new file mode 100644
--- /dev/null
+++ b/src/http/ngx_http_config.c
@@ -0,0 +1,214 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+#include <ngx_http.h>
+
+
+ngx_int_t
+ngx_http_config_add_hash(ngx_http_hash_conf_t *h, ngx_str_t *key, void *value,
+    ngx_uint_t flags)
+{
+    size_t           len;
+    ngx_str_t       *name;
+    ngx_uint_t       i, k, n, skip;
+    ngx_hash_key_t  *hk;
+    u_char           buf[2048];
+
+    if (!(flags & NGX_HTTP_WILDCARD_HASH)) {
+
+        /* exact hash */
+
+        k = 0;
+
+        for (i = 0; i < key->len; i++) {
+            key->data[i] = ngx_tolower(key->data[i]);
+            k = ngx_hash(k, key->data[i]);
+        }
+
+        k %= NGX_HTTP_CONFIG_HASH;
+
+        /* check conflicts in exact hash */
+
+        name = h->keys_hash[k].elts;
+
+        if (name) {
+            for (i = 0; i < h->keys_hash[k].nelts; i++) {
+                if (key->len != name[i].len) {
+                    continue;
+                }
+
+                if (ngx_strncmp(key->data, name[i].data, key->len) == 0) {
+                    return NGX_BUSY;
+                }
+            }
+
+        } else {
+            if (ngx_array_init(&h->keys_hash[k], h->temp_pool, 4,
+                               sizeof(ngx_str_t))
+                != NGX_OK)
+            {
+                return NGX_ERROR;
+            }
+        }
+
+        name = ngx_array_push(&h->keys_hash[k]);
+        if (name == NULL) {
+            return NGX_ERROR;
+        }
+
+        *name = *key;
+
+        hk = ngx_array_push(&h->keys);
+        if (hk == NULL) {
+            return NGX_ERROR;
+        }
+
+        hk->key = *key;
+        hk->key_hash = ngx_hash_key(key->data, key->len);
+        hk->value = value;
+
+    } else {
+
+        /* wildcard hash */
+
+        skip = (key->data[0] == '*') ? 2 : 1;
+        k = 0;
+
+        for (i = skip; i < key->len; i++) {
+            key->data[i] = ngx_tolower(key->data[i]);
+            k = ngx_hash(k, key->data[i]);
+        }
+
+        k %= NGX_HTTP_CONFIG_HASH;
+
+        if (skip == 1) {
+
+            /* check conflicts in exact hash for ".example.com" */
+
+            name = h->keys_hash[k].elts;
+
+            if (name) {
+                len = key->len - skip;
+
+                for (i = 0; i < h->keys_hash[k].nelts; i++) {
+                    if (len != name[i].len) {
+                        continue;
+                    }
+
+                    if (ngx_strncmp(&key->data[1], name[i].data, len) == 0) {
+                        return NGX_BUSY;
+                    }
+                }
+
+            } else {
+                if (ngx_array_init(&h->keys_hash[k], h->temp_pool, 4,
+                                   sizeof(ngx_str_t))
+                    != NGX_OK)
+                {
+                    return NGX_ERROR;
+                }
+            }
+
+            name = ngx_array_push(&h->keys_hash[k]);
+            if (name == NULL) {
+                return NGX_ERROR;
+            }
+
+            name->len = key->len - 1;
+            name->data = ngx_palloc(h->temp_pool, name->len);
+            if (name->data == NULL) {
+                return NGX_ERROR;
+            }
+
+            ngx_memcpy(name->data, &key->data[1], name->len);
+        }
+
+
+        /*
+         * convert "*.example.com" to "com.example.\0"
+         *      and ".example.com" to "com.example\0"
+         */
+
+        len = 0;
+        n = 0;
+
+        for (i = key->len - 1; i; i--) {
+            if (key->data[i] == '.') {
+                ngx_memcpy(&buf[n], &key->data[i + 1], len);
+                n += len;
+                buf[n++] = '.';
+                len = 0;
+                continue;
+            }
+
+            len++;
+        }
+
+        if (len) {
+            ngx_memcpy(&buf[n], &key->data[1], len);
+            n += len;
+        }
+
+        buf[n] = '\0';
+
+
+        /* check conflicts in wildcard hash */
+
+        name = h->dns_hash[k].elts;
+
+        if (name) {
+            len = key->len - skip;
+
+            for (i = 0; i < h->dns_hash[k].nelts; i++) {
+                if (len != name[i].len) {
+                    continue;
+                }
+
+                if (ngx_strncmp(key->data + skip, name[i].data, len) == 0) {
+                    return NGX_BUSY;
+                }
+            }
+
+        } else {
+            if (ngx_array_init(&h->dns_hash[k], h->temp_pool, 4,
+                               sizeof(ngx_str_t))
+                != NGX_OK)
+            {
+                return NGX_ERROR;
+            }
+        }
+
+        name = ngx_array_push(&h->dns_hash[k]);
+        if (name == NULL) {
+            return NGX_ERROR;
+        }
+
+        name->len = key->len - skip;
+        name->data = ngx_palloc(h->temp_pool, name->len);
+        if (name->data == NULL) {
+            return NGX_ERROR;
+        }
+        ngx_memcpy(name->data, key->data + skip, name->len);
+
+
+        ngx_memcpy(key->data, buf, key->len);
+        key->len--;
+
+        hk = ngx_array_push(&h->dns_wildcards);
+        if (hk == NULL) {
+            return NGX_ERROR;
+        }
+
+        hk->key = *key;
+        hk->key_hash = 0;
+        hk->value = value;
+    }
+
+    return NGX_OK;
+}