1 files changed, 1387 insertions, 0 deletions

diff --git a/src/lib/libcrypto/x509/x509_utl.c b/src/lib/libcrypto/x509/x509_utl.c
new file mode 100644
index 0000000000..4641152f74
--- /dev/null
+++ b/src/lib/libcrypto/x509/x509_utl.c
@@ -0,0 +1,1387 @@
+/* $OpenBSD: x509_utl.c,v 1.1 2020/06/04 15:19:32 jsing Exp $ */
+/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
+ * project.
+ */
+/* ====================================================================
+ * Copyright (c) 1999-2003 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+/* X509 v3 extension utilities */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/conf.h>
+#include <openssl/err.h>
+#include <openssl/x509v3.h>
+
+char *bn_to_string(const BIGNUM *bn);
+static char *strip_spaces(char *name);
+static int sk_strcmp(const char * const *a, const char * const *b);
+static STACK_OF(OPENSSL_STRING) *get_email(X509_NAME *name,
+    GENERAL_NAMES *gens);
+static void str_free(OPENSSL_STRING str);
+static int append_ia5(STACK_OF(OPENSSL_STRING) **sk, ASN1_IA5STRING *email);
+
+static int ipv4_from_asc(unsigned char *v4, const char *in);
+static int ipv6_from_asc(unsigned char *v6, const char *in);
+static int ipv6_cb(const char *elem, int len, void *usr);
+static int ipv6_hex(unsigned char *out, const char *in, int inlen);
+
+/* Add a CONF_VALUE name-value pair to stack. */
+int
+X509V3_add_value(const char *name, const char *value,
+    STACK_OF(CONF_VALUE) **extlist)
+{
+        CONF_VALUE *vtmp = NULL;
+        STACK_OF(CONF_VALUE) *free_exts = NULL;
+
+        if ((vtmp = calloc(1, sizeof(CONF_VALUE))) == NULL)
+                goto err;
+        if (name != NULL) {
+                if ((vtmp->name = strdup(name)) == NULL)
+                        goto err;
+        }
+        if (value != NULL) {
+                if ((vtmp->value = strdup(value)) == NULL)
+                        goto err;
+        }
+
+        if (*extlist == NULL) {
+                if ((free_exts = *extlist = sk_CONF_VALUE_new_null()) == NULL)
+                        goto err;
+        }
+
+        if (!sk_CONF_VALUE_push(*extlist, vtmp))
+                goto err;
+
+        return 1;
+
+ err:
+        X509V3error(ERR_R_MALLOC_FAILURE);
+        X509V3_conf_free(vtmp);
+        if (free_exts != NULL) {
+                sk_CONF_VALUE_free(*extlist);
+                *extlist = NULL;
+        }
+        return 0;
+}
+
+int
+X509V3_add_value_uchar(const char *name, const unsigned char *value,
+    STACK_OF(CONF_VALUE) **extlist)
+{
+        return X509V3_add_value(name, (const char *)value, extlist);
+}
+
+/* Free function for STACK_OF(CONF_VALUE) */
+
+void
+X509V3_conf_free(CONF_VALUE *conf)
+{
+        if (!conf)
+                return;
+        free(conf->name);
+        free(conf->value);
+        free(conf->section);
+        free(conf);
+}
+
+int
+X509V3_add_value_bool(const char *name, int asn1_bool,
+    STACK_OF(CONF_VALUE) **extlist)
+{
+        if (asn1_bool)
+                return X509V3_add_value(name, "TRUE", extlist);
+        return X509V3_add_value(name, "FALSE", extlist);
+}
+
+int
+X509V3_add_value_bool_nf(const char *name, int asn1_bool,
+    STACK_OF(CONF_VALUE) **extlist)
+{
+        if (asn1_bool)
+                return X509V3_add_value(name, "TRUE", extlist);
+        return 1;
+}
+
+char *
+bn_to_string(const BIGNUM *bn)
+{
+        const char *sign = "";
+        char *bnstr, *hex;
+        char *ret = NULL;
+
+        /* Only display small numbers in decimal, as conversion is quadratic. */
+        if (BN_num_bits(bn) < 128)
+                return BN_bn2dec(bn);
+
+        if ((hex = bnstr = BN_bn2hex(bn)) == NULL)
+                goto err;
+
+        if (BN_is_negative(bn)) {
+                sign = "-";
+                hex++;
+        }
+
+        if (asprintf(&ret, "%s0x%s", sign, hex) == -1)
+                ret = NULL;
+
+ err:
+        free(bnstr);
+        return ret;
+}
+
+char *
+i2s_ASN1_ENUMERATED(X509V3_EXT_METHOD *method, const ASN1_ENUMERATED *a)
+{
+        BIGNUM *bntmp;
+        char *strtmp = NULL;
+
+        if (a == NULL)
+                return NULL;
+        if ((bntmp = ASN1_ENUMERATED_to_BN(a, NULL)) == NULL ||
+            (strtmp = bn_to_string(bntmp)) == NULL)
+                X509V3error(ERR_R_MALLOC_FAILURE);
+        BN_free(bntmp);
+        return strtmp;
+}
+
+char *
+i2s_ASN1_INTEGER(X509V3_EXT_METHOD *method, const ASN1_INTEGER *a)
+{
+        BIGNUM *bntmp;
+        char *strtmp = NULL;
+
+        if (a == NULL)
+                return NULL;
+        if ((bntmp = ASN1_INTEGER_to_BN(a, NULL)) == NULL ||
+            (strtmp = bn_to_string(bntmp)) == NULL)
