crypto/x509/v3_utl.c

   1 /*
   2  * Copyright 1999-2020 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 "crypto/ctype.h"
  16 #include <openssl/conf.h>
  17 #include <openssl/crypto.h>
  18 #include <openssl/x509v3.h>
  19 #include "crypto/x509.h"
  20 #include <openssl/bn.h>
  21 #include "ext_dat.h"
  22 #include "x509_local.h"
  23
  24 DEFINE_STACK_OF(CONF_VALUE)
  25
  26 static char *strip_spaces(char *name);
  27 static int sk_strcmp(const char *const *a, const char *const *b);
  28 static STACK_OF(OPENSSL_STRING) *get_email(const X509_NAME *name,
  29                                            GENERAL_NAMES *gens);
  30 static void str_free(OPENSSL_STRING str);
  31 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk,
  32                       const ASN1_IA5STRING *email);
  33
  34 static int ipv4_from_asc(unsigned char *v4, const char *in);
  35 static int ipv6_from_asc(unsigned char *v6, const char *in);
  36 static int ipv6_cb(const char *elem, int len, void *usr);
  37 static int ipv6_hex(unsigned char *out, const char *in, int inlen);
  38
  39 /* Add a CONF_VALUE name value pair to stack */
  40
  41 int X509V3_add_value(const char *name, const char *value,
  42                      STACK_OF(CONF_VALUE) **extlist)
  43 {
  44     CONF_VALUE *vtmp = NULL;
  45     char *tname = NULL, *tvalue = NULL;
  46     int sk_allocated = (*extlist == NULL);
  47
  48     if (name && (tname = OPENSSL_strdup(name)) == NULL)
  49         goto err;
  50     if (value && (tvalue = OPENSSL_strdup(value)) == NULL)
  51         goto err;
  52     if ((vtmp = OPENSSL_malloc(sizeof(*vtmp))) == NULL)
  53         goto err;
  54     if (sk_allocated && (*extlist = sk_CONF_VALUE_new_null()) == NULL)
  55         goto err;
  56     vtmp->section = NULL;
  57     vtmp->name = tname;
  58     vtmp->value = tvalue;
  59     if (!sk_CONF_VALUE_push(*extlist, vtmp))
  60         goto err;
  61     return 1;
  62  err:
  63     X509V3err(X509V3_F_X509V3_ADD_VALUE, ERR_R_MALLOC_FAILURE);
  64     if (sk_allocated) {
  65         sk_CONF_VALUE_free(*extlist);
  66         *extlist = NULL;
  67     }
  68     OPENSSL_free(vtmp);
  69     OPENSSL_free(tname);
  70     OPENSSL_free(tvalue);
  71     return 0;
  72 }
  73
  74 int X509V3_add_value_uchar(const char *name, const unsigned char *value,
  75                            STACK_OF(CONF_VALUE) **extlist)
  76 {
  77     return X509V3_add_value(name, (const char *)value, extlist);
  78 }
  79
  80 /* Free function for STACK_OF(CONF_VALUE) */
  81
  82 void X509V3_conf_free(CONF_VALUE *conf)
  83 {
  84     if (!conf)
  85         return;
  86     OPENSSL_free(conf->name);
  87     OPENSSL_free(conf->value);
  88     OPENSSL_free(conf->section);
  89     OPENSSL_free(conf);
  90 }
  91
  92 int X509V3_add_value_bool(const char *name, int asn1_bool,
  93                           STACK_OF(CONF_VALUE) **extlist)
  94 {
  95     if (asn1_bool)
  96         return X509V3_add_value(name, "TRUE", extlist);
  97     return X509V3_add_value(name, "FALSE", extlist);
  98 }
  99
 100 int X509V3_add_value_bool_nf(const char *name, int asn1_bool,
 101                              STACK_OF(CONF_VALUE) **extlist)
 102 {
 103     if (asn1_bool)
 104         return X509V3_add_value(name, "TRUE", extlist);
 105     return 1;
 106 }
 107
 108 static char *bignum_to_string(const BIGNUM *bn)
 109 {
 110     char *tmp, *ret;
 111     size_t len;
 112
 113     /*
 114      * Display large numbers in hex and small numbers in decimal. Converting to
 115      * decimal takes quadratic time and is no more useful than hex for large
 116      * numbers.
