Parse non-v1 SCTs less awkwardly.
[openssl.git] / crypto / x509v3 / v3_utl.c
index 1f0db94776d1daa455f3127751f212e07a513370..de43c2fb3b2eb74430a7e7dd28e6539b4a6f5f77 100644 (file)
@@ -1,9 +1,9 @@
 /* v3_utl.c */
-/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
+ * project.
  */
 /* ====================================================================
- * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
+ * 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
 #include "cryptlib.h"
 #include <openssl/conf.h>
 #include <openssl/x509v3.h>
+#include <openssl/bn.h>
 
 static char *strip_spaces(char *name);
 static int sk_strcmp(const char * const *a, const char * const *b);
-static STACK *get_email(X509_NAME *name, GENERAL_NAMES *gens);
-static void str_free(void *str);
-static int append_ia5(STACK **sk, ASN1_IA5STRING *email);
+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 */
 
@@ -78,7 +84,7 @@ int X509V3_add_value(const char *name, const char *value,
        CONF_VALUE *vtmp = NULL;
        char *tname = NULL, *tvalue = NULL;
        if(name && !(tname = BUF_strdup(name))) goto err;
-       if(value && !(tvalue = BUF_strdup(value))) goto err;;
+       if(value && !(tvalue = BUF_strdup(value))) goto err;
        if(!(vtmp = (CONF_VALUE *)OPENSSL_malloc(sizeof(CONF_VALUE)))) goto err;
        if(!*extlist && !(*extlist = sk_CONF_VALUE_new_null())) goto err;
        vtmp->section = NULL;
@@ -354,12 +360,12 @@ static char *strip_spaces(char *name)
  * @@@ (Contents of buffer are always kept in ASCII, also on EBCDIC machines)
  */
 
-char *hex_to_string(unsigned char *buffer, long len)
+char *hex_to_string(const unsigned char *buffer, long len)
 {
        char *tmp, *q;
-       unsigned char *p;
+       const unsigned char *p;
        int i;
-       static char hexdig[] = "0123456789ABCDEF";
+       const static char hexdig[] = "0123456789ABCDEF";
        if(!buffer || !len) return NULL;
        if(!(tmp = OPENSSL_malloc(len * 3 + 1))) {
                X509V3err(X509V3_F_HEX_TO_STRING,ERR_R_MALLOC_FAILURE);
@@ -383,7 +389,7 @@ char *hex_to_string(unsigned char *buffer, long len)
  * a buffer
  */
 
-unsigned char *string_to_hex(char *str, long *len)
+unsigned char *string_to_hex(const char *str, long *len)
 {
        unsigned char *hexbuf, *q;
        unsigned char ch, cl, *p;
@@ -457,21 +463,48 @@ static int sk_strcmp(const char * const *a, const char * const *b)
        return strcmp(*a, *b);
 }
 
-STACK *X509_get1_email(X509 *x)
+STACK_OF(OPENSSL_STRING) *X509_get1_email(X509 *x)
 {
        GENERAL_NAMES *gens;
-       STACK *ret;
+       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 *X509_REQ_get1_email(X509_REQ *x)
+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 *ret;
+       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);
@@ -481,9 +514,9 @@ STACK *X509_REQ_get1_email(X509_REQ *x)
 }
 
 
-static STACK *get_email(X509_NAME *name, GENERAL_NAMES *gens)
+static STACK_OF(OPENSSL_STRING) *get_email(X509_NAME *name, GENERAL_NAMES *gens)
 {
-       STACK *ret = NULL;
+       STACK_OF(OPENSSL_STRING) *ret = NULL;
        X509_NAME_ENTRY *ne;
        ASN1_IA5STRING *email;
        GENERAL_NAME *gen;
@@ -492,7 +525,7 @@ static STACK *get_email(X509_NAME *name, GENERAL_NAMES *gens)
        i = -1;
        /* First supplied X509_NAME */
        while((i = X509_NAME_get_index_by_NID(name,
-                                        NID_pkcs9_emailAddress, i)) > 0) {
+                                        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;
@@ -506,23 +539,23 @@ static STACK *get_email(X509_NAME *name, GENERAL_NAMES *gens)
        return ret;
 }
 
-static void str_free(void *str)
+static void str_free(OPENSSL_STRING str)
 {
        OPENSSL_free(str);
 }
 
