mod_auth_ldap.c

Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相兼容的web服务器.这里给出的是Apache HTTP服务器的源码。

    sec->url = "";
    sec->host = NULL;
    sec->binddn = NULL;
    sec->bindpw = NULL;
    sec->deref = always;
    sec->group_attrib_is_dn = 1;

    sec->frontpage_hack = 0;
    sec->secure = 0;

    sec->user_is_dn = 0;
    sec->compare_dn_on_server = 0;

    return sec;
}

/* 
 * Use the ldap url parsing routines to break up the ldap url into
 * host and port.
 */
static const char *mod_auth_ldap_parse_url(cmd_parms *cmd, 
                                    void *config,
                                    const char *url)
{
    int result;
    apr_ldap_url_desc_t *urld;

    mod_auth_ldap_config_t *sec = config;

    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: `%s'", 
	         getpid(), url);

    result = apr_ldap_url_parse(url, &(urld));
    if (result != LDAP_SUCCESS) {
        switch (result) {
        case LDAP_URL_ERR_NOTLDAP:
            return "LDAP URL does not begin with ldap://";
        case LDAP_URL_ERR_NODN:
            return "LDAP URL does not have a DN";
        case LDAP_URL_ERR_BADSCOPE:
            return "LDAP URL has an invalid scope";
        case LDAP_URL_ERR_MEM:
            return "Out of memory parsing LDAP URL";
        default:
            return "Could not parse LDAP URL";
        }
    }
    sec->url = apr_pstrdup(cmd->pool, url);

    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: Host: %s", getpid(), urld->lud_host);
    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: Port: %d", getpid(), urld->lud_port);
    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: DN: %s", getpid(), urld->lud_dn);
    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: attrib: %s", getpid(), urld->lud_attrs? urld->lud_attrs[0] : "(null)");
    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: scope: %s", getpid(), 
	         (urld->lud_scope == LDAP_SCOPE_SUBTREE? "subtree" : 
		 urld->lud_scope == LDAP_SCOPE_BASE? "base" : 
		 urld->lud_scope == LDAP_SCOPE_ONELEVEL? "onelevel" : "unknown"));
    ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0,
	         cmd->server, "[%d] auth_ldap url parse: filter: %s", getpid(), urld->lud_filter);

    /* Set all the values, or at least some sane defaults */
    if (sec->host) {
        char *p = apr_palloc(cmd->pool, strlen(sec->host) + strlen(urld->lud_host) + 2);
        strcpy(p, urld->lud_host);
        strcat(p, " ");
        strcat(p, sec->host);
        sec->host = p;
    }
    else {
        sec->host = urld->lud_host? apr_pstrdup(cmd->pool, urld->lud_host) : "localhost";
    }
    sec->basedn = urld->lud_dn? apr_pstrdup(cmd->pool, urld->lud_dn) : "";
    if (urld->lud_attrs && urld->lud_attrs[0]) {
        int i = 1;
        while (urld->lud_attrs[i]) {
            i++;
        }
        sec->attributes = apr_pcalloc(cmd->pool, sizeof(char *) * (i+1));
        i = 0;
        while (urld->lud_attrs[i]) {
            sec->attributes[i] = apr_pstrdup(cmd->pool, urld->lud_attrs[i]);
            i++;
        }
        sec->attribute = sec->attributes[0];
    }
    else {
        sec->attribute = "uid";
    }

    sec->scope = urld->lud_scope == LDAP_SCOPE_ONELEVEL ?
        LDAP_SCOPE_ONELEVEL : LDAP_SCOPE_SUBTREE;

    if (urld->lud_filter) {
        if (urld->lud_filter[0] == '(') {
            /* 
	     * Get rid of the surrounding parens; later on when generating the
	     * filter, they'll be put back.
             */
            sec->filter = apr_pstrdup(cmd->pool, urld->lud_filter+1);
            sec->filter[strlen(sec->filter)-1] = '\0';
        }
        else {
            sec->filter = apr_pstrdup(cmd->pool, urld->lud_filter);
        }
    }
    else {
        sec->filter = "objectclass=*";
    }

