crypto/x509/v3_utl.c

   1 /*
   2  * Copyright 1999-2021 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 "internal/e_os.h"
  13 #include "internal/cryptlib.h"
  14 #include <stdio.h>
  15 #include <string.h>
  16 #include "crypto/ctype.h"
  17 #include <openssl/conf.h>
  18 #include <openssl/crypto.h>
  19 #include <openssl/x509v3.h>
  20 #include "crypto/x509.h"
  21 #include <openssl/bn.h>
  22 #include "ext_dat.h"
  23 #include "x509_local.h"
  24
  25 static char *strip_spaces(char *name);
  26 static int sk_strcmp(const char *const *a, const char *const *b);
  27 static STACK_OF(OPENSSL_STRING) *get_email(const X509_NAME *name,
  28                                            GENERAL_NAMES *gens);
  29 static void str_free(OPENSSL_STRING str);
  30 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk,
  31                       const ASN1_IA5STRING *email);
  32
  33 static int ipv4_from_asc(unsigned char *v4, const char *in);
  34 static int ipv6_from_asc(unsigned char *v6, const char *in);
  35 static int ipv6_cb(const char *elem, int len, void *usr);
  36 static int ipv6_hex(unsigned char *out, const char *in, int inlen);
  37
  38 /* Add a CONF_VALUE name value pair to stack */
  39
  40 static int x509v3_add_len_value(const char *name, const char *value,
  41                                 size_t vallen, STACK_OF(CONF_VALUE) **extlist)
  42 {
  43     CONF_VALUE *vtmp = NULL;
  44     char *tname = NULL, *tvalue = NULL;
  45     int sk_allocated = (*extlist == NULL);
  46
  47     if (name != NULL && (tname = OPENSSL_strdup(name)) == NULL)
  48         goto err;
  49     if (value != NULL) {
  50         /* We don't allow embedded NUL characters */
  51         if (memchr(value, 0, vallen) != NULL)
  52             goto err;
  53         tvalue = OPENSSL_strndup(value, vallen);
  54         if (tvalue == NULL)
  55             goto err;
  56     }
  57     if ((vtmp = OPENSSL_malloc(sizeof(*vtmp))) == NULL)
  58         goto err;
  59     if (sk_allocated && (*extlist = sk_CONF_VALUE_new_null()) == NULL)
  60         goto err;
  61     vtmp->section = NULL;
  62     vtmp->name = tname;
  63     vtmp->value = tvalue;
  64     if (!sk_CONF_VALUE_push(*extlist, vtmp))
  65         goto err;
  66     return 1;
  67  err:
  68     ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
  69     if (sk_allocated) {
  70         sk_CONF_VALUE_free(*extlist);
  71         *extlist = NULL;
  72     }
  73     OPENSSL_free(vtmp);
  74     OPENSSL_free(tname);
  75     OPENSSL_free(tvalue);
  76     return 0;
  77 }
  78
  79 int X509V3_add_value(const char *name, const char *value,
  80                      STACK_OF(CONF_VALUE) **extlist)
  81 {
  82     return x509v3_add_len_value(name, value,
  83                                 value != NULL ? strlen((const char *)value) : 0,
  84                                 extlist);
  85 }
  86
  87 int X509V3_add_value_uchar(const char *name, const unsigned char *value,
  88                            STACK_OF(CONF_VALUE) **extlist)
  89 {
  90     return x509v3_add_len_value(name, (const char *)value,
  91                                 value != NULL ? strlen((const char *)value) : 0,
  92                                 extlist);
  93 }
  94
  95 int x509v3_add_len_value_uchar(const char *name, const unsigned char *value,
  96                                size_t vallen, STACK_OF(CONF_VALUE) **extlist)
  97 {
  98     return x509v3_add_len_value(name, (const char *)value, vallen, extlist);
  99 }
 100
 101 /* Free function for STACK_OF(CONF_VALUE) */
 102
 103 void X509V3_conf_free(CONF_VALUE *conf)
 104 {
 105     if (!conf)
 106         return;
 107     OPENSSL_free(conf->name);
 108     OPENSSL_free(conf->value);
 109     OPENSSL_free(conf->section);
 110     OPENSSL_free(conf);
 111 }
 112
 113 int X509V3_add_value_bool(const char *name, int asn1_bool,
 114                           STACK_OF(CONF_VALUE) **extlist)
 115 {
 116     if (asn1_bool)
 117         return X509V3_add_value(name, "TRUE", extlist);
 118     return X509V3_add_value(name, "FALSE", extlist);
 119 }
 120
 121 int X509V3_add_value_bool_nf(const char *name, int asn1_bool,
 122                              STACK_OF(CONF_VALUE) **extlist)
 123 {
 124     if (asn1_bool)
 125         return X509V3_add_value(name, "TRUE", extlist);
 126     return 1;
 127 }
 128
 129 static char *bignum_to_string(const BIGNUM *bn)
 130 {
 131     char *tmp, *ret;
 132     size_t len;
 133
 134     /*
 135      * Display large numbers in hex and small numbers in decimal. Converting to
 136      * decimal takes quadratic time and is no more useful than hex for large
 137      * numbers.