 117      */
 118     if (BN_num_bits(bn) < 128)
 119         return BN_bn2dec(bn);
 120
 121     tmp = BN_bn2hex(bn);
 122     if (tmp == NULL)
 123         return NULL;
 124
 125     len = strlen(tmp) + 3;
 126     ret = OPENSSL_malloc(len);
 127     if (ret == NULL) {
 128         X509V3err(X509V3_F_BIGNUM_TO_STRING, ERR_R_MALLOC_FAILURE);
 129         OPENSSL_free(tmp);
 130         return NULL;
 131     }
 132
 133     /* Prepend "0x", but place it after the "-" if negative. */
 134     if (tmp[0] == '-') {
 135         OPENSSL_strlcpy(ret, "-0x", len);
 136         OPENSSL_strlcat(ret, tmp + 1, len);
 137     } else {
 138         OPENSSL_strlcpy(ret, "0x", len);
 139         OPENSSL_strlcat(ret, tmp, len);
 140     }
 141     OPENSSL_free(tmp);
 142     return ret;
 143 }
 144
 145 char *i2s_ASN1_ENUMERATED(X509V3_EXT_METHOD *method, const ASN1_ENUMERATED *a)
 146 {
 147     BIGNUM *bntmp = NULL;
 148     char *strtmp = NULL;
 149
 150     if (!a)
 151         return NULL;
 152     if ((bntmp = ASN1_ENUMERATED_to_BN(a, NULL)) == NULL
 153         || (strtmp = bignum_to_string(bntmp)) == NULL)
 154         X509V3err(X509V3_F_I2S_ASN1_ENUMERATED, ERR_R_MALLOC_FAILURE);
 155     BN_free(bntmp);
 156     return strtmp;
 157 }
 158
 159 char *i2s_ASN1_INTEGER(X509V3_EXT_METHOD *method, const ASN1_INTEGER *a)
 160 {
 161     BIGNUM *bntmp = NULL;
 162     char *strtmp = NULL;
 163
 164     if (!a)
 165         return NULL;
 166     if ((bntmp = ASN1_INTEGER_to_BN(a, NULL)) == NULL
 167         || (strtmp = bignum_to_string(bntmp)) == NULL)
 168         X509V3err(X509V3_F_I2S_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
 169     BN_free(bntmp);
 170     return strtmp;
 171 }
 172
 173 ASN1_INTEGER *s2i_ASN1_INTEGER(X509V3_EXT_METHOD *method, const char *value)
 174 {
 175     BIGNUM *bn = NULL;
 176     ASN1_INTEGER *aint;
 177     int isneg, ishex;
 178     int ret;
 179
 180     if (value == NULL) {
 181         X509V3err(X509V3_F_S2I_ASN1_INTEGER, X509V3_R_INVALID_NULL_VALUE);
 182         return NULL;
 183     }
 184     bn = BN_new();
 185     if (bn == NULL) {
 186         X509V3err(X509V3_F_S2I_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
 187         return NULL;
 188     }
 189     if (value[0] == '-') {
 190         value++;
 191         isneg = 1;
 192     } else {
 193         isneg = 0;
 194     }
 195
 196     if (value[0] == '0' && ((value[1] == 'x') || (value[1] == 'X'))) {
 197         value += 2;
 198         ishex = 1;
 199     } else {
 200         ishex = 0;
 201     }
 202
 203     if (ishex)
 204         ret = BN_hex2bn(&bn, value);
 205     else
 206         ret = BN_dec2bn(&bn, value);
 207
 208     if (!ret || value[ret]) {
 209         BN_free(bn);
 210         X509V3err(X509V3_F_S2I_ASN1_INTEGER, X509V3_R_BN_DEC2BN_ERROR);
 211         return NULL;
 212     }
 213
 214     if (isneg && BN_is_zero(bn))
 215         isneg = 0;
 216
 217     aint = BN_to_ASN1_INTEGER(bn, NULL);
 218     BN_free(bn);
 219     if (!aint) {
 220         X509V3err(X509V3_F_S2I_ASN1_INTEGER,
 221                   X509V3_R_BN_TO_ASN1_INTEGER_ERROR);
 222         return NULL;
 223     }
 224     if (isneg)
 225         aint->type |= V_ASN1_NEG;
 226     return aint;
 227 }
 228
 229 int X509V3_add_value_int(const char *name, const ASN1_INTEGER *aint,
 230                          STACK_OF(CONF_VALUE) **extlist)
 231 {
 232     char *strtmp;
 233     int ret;
 234
 235     if (!aint)
 236         return 1;
 237     if ((strtmp = i2s_ASN1_INTEGER(NULL, aint)) == NULL)
 238         return 0;
 239     ret = X509V3_add_value(name, strtmp, extlist);
 240     OPENSSL_free(strtmp);
 241     return ret;
 242 }
 243
 244 int X509V3_get_value_bool(const CONF_VALUE *value, int *asn1_bool)
 245 {
 246     const char *btmp;
 247
 248     if ((btmp = value->value) == NULL)
 249         goto err;
 250     if (strcmp(btmp, "TRUE") == 0
 251         || strcmp(btmp, "true") == 0
 252         || strcmp(btmp, "Y") == 0
 253         || strcmp(btmp, "y") == 0
 254         || strcmp(btmp, "YES") == 0
 255         || strcmp(btmp, "yes") == 0) {
 256         *asn1_bool = 0xff;
 257         return 1;
 258     }
 259     if (strcmp(btmp, "FALSE") == 0
 260         || strcmp(btmp, "false") == 0
 261         || strcmp(btmp, "N") == 0
 262         || strcmp(btmp, "n") == 0
 263         || strcmp(btmp, "NO") == 0
 264         || strcmp(btmp, "no") == 0) {
 265         *asn1_bool = 0;
 266         return 1;
 267     }
 268  err:
 269     X509V3err(X509V3_F_X509V3_GET_VALUE_BOOL,
 270               X509V3_R_INVALID_BOOLEAN_STRING);
 271     X509V3_conf_add_error_name_value(value);
 272     return 0;
 273 }
 274
 275 int X509V3_get_value_int(const CONF_VALUE *value, ASN1_INTEGER **aint)
 276 {
 277     ASN1_INTEGER *itmp;
 278
 279     if ((itmp = s2i_ASN1_INTEGER(NULL, value->value)) == NULL) {
 280         X509V3_conf_add_error_name_value(value);
 281         return 0;
 282     }
 283     *aint = itmp;
 284     return 1;
 285 }
 286
 287 #define HDR_NAME        1
 288 #define HDR_VALUE       2
 289
 290 /*
 291  * #define DEBUG
 292  */
 293
 294 STACK_OF(CONF_VALUE) *X509V3_parse_list(const char *line)
 295 {
 296     char *p, *q, c;
 297     char *ntmp, *vtmp;
 298     STACK_OF(CONF_VALUE) *values = NULL;
 299     char *linebuf;
 300     int state;
 301
 302     /* We are going to modify the line so copy it first */
 303     linebuf = OPENSSL_strdup(line);
 304     if (linebuf == NULL) {
 305         X509V3err(X509V3_F_X509V3_PARSE_LIST, ERR_R_MALLOC_FAILURE);
 306         goto err;
 307     }
 308     state = HDR_NAME;
 309     ntmp = NULL;
