/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*  apr_ldap_option.c -- LDAP options
 *
 *  The LDAP SDK allows the getting and setting of options on an LDAP
 *  connection.
 *
 */

#include "apr.h"
#include "apu.h"
#include "apu_config.h"

#if APU_DSO_BUILD
#define APU_DSO_LDAP_BUILD
#endif

#include "apr_ldap.h"
#include "apr_errno.h"
#include "apr_pools.h"
#include "apr_strings.h"
#include "apr_tables.h"

#if APR_HAS_LDAP

static void option_set_cert(apr_pool_t *pool, LDAP *ldap, const void *invalue,
                           apr_ldap_err_t *result);
static void option_set_tls(apr_pool_t *pool, LDAP *ldap, const void *invalue,
                          apr_ldap_err_t *result);

/**
 * APR LDAP get option function
 *
 * This function gets option values from a given LDAP session if
 * one was specified.
 */
APU_DECLARE_LDAP(int) apr_ldap_get_option(apr_pool_t *pool,
                                          LDAP *ldap,
                                          int option,
                                          void *outvalue,
                                          apr_ldap_err_t **result_err)
{
    apr_ldap_err_t *result;

    result = apr_pcalloc(pool, sizeof(apr_ldap_err_t));
    *result_err = result;
    if (!result) {
        return APR_ENOMEM;
    }

    /* get the option specified using the native LDAP function */
    result->rc = ldap_get_option(ldap, option, outvalue);

    /* handle the error case */
    if (result->rc != LDAP_SUCCESS) {
        result->msg = ldap_err2string(result-> rc);
        result->reason = apr_pstrdup(pool, "LDAP: Could not get an option");
        return APR_EGENERAL;
    }

    return APR_SUCCESS;

} 

/**
 * APR LDAP set option function
 *
 * This function sets option values to a given LDAP session if
 * one was specified.
 *
 * Where an option is not supported by an LDAP toolkit, this function
 * will try and apply legacy functions to achieve the same effect,
 * depending on the platform.
 */
APU_DECLARE_LDAP(int) apr_ldap_set_option(apr_pool_t *pool,
                                          LDAP *ldap,
                                          int option,
                                          const void *invalue,
                                          apr_ldap_err_t **result_err)
{
    apr_ldap_err_t *result;

    result = apr_pcalloc(pool, sizeof(apr_ldap_err_t));
    *result_err = result;
    if (!result) {
        return APR_ENOMEM;
    }

    switch (option) {
    case APR_LDAP_OPT_TLS_CERT:
        option_set_cert(pool, ldap, invalue, result);
        break;

    case APR_LDAP_OPT_TLS:
        option_set_tls(pool, ldap, invalue, result);
        break;
        
    case APR_LDAP_OPT_VERIFY_CERT:
#if APR_HAS_NETSCAPE_LDAPSDK || APR_HAS_SOLARIS_LDAPSDK || APR_HAS_MOZILLA_LDAPSK
        result->reason = "LDAP: Verify certificate not yet supported by APR on the "
                         "Netscape, Solaris or Mozilla LDAP SDKs";
        result->rc = -1;
        return APR_EGENERAL;
#endif
#if APR_HAS_NOVELL_LDAPSDK
        if (*((int*)invalue)) {
            result->rc = ldapssl_set_verify_mode(LDAPSSL_VERIFY_SERVER);
        }
        else {
            result->rc = ldapssl_set_verify_mode(LDAPSSL_VERIFY_NONE);
        }
#endif
#if APR_HAS_OPENLDAP_LDAPSDK
#ifdef LDAP_OPT_X_TLS
		/* This is not a per-connection setting so just pass NULL for the
		   Ldap connection handle */
        if (*((int*)invalue)) {
			int i = LDAP_OPT_X_TLS_DEMAND;
			result->rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_REQUIRE_CERT, &i);
        }
        else {
			int i = LDAP_OPT_X_TLS_NEVER;
			result->rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_REQUIRE_CERT, &i);
        }
#else
        result->reason = "LDAP: SSL/TLS not yet supported by APR on this "
                         "version of the OpenLDAP toolkit";
        result->rc = -1;
        return APR_EGENERAL;
#endif
#endif