 138      */
 139     if (BN_num_bits(bn) < 128)
 140         return BN_bn2dec(bn);
 141
 142     tmp = BN_bn2hex(bn);
 143     if (tmp == NULL)
 144         return NULL;
 145
 146     len = strlen(tmp) + 3;
 147     ret = OPENSSL_malloc(len);
 148     if (ret == NULL) {
 149         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 150         OPENSSL_free(tmp);
 151         return NULL;
 152     }
 153
 154     /* Prepend "0x", but place it after the "-" if negative. */
 155     if (tmp[0] == '-') {
 156         OPENSSL_strlcpy(ret, "-0x", len);
 157         OPENSSL_strlcat(ret, tmp + 1, len);
 158     } else {
 159         OPENSSL_strlcpy(ret, "0x", len);
 160         OPENSSL_strlcat(ret, tmp, len);
 161     }
 162     OPENSSL_free(tmp);
 163     return ret;
 164 }
 165
 166 char *i2s_ASN1_ENUMERATED(X509V3_EXT_METHOD *method, const ASN1_ENUMERATED *a)
 167 {
 168     BIGNUM *bntmp = NULL;
 169     char *strtmp = NULL;
 170
 171     if (!a)
 172         return NULL;
 173     if ((bntmp = ASN1_ENUMERATED_to_BN(a, NULL)) == NULL
 174         || (strtmp = bignum_to_string(bntmp)) == NULL)
 175         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 176     BN_free(bntmp);
 177     return strtmp;
 178 }
 179
 180 char *i2s_ASN1_INTEGER(X509V3_EXT_METHOD *method, const ASN1_INTEGER *a)
 181 {
 182     BIGNUM *bntmp = NULL;
 183     char *strtmp = NULL;
 184
 185     if (!a)
 186         return NULL;
 187     if ((bntmp = ASN1_INTEGER_to_BN(a, NULL)) == NULL
 188         || (strtmp = bignum_to_string(bntmp)) == NULL)
 189         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 190     BN_free(bntmp);
 191     return strtmp;
 192 }
 193
 194 ASN1_INTEGER *s2i_ASN1_INTEGER(X509V3_EXT_METHOD *method, const char *value)
 195 {
 196     BIGNUM *bn = NULL;
 197     ASN1_INTEGER *aint;
 198     int isneg, ishex;
 199     int ret;
 200
 201     if (value == NULL) {
 202         ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_NULL_VALUE);
 203         return NULL;
 204     }
 205     bn = BN_new();
 206     if (bn == NULL) {
 207         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 208         return NULL;
 209     }
 210     if (value[0] == '-') {
 211         value++;
 212         isneg = 1;
 213     } else {
 214         isneg = 0;
 215     }
 216
 217     if (value[0] == '0' && ((value[1] == 'x') || (value[1] == 'X'))) {
 218         value += 2;
 219         ishex = 1;
 220     } else {
 221         ishex = 0;
 222     }
 223
 224     if (ishex)
 225         ret = BN_hex2bn(&bn, value);
 226     else
 227         ret = BN_dec2bn(&bn, value);
 228
 229     if (!ret || value[ret]) {
 230         BN_free(bn);
 231         ERR_raise(ERR_LIB_X509V3, X509V3_R_BN_DEC2BN_ERROR);
 232         return NULL;
 233     }
 234
 235     if (isneg && BN_is_zero(bn))
 236         isneg = 0;
 237
 238     aint = BN_to_ASN1_INTEGER(bn, NULL);
 239     BN_free(bn);
 240     if (!aint) {
 241         ERR_raise(ERR_LIB_X509V3, X509V3_R_BN_TO_ASN1_INTEGER_ERROR);
 242         return NULL;
 243     }
 244     if (isneg)
 245         aint->type |= V_ASN1_NEG;
 246     return aint;
 247 }
 248
 249 int X509V3_add_value_int(const char *name, const ASN1_INTEGER *aint,
 250                          STACK_OF(CONF_VALUE) **extlist)
 251 {
 252     char *strtmp;
 253     int ret;
 254
 255     if (!aint)
 256         return 1;
 257     if ((strtmp = i2s_ASN1_INTEGER(NULL, aint)) == NULL)
 258         return 0;
 259     ret = X509V3_add_value(name, strtmp, extlist);
 260     OPENSSL_free(strtmp);
 261     return ret;
 262 }
 263
 264 int X509V3_get_value_bool(const CONF_VALUE *value, int *asn1_bool)
 265 {
 266     const char *btmp;
 267
 268     if ((btmp = value->value) == NULL)
 269         goto err;
 270     if (strcmp(btmp, "TRUE") == 0
 271         || strcmp(btmp, "true") == 0
 272         || strcmp(btmp, "Y") == 0
 273         || strcmp(btmp, "y") == 0
 274         || strcmp(btmp, "YES") == 0
 275         || strcmp(btmp, "yes") == 0) {
 276         *asn1_bool = 0xff;
 277         return 1;
 278     }
 279     if (strcmp(btmp, "FALSE") == 0
 280         || strcmp(btmp, "false") == 0
 281         || strcmp(btmp, "N") == 0
 282         || strcmp(btmp, "n") == 0
 283         || strcmp(btmp, "NO") == 0
 284         || strcmp(btmp, "no") == 0) {
 285         *asn1_bool = 0;
 286         return 1;
 287     }
 288  err:
 289     ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_BOOLEAN_STRING);
 290     X509V3_conf_add_error_name_value(value);
 291     return 0;
 292 }
 293
 294 int X509V3_get_value_int(const CONF_VALUE *value, ASN1_INTEGER **aint)
 295 {
 296     ASN1_INTEGER *itmp;
 297
 298     if ((itmp = s2i_ASN1_INTEGER(NULL, value->value)) == NULL) {
 299         X509V3_conf_add_error_name_value(value);
 300         return 0;
 301     }
 302     *aint = itmp;
 303     return 1;
 304 }
 305
 306 #define HDR_NAME        1
 307 #define HDR_VALUE       2
 308
 309 /*
 310  * #define DEBUG
 311  */
 312
 313 STACK_OF(CONF_VALUE) *X509V3_parse_list(const char *line)
 314 {
 315     char *p, *q, c;
 316     char *ntmp, *vtmp;
 317     STACK_OF(CONF_VALUE) *values = NULL;
 318     char *linebuf;
 319     int state;
 320
 321     /* We are going to modify the line so copy it first */
 322     linebuf = OPENSSL_strdup(line);
 323     if (linebuf == NULL) {
 324         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
 325         goto err;
 326     }
 327     state = HDR_NAME;
 328     ntmp = NULL;
 329     /* Go through all characters */
 330     for (p = linebuf, q = linebuf; (c = *p) && (c != '\r') && (c != '\n');
 331          p++) {
 332
 333         switch (state) {
 334         case HDR_NAME:
 335             if (c == ':') {
 336                 state = HDR_VALUE;
 337                 *p = 0;
 338                 ntmp = strip_spaces(q);
 339                 if (!ntmp) {