 310     /* Go through all characters */
 311     for (p = linebuf, q = linebuf; (c = *p) && (c != '\r') && (c != '\n');
 312          p++) {
 313
 314         switch (state) {
 315         case HDR_NAME:
 316             if (c == ':') {
 317                 state = HDR_VALUE;
 318                 *p = 0;
 319                 ntmp = strip_spaces(q);
 320                 if (!ntmp) {
 321                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 322                               X509V3_R_INVALID_EMPTY_NAME);
 323                     goto err;
 324                 }
 325                 q = p + 1;
 326             } else if (c == ',') {
 327                 *p = 0;
 328                 ntmp = strip_spaces(q);
 329                 q = p + 1;
 330                 if (!ntmp) {
 331                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 332                               X509V3_R_INVALID_EMPTY_NAME);
 333                     goto err;
 334                 }
 335                 X509V3_add_value(ntmp, NULL, &values);
 336             }
 337             break;
 338
 339         case HDR_VALUE:
 340             if (c == ',') {
 341                 state = HDR_NAME;
 342                 *p = 0;
 343                 vtmp = strip_spaces(q);
 344                 if (!vtmp) {
 345                     X509V3err(X509V3_F_X509V3_PARSE_LIST,
 346                               X509V3_R_INVALID_NULL_VALUE);
 347                     goto err;
 348                 }
 349                 X509V3_add_value(ntmp, vtmp, &values);
 350                 ntmp = NULL;
 351                 q = p + 1;
 352             }
 353
 354         }
 355     }
 356
 357     if (state == HDR_VALUE) {
 358         vtmp = strip_spaces(q);
 359         if (!vtmp) {
 360             X509V3err(X509V3_F_X509V3_PARSE_LIST,
 361                       X509V3_R_INVALID_NULL_VALUE);
 362             goto err;
 363         }
 364         X509V3_add_value(ntmp, vtmp, &values);
 365     } else {
 366         ntmp = strip_spaces(q);
 367         if (!ntmp) {
 368             X509V3err(X509V3_F_X509V3_PARSE_LIST, X509V3_R_INVALID_EMPTY_NAME);
 369             goto err;
 370         }
 371         X509V3_add_value(ntmp, NULL, &values);
 372     }
 373     OPENSSL_free(linebuf);
 374     return values;
 375
 376  err:
 377     OPENSSL_free(linebuf);
 378     sk_CONF_VALUE_pop_free(values, X509V3_conf_free);
 379     return NULL;
 380
 381 }
 382
 383 /* Delete leading and trailing spaces from a string */
 384 static char *strip_spaces(char *name)
 385 {
 386     char *p, *q;
 387
 388     /* Skip over leading spaces */
 389     p = name;
 390     while (*p && ossl_isspace(*p))
 391         p++;
 392     if (*p == '\0')
 393         return NULL;
 394     q = p + strlen(p) - 1;
 395     while ((q != p) && ossl_isspace(*q))
 396         q--;
 397     if (p != q)
 398         q[1] = 0;
 399     if (*p == '\0')
 400         return NULL;
 401     return p;
 402 }
 403
 404
 405 /*
 406  * V2I name comparison function: returns zero if 'name' matches cmp or cmp.*
 407  */
 408
 409 int v3_name_cmp(const char *name, const char *cmp)
 410 {
 411     int len, ret;
 412     char c;
 413
 414     len = strlen(cmp);
 415     if ((ret = strncmp(name, cmp, len)))
 416         return ret;
 417     c = name[len];
 418     if (!c || (c == '.'))
 419         return 0;
 420     return 1;
 421 }
 422
 423 static int sk_strcmp(const char *const *a, const char *const *b)
 424 {
 425     return strcmp(*a, *b);
 426 }
 427
 428 STACK_OF(OPENSSL_STRING) *X509_get1_email(X509 *x)
 429 {
 430     GENERAL_NAMES *gens;
 431     STACK_OF(OPENSSL_STRING) *ret;
 432
 433     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 434     ret = get_email(X509_get_subject_name(x), gens);
 435     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 436     return ret;
 437 }
 438
 439 STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x)
 440 {
 441     AUTHORITY_INFO_ACCESS *info;
 442     STACK_OF(OPENSSL_STRING) *ret = NULL;
 443     int i;
 444
 445     info = X509_get_ext_d2i(x, NID_info_access, NULL, NULL);
 446     if (!info)
 447         return NULL;
 448     for (i = 0; i < sk_ACCESS_DESCRIPTION_num(info); i++) {
 449         ACCESS_DESCRIPTION *ad = sk_ACCESS_DESCRIPTION_value(info, i);
 450         if (OBJ_obj2nid(ad->method) == NID_ad_OCSP) {
 451             if (ad->location->type == GEN_URI) {
 452                 if (!append_ia5
 453                     (&ret, ad->location->d.uniformResourceIdentifier))
 454                     break;
 455             }
 456         }
 457     }
 458     AUTHORITY_INFO_ACCESS_free(info);
 459     return ret;
 460 }
 461
 462 STACK_OF(OPENSSL_STRING) *X509_REQ_get1_email(X509_REQ *x)
 463 {
 464     GENERAL_NAMES *gens;
 465     STACK_OF(X509_EXTENSION) *exts;
 466     STACK_OF(OPENSSL_STRING) *ret;
 467
 468     exts = X509_REQ_get_extensions(x);
 469     gens = X509V3_get_d2i(exts, NID_subject_alt_name, NULL, NULL);
 470     ret = get_email(X509_REQ_get_subject_name(x), gens);
 471     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 472     sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
 473     return ret;
 474 }
 475
 476 static STACK_OF(OPENSSL_STRING) *get_email(const X509_NAME *name,
 477                                            GENERAL_NAMES *gens)
 478 {
 479     STACK_OF(OPENSSL_STRING) *ret = NULL;
 480     X509_NAME_ENTRY *ne;
 481     const ASN1_IA5STRING *email;
 482     GENERAL_NAME *gen;
 483     int i = -1;
 484
 485     /* Now add any email address(es) to STACK */
 486     /* First supplied X509_NAME */