        /* handle the error case */
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not set verify mode";
        }
        break;

    case APR_LDAP_OPT_REFERRALS:
        /* Setting this option is supported on at least TIVOLI_SDK and OpenLDAP. Folks
         * who know the NOVELL, NETSCAPE, MOZILLA, and SOLARIS SDKs should note here if
         * the SDK at least tolerates this option being set, or add an elif to handle
         * special cases (i.e. different LDAP_OPT_X value).
         */
        result->rc = ldap_set_option(ldap, LDAP_OPT_REFERRALS, (void *)invalue);

        if (result->rc != LDAP_SUCCESS) {
            result->reason = "Unable to set LDAP_OPT_REFERRALS.";
          return(result->rc);
        }
        break;

    case APR_LDAP_OPT_REFHOPLIMIT:
#if !defined(LDAP_OPT_REFHOPLIMIT) || APR_HAS_NOVELL_LDAPSDK
        /* If the LDAP_OPT_REFHOPLIMIT symbol is missing, assume that the
         * particular LDAP library has a reasonable default. So far certain
         * versions of the OpenLDAP SDK miss this symbol (but default to 5),
         * and the Microsoft SDK misses the symbol (the default is not known).
         */
        result->rc = LDAP_SUCCESS;
#else
        /* Setting this option is supported on at least TIVOLI_SDK. Folks who know
         * the NOVELL, NETSCAPE, MOZILLA, and SOLARIS SDKs should note here if
         * the SDK at least tolerates this option being set, or add an elif to handle
         * special cases so an error isn't returned if there is a perfectly good
         * default value that just can't be changed (like openLDAP).
         */
        result->rc = ldap_set_option(ldap, LDAP_OPT_REFHOPLIMIT, (void *)invalue);
#endif

        if (result->rc != LDAP_SUCCESS) {
            result->reason = "Unable to set LDAP_OPT_REFHOPLIMIT.";
          return(result->rc);
        }
        break;
        
    default:
        /* set the option specified using the native LDAP function */
        result->rc = ldap_set_option(ldap, option, (void *)invalue);
        
        /* handle the error case */
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not set an option";
        }
        break;
    }

    /* handle the error case */
    if (result->rc != LDAP_SUCCESS) {
        return APR_EGENERAL;
    }

    return APR_SUCCESS;

}

/**
 * Handle APR_LDAP_OPT_TLS
 *
 * This function sets the type of TLS to be applied to this connection.
 * The options are:
 * APR_LDAP_NONE: no encryption
 * APR_LDAP_SSL: SSL encryption (ldaps://)
 * APR_LDAP_STARTTLS: STARTTLS encryption
 * APR_LDAP_STOPTLS: Stop existing TLS connecttion
 */
static void option_set_tls(apr_pool_t *pool, LDAP *ldap, const void *invalue,
                          apr_ldap_err_t *result)
{
#if APR_HAS_LDAP_SSL /* compiled with ssl support */

    int tls = * (const int *)invalue;

    /* Netscape/Mozilla/Solaris SDK */
#if APR_HAS_NETSCAPE_LDAPSDK || APR_HAS_SOLARIS_LDAPSDK || APR_HAS_MOZILLA_LDAPSK
#if APR_HAS_LDAPSSL_INSTALL_ROUTINES
    if (tls == APR_LDAP_SSL) {
        result->rc = ldapssl_install_routines(ldap);
#ifdef LDAP_OPT_SSL
        /* apparently Netscape and Mozilla need this too, Solaris doesn't */
        if (result->rc == LDAP_SUCCESS) {
            result->rc = ldap_set_option(ldap, LDAP_OPT_SSL, LDAP_OPT_ON);
        }
#endif
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not switch SSL on for this "
                             "connection.";
        }
    }
    else if (tls == APR_LDAP_STARTTLS) {
        result->reason = "LDAP: STARTTLS is not supported by the "
                         "Netscape/Mozilla/Solaris SDK";
        result->rc = -1;
    }
    else if (tls == APR_LDAP_STOPTLS) {
        result->reason = "LDAP: STOPTLS is not supported by the "
                         "Netscape/Mozilla/Solaris SDK";
        result->rc = -1;
    }
#else
    if (tls != APR_LDAP_NONE) {
        result->reason = "LDAP: SSL/TLS is not supported by this version "
                         "of the Netscape/Mozilla/Solaris SDK";
        result->rc = -1;
    }
#endif
#endif