 340                     ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_EMPTY_NAME);
 341                     goto err;
 342                 }
 343                 q = p + 1;
 344             } else if (c == ',') {
 345                 *p = 0;
 346                 ntmp = strip_spaces(q);
 347                 q = p + 1;
 348                 if (!ntmp) {
 349                     ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_EMPTY_NAME);
 350                     goto err;
 351                 }
 352                 X509V3_add_value(ntmp, NULL, &values);
 353             }
 354             break;
 355
 356         case HDR_VALUE:
 357             if (c == ',') {
 358                 state = HDR_NAME;
 359                 *p = 0;
 360                 vtmp = strip_spaces(q);
 361                 if (!vtmp) {
 362                     ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_NULL_VALUE);
 363                     goto err;
 364                 }
 365                 X509V3_add_value(ntmp, vtmp, &values);
 366                 ntmp = NULL;
 367                 q = p + 1;
 368             }
 369
 370         }
 371     }
 372
 373     if (state == HDR_VALUE) {
 374         vtmp = strip_spaces(q);
 375         if (!vtmp) {
 376             ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_NULL_VALUE);
 377             goto err;
 378         }
 379         X509V3_add_value(ntmp, vtmp, &values);
 380     } else {
 381         ntmp = strip_spaces(q);
 382         if (!ntmp) {
 383             ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_EMPTY_NAME);
 384             goto err;
 385         }
 386         X509V3_add_value(ntmp, NULL, &values);
 387     }
 388     OPENSSL_free(linebuf);
 389     return values;
 390
 391  err:
 392     OPENSSL_free(linebuf);
 393     sk_CONF_VALUE_pop_free(values, X509V3_conf_free);
 394     return NULL;
 395
 396 }
 397
 398 /* Delete leading and trailing spaces from a string */
 399 static char *strip_spaces(char *name)
 400 {
 401     char *p, *q;
 402
 403     /* Skip over leading spaces */
 404     p = name;
 405     while (*p && ossl_isspace(*p))
 406         p++;
 407     if (*p == '\0')
 408         return NULL;
 409     q = p + strlen(p) - 1;
 410     while ((q != p) && ossl_isspace(*q))
 411         q--;
 412     if (p != q)
 413         q[1] = 0;
 414     if (*p == '\0')
 415         return NULL;
 416     return p;
 417 }
 418
 419
 420 /*
 421  * V2I name comparison function: returns zero if 'name' matches cmp or cmp.*
 422  */
 423
 424 int ossl_v3_name_cmp(const char *name, const char *cmp)
 425 {
 426     int len, ret;
 427     char c;
 428
 429     len = strlen(cmp);
 430     if ((ret = strncmp(name, cmp, len)))
 431         return ret;
 432     c = name[len];
 433     if (!c || (c == '.'))
 434         return 0;
 435     return 1;
 436 }
 437
 438 static int sk_strcmp(const char *const *a, const char *const *b)
 439 {
 440     return strcmp(*a, *b);
 441 }
 442
 443 STACK_OF(OPENSSL_STRING) *X509_get1_email(X509 *x)
 444 {
 445     GENERAL_NAMES *gens;
 446     STACK_OF(OPENSSL_STRING) *ret;
 447
 448     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 449     ret = get_email(X509_get_subject_name(x), gens);
 450     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 451     return ret;
 452 }
 453
 454 STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x)
 455 {
 456     AUTHORITY_INFO_ACCESS *info;
 457     STACK_OF(OPENSSL_STRING) *ret = NULL;
 458     int i;
 459
 460     info = X509_get_ext_d2i(x, NID_info_access, NULL, NULL);
 461     if (!info)
 462         return NULL;
 463     for (i = 0; i < sk_ACCESS_DESCRIPTION_num(info); i++) {
 464         ACCESS_DESCRIPTION *ad = sk_ACCESS_DESCRIPTION_value(info, i);
 465         if (OBJ_obj2nid(ad->method) == NID_ad_OCSP) {
 466             if (ad->location->type == GEN_URI) {
 467                 if (!append_ia5
 468                     (&ret, ad->location->d.uniformResourceIdentifier))
 469                     break;
 470             }
 471         }
 472     }
 473     AUTHORITY_INFO_ACCESS_free(info);
 474     return ret;
 475 }
 476
 477 STACK_OF(OPENSSL_STRING) *X509_REQ_get1_email(X509_REQ *x)
 478 {
 479     GENERAL_NAMES *gens;
 480     STACK_OF(X509_EXTENSION) *exts;
 481     STACK_OF(OPENSSL_STRING) *ret;
 482
 483     exts = X509_REQ_get_extensions(x);
 484     gens = X509V3_get_d2i(exts, NID_subject_alt_name, NULL, NULL);
 485     ret = get_email(X509_REQ_get_subject_name(x), gens);
 486     sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
 487     sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
 488     return ret;
 489 }
 490
 491 static STACK_OF(OPENSSL_STRING) *get_email(const X509_NAME *name,
 492                                            GENERAL_NAMES *gens)
 493 {
 494     STACK_OF(OPENSSL_STRING) *ret = NULL;
 495     X509_NAME_ENTRY *ne;
 496     const ASN1_IA5STRING *email;
 497     GENERAL_NAME *gen;
 498     int i = -1;
 499
 500     /* Now add any email address(es) to STACK */
 501     /* First supplied X509_NAME */
 502     while ((i = X509_NAME_get_index_by_NID(name,
 503                                            NID_pkcs9_emailAddress, i)) >= 0) {
 504         ne = X509_NAME_get_entry(name, i);
 505         email = X509_NAME_ENTRY_get_data(ne);
 506         if (!append_ia5(&ret, email))
 507             return NULL;
 508     }
 509     for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 510         gen = sk_GENERAL_NAME_value(gens, i);
 511         if (gen->type != GEN_EMAIL)
 512             continue;
 513         if (!append_ia5(&ret, gen->d.ia5))
 514             return NULL;
 515     }
 516     return ret;
 517 }
 518
 519 static void str_free(OPENSSL_STRING str)
 520 {
 521     OPENSSL_free(str);
 522 }
 523
 524 static int append_ia5(STACK_OF(OPENSSL_STRING) **sk,
 525                       const ASN1_IA5STRING *email)
 526 {
 527     char *emtmp;
 528