 487     while ((i = X509_NAME_get_index_by_NID(name,
 488                                            NID_pkcs9_emailAddress, i)) >= 0) {
 489         ne = X509_NAME_get_entry(name, i);
 490         email = X509_NAME_ENTRY_get_data(ne);
 491         if (!append_ia5(&ret, email))
 492             return NULL;
 493     }
 494     for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 495         gen = sk_GENERAL_NAME_value(gens, i);
 496         if (gen->type != GEN_EMAIL)
 497             continue;
 498         if (!append_ia5(&ret, gen->d.ia5))
 499             return NULL;
 500     }
 501     return ret;
 502 }
 503
 504 static void str_free(OPENSSL_STRING str)
 505 {
 506     OPENSSL_free(str);
 507 }
 508
 509 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk,
 510                       const ASN1_IA5STRING *email)
 511 {
 512     char *emtmp;
 513
 514     /* First some sanity checks */
 515     if (email->type != V_ASN1_IA5STRING)
 516         return 1;
 517     if (!email->data || !email->length)
 518         return 1;
 519     if (*sk == NULL)
 520         *sk = sk_OPENSSL_STRING_new(sk_strcmp);
 521     if (*sk == NULL)
 522         return 0;
 523     /* Don't add duplicates */
 524     if (sk_OPENSSL_STRING_find(*sk, (char *)email->data) != -1)
 525         return 1;
 526     emtmp = OPENSSL_strdup((char *)email->data);
 527     if (emtmp == NULL || !sk_OPENSSL_STRING_push(*sk, emtmp)) {
 528         OPENSSL_free(emtmp); /* free on push failure */
 529         X509_email_free(*sk);
 530         *sk = NULL;
 531         return 0;
 532     }
 533     return 1;
 534 }
 535
 536 void X509_email_free(STACK_OF(OPENSSL_STRING) *sk)
 537 {
 538     sk_OPENSSL_STRING_pop_free(sk, str_free);
 539 }
 540
 541 typedef int (*equal_fn) (const unsigned char *pattern, size_t pattern_len,
 542                          const unsigned char *subject, size_t subject_len,
 543                          unsigned int flags);
 544
 545 /* Skip pattern prefix to match "wildcard" subject */
 546 static void skip_prefix(const unsigned char **p, size_t *plen,
 547                         size_t subject_len,
 548                         unsigned int flags)
 549 {
 550     const unsigned char *pattern = *p;
 551     size_t pattern_len = *plen;
 552
 553     /*
 554      * If subject starts with a leading '.' followed by more octets, and
 555      * pattern is longer, compare just an equal-length suffix with the
 556      * full subject (starting at the '.'), provided the prefix contains
 557      * no NULs.
 558      */
 559     if ((flags & _X509_CHECK_FLAG_DOT_SUBDOMAINS) == 0)
 560         return;
 561
 562     while (pattern_len > subject_len && *pattern) {
 563         if ((flags & X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS) &&
 564             *pattern == '.')
 565             break;
 566         ++pattern;
 567         --pattern_len;
 568     }
 569
 570     /* Skip if entire prefix acceptable */
 571     if (pattern_len == subject_len) {
 572         *p = pattern;
 573         *plen = pattern_len;
 574     }
 575 }
 576
 577 /* Compare while ASCII ignoring case. */
 578 static int equal_nocase(const unsigned char *pattern, size_t pattern_len,
 579                         const unsigned char *subject, size_t subject_len,
 580                         unsigned int flags)
 581 {
 582     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 583     if (pattern_len != subject_len)
 584         return 0;
 585     while (pattern_len != 0) {
 586         unsigned char l = *pattern;
 587         unsigned char r = *subject;
 588
 589         /* The pattern must not contain NUL characters. */
 590         if (l == 0)
 591             return 0;
 592         if (l != r) {
 593             if ('A' <= l && l <= 'Z')
 594                 l = (l - 'A') + 'a';
 595             if ('A' <= r && r <= 'Z')
 596                 r = (r - 'A') + 'a';
 597             if (l != r)
 598                 return 0;
 599         }
 600         ++pattern;
 601         ++subject;
 602         --pattern_len;
 603     }
 604     return 1;
 605 }
 606
 607 /* Compare using memcmp. */
 608 static int equal_case(const unsigned char *pattern, size_t pattern_len,
 609                       const unsigned char *subject, size_t subject_len,
 610                       unsigned int flags)
 611 {
 612     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 613     if (pattern_len != subject_len)
 614         return 0;
 615     return !memcmp(pattern, subject, pattern_len);
 616 }
 617
 618 /*
 619  * RFC 5280, section 7.5, requires that only the domain is compared in a
 620  * case-insensitive manner.
 621  */
 622 static int equal_email(const unsigned char *a, size_t a_len,
 623                        const unsigned char *b, size_t b_len,
 624                        unsigned int unused_flags)
 625 {
 626     size_t i = a_len;
 627
 628     if (a_len != b_len)
 629         return 0;
 630     /*
 631      * We search backwards for the '@' character, so that we do not have to
 632      * deal with quoted local-parts.  The domain part is compared in a
 633      * case-insensitive manner.
 634      */
 635     while (i > 0) {
 636         --i;
 637         if (a[i] == '@' || b[i] == '@') {
 638             if (!equal_nocase(a + i, a_len - i, b + i, a_len - i, 0))
 639                 return 0;
 640             break;
 641         }
 642     }
 643     if (i == 0)
 644         i = a_len;
 645     return equal_case(a, i, b, i, 0);
 646 }
 647
 648 /*
 649  * Compare the prefix and suffix with the subject, and check that the
 650  * characters in-between are valid.