+                X509V3error(ERR_R_MALLOC_FAILURE);
+        BN_free(bntmp);
+        return strtmp;
+}
+
+ASN1_INTEGER *
+s2i_ASN1_INTEGER(X509V3_EXT_METHOD *method, const char *value)
+{
+        BIGNUM *bn = NULL;
+        ASN1_INTEGER *aint;
+        int isneg, ishex;
+        int ret;
+
+        if (!value) {
+                X509V3error(X509V3_R_INVALID_NULL_VALUE);
+                return 0;
+        }
+        bn = BN_new();
+        if (value[0] == '-') {
+                value++;
+                isneg = 1;
+        } else
+                isneg = 0;
+
+        if (value[0] == '0' && ((value[1] == 'x') || (value[1] == 'X'))) {
+                value += 2;
+                ishex = 1;
+        } else
+                ishex = 0;
+
+        if (ishex)
+                ret = BN_hex2bn(&bn, value);
+        else
+                ret = BN_dec2bn(&bn, value);
+
+        if (!ret || value[ret]) {
+                BN_free(bn);
+                X509V3error(X509V3_R_BN_DEC2BN_ERROR);
+                return 0;
+        }
+
+        if (isneg && BN_is_zero(bn))
+                isneg = 0;
+
+        aint = BN_to_ASN1_INTEGER(bn, NULL);
+        BN_free(bn);
+        if (!aint) {
+                X509V3error(X509V3_R_BN_TO_ASN1_INTEGER_ERROR);
+                return 0;
+        }
+        if (isneg)
+                aint->type |= V_ASN1_NEG;
+        return aint;
+}
+
+int
+X509V3_add_value_int(const char *name, const ASN1_INTEGER *aint,
+    STACK_OF(CONF_VALUE) **extlist)
+{
+        char *strtmp;
+        int ret;
+
+        if (!aint)
+                return 1;
+        if (!(strtmp = i2s_ASN1_INTEGER(NULL, aint)))
+                return 0;
+        ret = X509V3_add_value(name, strtmp, extlist);
+        free(strtmp);
+        return ret;
+}
+
+int
+X509V3_get_value_bool(const CONF_VALUE *value, int *asn1_bool)
+{
+        char *btmp;
+
+        if (!(btmp = value->value))
+                goto err;
+        if (!strcmp(btmp, "TRUE") || !strcmp(btmp, "true") ||
+            !strcmp(btmp, "Y") || !strcmp(btmp, "y") ||
+            !strcmp(btmp, "YES") || !strcmp(btmp, "yes")) {
+                *asn1_bool = 0xff;
+                return 1;
+        } else if (!strcmp(btmp, "FALSE") || !strcmp(btmp, "false") ||
+            !strcmp(btmp, "N") || !strcmp(btmp, "n") ||
+            !strcmp(btmp, "NO") || !strcmp(btmp, "no")) {
+                *asn1_bool = 0;
+                return 1;
+        }
+
+ err:
+        X509V3error(X509V3_R_INVALID_BOOLEAN_STRING);
+        X509V3_conf_err(value);
+        return 0;
+}
+
+int
+X509V3_get_value_int(const CONF_VALUE *value, ASN1_INTEGER **aint)
+{
+        ASN1_INTEGER *itmp;
+
+        if (!(itmp = s2i_ASN1_INTEGER(NULL, value->value))) {
+                X509V3_conf_err(value);
+                return 0;
+        }
+        *aint = itmp;
+        return 1;
+}
+
+#define HDR_NAME        1
+#define HDR_VALUE       2
+
+/*#define DEBUG*/
+
+STACK_OF(CONF_VALUE) *
+X509V3_parse_list(const char *line)
+{
+        char *p, *q, c;
+        char *ntmp, *vtmp;
+        STACK_OF(CONF_VALUE) *values = NULL;
+        char *linebuf;
+        int state;
+
+        /* We are going to modify the line so copy it first */
+        if ((linebuf = strdup(line)) == NULL) {
+                X509V3error(ERR_R_MALLOC_FAILURE);
+                goto err;
+        }
+        state = HDR_NAME;
+        ntmp = NULL;
+
+        /* Go through all characters */
+        for (p = linebuf, q = linebuf; (c = *p) && (c != '\r') &&
+            (c != '\n'); p++) {
+
+                switch (state) {
+                case HDR_NAME:
+                        if (c == ':') {
+                                state = HDR_VALUE;
+                                *p = 0;
+                                ntmp = strip_spaces(q);
+                                if (!ntmp) {
+                                        X509V3error(X509V3_R_INVALID_NULL_NAME);
+                                        goto err;
+                                }
+                                q = p + 1;
+                        } else if (c == ',') {
+                                *p = 0;
+                                ntmp = strip_spaces(q);
+                                q = p + 1;
+                                if (!ntmp) {
+                                        X509V3error(X509V3_R_INVALID_NULL_NAME);
+                                        goto err;
+                                }
+                                X509V3_add_value(ntmp, NULL, &values);
+                        }
+                        break;
+
+                case HDR_VALUE:
+                        if (c == ',') {