 529     /* First some sanity checks */
 530     if (email->type != V_ASN1_IA5STRING)
 531         return 1;
 532     if (email->data == NULL || email->length == 0)
 533         return 1;
 534     if (memchr(email->data, 0, email->length) != NULL)
 535         return 1;
 536     if (*sk == NULL)
 537         *sk = sk_OPENSSL_STRING_new(sk_strcmp);
 538     if (*sk == NULL)
 539         return 0;
 540
 541     emtmp = OPENSSL_strndup((char *)email->data, email->length);
 542     if (emtmp == NULL)
 543         return 0;
 544
 545     /* Don't add duplicates */
 546     if (sk_OPENSSL_STRING_find(*sk, emtmp) != -1) {
 547         OPENSSL_free(emtmp);
 548         return 1;
 549     }
 550     if (!sk_OPENSSL_STRING_push(*sk, emtmp)) {
 551         OPENSSL_free(emtmp); /* free on push failure */
 552         X509_email_free(*sk);
 553         *sk = NULL;
 554         return 0;
 555     }
 556     return 1;
 557 }
 558
 559 void X509_email_free(STACK_OF(OPENSSL_STRING) *sk)
 560 {
 561     sk_OPENSSL_STRING_pop_free(sk, str_free);
 562 }
 563
 564 typedef int (*equal_fn) (const unsigned char *pattern, size_t pattern_len,
 565                          const unsigned char *subject, size_t subject_len,
 566                          unsigned int flags);
 567
 568 /* Skip pattern prefix to match "wildcard" subject */
 569 static void skip_prefix(const unsigned char **p, size_t *plen,
 570                         size_t subject_len,
 571                         unsigned int flags)
 572 {
 573     const unsigned char *pattern = *p;
 574     size_t pattern_len = *plen;
 575
 576     /*
 577      * If subject starts with a leading '.' followed by more octets, and
 578      * pattern is longer, compare just an equal-length suffix with the
 579      * full subject (starting at the '.'), provided the prefix contains
 580      * no NULs.
 581      */
 582     if ((flags & _X509_CHECK_FLAG_DOT_SUBDOMAINS) == 0)
 583         return;
 584
 585     while (pattern_len > subject_len && *pattern) {
 586         if ((flags & X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS) &&
 587             *pattern == '.')
 588             break;
 589         ++pattern;
 590         --pattern_len;
 591     }
 592
 593     /* Skip if entire prefix acceptable */
 594     if (pattern_len == subject_len) {
 595         *p = pattern;
 596         *plen = pattern_len;
 597     }
 598 }
 599
 600 /* Compare while ASCII ignoring case. */
 601 static int equal_nocase(const unsigned char *pattern, size_t pattern_len,
 602                         const unsigned char *subject, size_t subject_len,
 603                         unsigned int flags)
 604 {
 605     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 606     if (pattern_len != subject_len)
 607         return 0;
 608     while (pattern_len != 0) {
 609         unsigned char l = *pattern;
 610         unsigned char r = *subject;
 611
 612         /* The pattern must not contain NUL characters. */
 613         if (l == 0)
 614             return 0;
 615         if (l != r) {
 616             if ('A' <= l && l <= 'Z')
 617                 l = (l - 'A') + 'a';
 618             if ('A' <= r && r <= 'Z')
 619                 r = (r - 'A') + 'a';
 620             if (l != r)
 621                 return 0;
 622         }
 623         ++pattern;
 624         ++subject;
 625         --pattern_len;
 626     }
 627     return 1;
 628 }
 629
 630 /* Compare using memcmp. */
 631 static int equal_case(const unsigned char *pattern, size_t pattern_len,
 632                       const unsigned char *subject, size_t subject_len,
 633                       unsigned int flags)
 634 {
 635     skip_prefix(&pattern, &pattern_len, subject_len, flags);
 636     if (pattern_len != subject_len)
 637         return 0;
 638     return !memcmp(pattern, subject, pattern_len);
 639 }
 640
 641 /*
 642  * RFC 5280, section 7.5, requires that only the domain is compared in a
 643  * case-insensitive manner.
 644  */
 645 static int equal_email(const unsigned char *a, size_t a_len,
 646                        const unsigned char *b, size_t b_len,
 647                        unsigned int unused_flags)
 648 {
 649     size_t i = a_len;
 650
 651     if (a_len != b_len)
 652         return 0;
 653     /*
 654      * We search backwards for the '@' character, so that we do not have to
 655      * deal with quoted local-parts.  The domain part is compared in a
 656      * case-insensitive manner.
 657      */
 658     while (i > 0) {
 659         --i;
 660         if (a[i] == '@' || b[i] == '@') {
 661             if (!equal_nocase(a + i, a_len - i, b + i, a_len - i, 0))
 662                 return 0;
 663             break;
 664         }
 665     }
 666     if (i == 0)
 667         i = a_len;
 668     return equal_case(a, i, b, i, 0);
 669 }
 670
 671 /*
 672  * Compare the prefix and suffix with the subject, and check that the
 673  * characters in-between are valid.
 674  */
 675 static int wildcard_match(const unsigned char *prefix, size_t prefix_len,
 676                           const unsigned char *suffix, size_t suffix_len,
 677                           const unsigned char *subject, size_t subject_len,
 678                           unsigned int flags)
 679 {
 680     const unsigned char *wildcard_start;
 681     const unsigned char *wildcard_end;
 682     const unsigned char *p;
 683     int allow_multi = 0;
 684     int allow_idna = 0;
 685
 686     if (subject_len < prefix_len + suffix_len)
 687         return 0;
 688     if (!equal_nocase(prefix, prefix_len, subject, prefix_len, flags))
 689         return 0;
 690     wildcard_start = subject + prefix_len;
 691     wildcard_end = subject + (subject_len - suffix_len);
 692     if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len, flags))
 693         return 0;
 694     /*
 695      * If the wildcard makes up the entire first label, it must match at
 696      * least one character.