 651  */
 652 static int wildcard_match(const unsigned char *prefix, size_t prefix_len,
 653                           const unsigned char *suffix, size_t suffix_len,
 654                           const unsigned char *subject, size_t subject_len,
 655                           unsigned int flags)
 656 {
 657     const unsigned char *wildcard_start;
 658     const unsigned char *wildcard_end;
 659     const unsigned char *p;
 660     int allow_multi = 0;
 661     int allow_idna = 0;
 662
 663     if (subject_len < prefix_len + suffix_len)
 664         return 0;
 665     if (!equal_nocase(prefix, prefix_len, subject, prefix_len, flags))
 666         return 0;
 667     wildcard_start = subject + prefix_len;
 668     wildcard_end = subject + (subject_len - suffix_len);
 669     if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len, flags))
 670         return 0;
 671     /*
 672      * If the wildcard makes up the entire first label, it must match at
 673      * least one character.
 674      */
 675     if (prefix_len == 0 && *suffix == '.') {
 676         if (wildcard_start == wildcard_end)
 677             return 0;
 678         allow_idna = 1;
 679         if (flags & X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS)
 680             allow_multi = 1;
 681     }
 682     /* IDNA labels cannot match partial wildcards */
 683     if (!allow_idna &&
 684         subject_len >= 4 && strncasecmp((char *)subject, "xn--", 4) == 0)
 685         return 0;
 686     /* The wildcard may match a literal '*' */
 687     if (wildcard_end == wildcard_start + 1 && *wildcard_start == '*')
 688         return 1;
 689     /*
 690      * Check that the part matched by the wildcard contains only
 691      * permitted characters and only matches a single label unless
 692      * allow_multi is set.
 693      */
 694     for (p = wildcard_start; p != wildcard_end; ++p)
 695         if (!(('0' <= *p && *p <= '9') ||
 696               ('A' <= *p && *p <= 'Z') ||
 697               ('a' <= *p && *p <= 'z') ||
 698               *p == '-' || (allow_multi && *p == '.')))
 699             return 0;
 700     return 1;
 701 }
 702
 703 #define LABEL_START     (1 << 0)
 704 #define LABEL_END       (1 << 1)
 705 #define LABEL_HYPHEN    (1 << 2)
 706 #define LABEL_IDNA      (1 << 3)
 707
 708 static const unsigned char *valid_star(const unsigned char *p, size_t len,
 709                                        unsigned int flags)
 710 {
 711     const unsigned char *star = 0;
 712     size_t i;
 713     int state = LABEL_START;
 714     int dots = 0;
 715
 716     for (i = 0; i < len; ++i) {
 717         /*
 718          * Locate first and only legal wildcard, either at the start
 719          * or end of a non-IDNA first and not final label.
 720          */
 721         if (p[i] == '*') {
 722             int atstart = (state & LABEL_START);
 723             int atend = (i == len - 1 || p[i + 1] == '.');
 724             /*-
 725              * At most one wildcard per pattern.
 726              * No wildcards in IDNA labels.
 727              * No wildcards after the first label.
 728              */
 729             if (star != NULL || (state & LABEL_IDNA) != 0 || dots)
 730                 return NULL;
 731             /* Only full-label '*.example.com' wildcards? */
 732             if ((flags & X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)
 733                 && (!atstart || !atend))
 734                 return NULL;
 735             /* No 'foo*bar' wildcards */
 736             if (!atstart && !atend)
 737                 return NULL;
 738             star = &p[i];
 739             state &= ~LABEL_START;
 740         } else if (('a' <= p[i] && p[i] <= 'z')
 741                    || ('A' <= p[i] && p[i] <= 'Z')
 742                    || ('0' <= p[i] && p[i] <= '9')) {
 743             if ((state & LABEL_START) != 0
 744                 && len - i >= 4 && strncasecmp((char *)&p[i], "xn--", 4) == 0)
 745                 state |= LABEL_IDNA;
 746             state &= ~(LABEL_HYPHEN | LABEL_START);
 747         } else if (p[i] == '.') {
 748             if ((state & (LABEL_HYPHEN | LABEL_START)) != 0)
 749                 return NULL;
 750             state = LABEL_START;
 751             ++dots;
 752         } else if (p[i] == '-') {
 753             /* no domain/subdomain starts with '-' */
 754             if ((state & LABEL_START) != 0)
 755                 return NULL;
 756             state |= LABEL_HYPHEN;
 757         } else {
 758             return NULL;
 759         }
 760     }
 761
 762     /*
 763      * The final label must not end in a hyphen or ".", and
 764      * there must be at least two dots after the star.
 765      */
 766     if ((state & (LABEL_START | LABEL_HYPHEN)) != 0 || dots < 2)
 767         return NULL;
 768     return star;
 769 }
 770
 771 /* Compare using wildcards. */
 772 static int equal_wildcard(const unsigned char *pattern, size_t pattern_len,
 773                           const unsigned char *subject, size_t subject_len,
 774                           unsigned int flags)
 775 {
 776     const unsigned char *star = NULL;
 777
 778     /*
 779      * Subject names starting with '.' can only match a wildcard pattern
 780      * via a subject sub-domain pattern suffix match.
 781      */
 782     if (!(subject_len > 1 && subject[0] == '.'))
 783         star = valid_star(pattern, pattern_len, flags);
 784     if (star == NULL)
 785         return equal_nocase(pattern, pattern_len,
 786                             subject, subject_len, flags);
 787     return wildcard_match(pattern, star - pattern,
 788                           star + 1, (pattern + pattern_len) - star - 1,
 789                           subject, subject_len, flags);
 790 }
 791
 792 /*
 793  * Compare an ASN1_STRING to a supplied string. If they match return 1. If
 794  * cmp_type > 0 only compare if string matches the type, otherwise convert it
 795  * to UTF8.