      /* "ldaps" indicates secure ldap connections desired
      */
    if (strncasecmp(url, "ldaps", 5) == 0)
    {
        sec->secure = 1;
        sec->port = urld->lud_port? urld->lud_port : LDAPS_PORT;
        ap_log_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0, cmd->server,
                     "LDAP: auth_ldap using SSL connections");
    }
    else
    {
        sec->secure = 0;
        sec->port = urld->lud_port? urld->lud_port : LDAP_PORT;
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, 
                     "LDAP: auth_ldap not using SSL connections");
    }

    sec->have_ldap_url = 1;
    apr_ldap_free_urldesc(urld);
    return NULL;
}

static const char *mod_auth_ldap_set_deref(cmd_parms *cmd, void *config, const char *arg)
{
    mod_auth_ldap_config_t *sec = config;

    if (strcmp(arg, "never") == 0 || strcasecmp(arg, "off") == 0) {
        sec->deref = never;
    }
    else if (strcmp(arg, "searching") == 0) {
        sec->deref = searching;
    }
    else if (strcmp(arg, "finding") == 0) {
        sec->deref = finding;
    }
    else if (strcmp(arg, "always") == 0 || strcasecmp(arg, "on") == 0) {
        sec->deref = always;
    }
    else {
        return "Unrecognized value for AuthLDAPAliasDereference directive";
    }
    return NULL;
}

static const char *mod_auth_ldap_add_group_attribute(cmd_parms *cmd, void *config, const char *arg)
{
    struct mod_auth_ldap_groupattr_entry_t *new;

    mod_auth_ldap_config_t *sec = config;

    if (sec->groupattr->nelts > GROUPATTR_MAX_ELTS)
        return "Too many AuthLDAPGroupAttribute directives";

    new = apr_array_push(sec->groupattr);
    new->name = apr_pstrdup(cmd->pool, arg);
  
    return NULL;
}

static const char *set_charset_config(cmd_parms *cmd, void *config, const char *arg)
{
    ap_set_module_config(cmd->server->module_config, &auth_ldap_module,
                         (void *)arg);
    return NULL;
}


command_rec mod_auth_ldap_cmds[] = {
    AP_INIT_TAKE1("AuthLDAPURL", mod_auth_ldap_parse_url, NULL, OR_AUTHCFG, 
                  "URL to define LDAP connection. This should be an RFC 2255 complaint\n"
                  "URL of the form ldap://host[:port]/basedn[?attrib[?scope[?filter]]].\n"
                  "<ul>\n"
                  "<li>Host is the name of the LDAP server. Use a space separated list of hosts \n"
                  "to specify redundant servers.\n"
                  "<li>Port is optional, and specifies the port to connect to.\n"
                  "<li>basedn specifies the base DN to start searches from\n"
                  "<li>Attrib specifies what attribute to search for in the directory. If not "
                  "provided, it defaults to <b>uid</b>.\n"
                  "<li>Scope is the scope of the search, and can be either <b>sub</b> or "
                  "<b>one</b>. If not provided, the default is <b>sub</b>.\n"
                  "<li>Filter is a filter to use in the search. If not provided, "
                  "defaults to <b>(objectClass=*)</b>.\n"
                  "</ul>\n"
                  "Searches are performed using the attribute and the filter combined. "
                  "For example, assume that the\n"
                  "LDAP URL is <b>ldap://ldap.airius.com/ou=People, o=Airius?uid?sub?(posixid=*)</b>. "
                  "Searches will\n"
                  "be done using the filter <b>(&((posixid=*))(uid=<i>username</i>))</b>, "
                  "where <i>username</i>\n"
                  "is the user name passed by the HTTP client. The search will be a subtree "
                  "search on the branch <b>ou=People, o=Airius</b>."),

    AP_INIT_TAKE1("AuthLDAPBindDN", ap_set_string_slot,
                  (void *)APR_OFFSETOF(mod_auth_ldap_config_t, binddn), OR_AUTHCFG,
                  "DN to use to bind to LDAP server. If not provided, will do an anonymous bind."),

    AP_INIT_TAKE1("AuthLDAPBindPassword", ap_set_string_slot,
                  (void *)APR_OFFSETOF(mod_auth_ldap_config_t, bindpw), OR_AUTHCFG,
                  "Password to use to bind to LDAP server. If not provided, will do an anonymous bind."),

    AP_INIT_FLAG("AuthLDAPRemoteUserIsDN", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, user_is_dn), OR_AUTHCFG,
                 "Set to 'on' to set the REMOTE_USER environment variable to be the full "
                 "DN of the remote user. By default, this is set to off, meaning that "
                 "the REMOTE_USER variable will contain whatever value the remote user sent."),

    AP_INIT_FLAG("AuthLDAPAuthoritative", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, auth_authoritative), OR_AUTHCFG,
                 "Set to 'off' to allow access control to be passed along to lower modules if "
                 "the UserID and/or group is not known to this module"),

    AP_INIT_FLAG("AuthLDAPCompareDNOnServer", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, compare_dn_on_server), OR_AUTHCFG,
                 "Set to 'on' to force auth_ldap to do DN compares (for the \"require dn\" "
                 "directive) using the server, and set it 'off' to do the compares locally "
                 "(at the expense of possible false matches). See the documentation for "
                 "a complete description of this option."),

    AP_INIT_ITERATE("AuthLDAPGroupAttribute", mod_auth_ldap_add_group_attribute, NULL, OR_AUTHCFG,
                    "A list of attributes used to define group membership - defaults to "
                    "member and uniquemember"),