+                                state = HDR_NAME;
+                                *p = 0;
+                                vtmp = strip_spaces(q);
+                                if (!vtmp) {
+                                        X509V3error(X509V3_R_INVALID_NULL_VALUE);
+                                        goto err;
+                                }
+                                X509V3_add_value(ntmp, vtmp, &values);
+                                ntmp = NULL;
+                                q = p + 1;
+                        }
+
+                }
+        }
+
+        if (state == HDR_VALUE) {
+                vtmp = strip_spaces(q);
+                if (!vtmp) {
+                        X509V3error(X509V3_R_INVALID_NULL_VALUE);
+                        goto err;
+                }
+                X509V3_add_value(ntmp, vtmp, &values);
+        } else {
+                ntmp = strip_spaces(q);
+                if (!ntmp) {
+                        X509V3error(X509V3_R_INVALID_NULL_NAME);
+                        goto err;
+                }
+                X509V3_add_value(ntmp, NULL, &values);
+        }
+        free(linebuf);
+        return values;
+
+ err:
+        free(linebuf);
+        sk_CONF_VALUE_pop_free(values, X509V3_conf_free);
+        return NULL;
+
+}
+
+/* Delete leading and trailing spaces from a string */
+static char *
+strip_spaces(char *name)
+{
+        char *p, *q;
+
+        /* Skip over leading spaces */
+        p = name;
+        while (*p && isspace((unsigned char)*p))
+                p++;
+        if (!*p)
+                return NULL;
+        q = p + strlen(p) - 1;
+        while ((q != p) && isspace((unsigned char)*q))
+                q--;
+        if (p != q)
+                q[1] = 0;
+        if (!*p)
+                return NULL;
+        return p;
+}
+
+/* hex string utilities */
+
+/* Given a buffer of length 'len' return a malloc'ed string with its
+ * hex representation
+ */
+char *
+hex_to_string(const unsigned char *buffer, long len)
+{
+        char *tmp, *q;
+        const unsigned char *p;
+        int i;
+        static const char hexdig[] = "0123456789ABCDEF";
+
+        if (!buffer || !len)
+                return NULL;
+        if (!(tmp = malloc(len * 3 + 1))) {
+                X509V3error(ERR_R_MALLOC_FAILURE);
+                return NULL;
+        }
+        q = tmp;
+        for (i = 0, p = buffer; i < len; i++, p++) {
+                *q++ = hexdig[(*p >> 4) & 0xf];
+                *q++ = hexdig[*p & 0xf];
+                *q++ = ':';
+        }
+        q[-1] = 0;
+        return tmp;
+}
+
+/* Give a string of hex digits convert to
+ * a buffer
+ */
+
+unsigned char *
+string_to_hex(const char *str, long *len)
+{
+        unsigned char *hexbuf, *q;
+        unsigned char ch, cl, *p;
+        if (!str) {
+                X509V3error(X509V3_R_INVALID_NULL_ARGUMENT);
+                return NULL;
+        }
+        if (!(hexbuf = malloc(strlen(str) >> 1)))
+                goto err;
+        for (p = (unsigned char *)str, q = hexbuf; *p; ) {
+                ch = *p++;
+                if (ch == ':')
+                        continue;
+                cl = *p++;
+                if (!cl) {
+                        X509V3error(X509V3_R_ODD_NUMBER_OF_DIGITS);
+                        free(hexbuf);
+                        return NULL;
+                }
+                ch = tolower(ch);
+                cl = tolower(cl);
+
+                if ((ch >= '0') && (ch <= '9'))
+                        ch -= '0';
+                else if ((ch >= 'a') && (ch <= 'f'))
+                        ch -= 'a' - 10;
+                else
+                        goto badhex;
+
+                if ((cl >= '0') && (cl <= '9'))
+                        cl -= '0';
+                else if ((cl >= 'a') && (cl <= 'f'))
+                        cl -= 'a' - 10;
+                else
+                        goto badhex;
+
+                *q++ = (ch << 4) | cl;
+        }
+
+        if (len)
+                *len = q - hexbuf;
+
+        return hexbuf;
+
+ err:
+        free(hexbuf);
+        X509V3error(ERR_R_MALLOC_FAILURE);
+        return NULL;
+
+ badhex:
+        free(hexbuf);
+        X509V3error(X509V3_R_ILLEGAL_HEX_DIGIT);
+        return NULL;
+}
+
+/* V2I name comparison function: returns zero if 'name' matches
+ * cmp or cmp.*
+ */
+
+int
+name_cmp(const char *name, const char *cmp)
+{
+        int len, ret;
+        char c;
+
+        len = strlen(cmp);
+        if ((ret = strncmp(name, cmp, len)))
+                return ret;
+        c = name[len];
+        if (!c || (c=='.'))