 697      */
 698     if (prefix_len == 0 && *suffix == '.') {
 699         if (wildcard_start == wildcard_end)
 700             return 0;
 701         allow_idna = 1;
 702         if (flags & X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS)
 703             allow_multi = 1;
 704     }
 705     /* IDNA labels cannot match partial wildcards */
 706     if (!allow_idna &&
 707         subject_len >= 4 && HAS_CASE_PREFIX((const char *)subject, "xn--"))
 708         return 0;
 709     /* The wildcard may match a literal '*' */
 710     if (wildcard_end == wildcard_start + 1 && *wildcard_start == '*')
 711         return 1;
 712     /*
 713      * Check that the part matched by the wildcard contains only
 714      * permitted characters and only matches a single label unless
 715      * allow_multi is set.
 716      */
 717     for (p = wildcard_start; p != wildcard_end; ++p)
 718         if (!(('0' <= *p && *p <= '9') ||
 719               ('A' <= *p && *p <= 'Z') ||
 720               ('a' <= *p && *p <= 'z') ||
 721               *p == '-' || (allow_multi && *p == '.')))
 722             return 0;
 723     return 1;
 724 }
 725
 726 #define LABEL_START     (1 << 0)
 727 #define LABEL_END       (1 << 1)
 728 #define LABEL_HYPHEN    (1 << 2)
 729 #define LABEL_IDNA      (1 << 3)
 730
 731 static const unsigned char *valid_star(const unsigned char *p, size_t len,
 732                                        unsigned int flags)
 733 {
 734     const unsigned char *star = 0;
 735     size_t i;
 736     int state = LABEL_START;
 737     int dots = 0;
 738
 739     for (i = 0; i < len; ++i) {
 740         /*
 741          * Locate first and only legal wildcard, either at the start
 742          * or end of a non-IDNA first and not final label.
 743          */
 744         if (p[i] == '*') {
 745             int atstart = (state & LABEL_START);
 746             int atend = (i == len - 1 || p[i + 1] == '.');
 747             /*-
 748              * At most one wildcard per pattern.
 749              * No wildcards in IDNA labels.
 750              * No wildcards after the first label.
 751              */
 752             if (star != NULL || (state & LABEL_IDNA) != 0 || dots)
 753                 return NULL;
 754             /* Only full-label '*.example.com' wildcards? */
 755             if ((flags & X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)
 756                 && (!atstart || !atend))
 757                 return NULL;
 758             /* No 'foo*bar' wildcards */
 759             if (!atstart && !atend)
 760                 return NULL;
 761             star = &p[i];
 762             state &= ~LABEL_START;
 763         } else if (('a' <= p[i] && p[i] <= 'z')
 764                    || ('A' <= p[i] && p[i] <= 'Z')
 765                    || ('0' <= p[i] && p[i] <= '9')) {
 766             if ((state & LABEL_START) != 0
 767                 && len - i >= 4 && HAS_CASE_PREFIX((const char *)&p[i], "xn--"))
 768                 state |= LABEL_IDNA;
 769             state &= ~(LABEL_HYPHEN | LABEL_START);
 770         } else if (p[i] == '.') {
 771             if ((state & (LABEL_HYPHEN | LABEL_START)) != 0)
 772                 return NULL;
 773             state = LABEL_START;
 774             ++dots;
 775         } else if (p[i] == '-') {
 776             /* no domain/subdomain starts with '-' */
 777             if ((state & LABEL_START) != 0)
 778                 return NULL;
 779             state |= LABEL_HYPHEN;
 780         } else {
 781             return NULL;
 782         }
 783     }
 784
 785     /*
 786      * The final label must not end in a hyphen or ".", and
 787      * there must be at least two dots after the star.
 788      */
 789     if ((state & (LABEL_START | LABEL_HYPHEN)) != 0 || dots < 2)
 790         return NULL;
 791     return star;
 792 }
 793
 794 /* Compare using wildcards. */
 795 static int equal_wildcard(const unsigned char *pattern, size_t pattern_len,
 796                           const unsigned char *subject, size_t subject_len,
 797                           unsigned int flags)
 798 {
 799     const unsigned char *star = NULL;
 800
 801     /*
 802      * Subject names starting with '.' can only match a wildcard pattern
 803      * via a subject sub-domain pattern suffix match.
 804      */
 805     if (!(subject_len > 1 && subject[0] == '.'))
 806         star = valid_star(pattern, pattern_len, flags);
 807     if (star == NULL)
 808         return equal_nocase(pattern, pattern_len,
 809                             subject, subject_len, flags);
 810     return wildcard_match(pattern, star - pattern,
 811                           star + 1, (pattern + pattern_len) - star - 1,
 812                           subject, subject_len, flags);
 813 }
 814
 815 /*
 816  * Compare an ASN1_STRING to a supplied string. If they match return 1. If
 817  * cmp_type > 0 only compare if string matches the type, otherwise convert it
 818  * to UTF8.
 819  */
 820
 821 static int do_check_string(const ASN1_STRING *a, int cmp_type, equal_fn equal,
 822                            unsigned int flags, const char *b, size_t blen,
 823                            char **peername)
 824 {
 825     int rv = 0;
 826
 827     if (!a->data || !a->length)
 828         return 0;
 829     if (cmp_type > 0) {
 830         if (cmp_type != a->type)
 831             return 0;
 832         if (cmp_type == V_ASN1_IA5STRING)
 833             rv = equal(a->data, a->length, (unsigned char *)b, blen, flags);
 834         else if (a->length == (int)blen && !memcmp(a->data, b, blen))
 835             rv = 1;
 836         if (rv > 0 && peername)
 837             *peername = OPENSSL_strndup((char *)a->data, a->length);
 838     } else {
 839         int astrlen;
 840         unsigned char *astr;
 841         astrlen = ASN1_STRING_to_UTF8(&astr, a);
 842         if (astrlen < 0) {
 843             /*
 844              * -1 could be an internal malloc failure or a decoding error from
 845              * malformed input; we can't distinguish.
