+/*-
+ * Check a certificate conforms to a specified set of constraints.
+ * Return values:
+ * X509_V_OK: All constraints obeyed.
+ * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
+ * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
+ * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
+ * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
+ * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
+ * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
+ */
+
+int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
+ {
+ int r, i;
+ X509_NAME *nm;
+
+ nm = X509_get_subject_name(x);
+
+ if (X509_NAME_entry_count(nm) > 0)
+ {
+ GENERAL_NAME gntmp;
+ gntmp.type = GEN_DIRNAME;
+ gntmp.d.directoryName = nm;
+
+ r = nc_match(&gntmp, nc);
+
+ if (r != X509_V_OK)
+ return r;
+
+ gntmp.type = GEN_EMAIL;
+
+
+ /* Process any email address attributes in subject name */
+
+ for (i = -1;;)
+ {
+ X509_NAME_ENTRY *ne;
+ i = X509_NAME_get_index_by_NID(nm,
+ NID_pkcs9_emailAddress,
+ i);
+ if (i == -1)
+ break;
+ ne = X509_NAME_get_entry(nm, i);
+ gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
+ if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+
+ r = nc_match(&gntmp, nc);
+
+ if (r != X509_V_OK)
+ return r;
+ }
+
+ }
+
+ for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++)
+ {
+ GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
+ r = nc_match(gen, nc);
+ if (r != X509_V_OK)
+ return r;
+ }
+
+ return X509_V_OK;
+
+ }
+
+static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
+ {
+ GENERAL_SUBTREE *sub;
+ int i, r, match = 0;
+
+ /* Permitted subtrees: if any subtrees exist of matching the type
+ * at least one subtree must match.
+ */
+
+ for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++)
+ {
+ sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
+ if (gen->type != sub->base->type)
+ continue;
+ if (sub->minimum || sub->maximum)
+ return X509_V_ERR_SUBTREE_MINMAX;
+ /* If we already have a match don't bother trying any more */
+ if (match == 2)
+ continue;
+ if (match == 0)
+ match = 1;
+ r = nc_match_single(gen, sub->base);
+ if (r == X509_V_OK)
+ match = 2;
+ else if (r != X509_V_ERR_PERMITTED_VIOLATION)
+ return r;
+ }
+
+ if (match == 1)
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ /* Excluded subtrees: must not match any of these */
+
+ for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++)
+ {
+ sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
+ if (gen->type != sub->base->type)
+ continue;
+ if (sub->minimum || sub->maximum)
+ return X509_V_ERR_SUBTREE_MINMAX;
+
+ r = nc_match_single(gen, sub->base);
+ if (r == X509_V_OK)
+ return X509_V_ERR_EXCLUDED_VIOLATION;
+ else if (r != X509_V_ERR_PERMITTED_VIOLATION)
+ return r;
+
+ }
+
+ return X509_V_OK;
+
+ }
+
+static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
+ {
+ switch(base->type)
+ {
+ case GEN_DIRNAME:
+ return nc_dn(gen->d.directoryName, base->d.directoryName);
+
+ case GEN_DNS:
+ return nc_dns(gen->d.dNSName, base->d.dNSName);
+
+ case GEN_EMAIL:
+ return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
+
+ case GEN_URI:
+ return nc_uri(gen->d.uniformResourceIdentifier,
+ base->d.uniformResourceIdentifier);
+
+ case GEN_IPADD:
+ return nc_ip(gen->d.iPAddress, base->d.iPAddress);
+
+ default:
+ return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
+ }
+
+ }
+
+/* directoryName name constraint matching.
+ * The canonical encoding of X509_NAME makes this comparison easy. It is
+ * matched if the subtree is a subset of the name.
+ */
+
+static int nc_dn(X509_NAME *nm, X509_NAME *base)
+ {
+ /* Ensure canonical encodings are up to date. */
+ if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
+ return X509_V_ERR_OUT_OF_MEM;
+ if (base->modified && i2d_X509_NAME(base, NULL) < 0)
+ return X509_V_ERR_OUT_OF_MEM;
+ if (base->canon_enclen > nm->canon_enclen)
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ return X509_V_OK;
+ }
+
+static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
+ {
+ char *baseptr = (char *)base->data;
+ char *dnsptr = (char *)dns->data;
+ /* Empty matches everything */
+ if (!*baseptr)
+ return X509_V_OK;
+ /* Otherwise can add zero or more components on the left so
+ * compare RHS and if dns is longer and expect '.' as preceding
+ * character.