+                return 0;
+        return 1;
+}
+
+static int
+sk_strcmp(const char * const *a, const char * const *b)
+{
+        return strcmp(*a, *b);
+}
+
+STACK_OF(OPENSSL_STRING) *
+X509_get1_email(X509 *x)
+{
+        GENERAL_NAMES *gens;
+        STACK_OF(OPENSSL_STRING) *ret;
+
+        gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
+        ret = get_email(X509_get_subject_name(x), gens);
+        sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
+        return ret;
+}
+
+STACK_OF(OPENSSL_STRING) *
+X509_get1_ocsp(X509 *x)
+{
+        AUTHORITY_INFO_ACCESS *info;
+        STACK_OF(OPENSSL_STRING) *ret = NULL;
+        int i;
+
+        info = X509_get_ext_d2i(x, NID_info_access, NULL, NULL);
+        if (!info)
+                return NULL;
+        for (i = 0; i < sk_ACCESS_DESCRIPTION_num(info); i++) {
+                ACCESS_DESCRIPTION *ad = sk_ACCESS_DESCRIPTION_value(info, i);
+                if (OBJ_obj2nid(ad->method) == NID_ad_OCSP) {
+                        if (ad->location->type == GEN_URI) {
+                                if (!append_ia5(&ret,
+                                    ad->location->d.uniformResourceIdentifier))
+                                        break;
+                        }
+                }
+        }
+        AUTHORITY_INFO_ACCESS_free(info);
+        return ret;
+}
+
+STACK_OF(OPENSSL_STRING) *
+X509_REQ_get1_email(X509_REQ *x)
+{
+        GENERAL_NAMES *gens;
+        STACK_OF(X509_EXTENSION) *exts;
+        STACK_OF(OPENSSL_STRING) *ret;
+
+        exts = X509_REQ_get_extensions(x);
+        gens = X509V3_get_d2i(exts, NID_subject_alt_name, NULL, NULL);
+        ret = get_email(X509_REQ_get_subject_name(x), gens);
+        sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
+        sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
+        return ret;
+}
+
+
+static STACK_OF(OPENSSL_STRING) *
+get_email(X509_NAME *name, GENERAL_NAMES *gens)
+{
+        STACK_OF(OPENSSL_STRING) *ret = NULL;
+        X509_NAME_ENTRY *ne;
+        ASN1_IA5STRING *email;
+        GENERAL_NAME *gen;
+        int i;
+
+        /* Now add any email address(es) to STACK */
+        i = -1;
+
+        /* First supplied X509_NAME */
+        while ((i = X509_NAME_get_index_by_NID(name,
+            NID_pkcs9_emailAddress, i)) >= 0) {
+                ne = X509_NAME_get_entry(name, i);
+                email = X509_NAME_ENTRY_get_data(ne);
+                if (!append_ia5(&ret, email))
+                        return NULL;
+        }
+        for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
+                gen = sk_GENERAL_NAME_value(gens, i);
+                if (gen->type != GEN_EMAIL)
+                        continue;
+                if (!append_ia5(&ret, gen->d.ia5))
+                        return NULL;
+        }
+        return ret;
+}
+
+static void
+str_free(OPENSSL_STRING str)
+{
+        free(str);
+}
+
+static int
+append_ia5(STACK_OF(OPENSSL_STRING) **sk, ASN1_IA5STRING *email)
+{
+        char *emtmp;
+
+        /* First some sanity checks */
+        if (email->type != V_ASN1_IA5STRING)
+                return 1;
+        if (!email->data || !email->length)
+                return 1;
+        if (!*sk)
+                *sk = sk_OPENSSL_STRING_new(sk_strcmp);
+        if (!*sk)
+                return 0;
+        /* Don't add duplicates */
+        if (sk_OPENSSL_STRING_find(*sk, (char *)email->data) != -1)
+                return 1;
+        emtmp = strdup((char *)email->data);
+        if (!emtmp || !sk_OPENSSL_STRING_push(*sk, emtmp)) {
+                X509_email_free(*sk);
+                *sk = NULL;
+                return 0;
+        }
+        return 1;
+}
+
+void
+X509_email_free(STACK_OF(OPENSSL_STRING) *sk)
+{
+        sk_OPENSSL_STRING_pop_free(sk, str_free);
+}
+
+typedef int (*equal_fn)(const unsigned char *pattern, size_t pattern_len,
+    const unsigned char *subject, size_t subject_len, unsigned int flags);
+
+/* Skip pattern prefix to match "wildcard" subject */
+static void
+skip_prefix(const unsigned char **p, size_t *plen, const unsigned char *subject,
+    size_t subject_len, unsigned int flags)
+{
+        const unsigned char *pattern = *p;
+        size_t pattern_len = *plen;
+
+        /*
+         * If subject starts with a leading '.' followed by more octets, and
+         * pattern is longer, compare just an equal-length suffix with the
+         * full subject (starting at the '.'), provided the prefix contains
+         * no NULs.
+         */
+        if ((flags & _X509_CHECK_FLAG_DOT_SUBDOMAINS) == 0)
+                return;
+
+        while (pattern_len > subject_len && *pattern) {
+                if ((flags & X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS) &&
+                    *pattern == '.')
+                        break;
+                ++pattern;
+                --pattern_len;
+        }
+
+        /* Skip if entire prefix acceptable */
+        if (pattern_len == subject_len) {
+                *p = pattern;
+                *plen = pattern_len;
+        }
+}
+
+/*
+ * Open/BoringSSL uses memcmp for "equal_case" while their
+ * "equal_nocase" function is a hand-rolled strncasecmp that does not
+ * allow \0 in the pattern. Since an embedded \0 is likely a sign of
+ * problems, we simply don't allow it in either case, and then we use
+ * standard libc funcitons.
+ */
+
+/* Compare using strncasecmp */
+static int
+equal_nocase(const unsigned char *pattern, size_t pattern_len,
+    const unsigned char *subject, size_t subject_len, unsigned int flags)
+{
+        if (memchr(pattern, '\0', pattern_len) != NULL)
+                return 0;
+        if (memchr(subject, '\0', subject_len) != NULL)
+                return 0;
+        skip_prefix(&pattern, &pattern_len, subject, subject_len, flags);
+        if (pattern_len != subject_len)
+                return 0;
+        return (strncasecmp(pattern, subject, pattern_len) == 0);
+}
+
+/* Compare using strncmp. */
+static int
+equal_case(const unsigned char *pattern, size_t pattern_len,
+    const unsigned char *subject, size_t subject_len, unsigned int flags)
+{
+        if (memchr(pattern, 0, pattern_len) != NULL)
+                return 0;
+        if (memchr(subject, 0, subject_len) != NULL)
+                return 0;
+        skip_prefix(&pattern, &pattern_len, subject, subject_len, flags);
+        if (pattern_len != subject_len)
+                return 0;
+        return (strncmp(pattern, subject, pattern_len) == 0);
+}
+
+/*
+ * RFC 5280, section 7.5, requires that only the domain is compared in a
+ * case-insensitive manner.
