847         alt_type = V_ASN1_OCTET_STRING;
 848         equal = equal_case;
 849     }
 850
 851     if (chklen == 0)
 852         chklen = strlen(chk);
 853
 854     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 855     if (gens) {
 856         for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 857             GENERAL_NAME *gen;
 858             ASN1_STRING *cstr;
 859             gen = sk_GENERAL_NAME_value(gens, i);
 860             if (gen->type != check_type)
 861                 continue;
 862             san_present = 1;
 863             if (check_type == GEN_EMAIL)
 864                 cstr = gen->d.rfc822Name;
 865             else if (check_type == GEN_DNS)
 866                 cstr = gen->d.dNSName;
 867             else
 868                 cstr = gen->d.iPAddress;
 869             /* Positive on success, negative on error! */
 870             if ((rv = do_check_string(cstr, alt_type, equal, flags,
 871                                       chk, chklen, peername)) != 0)
 872                 break;
 873         }
 874         GENERAL_NAMES_free(gens);
 875         if (rv != 0)
 876             return rv;
 877         if (san_present && !(flags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT))
 878             return 0;
 879     }
 880
 881     /* We're done if CN-ID is not pertinent */
 882     if (cnid == NID_undef || (flags & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT))
 883         return 0;
 884
 885     i = -1;
 886     name = X509_get_subject_name(x);
 887     while ((i = X509_NAME_get_index_by_NID(name, cnid, i)) >= 0) {
 888         const X509_NAME_ENTRY *ne = X509_NAME_get_entry(name, i);
 889         const ASN1_STRING *str = X509_NAME_ENTRY_get_data(ne);
 890
 891         /* Positive on success, negative on error! */
 892         if ((rv = do_check_string(str, -1, equal, flags,
 893                                   chk, chklen, peername)) != 0)
 894             return rv;
 895     }
 896     return 0;
 897 }
 898
 899 int X509_check_host(X509 *x, const char *chk, size_t chklen,
 900                     unsigned int flags, char **peername)
 901 {
 902     if (chk == NULL)
 903         return -2;
 904     /*
 905      * Embedded NULs are disallowed, except as the last character of a
 906      * string of length 2 or more (tolerate caller including terminating
 907      * NUL in string length).
 908      */
 909     if (chklen == 0)
 910         chklen = strlen(chk);
 911     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 912         return -2;
 913     if (chklen > 1 && chk[chklen - 1] == '\0')
 914         --chklen;
 915     return do_x509_check(x, chk, chklen, flags, GEN_DNS, peername);
 916 }
 917
 918 int X509_check_email(X509 *x, const char *chk, size_t chklen,
 919                      unsigned int flags)
 920 {
 921     if (chk == NULL)
 922         return -2;
 923     /*
 924      * Embedded NULs are disallowed, except as the last character of a
 925      * string of length 2 or more (tolerate caller including terminating
 926      * NUL in string length).
 927      */
 928     if (chklen == 0)
 929         chklen = strlen((char *)chk);
 930     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 931         return -2;
 932     if (chklen > 1 && chk[chklen - 1] == '\0')
 933         --chklen;
 934     return do_x509_check(x, chk, chklen, flags, GEN_EMAIL, NULL);
 935 }
 936
 937 int X509_check_ip(X509 *x, const unsigned char *chk, size_t chklen,
 938                   unsigned int flags)
 939 {
 940     if (chk == NULL)
 941         return -2;
 942     return do_x509_check(x, (char *)chk, chklen, flags, GEN_IPADD, NULL);
 943 }
 944
 945 int X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags)
 946 {
 947     unsigned char ipout[16];
 948     size_t iplen;
 949
 950     if (ipasc == NULL)
 951         return -2;
 952     iplen = (size_t)a2i_ipadd(ipout, ipasc);
 953     if (iplen == 0)
 954         return -2;
 955     return do_x509_check(x, (char *)ipout, iplen, flags, GEN_IPADD, NULL);
 956 }
 957
 958 /*
 959  * Convert IP addresses both IPv4 and IPv6 into an OCTET STRING compatible
 960  * with RFC3280.