 846              */
 847             return -1;
 848         }
 849         rv = equal(astr, astrlen, (unsigned char *)b, blen, flags);
 850         if (rv > 0 && peername)
 851             *peername = OPENSSL_strndup((char *)astr, astrlen);
 852         OPENSSL_free(astr);
 853     }
 854     return rv;
 855 }
 856
 857 static int do_x509_check(X509 *x, const char *chk, size_t chklen,
 858                          unsigned int flags, int check_type, char **peername)
 859 {
 860     GENERAL_NAMES *gens = NULL;
 861     const X509_NAME *name = NULL;
 862     int i;
 863     int cnid = NID_undef;
 864     int alt_type;
 865     int san_present = 0;
 866     int rv = 0;
 867     equal_fn equal;
 868
 869     /* See below, this flag is internal-only */
 870     flags &= ~_X509_CHECK_FLAG_DOT_SUBDOMAINS;
 871     if (check_type == GEN_EMAIL) {
 872         cnid = NID_pkcs9_emailAddress;
 873         alt_type = V_ASN1_IA5STRING;
 874         equal = equal_email;
 875     } else if (check_type == GEN_DNS) {
 876         cnid = NID_commonName;
 877         /* Implicit client-side DNS sub-domain pattern */
 878         if (chklen > 1 && chk[0] == '.')
 879             flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;
 880         alt_type = V_ASN1_IA5STRING;
 881         if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
 882             equal = equal_nocase;
 883         else
 884             equal = equal_wildcard;
 885     } else {
 886         alt_type = V_ASN1_OCTET_STRING;
 887         equal = equal_case;
 888     }
 889
 890     if (chklen == 0)
 891         chklen = strlen(chk);
 892
 893     gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
 894     if (gens) {
 895         for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 896             GENERAL_NAME *gen;
 897             ASN1_STRING *cstr;
 898
 899             gen = sk_GENERAL_NAME_value(gens, i);
 900             if ((gen->type == GEN_OTHERNAME) && (check_type == GEN_EMAIL)) {
 901                 if (OBJ_obj2nid(gen->d.otherName->type_id) ==
 902                     NID_id_on_SmtpUTF8Mailbox) {
 903                     san_present = 1;
 904
 905                     /*
 906                      * If it is not a UTF8String then that is unexpected and we
 907                      * treat it as no match
 908                      */
 909                     if (gen->d.otherName->value->type == V_ASN1_UTF8STRING) {
 910                         cstr = gen->d.otherName->value->value.utf8string;
 911
 912                         /* Positive on success, negative on error! */
 913                         if ((rv = do_check_string(cstr, 0, equal, flags,
 914                                                 chk, chklen, peername)) != 0)
 915                             break;
 916                     }
 917                 } else
 918                     continue;
 919             } else {
 920                 if ((gen->type != check_type) && (gen->type != GEN_OTHERNAME))
 921                     continue;
 922             }
 923             san_present = 1;
 924             if (check_type == GEN_EMAIL)
 925                 cstr = gen->d.rfc822Name;
 926             else if (check_type == GEN_DNS)
 927                 cstr = gen->d.dNSName;
 928             else
 929                 cstr = gen->d.iPAddress;
 930             /* Positive on success, negative on error! */
 931             if ((rv = do_check_string(cstr, alt_type, equal, flags,
 932                                       chk, chklen, peername)) != 0)
 933                 break;
 934         }
 935         GENERAL_NAMES_free(gens);
 936         if (rv != 0)
 937             return rv;
 938         if (san_present && !(flags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT))
 939             return 0;
 940     }
 941
 942     /* We're done if CN-ID is not pertinent */
 943     if (cnid == NID_undef || (flags & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT))
 944         return 0;
 945
 946     i = -1;
 947     name = X509_get_subject_name(x);
 948     while ((i = X509_NAME_get_index_by_NID(name, cnid, i)) >= 0) {
 949         const X509_NAME_ENTRY *ne = X509_NAME_get_entry(name, i);
 950         const ASN1_STRING *str = X509_NAME_ENTRY_get_data(ne);
 951
 952         /* Positive on success, negative on error! */
 953         if ((rv = do_check_string(str, -1, equal, flags,
 954                                   chk, chklen, peername)) != 0)
 955             return rv;
 956     }
 957     return 0;
 958 }
 959
 960 int X509_check_host(X509 *x, const char *chk, size_t chklen,
 961                     unsigned int flags, char **peername)
 962 {
 963     if (chk == NULL)
 964         return -2;
 965     /*
 966      * Embedded NULs are disallowed, except as the last character of a
 967      * string of length 2 or more (tolerate caller including terminating
 968      * NUL in string length).
 969      */
 970     if (chklen == 0)
 971         chklen = strlen(chk);
 972     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 973         return -2;
 974     if (chklen > 1 && chk[chklen - 1] == '\0')
 975         --chklen;
 976     return do_x509_check(x, chk, chklen, flags, GEN_DNS, peername);
 977 }
 978
 979 int X509_check_email(X509 *x, const char *chk, size_t chklen,
 980                      unsigned int flags)
 981 {
 982     if (chk == NULL)
 983         return -2;
 984     /*
 985      * Embedded NULs are disallowed, except as the last character of a
 986      * string of length 2 or more (tolerate caller including terminating
 987      * NUL in string length).