+ */
+static int
+equal_email(const unsigned char *a, size_t a_len, const unsigned char *b,
+    size_t b_len, unsigned int unused_flags)
+{
+        size_t pos = a_len;
+        if (a_len != b_len)
+                return 0;
+        /*
+         * We search backwards for the '@' character, so that we do not have to
+         * deal with quoted local-parts.  The domain part is compared in a
+         * case-insensitive manner.
+         */
+        while (pos > 0) {
+                pos--;
+                if (a[pos] == '@' || b[pos] == '@') {
+                        if (!equal_nocase(a + pos, a_len - pos, b + pos,
+                            a_len - pos, 0))
+                                return 0;
+                        break;
+                }
+        }
+        if (pos == 0)
+                pos = a_len;
+        return equal_case(a, pos, b, pos, 0);
+}
+
+/*
+ * Compare the prefix and suffix with the subject, and check that the
+ * characters in-between are valid.
+ */
+static int
+wildcard_match(const unsigned char *prefix, size_t prefix_len,
+    const unsigned char *suffix, size_t suffix_len,
+    const unsigned char *subject, size_t subject_len, unsigned int flags)
+{
+        const unsigned char *wildcard_start;
+        const unsigned char *wildcard_end;
+        const unsigned char *p;
+        int allow_multi = 0;
+        int allow_idna = 0;
+
+        if (subject_len < prefix_len + suffix_len)
+                return 0;
+        if (!equal_nocase(prefix, prefix_len, subject, prefix_len, flags))
+                return 0;
+        wildcard_start = subject + prefix_len;
+        wildcard_end = subject + (subject_len - suffix_len);
+        if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len, flags))
+                return 0;
+        /*
+         * If the wildcard makes up the entire first label, it must match at
+         * least one character.
+         */
+        if (prefix_len == 0 && *suffix == '.') {
+                if (wildcard_start == wildcard_end)
+                        return 0;
+                allow_idna = 1;
+                if (flags & X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS)
+                        allow_multi = 1;
+        }
+        /* IDNA labels cannot match partial wildcards */
+        if (!allow_idna &&
+            subject_len >= 4
+            && strncasecmp((char *)subject, "xn--", 4) == 0)
+                return 0;
+        /* The wildcard may match a literal '*' */
+        if (wildcard_end == wildcard_start + 1 && *wildcard_start == '*')
+                return 1;
+        /*
+         * Check that the part matched by the wildcard contains only
+         * permitted characters and only matches a single label unless
+         * allow_multi is set.
+         */
+        for (p = wildcard_start; p != wildcard_end; ++p)
+                if (!(('0' <= *p && *p <= '9') || ('A' <= *p && *p <= 'Z') ||
+                    ('a' <= *p && *p <= 'z') || *p == '-' ||
+                    (allow_multi && *p == '.')))
+                        return 0;
+        return 1;
+}
+
+#define LABEL_START     (1 << 0)
+#define LABEL_END       (1 << 1)
+#define LABEL_HYPHEN    (1 << 2)
+#define LABEL_IDNA      (1 << 3)
+
+static const unsigned char *
+valid_star(const unsigned char *p, size_t len, unsigned int flags)
+{
+        const unsigned char *star = 0;
+        size_t i;
+        int state = LABEL_START;
+        int dots = 0;
+        for (i = 0; i < len; ++i) {
+                /*
+                 * Locate first and only legal wildcard, either at the start
+                 * or end of a non-IDNA first and not final label.
+                 */
+                if (p[i] == '*') {
+                        int atstart = (state & LABEL_START);
+                        int atend = (i == len - 1 || p[i + 1] == '.');
+                        /*
+                         * At most one wildcard per pattern.
+                         * No wildcards in IDNA labels.
+                         * No wildcards after the first label.
+                         */
+                        if (star != NULL || (state & LABEL_IDNA) != 0 || dots)
+                                return NULL;
+                        /* Only full-label '*.example.com' wildcards? */
+                        if ((flags & X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)
+                            && (!atstart || !atend))
+                                return NULL;
+                        /* No 'foo*bar' wildcards */
+                        if (!atstart && !atend)
+                                return NULL;
+                        star = &p[i];
+                        state &= ~LABEL_START;
+                } else if ((state & LABEL_START) != 0) {
+                        /*
+                         * At the start of a label, skip any "xn--" and
+                         * remain in the LABEL_START state, but set the
+                         * IDNA label state
+                         */
+                        if ((state & LABEL_IDNA) == 0 && len - i >= 4
+                            && strncasecmp((char *)&p[i], "xn--", 4) == 0) {
+                                i += 3;
+                                state |= LABEL_IDNA;
+                                continue;
+                        }
+                        /* Labels must start with a letter or digit */
+                        state &= ~LABEL_START;
+                        if (('a' <= p[i] && p[i] <= 'z')
+                            || ('A' <= p[i] && p[i] <= 'Z')
+                            || ('0' <= p[i] && p[i] <= '9'))
+                                continue;
+                        return NULL;
+                } else if (('a' <= p[i] && p[i] <= 'z')
+                    || ('A' <= p[i] && p[i] <= 'Z')
+                    || ('0' <= p[i] && p[i] <= '9')) {
+                        state &= LABEL_IDNA;
+                        continue;
+                } else if (p[i] == '.') {
+                        if (state & (LABEL_HYPHEN | LABEL_START))
+                                return NULL;
+                        state = LABEL_START;
+                        ++dots;
+                } else if (p[i] == '-') {
+                        /* no domain/subdomain starts with '-' */
+                        if ((state & LABEL_START) != 0)
+                                return NULL;
+                        state |= LABEL_HYPHEN;
+                } else
+                        return NULL;
+        }
+
+        /*
+         * The final label must not end in a hyphen or ".", and
+         * there must be at least two dots after the star.