 796  */
 797
 798 static int do_check_string(const ASN1_STRING *a, int cmp_type, equal_fn equal,
 799                            unsigned int flags, const char *b, size_t blen,
 800                            char **peername)
 801 {
 802     int rv = 0;
 803
 804     if (!a->data || !a->length)
 805         return 0;
 806     if (cmp_type > 0) {
 807         if (cmp_type != a->type)
 808             return 0;
 809         if (cmp_type == V_ASN1_IA5STRING)
 810             rv = equal(a->data, a->length, (unsigned char *)b, blen, flags);
 811         else if (a->length == (int)blen && !memcmp(a->data, b, blen))
 812             rv = 1;
 813         if (rv > 0 && peername)
 814             *peername = OPENSSL_strndup((char *)a->data, a->length);
 815     } else {
 816         int astrlen;
 817         unsigned char *astr;
 818         astrlen = ASN1_STRING_to_UTF8(&astr, a);
 819         if (astrlen < 0) {
 820             /*
 821              * -1 could be an internal malloc failure or a decoding error from
 822              * malformed input; we can't distinguish.
 823              */
 824             return -1;
 825         }
 826         rv = equal(astr, astrlen, (unsigned char *)b, blen, flags);
 827         if (rv > 0 && peername)
 828             *peername = OPENSSL_strndup((char *)astr, astrlen);
 829         OPENSSL_free(astr);
 830     }
 831     return rv;
 832 }
 833
 834 static int do_x509_check(X509 *x, const char *chk, size_t chklen,
 835                          unsigned int flags, int check_type, char **peername)
 836 {
 837     GENERAL_NAMES *gens = NULL;
 838     const X509_NAME *name = NULL;
 839     int i;
 840     int cnid = NID_undef;
 841     int alt_type;
 842     int san_present = 0;
 843     int rv = 0;
 844     equal_fn equal;
 845
 846     /* See below, this flag is internal-only */
 847     flags &= ~_X509_CHECK_FLAG_DOT_SUBDOMAINS;
 848     if (check_type == GEN_EMAIL) {
 849         cnid = NID_pkcs9_emailAddress;
 850         alt_type = V_ASN1_IA5STRING;
 851         equal = equal_email;
 852     } else if (check_type == GEN_DNS) {
 853         cnid = NID_commonName;
 854         /* Implicit client-side DNS sub-domain pattern */
 855         if (chklen > 1 && chk[0] == '.')
 856             flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;
 857         alt_type = V_ASN1_IA5STRING;
 858         if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
 859             equal = equal_nocase;
 860         else
 861             equal = equal_wildcard;
 862     } else {
 863         alt_type = V_ASN1_OCTET_STRING;
 864         equal = equal_case;
 865     }
 866
 867     if (chklen == 0)
 868         chklen = strlen(chk);
 869
 870     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 871     if (gens) {
 872         for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 873             GENERAL_NAME *gen;
 874             ASN1_STRING *cstr;
 875
 876             gen = sk_GENERAL_NAME_value(gens, i);
 877             if ((gen->type == GEN_OTHERNAME) && (check_type == GEN_EMAIL)) {
 878                 if (OBJ_obj2nid(gen->d.otherName->type_id) ==
 879                     NID_id_on_SmtpUTF8Mailbox) {
 880                     san_present = 1;
 881                     cstr = gen->d.otherName->value->value.utf8string;
 882
 883                     /* Positive on success, negative on error! */
 884                     if ((rv = do_check_string(cstr, 0, equal, flags,
 885                                               chk, chklen, peername)) != 0)
 886                         break;
 887                 } else
 888                     continue;
 889             } else {
 890                 if ((gen->type != check_type) && (gen->type != GEN_OTHERNAME))
 891                     continue;
 892             }
 893             san_present = 1;
 894             if (check_type == GEN_EMAIL)
 895                 cstr = gen->d.rfc822Name;
 896             else if (check_type == GEN_DNS)
 897                 cstr = gen->d.dNSName;
 898             else
 899                 cstr = gen->d.iPAddress;
 900             /* Positive on success, negative on error! */
 901             if ((rv = do_check_string(cstr, alt_type, equal, flags,
 902                                       chk, chklen, peername)) != 0)
 903                 break;
 904         }
 905         GENERAL_NAMES_free(gens);
 906         if (rv != 0)
 907             return rv;
 908         if (san_present && !(flags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT))
 909             return 0;
 910     }
 911
 912     /* We're done if CN-ID is not pertinent */
 913     if (cnid == NID_undef || (flags & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT))
 914         return 0;
 915
 916     i = -1;
 917     name = X509_get_subject_name(x);
 918     while ((i = X509_NAME_get_index_by_NID(name, cnid, i)) >= 0) {
 919         const X509_NAME_ENTRY *ne = X509_NAME_get_entry(name, i);
 920         const ASN1_STRING *str = X509_NAME_ENTRY_get_data(ne);
 921
 922         /* Positive on success, negative on error! */
 923         if ((rv = do_check_string(str, -1, equal, flags,
 924                                   chk, chklen, peername)) != 0)
 925             return rv;
 926     }
 927     return 0;
 928 }
 929
 930 int X509_check_host(X509 *x, const char *chk, size_t chklen,
 931                     unsigned int flags, char **peername)
 932 {
 933     if (chk == NULL)
 934         return -2;
 935     /*
 936      * Embedded NULs are disallowed, except as the last character of a
 937      * string of length 2 or more (tolerate caller including terminating
 938      * NUL in string length).
 939      */
 940     if (chklen == 0)
 941         chklen = strlen(chk);
 942     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 943         return -2;
 944     if (chklen > 1 && chk[chklen - 1] == '\0')
 945         --chklen;
 946     return do_x509_check(x, chk, chklen, flags, GEN_DNS, peername);
 947 }
 948
 949 int X509_check_email(X509 *x, const char *chk, size_t chklen,
 950                      unsigned int flags)
 951 {
 952     if (chk == NULL)
 953         return -2;
 954     /*
 955      * Embedded NULs are disallowed, except as the last character of a
 956      * string of length 2 or more (tolerate caller including terminating
 957      * NUL in string length).