 988      */
 989     if (chklen == 0)
 990         chklen = strlen((char *)chk);
 991     else if (memchr(chk, '\0', chklen > 1 ? chklen - 1 : chklen))
 992         return -2;
 993     if (chklen > 1 && chk[chklen - 1] == '\0')
 994         --chklen;
 995     return do_x509_check(x, chk, chklen, flags, GEN_EMAIL, NULL);
 996 }
 997
 998 int X509_check_ip(X509 *x, const unsigned char *chk, size_t chklen,
 999                   unsigned int flags)
1000 {
1001     if (chk == NULL)
1002         return -2;
1003     return do_x509_check(x, (char *)chk, chklen, flags, GEN_IPADD, NULL);
1004 }
1005
1006 int X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags)
1007 {
1008     unsigned char ipout[16];
1009     size_t iplen;
1010
1011     if (ipasc == NULL)
1012         return -2;
1013     iplen = (size_t)ossl_a2i_ipadd(ipout, ipasc);
1014     if (iplen == 0)
1015         return -2;
1016     return do_x509_check(x, (char *)ipout, iplen, flags, GEN_IPADD, NULL);
1017 }
1018
1019 char *ossl_ipaddr_to_asc(unsigned char *p, int len)
1020 {
1021     /*
1022      * 40 is enough space for the longest IPv6 address + nul terminator byte
1023      * XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX\0
1024      */
1025     char buf[40], *out;
1026     int i = 0, remain = 0, bytes = 0;
1027
1028     switch (len) {
1029     case 4: /* IPv4 */
1030         BIO_snprintf(buf, sizeof(buf), "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
1031         break;
1032     case 16: /* IPv6 */
1033         for (out = buf, i = 8, remain = sizeof(buf);
1034              i-- > 0 && bytes >= 0;
1035              remain -= bytes, out += bytes) {
1036             const char *template = (i > 0 ? "%X:" : "%X");
1037
1038             bytes = BIO_snprintf(out, remain, template, p[0] << 8 | p[1]);
1039             p += 2;
1040         }
1041         break;
1042     default:
1043         BIO_snprintf(buf, sizeof(buf), "<invalid length=%d>", len);
1044         break;
1045     }
1046     return OPENSSL_strdup(buf);
1047 }
1048
1049 /*
1050  * Convert IP addresses both IPv4 and IPv6 into an OCTET STRING compatible
1051  * with RFC3280.
1052  */
1053
1054 ASN1_OCTET_STRING *a2i_IPADDRESS(const char *ipasc)
1055 {
1056     unsigned char ipout[16];
1057     ASN1_OCTET_STRING *ret;
1058     int iplen;
1059
1060     /* If string contains a ':' assume IPv6 */
1061
1062     iplen = ossl_a2i_ipadd(ipout, ipasc);
1063
1064     if (!iplen)
1065         return NULL;
1066
1067     ret = ASN1_OCTET_STRING_new();
1068     if (ret == NULL)
1069         return NULL;
1070     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen)) {
1071         ASN1_OCTET_STRING_free(ret);
1072         return NULL;
1073     }
1074     return ret;
1075 }
1076
1077 ASN1_OCTET_STRING *a2i_IPADDRESS_NC(const char *ipasc)
1078 {
1079     ASN1_OCTET_STRING *ret = NULL;
1080     unsigned char ipout[32];
1081     char *iptmp = NULL, *p;
1082     int iplen1, iplen2;
1083
1084     p = strchr(ipasc, '/');
1085     if (p == NULL)
1086         return NULL;
1087     iptmp = OPENSSL_strdup(ipasc);
1088     if (iptmp == NULL)
1089         return NULL;
1090     p = iptmp + (p - ipasc);
1091     *p++ = 0;
1092
1093     iplen1 = ossl_a2i_ipadd(ipout, iptmp);
1094
1095     if (!iplen1)
1096         goto err;
1097
1098     iplen2 = ossl_a2i_ipadd(ipout + iplen1, p);
1099
1100     OPENSSL_free(iptmp);
1101     iptmp = NULL;
1102
1103     if (!iplen2 || (iplen1 != iplen2))
1104         goto err;
1105
1106     ret = ASN1_OCTET_STRING_new();
1107     if (ret == NULL)
1108         goto err;
1109     if (!ASN1_OCTET_STRING_set(ret, ipout, iplen1 + iplen2))
1110         goto err;
1111
1112     return ret;
1113
1114  err:
1115     OPENSSL_free(iptmp);
1116     ASN1_OCTET_STRING_free(ret);
1117     return NULL;
1118 }
1119
1120 int ossl_a2i_ipadd(unsigned char *ipout, const char *ipasc)
1121 {
1122     /* If string contains a ':' assume IPv6 */
1123
1124     if (strchr(ipasc, ':')) {
1125         if (!ipv6_from_asc(ipout, ipasc))
1126             return 0;
1127         return 16;
1128     } else {
1129         if (!ipv4_from_asc(ipout, ipasc))
1130             return 0;
1131         return 4;
1132     }
1133 }
1134
1135 static int ipv4_from_asc(unsigned char *v4, const char *in)
1136 {
1137     const char *p;
1138     int a0, a1, a2, a3, n;
1139
1140     if (sscanf(in, "%d.%d.%d.%d%n", &a0, &a1, &a2, &a3, &n) != 4)
1141         return 0;
1142     if ((a0 < 0) || (a0 > 255) || (a1 < 0) || (a1 > 255)
1143         || (a2 < 0) || (a2 > 255) || (a3 < 0) || (a3 > 255))
1144         return 0;
1145     p = in + n;
1146     if (!(*p == '\0' || ossl_isspace(*p)))
1147         return 0;
1148     v4[0] = a0;
1149     v4[1] = a1;
1150     v4[2] = a2;
1151     v4[3] = a3;
1152     return 1;
1153 }
1154
1155 typedef struct {
1156     /* Temporary store for IPV6 output */
1157     unsigned char tmp[16];
1158     /* Total number of bytes in tmp */
1159     int total;
1160     /* The position of a zero (corresponding to '::') */
1161     int zero_pos;
1162     /* Number of zeroes */
1163     int zero_cnt;
1164 } IPV6_STAT;
1165
1166 static int ipv6_from_asc(unsigned char *v6, const char *in)
1167 {
1168     IPV6_STAT v6stat;
1169
1170     v6stat.total = 0;
1171     v6stat.zero_pos = -1;
1172     v6stat.zero_cnt = 0;
1173     /*
1174      * Treat the IPv6 representation as a list of values separated by ':'.