 961  */
 962
 963 ASN1_OCTET_STRING *a2i_IPADDRESS(const char *ipasc)
 964 {
 965     unsigned char ipout[16];
 966     ASN1_OCTET_STRING *ret;
 967     int iplen;
 968
 969     /* If string contains a ':' assume IPv6 */
 970
 971     iplen = a2i_ipadd(ipout, ipasc);
 972
 973     if (!iplen)
 974         return NULL;
 975
 976     ret = ASN1_OCTET_STRING_new();
 977     if (ret == NULL)
 978         return NULL;
 979     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen)) {
 980         ASN1_OCTET_STRING_free(ret);
 981         return NULL;
 982     }
 983     return ret;
 984 }
 985
 986 ASN1_OCTET_STRING *a2i_IPADDRESS_NC(const char *ipasc)
 987 {
 988     ASN1_OCTET_STRING *ret = NULL;
 989     unsigned char ipout[32];
 990     char *iptmp = NULL, *p;
 991     int iplen1, iplen2;
 992     p = strchr(ipasc, '/');
 993     if (!p)
 994         return NULL;
 995     iptmp = OPENSSL_strdup(ipasc);
 996     if (!iptmp)
 997         return NULL;
 998     p = iptmp + (p - ipasc);
 999     *p++ = 0;
1000
1001     iplen1 = a2i_ipadd(ipout, iptmp);
1002
1003     if (!iplen1)
1004         goto err;
1005
1006     iplen2 = a2i_ipadd(ipout + iplen1, p);
1007
1008     OPENSSL_free(iptmp);
1009     iptmp = NULL;
1010
1011     if (!iplen2 || (iplen1 != iplen2))
1012         goto err;
1013
1014     ret = ASN1_OCTET_STRING_new();
1015     if (ret == NULL)
1016         goto err;
1017     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen1 + iplen2))
1018         goto err;
1019
1020     return ret;
1021
1022  err:
1023     OPENSSL_free(iptmp);
1024     ASN1_OCTET_STRING_free(ret);
1025     return NULL;
1026 }
1027
1028 int a2i_ipadd(unsigned char *ipout, const char *ipasc)
1029 {
1030     /* If string contains a ':' assume IPv6 */
1031
1032     if (strchr(ipasc, ':')) {
1033         if (!ipv6_from_asc(ipout, ipasc))
1034             return 0;
1035         return 16;
1036     } else {
1037         if (!ipv4_from_asc(ipout, ipasc))
1038             return 0;
1039         return 4;
1040     }
1041 }
1042
1043 static int ipv4_from_asc(unsigned char *v4, const char *in)
1044 {
1045     int a0, a1, a2, a3;
1046     if (sscanf(in, "%d.%d.%d.%d", &a0, &a1, &a2, &a3) != 4)
1047         return 0;
1048     if ((a0 < 0) || (a0 > 255) || (a1 < 0) || (a1 > 255)
1049         || (a2 < 0) || (a2 > 255) || (a3 < 0) || (a3 > 255))
1050         return 0;
1051     v4[0] = a0;
1052     v4[1] = a1;
1053     v4[2] = a2;
1054     v4[3] = a3;
1055     return 1;
1056 }
1057
1058 typedef struct {
1059     /* Temporary store for IPV6 output */
1060     unsigned char tmp[16];
1061     /* Total number of bytes in tmp */
1062     int total;
1063     /* The position of a zero (corresponding to '::') */
1064     int zero_pos;
1065     /* Number of zeroes */
1066     int zero_cnt;
1067 } IPV6_STAT;
1068
1069 static int ipv6_from_asc(unsigned char *v6, const char *in)
1070 {
1071     IPV6_STAT v6stat;
1072     v6stat.total = 0;
1073     v6stat.zero_pos = -1;
1074     v6stat.zero_cnt = 0;
1075     /*
1076      * Treat the IPv6 representation as a list of values separated by ':'.
1077      * The presence of a '::' will parse as one, two or three zero length
1078      * elements.