 958      */
 959     if (chklen == 0)
 960         chklen = strlen((char *)chk);
 961     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 962         return -2;
 963     if (chklen > 1 && chk[chklen - 1] == '\0')
 964         --chklen;
 965     return do_x509_check(x, chk, chklen, flags, GEN_EMAIL, NULL);
 966 }
 967
 968 int X509_check_ip(X509 *x, const unsigned char *chk, size_t chklen,
 969                   unsigned int flags)
 970 {
 971     if (chk == NULL)
 972         return -2;
 973     return do_x509_check(x, (char *)chk, chklen, flags, GEN_IPADD, NULL);
 974 }
 975
 976 int X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags)
 977 {
 978     unsigned char ipout[16];
 979     size_t iplen;
 980
 981     if (ipasc == NULL)
 982         return -2;
 983     iplen = (size_t)a2i_ipadd(ipout, ipasc);
 984     if (iplen == 0)
 985         return -2;
 986     return do_x509_check(x, (char *)ipout, iplen, flags, GEN_IPADD, NULL);
 987 }
 988
 989 char *ipaddr_to_asc(unsigned char *p, int len)
 990 {
 991     /*
 992      * 40 is enough space for the longest IPv6 address + nul terminator byte
 993      * XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX\0
 994      */
 995     char buf[40], *out;
 996     int i = 0, remain = 0, bytes = 0;
 997
 998     switch (len) {
 999     case 4: /* IPv4 */
1000         BIO_snprintf(buf, sizeof(buf), "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
1001         break;
1002         /* TODO possibly combine with static i2r_address() in v3_addr.c */
1003     case 16: /* IPv6 */
1004         for (out = buf, i = 8, remain = sizeof(buf);
1005              i-- > 0 && bytes >= 0;
1006              remain -= bytes, out += bytes) {
1007             const char *template = (i > 0 ? "%X:" : "%X");
1008
1009             bytes = BIO_snprintf(out, remain, template, p[0] << 8 | p[1]);
1010             p += 2;
1011         }
1012         break;
1013     default:
1014         BIO_snprintf(buf, sizeof(buf), "<invalid length=%d>", len);
1015         break;
1016     }
1017     return OPENSSL_strdup(buf);
1018 }
1019
1020 /*
1021  * Convert IP addresses both IPv4 and IPv6 into an OCTET STRING compatible
1022  * with RFC3280.
1023  */
1024
1025 ASN1_OCTET_STRING *a2i_IPADDRESS(const char *ipasc)
1026 {
1027     unsigned char ipout[16];
1028     ASN1_OCTET_STRING *ret;
1029     int iplen;
1030
1031     /* If string contains a ':' assume IPv6 */
1032
1033     iplen = a2i_ipadd(ipout, ipasc);
1034
1035     if (!iplen)
1036         return NULL;
1037
1038     ret = ASN1_OCTET_STRING_new();
1039     if (ret == NULL)
1040         return NULL;
1041     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen)) {
1042         ASN1_OCTET_STRING_free(ret);
1043         return NULL;
1044     }
1045     return ret;
1046 }
1047
1048 ASN1_OCTET_STRING *a2i_IPADDRESS_NC(const char *ipasc)
1049 {
1050     ASN1_OCTET_STRING *ret = NULL;
1051     unsigned char ipout[32];
1052     char *iptmp = NULL, *p;
1053     int iplen1, iplen2;
1054
1055     p = strchr(ipasc, '/');
1056     if (p == NULL)
1057         return NULL;
1058     iptmp = OPENSSL_strdup(ipasc);
1059     if (iptmp == NULL)
1060         return NULL;
1061     p = iptmp + (p - ipasc);
1062     *p++ = 0;
1063
1064     iplen1 = a2i_ipadd(ipout, iptmp);
1065
1066     if (!iplen1)
1067         goto err;
1068
1069     iplen2 = a2i_ipadd(ipout + iplen1, p);
1070
1071     OPENSSL_free(iptmp);
1072     iptmp = NULL;
1073
1074     if (!iplen2 || (iplen1 != iplen2))
1075         goto err;
1076
1077     ret = ASN1_OCTET_STRING_new();
1078     if (ret == NULL)
1079         goto err;
1080     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen1 + iplen2))
1081         goto err;
1082
1083     return ret;
1084
1085  err:
1086     OPENSSL_free(iptmp);
1087     ASN1_OCTET_STRING_free(ret);
1088     return NULL;
1089 }
1090
1091 int a2i_ipadd(unsigned char *ipout, const char *ipasc)
1092 {
1093     /* If string contains a ':' assume IPv6 */
1094
1095     if (strchr(ipasc, ':')) {
1096         if (!ipv6_from_asc(ipout, ipasc))
1097             return 0;
1098         return 16;
1099     } else {
1100         if (!ipv4_from_asc(ipout, ipasc))
1101             return 0;
1102         return 4;
1103     }
1104 }
1105
1106 static int ipv4_from_asc(unsigned char *v4, const char *in)
1107 {
1108     int a0, a1, a2, a3;
1109
1110     if (sscanf(in, "%d.%d.%d.%d", &a0, &a1, &a2, &a3) != 4)
1111         return 0;
1112     if ((a0 < 0) || (a0 > 255) || (a1 < 0) || (a1 > 255)
1113         || (a2 < 0) || (a2 > 255) || (a3 < 0) || (a3 > 255))
1114         return 0;
1115     v4[0] = a0;
1116     v4[1] = a1;
1117     v4[2] = a2;
1118     v4[3] = a3;
1119     return 1;
1120 }
1121
1122 typedef struct {
1123     /* Temporary store for IPV6 output */
1124     unsigned char tmp[16];
1125     /* Total number of bytes in tmp */
1126     int total;
1127     /* The position of a zero (corresponding to '::') */
1128     int zero_pos;
1129     /* Number of zeroes */
1130     int zero_cnt;
1131 } IPV6_STAT;
1132
1133 static int ipv6_from_asc(unsigned char *v6, const char *in)
1134 {
1135     IPV6_STAT v6stat;
1136
1137     v6stat.total = 0;
1138     v6stat.zero_pos = -1;
1139     v6stat.zero_cnt = 0;
1140     /*
1141      * Treat the IPv6 representation as a list of values separated by ':'.