    /* Novell SDK */
#if APR_HAS_NOVELL_LDAPSDK
    /* ldapssl_install_routines(ldap)
     * Behavior is unpredictable when other LDAP functions are called
     * between the ldap_init function and the ldapssl_install_routines
     * function.
     * 
     * STARTTLS is supported by the ldap_start_tls_s() method
     */
    if (tls == APR_LDAP_SSL) {
        result->rc = ldapssl_install_routines(ldap);
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not switch SSL on for this "
                             "connection.";
        }
    }
    if (tls == APR_LDAP_STARTTLS) {
        result->rc = ldapssl_start_tls(ldap);
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not start TLS on this connection";
        }
    }
    else if (tls == APR_LDAP_STOPTLS) {
        result->rc = ldapssl_stop_tls(ldap);
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result->rc);
            result->reason = "LDAP: Could not stop TLS on this connection";
        }
    }
#endif

    /* OpenLDAP SDK */
#if APR_HAS_OPENLDAP_LDAPSDK
#ifdef LDAP_OPT_X_TLS
    if (tls == APR_LDAP_SSL) {
        int SSLmode = LDAP_OPT_X_TLS_HARD;
        result->rc = ldap_set_option(ldap, LDAP_OPT_X_TLS, &SSLmode);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: ldap_set_option failed. "
                             "Could not set LDAP_OPT_X_TLS to "
                             "LDAP_OPT_X_TLS_HARD";
            result->msg = ldap_err2string(result->rc);
        }   
    }
    else if (tls == APR_LDAP_STARTTLS) {
        result->rc = ldap_start_tls_s(ldap, NULL, NULL);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: ldap_start_tls_s() failed";
            result->msg = ldap_err2string(result->rc);
        }
    }
    else if (tls == APR_LDAP_STOPTLS) {
        result->reason = "LDAP: STOPTLS is not supported by the "
                         "OpenLDAP SDK";
        result->rc = -1;
    }
#else
    if (tls != APR_LDAP_NONE) {
        result->reason = "LDAP: SSL/TLS not yet supported by APR on this "
                         "version of the OpenLDAP toolkit";
        result->rc = -1;
    }
#endif
#endif

    /* Microsoft SDK */
#if APR_HAS_MICROSOFT_LDAPSDK
    if (tls == APR_LDAP_NONE) {
        ULONG ul = (ULONG) LDAP_OPT_OFF;
        result->rc = ldap_set_option(ldap, LDAP_OPT_SSL, &ul);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: an attempt to set LDAP_OPT_SSL off "
                             "failed.";
            result->msg = ldap_err2string(result->rc);
        }
    }
    else if (tls == APR_LDAP_SSL) {
        ULONG ul = (ULONG) LDAP_OPT_ON;
        result->rc = ldap_set_option(ldap, LDAP_OPT_SSL, &ul);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: an attempt to set LDAP_OPT_SSL on "
                             "failed.";
            result->msg = ldap_err2string(result->rc);
        }
    }
#if APR_HAS_LDAP_START_TLS_S
    else if (tls == APR_LDAP_STARTTLS) {
        result->rc = ldap_start_tls_s(ldap, NULL, NULL, NULL, NULL);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: ldap_start_tls_s() failed";
            result->msg = ldap_err2string(result->rc);
        }
    }
    else if (tls == APR_LDAP_STOPTLS) {
        result->rc = ldap_stop_tls_s(ldap);
        if (result->rc != LDAP_SUCCESS) {
            result->reason = "LDAP: ldap_stop_tls_s() failed";
            result->msg = ldap_err2string(result->rc);
        }
    }
#endif
#endif