    AP_INIT_FLAG("AuthLDAPGroupAttributeIsDN", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, group_attrib_is_dn), OR_AUTHCFG,
                 "If set to 'on', auth_ldap uses the DN that is retrieved from the server for"
                 "subsequent group comparisons. If set to 'off', auth_ldap uses the string"
                 "provided by the client directly. Defaults to 'on'."),

    AP_INIT_TAKE1("AuthLDAPDereferenceAliases", mod_auth_ldap_set_deref, NULL, OR_AUTHCFG,
                  "Determines how aliases are handled during a search. Can bo one of the"
                  "values \"never\", \"searching\", \"finding\", or \"always\". "
                  "Defaults to always."),

    AP_INIT_FLAG("AuthLDAPEnabled", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, enabled), OR_AUTHCFG,
                 "Set to off to disable auth_ldap, even if it's been enabled in a higher tree"),
 
    AP_INIT_FLAG("AuthLDAPFrontPageHack", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(mod_auth_ldap_config_t, frontpage_hack), OR_AUTHCFG,
                 "Set to 'on' to support Microsoft FrontPage"),

    AP_INIT_TAKE1("AuthLDAPCharsetConfig", set_charset_config, NULL, RSRC_CONF,
                  "Character set conversion configuration file. If omitted, character set"
                  "conversion is disabled."),

    {NULL}
};

static int auth_ldap_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s)
{
    ap_configfile_t *f;
    char l[MAX_STRING_LEN];
    const char *charset_confname = ap_get_module_config(s->module_config,
                                                      &auth_ldap_module);
    apr_status_t status;
    
    /*
    mod_auth_ldap_config_t *sec = (mod_auth_ldap_config_t *)
                                    ap_get_module_config(s->module_config, 
                                                         &auth_ldap_module);

    if (sec->secure)
    {
        if (!util_ldap_ssl_supported(s))
        {
            ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, 
                     "LDAP: SSL connections (ldaps://) not supported by utilLDAP");
            return(!OK);
        }
    }
    */

    /* make sure that mod_ldap (util_ldap) is loaded */
    if (ap_find_linked_module("util_ldap.c") == NULL) {
        ap_log_error(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, s,
                     "Module mod_ldap missing. Mod_ldap (aka. util_ldap) "
                     "must be loaded in order for mod_auth_ldap to function properly");
        return HTTP_INTERNAL_SERVER_ERROR;

    }

    if (!charset_confname) {
        return OK;
    }

    charset_confname = ap_server_root_relative(p, charset_confname);
    if (!charset_confname) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_EBADPATH, s,
                     "Invalid charset conversion config path %s", 
                     (const char *)ap_get_module_config(s->module_config,
                                                        &auth_ldap_module));
        return HTTP_INTERNAL_SERVER_ERROR;
    }
    if ((status = ap_pcfg_openfile(&f, ptemp, charset_confname)) 
                != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_ERR, status, s,
                     "could not open charset conversion config file %s.", 
                     charset_confname);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    charset_conversions = apr_hash_make(p);

    while (!(ap_cfg_getline(l, MAX_STRING_LEN, f))) {
        const char *ll = l;
        char *lang;

        if (l[0] == '#') {
            continue;
        }
        lang = ap_getword_conf(p, &ll);
        ap_str_tolower(lang);

        if (ll[0]) {
            char *charset = ap_getword_conf(p, &ll);
            apr_hash_set(charset_conversions, lang, APR_HASH_KEY_STRING, charset);
        }
    }
    ap_cfg_closefile(f);
    
    to_charset = derive_codepage_from_lang (p, "utf-8");
    if (to_charset == NULL) {
        ap_log_error(APLOG_MARK, APLOG_ERR, status, s,
                     "could not find the UTF-8 charset in the file %s.", 
                     charset_confname);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    return OK;
}

static void mod_auth_ldap_register_hooks(apr_pool_t *p)
{
    ap_hook_post_config(auth_ldap_post_config,NULL,NULL,APR_HOOK_MIDDLE);
    ap_hook_check_user_id(mod_auth_ldap_check_user_id, NULL, NULL, APR_HOOK_MIDDLE);
    ap_hook_auth_checker(mod_auth_ldap_auth_checker, NULL, NULL, APR_HOOK_MIDDLE);
}

module auth_ldap_module = {
   STANDARD20_MODULE_STUFF,
   mod_auth_ldap_create_dir_config,	/* dir config creater */
   NULL,				/* dir merger --- default is to override */
   NULL,				/* server config */
   NULL,				/* merge server config */
   mod_auth_ldap_cmds,			/* command table */
   mod_auth_ldap_register_hooks,	/* set up request processing hooks */
};