-static int append_ia5(STACK **sk, ASN1_IA5STRING *email)
+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_new(sk_strcmp);
+       if(!*sk) *sk = sk_OPENSSL_STRING_new(sk_strcmp);
        if(!*sk) return 0;
        /* Don't add duplicates */
-       if(sk_find(*sk, (char *)email->data) != -1) return 1;
+       if(sk_OPENSSL_STRING_find(*sk, (char *)email->data) != -1) return 1;
        emtmp = BUF_strdup((char *)email->data);
-       if(!emtmp || !sk_push(*sk, emtmp)) {
+       if(!emtmp || !sk_OPENSSL_STRING_push(*sk, emtmp)) {
                X509_email_free(*sk);
                *sk = NULL;
                return 0;
@@ -530,7 +563,611 @@ static int append_ia5(STACK **sk, ASN1_IA5STRING *email)
        return 1;
 }
 
-void X509_email_free(STACK *sk)
+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);
+
+/* Compare while ASCII ignoring case. */
+static int equal_nocase(const unsigned char *pattern, size_t pattern_len,
+                       const unsigned char *subject, size_t subject_len)
+       {
+       if (pattern_len != subject_len)
+               return 0;
+       while (pattern_len)
+               {
+               unsigned char l = *pattern;
+               unsigned char r = *subject;
+               /* The pattern must not contain NUL characters. */
+               if (l == 0)
+                       return 0;
+               if (l != r)
+                       {
+                       if ('A' <= l && l <= 'Z')
+                               l = (l - 'A') + 'a';
+                       if ('A' <= r && r <= 'Z')
+                               r = (r - 'A') + 'a';
+                       if (l != r)
+                               return 0;
+                       }
+               ++pattern;
+               ++subject;
+               --pattern_len;
+               }
+       return 1;
+       }
+
+/* Compare using memcmp. */
+static int equal_case(const unsigned char *pattern, size_t pattern_len,
+                     const unsigned char *subject, size_t subject_len)
 {
-       sk_pop_free(sk, str_free);
+       /* The pattern must not contain NUL characters. */
+       if (memchr(pattern, '\0', pattern_len) != NULL)
+               return 0;
+       if (pattern_len != subject_len)
+               return 0;
+       return !memcmp(pattern, subject, pattern_len);
 }
+
+/* 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)
+       {
+       size_t i = 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 (i > 0)
+               {
+               --i;
+               if (a[i] == '@' || b[i] == '@')
+                       {
+                       if (!equal_nocase(a + i, a_len - i,
+                                         b + i, a_len - i))
+                               return 0;
+                       break;
+                       }
+               }
+       if (i == 0)
+               i = a_len;
+       return equal_case(a, i, b, i);
+       }
+
+/* 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)
+       {
+       const unsigned char *wildcard_start;
+       const unsigned char *wildcard_end;
+       const unsigned char *p;
+       if (subject_len < prefix_len + suffix_len)
+               return 0;
+       if (!equal_nocase(prefix, prefix_len, subject, prefix_len))
+               return 0;
+       wildcard_start = subject + prefix_len;
+       wildcard_end = subject + (subject_len - suffix_len);
+       if (!equal_nocase(wildcard_end, suffix_len, suffix, suffix_len))
+               return 0;
+       /* The wildcard must match at least one character. */
+       if (wildcard_start == wildcard_end)
+               return 0;
+       /* Check that the part matched by the wildcard contains only
+          permitted characters and only matches a single label. */
+       for (p = wildcard_start; p != wildcard_end; ++p)
+               if (!(('0' <= *p && *p <= '9') ||
+                     ('A' <= *p && *p <= 'Z') ||
+                     ('a' <= *p && *p <= 'z') ||
+                     *p == '-'))
+                       return 0;
+       return 1;
+       }
+
+/* Checks if the memory region consistens of [0-9A-Za-z.-]. */
+static int valid_domain_characters(const unsigned char *p, size_t len)
+       {
+       while (len)
+               {
+               if (!(('0' <= *p && *p <= '9') ||
+                     ('A' <= *p && *p <= 'Z') ||
+                     ('a' <= *p && *p <= 'z') ||
+                     *p == '-' || *p == '.'))
+                       return 0;
+               ++p;
+               --len;
+               }
+       return 1;
+       }
+
+/* Find the '*' in a wildcard pattern.  If no such character is found
+   or the pattern is otherwise invalid, returns NULL. */
+static const unsigned char *wildcard_find_star(const unsigned char *pattern,
+                                              size_t pattern_len)
+       {
+       const unsigned char *star = memchr(pattern, '*', pattern_len);
+       size_t dot_count = 0;
+       const unsigned char *suffix_start;
+       size_t suffix_length;
+       if (star == NULL)
+               return NULL;
+       suffix_start = star + 1;
+       suffix_length = (pattern + pattern_len) - (star + 1);
+       if (!(valid_domain_characters(pattern, star - pattern) &&
+             valid_domain_characters(suffix_start, suffix_length)))
+               return NULL;
+       /* Check that the suffix matches at least two labels. */
+       while (suffix_length)
+               {
+               if (*suffix_start == '.')
+                       ++dot_count;
+               ++suffix_start;
+               --suffix_length;
+               }
+       if (dot_count < 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)