+         */
+        if ((state & (LABEL_START | LABEL_HYPHEN)) != 0 || dots < 2)
+                return NULL;
+        return star;
+}
+
+/* Compare using wildcards. */
+static int
+equal_wildcard(const unsigned char *pattern, size_t pattern_len,
+    const unsigned char *subject, size_t subject_len, unsigned int flags)
+{
+        const unsigned char *star = NULL;
+
+        /*
+         * Subject names starting with '.' can only match a wildcard pattern
+         * via a subject sub-domain pattern suffix match.
+         */
+        if (!(subject_len > 1 && subject[0] == '.'))
+                star = valid_star(pattern, pattern_len, flags);
+        if (star == NULL)
+                return equal_nocase(pattern, pattern_len,
+                    subject, subject_len, flags);
+        return wildcard_match(pattern, star - pattern,
+            star + 1, (pattern + pattern_len) - star - 1,
+            subject, subject_len, flags);
+}
+
+/*
+ * Compare an ASN1_STRING to a supplied string. If they match return 1. If
+ * cmp_type > 0 only compare if string matches the type, otherwise convert it
+ * to UTF8.
+ */
+
+static int
+do_check_string(ASN1_STRING *a, int cmp_type, equal_fn equal,
+    unsigned int flags, const char *b, size_t blen, char **peername)
+{
+        int rv = 0;
+
+        if (!a->data || !a->length)
+                return 0;
+        if (cmp_type > 0) {
+                if (cmp_type != a->type)
+                        return 0;
+                if (cmp_type == V_ASN1_IA5STRING)
+                        rv = equal(a->data, a->length, (unsigned char *)b,
+                            blen, flags);
+                else if (a->length == (int)blen && !memcmp(a->data, b, blen))
+                        rv = 1;
+                if (rv > 0 && peername &&
+                    (*peername = strndup((char *)a->data, a->length)) == NULL)
+                        rv = -1;
+        } else {
+                int astrlen;
+                unsigned char *astr;
+                astrlen = ASN1_STRING_to_UTF8(&astr, a);
+                if (astrlen < 0)
+                        return -1;
+                rv = equal(astr, astrlen, (unsigned char *)b, blen, flags);
+                if (rv > 0 && peername &&
+                    (*peername = strndup((char *)astr, astrlen)) == NULL)
+                        rv = -1;
+                free(astr);
+        }
+        return rv;
+}
+
+static int
+do_x509_check(X509 *x, const char *chk, size_t chklen, unsigned int flags,
+    int check_type, char **peername)
+{
+        GENERAL_NAMES *gens = NULL;
+        X509_NAME *name = NULL;
+        size_t i;
+        int j;
+        int cnid = NID_undef;
+        int alt_type;
+        int san_present = 0;
+        int rv = 0;
+        equal_fn equal;
+
+        /* See below, this flag is internal-only */
+        flags &= ~_X509_CHECK_FLAG_DOT_SUBDOMAINS;
+        if (check_type == GEN_EMAIL) {
+                cnid = NID_pkcs9_emailAddress;
+                alt_type = V_ASN1_IA5STRING;
+                equal = equal_email;
+        } else if (check_type == GEN_DNS) {
+                cnid = NID_commonName;
+                /* Implicit client-side DNS sub-domain pattern */
+                if (chklen > 1 && chk[0] == '.')