+ */
+ if (dns->length > base->length)
+ {
+ dnsptr += dns->length - base->length;
+ if (dnsptr[-1] != '.')
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ }
+
+ if (strcasecmp(baseptr, dnsptr))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ return X509_V_OK;
+
+ }
+
+static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
+ {
+ const char *baseptr = (char *)base->data;
+ const char *emlptr = (char *)eml->data;
+
+ const char *baseat = strchr(baseptr, '@');
+ const char *emlat = strchr(emlptr, '@');
+ if (!emlat)
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+ /* Special case: inital '.' is RHS match */
+ if (!baseat && (*baseptr == '.'))
+ {
+ if (eml->length > base->length)
+ {
+ emlptr += eml->length - base->length;
+ if (!strcasecmp(baseptr, emlptr))
+ return X509_V_OK;
+ }
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ }
+
+ /* If we have anything before '@' match local part */
+
+ if (baseat)
+ {
+ if (baseat != baseptr)
+ {
+ if ((baseat - baseptr) != (emlat - emlptr))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ /* Case sensitive match of local part */
+ if (strncmp(baseptr, emlptr, emlat - emlptr))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ }
+ /* Position base after '@' */
+ baseptr = baseat + 1;
+ }
+ emlptr = emlat + 1;
+ /* Just have hostname left to match: case insensitive */
+ if (strcasecmp(baseptr, emlptr))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ return X509_V_OK;
+
+ }
+
+static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
+ {
+ const char *baseptr = (char *)base->data;
+ const char *hostptr = (char *)uri->data;
+ const char *p = strchr(hostptr, ':');
+ int hostlen;
+ /* Check for foo:// and skip past it */
+ if (!p || (p[1] != '/') || (p[2] != '/'))
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+ hostptr = p + 3;
+
+ /* Determine length of hostname part of URI */
+
+ /* Look for a port indicator as end of hostname first */
+
+ p = strchr(hostptr, ':');
+ /* Otherwise look for trailing slash */
+ if (!p)
+ p = strchr(hostptr, '/');
+
+ if (!p)
+ hostlen = strlen(hostptr);
+ else
+ hostlen = p - hostptr;
+
+ if (hostlen == 0)
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+
+ /* Special case: inital '.' is RHS match */
+ if (*baseptr == '.')
+ {
+ if (hostlen > base->length)
+ {
+ p = hostptr + hostlen - base->length;
+ if (!strncasecmp(p, baseptr, base->length))
+ return X509_V_OK;
+ }
+ return X509_V_ERR_PERMITTED_VIOLATION;
+ }
+
+ if ((base->length != (int)hostlen) || strncasecmp(hostptr, baseptr, hostlen))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ return X509_V_OK;
+
+ }
+
+static int nc_ip(ASN1_OCTET_STRING *ip, ASN1_OCTET_STRING *base)
+ {
+ int hostlen, baselen, i;
+ unsigned char *hostptr, *baseptr, *maskptr;
+ hostptr = ip->data;
+ hostlen = ip->length;
+ baseptr = base->data;
+ baselen = base->length;
+
+ /* Invalid if not IPv4 or IPv6 */
+ if (! ((hostlen == 4) || (hostlen==16)) )
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+ if (! ((baselen == 8) || (baselen==32)) )
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+
+ /* Do not match IPv4 with IPv6 */
+ if (hostlen*2 != baselen)
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ maskptr = base->data + hostlen;
+
+ /* Considering possible not aligned base ipAddress */
+ /* Not checking for wrong mask definition: i.e.: 255.0.255.0*/
+ for (i = 0; i < hostlen; i++)
+ if ((hostptr[i] & maskptr[i]) != (baseptr[i] & maskptr[i]))
+ return X509_V_ERR_PERMITTED_VIOLATION;
+
+ return X509_V_OK;
+
+ }
projects / openssl.git / blobdiff