+       {
+       const unsigned char *star = wildcard_find_star(pattern, pattern_len);
+       if (star == NULL)
+               return equal_nocase(pattern, pattern_len,
+                                   subject, subject_len);
+       return wildcard_match(pattern, star - pattern,
+                             star + 1, (pattern + pattern_len) - star - 1,
+                             subject, subject_len);
+       }
+
+/* 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,
+                               const unsigned char *b, size_t blen)
+       {
+       if (!a->data || !a->length)
+               return 0;
+       if (cmp_type > 0)
+               {
+               if (cmp_type != a->type)
+                       return 0;
+               if (cmp_type == V_ASN1_IA5STRING)
+                       return equal(a->data, a->length, b, blen);
+               if (a->length == (int)blen && !memcmp(a->data, b, blen))
+                       return 1;
+               else
+                       return 0;
+               }
+       else
+               {
+               int astrlen, rv;
+               unsigned char *astr;
+               astrlen = ASN1_STRING_to_UTF8(&astr, a);
+               if (astrlen < 0)
+                       return -1;
+               rv = equal(astr, astrlen, b, blen);
+               OPENSSL_free(astr);
+               return rv;
+               }
+       }
+
+static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen,
+                                       unsigned int flags, int check_type)
+       {
+       GENERAL_NAMES *gens = NULL;
+       X509_NAME *name = NULL;
+       int i;
+       int cnid;
+       int alt_type;
+       equal_fn equal;
+       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;
+               alt_type = V_ASN1_IA5STRING;
+               if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
+                       equal = equal_nocase;
+               else
+                       equal = equal_wildcard;
+               }
+       else
+               {
+               cnid = 0;
+               alt_type = V_ASN1_OCTET_STRING;
+               equal = equal_case;
+               }
+
+       if (chklen == 0)
+               chklen = strlen((const char *)chk);
+
+       gens = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
+       if (gens)
+               {
+               int rv = 0;
+               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;
+                       if (check_type == GEN_EMAIL)
+                               cstr = gen->d.rfc822Name;
+                       else if (check_type == GEN_DNS)
+                               cstr = gen->d.dNSName;
+                       else
+                               cstr = gen->d.iPAddress;
+                       if (do_check_string(cstr, alt_type, equal, chk, chklen))
+                               {
+                               rv = 1;
+                               break;
+                               }
+                       }
+               GENERAL_NAMES_free(gens);
+               if (rv)
+                       return 1;
+               if (!(flags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) || !cnid)
+                       return 0;
+               }
+       i = -1;
+       name = X509_get_subject_name(x);
+       while((i = X509_NAME_get_index_by_NID(name, cnid, i)) >= 0)
+               {
+               X509_NAME_ENTRY *ne;
+               ASN1_STRING *str;
+               ne = X509_NAME_get_entry(name, i);
+               str = X509_NAME_ENTRY_get_data(ne);
+               if (do_check_string(str, -1, equal, chk, chklen))
+                       return 1;
+               }
+       return 0;
+       }
+
+int X509_check_host(X509 *x, const unsigned char *chk, size_t chklen,
+                                       unsigned int flags)
+       {
+       return do_x509_check(x, chk, chklen, flags, GEN_DNS);
+       }
+
+int X509_check_email(X509 *x, const unsigned char *chk, size_t chklen,
+                                       unsigned int flags)
+       {
+       return do_x509_check(x, chk, chklen, flags, GEN_EMAIL);
+       }
+
+int X509_check_ip(X509 *x, const unsigned char *chk, size_t chklen,
+                                       unsigned int flags)
+       {
+       return do_x509_check(x, chk, chklen, flags, GEN_IPADD);
+       }
+
+int X509_check_ip_asc(X509 *x, const char *ipasc, unsigned int flags)
+       {
+       unsigned char ipout[16];
+       int iplen;
+       iplen = a2i_ipadd(ipout, ipasc);
+       if (iplen == 0)
+               return -2;
+       return do_x509_check(x, ipout, (size_t)iplen, flags, GEN_IPADD);
+       }
+
+/* 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 = BUF_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);
+
+       OPENSSL_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:
+       if (iptmp)
+               OPENSSL_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++) 
+#ifndef CHARSET_EBCDIC
+                       if ((*p == ':') || (*p == ',') || (*p == '.'))
+#else
+                       if ((*p == os_toascii[':']) || (*p == os_toascii[',']) || (*p == os_toascii['.']))
+#endif
+                               {
+                               p++;
+                               if(*p) type = p;
+                               break;
+                               }
+#ifndef CHARSET_EBCDIC
+               if (*type == '+')
+#else
+               if (*type == os_toascii['+'])
+#endif
+                       {
+                       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;
+       }