+                        flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;
+                alt_type = V_ASN1_IA5STRING;
+                if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
+                        equal = equal_nocase;
+                else
+                        equal = equal_wildcard;
+        } else {
+                alt_type = V_ASN1_OCTET_STRING;
+                equal = equal_case;
+        }
+
+        gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
+        if (gens != NULL) {
+                for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
+                        GENERAL_NAME *gen;
+                        ASN1_STRING *cstr;
+                        gen = sk_GENERAL_NAME_value(gens, i);
+                        if (gen->type != check_type)
+                                continue;
+                        san_present = 1;
+                        if (check_type == GEN_EMAIL)
+                                cstr = gen->d.rfc822Name;
+                        else if (check_type == GEN_DNS)
+                                cstr = gen->d.dNSName;
+                        else
+                                cstr = gen->d.iPAddress;
+                        /* Positive on success, negative on error! */
+                        if ((rv = do_check_string(cstr, alt_type, equal, flags,
+                            chk, chklen, peername)) != 0)
+                                break;
+                }
+                GENERAL_NAMES_free(gens);
+                if (rv != 0)
+                        return rv;
+                if (cnid == NID_undef ||
+                    (san_present &&
+                    !(flags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT)))
+                        return 0;
+        }
+
+        /* We're done if CN-ID is not pertinent */
+        if (cnid == NID_undef)
+                return 0;
+
+        j = -1;
+        name = X509_get_subject_name(x);
+        while ((j = X509_NAME_get_index_by_NID(name, cnid, j)) >= 0) {
+                X509_NAME_ENTRY *ne;
+                ASN1_STRING *str;
+                if ((ne = X509_NAME_get_entry(name, j)) == NULL)
+                        return -1;
+                if ((str = X509_NAME_ENTRY_get_data(ne)) == NULL)
+                        return -1;
+                /* Positive on success, negative on error! */
+                if ((rv = do_check_string(str, -1, equal, flags,
+                         chk, chklen, peername)) != 0)
+                        return rv;
+        }
+        return 0;
+}
+
+int
+X509_check_host(X509 *x, const char *chk, size_t chklen, unsigned int flags,
+    char **peername)
+{
+        if (chk == NULL)
+                return -2;
+        if (chklen == 0)
+                chklen = strlen(chk);
+        else if (memchr(chk, '\0', chklen))
+                return -2;
+        return do_x509_check(x, chk, chklen, flags, GEN_DNS, peername);
+}
+
+int
+X509_check_email(X509 *x, const char *chk, size_t chklen, unsigned int flags)
+{
+        if (chk == NULL)
+                return -2;
+        if (chklen == 0)
+                chklen = strlen(chk);
+        else if (memchr(chk, '\0', chklen))
+                return -2;
+        return do_x509_check(x, chk, chklen, flags, GEN_EMAIL, NULL);
+}
+
+int
+X509_check_ip(X509 *x, const unsigned char *chk, size_t chklen,
+    unsigned int flags)
+{
+        if (chk == NULL)
+                return -2;
+        return do_x509_check(x, (char *)chk, chklen, flags, GEN_IPADD, NULL);
+}
+
+int
+X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags)
+{
+        unsigned char ipout[16];
+        size_t iplen;
+
+        if (ipasc == NULL)
+                return -2;
+        iplen = (size_t)a2i_ipadd(ipout, ipasc);
+        if (iplen == 0)
+                return -2;
+        return do_x509_check(x, (char *)ipout, iplen, flags, GEN_IPADD, NULL);
+}
+
+/* Convert IP addresses both IPv4 and IPv6 into an
+ * OCTET STRING compatible with RFC3280.
+ */
+
+ASN1_OCTET_STRING *
+a2i_IPADDRESS(const char *ipasc)
+{
+        unsigned char ipout[16];
+        ASN1_OCTET_STRING *ret;
+        int iplen;
+
+        /* If string contains a ':' assume IPv6 */
+
+        iplen = a2i_ipadd(ipout, ipasc);
+
+        if (!iplen)
+                return NULL;
+
+        ret = ASN1_OCTET_STRING_new();
+        if (!ret)
+                return NULL;
+        if (!ASN1_OCTET_STRING_set(ret, ipout, iplen)) {
+                ASN1_OCTET_STRING_free(ret);
+                return NULL;
+        }
+        return ret;
+}
+
+ASN1_OCTET_STRING *
+a2i_IPADDRESS_NC(const char *ipasc)
+{
+        ASN1_OCTET_STRING *ret = NULL;
+        unsigned char ipout[32];
+        char *iptmp = NULL, *p;
+        int iplen1, iplen2;
+
+        p = strchr(ipasc, '/');
+        if (!p)
+                return NULL;
+        iptmp = strdup(ipasc);
+        if (!iptmp)
+                return NULL;
+        p = iptmp + (p - ipasc);
+        *p++ = 0;
+
+        iplen1 = a2i_ipadd(ipout, iptmp);
+
+        if (!iplen1)
+                goto err;
+
+        iplen2 = a2i_ipadd(ipout + iplen1, p);
+
+        free(iptmp);
+        iptmp = NULL;
+
+        if (!iplen2 || (iplen1 != iplen2))
+                goto err;
+
+        ret = ASN1_OCTET_STRING_new();
+        if (!ret)
+                goto err;
+        if (!ASN1_OCTET_STRING_set(ret, ipout, iplen1 + iplen2))
+                goto err;
+
+        return ret;
+
+ err:
+        free(iptmp);
+        if (ret)
+                ASN1_OCTET_STRING_free(ret);
+        return NULL;
+}
+
+
+int
+a2i_ipadd(unsigned char *ipout, const char *ipasc)
+{
+        /* If string contains a ':' assume IPv6 */
+
+        if (strchr(ipasc, ':')) {
+                if (!ipv6_from_asc(ipout, ipasc))
+                        return 0;
+                return 16;
+        } else {
+                if (!ipv4_from_asc(ipout, ipasc))
+                        return 0;
+                return 4;
+        }
+}
+
+static int
+ipv4_from_asc(unsigned char *v4, const char *in)
+{
+        int a0, a1, a2, a3;
+        if (sscanf(in, "%d.%d.%d.%d", &a0, &a1, &a2, &a3) != 4)
+                return 0;
+        if ((a0 < 0) || (a0 > 255) || (a1 < 0) || (a1 > 255) ||
+            (a2 < 0) || (a2 > 255) || (a3 < 0) || (a3 > 255))
+                return 0;
+        v4[0] = a0;
+        v4[1] = a1;
+        v4[2] = a2;
+        v4[3] = a3;
+        return 1;
+}
+
+typedef struct {
+        /* Temporary store for IPV6 output */
+        unsigned char tmp[16];
+        /* Total number of bytes in tmp */
+        int total;
+        /* The position of a zero (corresponding to '::') */
+        int zero_pos;
+        /* Number of zeroes */
+        int zero_cnt;
+} IPV6_STAT;
+
+
+static int
+ipv6_from_asc(unsigned char *v6, const char *in)
+{
+        IPV6_STAT v6stat;
+
+        v6stat.total = 0;
+        v6stat.zero_pos = -1;
+        v6stat.zero_cnt = 0;
+
+        /* Treat the IPv6 representation as a list of values
+         * separated by ':'. The presence of a '::' will parse
+         * as one, two or three zero length elements.