1079      */
1080     if (!CONF_parse_list(in, ':', 0, ipv6_cb, &v6stat))
1081         return 0;
1082
1083     /* Now for some sanity checks */
1084
1085     if (v6stat.zero_pos == -1) {
1086         /* If no '::' must have exactly 16 bytes */
1087         if (v6stat.total != 16)
1088             return 0;
1089     } else {
1090         /* If '::' must have less than 16 bytes */
1091         if (v6stat.total == 16)
1092             return 0;
1093         /* More than three zeroes is an error */
1094         if (v6stat.zero_cnt > 3)
1095             return 0;
1096         /* Can only have three zeroes if nothing else present */
1097         else if (v6stat.zero_cnt == 3) {
1098             if (v6stat.total > 0)
1099                 return 0;
1100         }
1101         /* Can only have two zeroes if at start or end */
1102         else if (v6stat.zero_cnt == 2) {
1103             if ((v6stat.zero_pos != 0)
1104                 && (v6stat.zero_pos != v6stat.total))
1105                 return 0;
1106         } else
1107             /* Can only have one zero if *not* start or end */
1108         {
1109             if ((v6stat.zero_pos == 0)
1110                 || (v6stat.zero_pos == v6stat.total))
1111                 return 0;
1112         }
1113     }
1114
1115     /* Format result */
1116
1117     if (v6stat.zero_pos >= 0) {
1118         /* Copy initial part */
1119         memcpy(v6, v6stat.tmp, v6stat.zero_pos);
1120         /* Zero middle */
1121         memset(v6 + v6stat.zero_pos, 0, 16 - v6stat.total);
1122         /* Copy final part */
1123         if (v6stat.total != v6stat.zero_pos)
1124             memcpy(v6 + v6stat.zero_pos + 16 - v6stat.total,
1125                    v6stat.tmp + v6stat.zero_pos,
1126                    v6stat.total - v6stat.zero_pos);
1127     } else
1128         memcpy(v6, v6stat.tmp, 16);
1129
1130     return 1;
1131 }
1132
1133 static int ipv6_cb(const char *elem, int len, void *usr)
1134 {
1135     IPV6_STAT *s = usr;
1136     /* Error if 16 bytes written */
1137     if (s->total == 16)
1138         return 0;
1139     if (len == 0) {
1140         /* Zero length element, corresponds to '::' */
1141         if (s->zero_pos == -1)
1142             s->zero_pos = s->total;
1143         /* If we've already got a :: its an error */
1144         else if (s->zero_pos != s->total)
1145             return 0;
1146         s->zero_cnt++;
1147     } else {
1148         /* If more than 4 characters could be final a.b.c.d form */
1149         if (len > 4) {
1150             /* Need at least 4 bytes left */
1151             if (s->total > 12)
1152                 return 0;
1153             /* Must be end of string */
1154             if (elem[len])
1155                 return 0;
1156             if (!ipv4_from_asc(s->tmp + s->total, elem))
1157                 return 0;
1158             s->total += 4;
1159         } else {
1160             if (!ipv6_hex(s->tmp + s->total, elem, len))
1161                 return 0;
1162             s->total += 2;
1163         }
1164     }
1165     return 1;
1166 }
1167
1168 /*
1169  * Convert a string of up to 4 hex digits into the corresponding IPv6 form.
1170  */
1171
1172 static int ipv6_hex(unsigned char *out, const char *in, int inlen)
1173 {
1174     unsigned char c;
1175     unsigned int num = 0;
1176     int x;
1177
1178     if (inlen > 4)
1179         return 0;
1180     while (inlen--) {
1181         c = *in++;
1182         num <<= 4;
1183         x = OPENSSL_hexchar2int(c);
1184         if (x < 0)
1185             return 0;
1186         num |= (char)x;
1187     }
1188     out[0] = num >> 8;
1189     out[1] = num & 0xff;
1190     return 1;
1191 }
1192
1193 int X509V3_NAME_from_section(X509_NAME *nm, STACK_OF(CONF_VALUE) *dn_sk,
1194                              unsigned long chtype)
1195 {
1196     CONF_VALUE *v;
1197     int i, mval, spec_char, plus_char;
1198     char *p, *type;
1199     if (!nm)
1200         return 0;
1201
1202     for (i = 0; i < sk_CONF_VALUE_num(dn_sk); i++) {
1203         v = sk_CONF_VALUE_value(dn_sk, i);
1204         type = v->name;
1205         /*
1206          * Skip past any leading X. X: X, etc to allow for multiple instances
1207          */
1208         for (p = type; *p; p++) {
1209 #ifndef CHARSET_EBCDIC
1210             spec_char = ((*p == ':') || (*p == ',') || (*p == '.'));
1211 #else
1212             spec_char = ((*p == os_toascii[':']) || (*p == os_toascii[','])
1213                     || (*p == os_toascii['.']));
1214 #endif
1215             if (spec_char) {
1216                 p++;
1217                 if (*p)
1218                     type = p;
1219                 break;
1220             }
1221         }
1222 #ifndef CHARSET_EBCDIC
1223         plus_char = (*type == '+');
1224 #else
1225         plus_char = (*type == os_toascii['+']);
1226 #endif
1227         if (plus_char) {
1228             mval = -1;
1229             type++;
1230         } else
1231             mval = 0;
1232         if (!X509_NAME_add_entry_by_txt(nm, type, chtype,
1233                                         (unsigned char *)v->value, -1, -1,
1234                                         mval))
1235             return 0;
1236
1237     }
1238     return 1;
1239 }