1142      * The presence of a '::' will parse as one, two or three zero length
1143      * elements.
1144      */
1145     if (!CONF_parse_list(in, ':', 0, ipv6_cb, &v6stat))
1146         return 0;
1147
1148     /* Now for some sanity checks */
1149
1150     if (v6stat.zero_pos == -1) {
1151         /* If no '::' must have exactly 16 bytes */
1152         if (v6stat.total != 16)
1153             return 0;
1154     } else {
1155         /* If '::' must have less than 16 bytes */
1156         if (v6stat.total == 16)
1157             return 0;
1158         /* More than three zeroes is an error */
1159         if (v6stat.zero_cnt > 3) {
1160             return 0;
1161         /* Can only have three zeroes if nothing else present */
1162         } else if (v6stat.zero_cnt == 3) {
1163             if (v6stat.total > 0)
1164                 return 0;
1165         } else if (v6stat.zero_cnt == 2) {
1166             /* Can only have two zeroes if at start or end */
1167             if ((v6stat.zero_pos != 0)
1168                 && (v6stat.zero_pos != v6stat.total))
1169                 return 0;
1170         } else {
1171             /* Can only have one zero if *not* start or end */
1172             if ((v6stat.zero_pos == 0)
1173                 || (v6stat.zero_pos == v6stat.total))
1174                 return 0;
1175         }
1176     }
1177
1178     /* Format result */
1179
1180     if (v6stat.zero_pos >= 0) {
1181         /* Copy initial part */
1182         memcpy(v6, v6stat.tmp, v6stat.zero_pos);
1183         /* Zero middle */
1184         memset(v6 + v6stat.zero_pos, 0, 16 - v6stat.total);
1185         /* Copy final part */
1186         if (v6stat.total != v6stat.zero_pos)
1187             memcpy(v6 + v6stat.zero_pos + 16 - v6stat.total,
1188                    v6stat.tmp + v6stat.zero_pos,
1189                    v6stat.total - v6stat.zero_pos);
1190     } else {
1191         memcpy(v6, v6stat.tmp, 16);
1192     }
1193
1194     return 1;
1195 }
1196
1197 static int ipv6_cb(const char *elem, int len, void *usr)
1198 {
1199     IPV6_STAT *s = usr;
1200
1201     /* Error if 16 bytes written */
1202     if (s->total == 16)
1203         return 0;
1204     if (len == 0) {
1205         /* Zero length element, corresponds to '::' */
1206         if (s->zero_pos == -1)
1207             s->zero_pos = s->total;
1208         /* If we've already got a :: its an error */
1209         else if (s->zero_pos != s->total)
1210             return 0;
1211         s->zero_cnt++;
1212     } else {
1213         /* If more than 4 characters could be final a.b.c.d form */
1214         if (len > 4) {
1215             /* Need at least 4 bytes left */
1216             if (s->total > 12)
1217                 return 0;
1218             /* Must be end of string */
1219             if (elem[len])
1220                 return 0;
1221             if (!ipv4_from_asc(s->tmp + s->total, elem))
1222                 return 0;
1223             s->total += 4;
1224         } else {
1225             if (!ipv6_hex(s->tmp + s->total, elem, len))
1226                 return 0;
1227             s->total += 2;
1228         }
1229     }
1230     return 1;
1231 }
1232
1233 /*
1234  * Convert a string of up to 4 hex digits into the corresponding IPv6 form.
1235  */
1236
1237 static int ipv6_hex(unsigned char *out, const char *in, int inlen)
1238 {
1239     unsigned char c;
1240     unsigned int num = 0;
1241     int x;
1242
1243     if (inlen > 4)
1244         return 0;
1245     while (inlen--) {
1246         c = *in++;
1247         num <<= 4;
1248         x = OPENSSL_hexchar2int(c);
1249         if (x < 0)
1250             return 0;
1251         num |= (char)x;
1252     }
1253     out[0] = num >> 8;
1254     out[1] = num & 0xff;
1255     return 1;
1256 }
1257
1258 int X509V3_NAME_from_section(X509_NAME *nm, STACK_OF(CONF_VALUE) *dn_sk,
1259                              unsigned long chtype)
1260 {
1261     CONF_VALUE *v;
1262     int i, mval, spec_char, plus_char;
1263     char *p, *type;
1264
1265     if (!nm)
1266         return 0;
1267
1268     for (i = 0; i < sk_CONF_VALUE_num(dn_sk); i++) {
1269         v = sk_CONF_VALUE_value(dn_sk, i);
1270         type = v->name;
1271         /*
1272          * Skip past any leading X. X: X, etc to allow for multiple instances
1273          */
1274         for (p = type; *p; p++) {
1275 #ifndef CHARSET_EBCDIC
1276             spec_char = ((*p == ':') || (*p == ',') || (*p == '.'));
1277 #else
1278             spec_char = ((*p == os_toascii[':']) || (*p == os_toascii[','])
1279                          || (*p == os_toascii['.']));
1280 #endif
1281             if (spec_char) {
1282                 p++;
1283                 if (*p)
1284                     type = p;
1285                 break;
1286             }
1287         }
1288 #ifndef CHARSET_EBCDIC
1289         plus_char = (*type == '+');
1290 #else
1291         plus_char = (*type == os_toascii['+']);
1292 #endif
1293         if (plus_char) {
1294             mval = -1;
1295             type++;
1296         } else {
1297             mval = 0;
1298         }
1299         if (!X509_NAME_add_entry_by_txt(nm, type, chtype,
1300                                         (unsigned char *)v->value, -1, -1,
1301                                         mval))
1302             return 0;
1303
1304     }
1305     return 1;
1306 }