+         */
+        if (!CONF_parse_list(in, ':', 0, ipv6_cb, &v6stat))
+                return 0;
+
+        /* Now for some sanity checks */
+
+        if (v6stat.zero_pos == -1) {
+                /* If no '::' must have exactly 16 bytes */
+                if (v6stat.total != 16)
+                        return 0;
+        } else {
+                /* If '::' must have less than 16 bytes */
+                if (v6stat.total == 16)
+                        return 0;
+                /* More than three zeroes is an error */
+                if (v6stat.zero_cnt > 3)
+                        return 0;
+                /* Can only have three zeroes if nothing else present */
+                else if (v6stat.zero_cnt == 3) {
+                        if (v6stat.total > 0)
+                                return 0;
+                }
+                /* Can only have two zeroes if at start or end */
+                else if (v6stat.zero_cnt == 2) {
+                        if ((v6stat.zero_pos != 0) &&
+                            (v6stat.zero_pos != v6stat.total))
+                                return 0;
+                } else
+                        /* Can only have one zero if *not* start or end */
+                {
+                        if ((v6stat.zero_pos == 0) ||
+                            (v6stat.zero_pos == v6stat.total))
+                                return 0;
+                }
+        }
+
+        /* Format result */
+
+        if (v6stat.zero_pos >= 0) {
+                /* Copy initial part */
+                memcpy(v6, v6stat.tmp, v6stat.zero_pos);
+                /* Zero middle */
+                memset(v6 + v6stat.zero_pos, 0, 16 - v6stat.total);
+                /* Copy final part */
+                if (v6stat.total != v6stat.zero_pos)
+                        memcpy(v6 + v6stat.zero_pos + 16 - v6stat.total,
+                            v6stat.tmp + v6stat.zero_pos,
+                            v6stat.total - v6stat.zero_pos);
+        } else
+                memcpy(v6, v6stat.tmp, 16);
+
+        return 1;
+}
+
+static int
+ipv6_cb(const char *elem, int len, void *usr)
+{
+        IPV6_STAT *s = usr;
+
+        /* Error if 16 bytes written */
+        if (s->total == 16)
+                return 0;
+        if (len == 0) {
+                /* Zero length element, corresponds to '::' */
+                if (s->zero_pos == -1)
+                        s->zero_pos = s->total;
+                /* If we've already got a :: its an error */
+                else if (s->zero_pos != s->total)
+                        return 0;
+                s->zero_cnt++;
+        } else {
+                /* If more than 4 characters could be final a.b.c.d form */
+                if (len > 4) {
+                        /* Need at least 4 bytes left */
+                        if (s->total > 12)
+                                return 0;
+                        /* Must be end of string */
+                        if (elem[len])
+                                return 0;
+                        if (!ipv4_from_asc(s->tmp + s->total, elem))
+                                return 0;
+                        s->total += 4;
+                } else {
+                        if (!ipv6_hex(s->tmp + s->total, elem, len))
+                                return 0;
+                        s->total += 2;
+                }
+        }
+        return 1;
+}
+
+/* Convert a string of up to 4 hex digits into the corresponding
+ * IPv6 form.
+ */
+
+static int
+ipv6_hex(unsigned char *out, const char *in, int inlen)
+{
+        unsigned char c;
+        unsigned int num = 0;
+
+        if (inlen > 4)
+                return 0;
+        while (inlen--) {
+                c = *in++;
+                num <<= 4;
+                if ((c >= '0') && (c <= '9'))
+                        num |= c - '0';
+                else if ((c >= 'A') && (c <= 'F'))
+                        num |= c - 'A' + 10;
+                else if ((c >= 'a') && (c <= 'f'))
+                        num |=  c - 'a' + 10;
+                else
+                        return 0;
+        }
+        out[0] = num >> 8;
+        out[1] = num & 0xff;
+        return 1;
+}
+
+int
+X509V3_NAME_from_section(X509_NAME *nm, STACK_OF(CONF_VALUE)*dn_sk,
+    unsigned long chtype)
+{
+        CONF_VALUE *v;
+        int i, mval;
+        char *p, *type;
+
+        if (!nm)
+                return 0;
+
+        for (i = 0; i < sk_CONF_VALUE_num(dn_sk); i++) {
+                v = sk_CONF_VALUE_value(dn_sk, i);
+                type = v->name;
+                /* Skip past any leading X. X: X, etc to allow for
+                 * multiple instances
+                 */
+                for (p = type; *p; p++)
+                        if ((*p == ':') || (*p == ',') || (*p == '.')) {
+                                p++;
+                                if (*p)
+                                        type = p;
+                                break;
+                        }
+                if (*type == '+') {
+                        mval = -1;
+                        type++;
+                } else
+                        mval = 0;
+                if (!X509_NAME_add_entry_by_txt(nm, type, chtype,
+                    (unsigned char *) v->value, -1, -1, mval))
+                        return 0;
+        }
+        return 1;
+}