1175      * The presence of a '::' will parse as one, two or three zero length
1176      * elements.
1177      */
1178     if (!CONF_parse_list(in, ':', 0, ipv6_cb, &v6stat))
1179         return 0;
1180
1181     /* Now for some sanity checks */
1182
1183     if (v6stat.zero_pos == -1) {
1184         /* If no '::' must have exactly 16 bytes */
1185         if (v6stat.total != 16)
1186             return 0;
1187     } else {
1188         /* If '::' must have less than 16 bytes */
1189         if (v6stat.total == 16)
1190             return 0;
1191         /* More than three zeroes is an error */
1192         if (v6stat.zero_cnt > 3) {
1193             return 0;
1194         /* Can only have three zeroes if nothing else present */
1195         } else if (v6stat.zero_cnt == 3) {
1196             if (v6stat.total > 0)
1197                 return 0;
1198         } else if (v6stat.zero_cnt == 2) {
1199             /* Can only have two zeroes if at start or end */
1200             if ((v6stat.zero_pos != 0)
1201                 && (v6stat.zero_pos != v6stat.total))
1202                 return 0;
1203         } else {
1204             /* Can only have one zero if *not* start or end */
1205             if ((v6stat.zero_pos == 0)
1206                 || (v6stat.zero_pos == v6stat.total))
1207                 return 0;
1208         }
1209     }
1210
1211     /* Format result */
1212
1213     if (v6stat.zero_pos >= 0) {
1214         /* Copy initial part */
1215         memcpy(v6, v6stat.tmp, v6stat.zero_pos);
1216         /* Zero middle */
1217         memset(v6 + v6stat.zero_pos, 0, 16 - v6stat.total);
1218         /* Copy final part */
1219         if (v6stat.total != v6stat.zero_pos)
1220             memcpy(v6 + v6stat.zero_pos + 16 - v6stat.total,
1221                    v6stat.tmp + v6stat.zero_pos,
1222                    v6stat.total - v6stat.zero_pos);
1223     } else {
1224         memcpy(v6, v6stat.tmp, 16);
1225     }
1226
1227     return 1;
1228 }
1229
1230 static int ipv6_cb(const char *elem, int len, void *usr)
1231 {
1232     IPV6_STAT *s = usr;
1233
1234     /* Error if 16 bytes written */
1235     if (s->total == 16)
1236         return 0;
1237     if (len == 0) {
1238         /* Zero length element, corresponds to '::' */
1239         if (s->zero_pos == -1)
1240             s->zero_pos = s->total;
1241         /* If we've already got a :: its an error */
1242         else if (s->zero_pos != s->total)
1243             return 0;
1244         s->zero_cnt++;
1245     } else {
1246         /* If more than 4 characters could be final a.b.c.d form */
1247         if (len > 4) {
1248             /* Need at least 4 bytes left */
1249             if (s->total > 12)
1250                 return 0;
1251             /* Must be end of string */
1252             if (elem[len])
1253                 return 0;
1254             if (!ipv4_from_asc(s->tmp + s->total, elem))
1255                 return 0;
1256             s->total += 4;
1257         } else {
1258             if (!ipv6_hex(s->tmp + s->total, elem, len))
1259                 return 0;
1260             s->total += 2;
1261         }
1262     }
1263     return 1;
1264 }
1265
1266 /*
1267  * Convert a string of up to 4 hex digits into the corresponding IPv6 form.
1268  */
1269
1270 static int ipv6_hex(unsigned char *out, const char *in, int inlen)
1271 {
1272     unsigned char c;
1273     unsigned int num = 0;
1274     int x;
1275
1276     if (inlen > 4)
1277         return 0;
1278     while (inlen--) {
1279         c = *in++;
1280         num <<= 4;
1281         x = OPENSSL_hexchar2int(c);
1282         if (x < 0)
1283             return 0;
1284         num |= (char)x;
1285     }
1286     out[0] = num >> 8;
1287     out[1] = num & 0xff;
1288     return 1;
1289 }
1290
1291 int X509V3_NAME_from_section(X509_NAME *nm, STACK_OF(CONF_VALUE) *dn_sk,
1292                              unsigned long chtype)
1293 {
1294     CONF_VALUE *v;
1295     int i, mval, spec_char, plus_char;
1296     char *p, *type;
1297
1298     if (!nm)
1299         return 0;
1300
1301     for (i = 0; i < sk_CONF_VALUE_num(dn_sk); i++) {
1302         v = sk_CONF_VALUE_value(dn_sk, i);
1303         type = v->name;
1304         /*
1305          * Skip past any leading X. X: X, etc to allow for multiple instances
1306          */
1307         for (p = type; *p; p++) {
1308 #ifndef CHARSET_EBCDIC
1309             spec_char = ((*p == ':') || (*p == ',') || (*p == '.'));
1310 #else
1311             spec_char = ((*p == os_toascii[':']) || (*p == os_toascii[','])
1312                          || (*p == os_toascii['.']));
1313 #endif
1314             if (spec_char) {
1315                 p++;
1316                 if (*p)
1317                     type = p;
1318                 break;
1319             }
1320         }
1321 #ifndef CHARSET_EBCDIC
1322         plus_char = (*type == '+');
1323 #else
1324         plus_char = (*type == os_toascii['+']);
1325 #endif
1326         if (plus_char) {
1327             mval = -1;
1328             type++;
1329         } else {
1330             mval = 0;
1331         }
1332         if (!X509_NAME_add_entry_by_txt(nm, type, chtype,
1333                                         (unsigned char *)v->value, -1, -1,
1334                                         mval))
1335             return 0;
1336
1337     }
1338     return 1;
1339 }