#if APR_HAS_OTHER_LDAPSDK
    if (tls != APR_LDAP_NONE) {
        result->reason = "LDAP: SSL/TLS is currently not supported by "
                         "APR on this LDAP SDK";
        result->rc = -1;
    }
#endif

#endif /* APR_HAS_LDAP_SSL */

}

/**
 * Handle APR_LDAP_OPT_TLS_CACERTFILE
 *
 * This function sets the CA certificate for further SSL/TLS connections.
 *
 * The file provided are in different formats depending on the toolkit used:
 *
 * Netscape: cert7.db file
 * Novell: PEM or DER
 * OpenLDAP: PEM (others supported?)
 * Microsoft: unknown
 * Solaris: unknown
 */
static void option_set_cert(apr_pool_t *pool, LDAP *ldap,
                           const void *invalue, apr_ldap_err_t *result)
{
#if APR_HAS_LDAP_SSL
#if APR_HAS_LDAPSSL_CLIENT_INIT || APR_HAS_OPENLDAP_LDAPSDK
    apr_array_header_t *certs = (apr_array_header_t *)invalue;
    struct apr_ldap_opt_tls_cert_t *ents = (struct apr_ldap_opt_tls_cert_t *)certs->elts;
    int i = 0;
#endif

    /* Netscape/Mozilla/Solaris SDK */
#if APR_HAS_NETSCAPE_LDAPSDK || APR_HAS_SOLARIS_LDAPSDK || APR_HAS_MOZILLA_LDAPSDK
#if APR_HAS_LDAPSSL_CLIENT_INIT
    const char *nickname = NULL;
    const char *secmod = NULL;
    const char *key3db = NULL;
    const char *cert7db = NULL;
    const char *password = NULL;

    /* set up cert7.db, key3.db and secmod parameters */
    for (i = 0; i < certs->nelts; i++) {
        switch (ents[i].type) {
        case APR_LDAP_CA_TYPE_CERT7_DB:
            cert7db = ents[i].path;
            break;
        case APR_LDAP_CA_TYPE_SECMOD:
            secmod = ents[i].path;
            break;
        case APR_LDAP_CERT_TYPE_KEY3_DB:
            key3db = ents[i].path;
            break;
        case APR_LDAP_CERT_TYPE_NICKNAME:
            nickname = ents[i].path;
            password = ents[i].password;
            break;
        default:
            result->rc = -1;
            result->reason = "LDAP: The Netscape/Mozilla LDAP SDK only "
                "understands the CERT7, KEY3 and SECMOD "
                "file types.";
            break;
        }
        if (result->rc != LDAP_SUCCESS) {
            break;
        }
    }

    /* actually set the certificate parameters */
    if (result->rc == LDAP_SUCCESS) {
        if (nickname) {
            result->rc = ldapssl_enable_clientauth(ldap, "",
                                                   (char *)password,
                                                   (char *)nickname);
            if (result->rc != LDAP_SUCCESS) {
                result->reason = "LDAP: could not set client certificate: "
                                 "ldapssl_enable_clientauth() failed.";
                result->msg = ldap_err2string(result->rc);
            }
        }
        else if (secmod) {
            result->rc = ldapssl_advclientauth_init(cert7db, NULL,
                                                    key3db ? 1 : 0, key3db, NULL,
                                                    1, secmod, LDAPSSL_AUTH_CNCHECK);
            if (result->rc != LDAP_SUCCESS) {
                result->reason = "LDAP: ldapssl_advclientauth_init() failed.";
                result->msg = ldap_err2string(result->rc);
            }
        }
        else if (key3db) {
            result->rc = ldapssl_clientauth_init(cert7db, NULL,
                                                    1, key3db, NULL);
            if (result->rc != LDAP_SUCCESS) {
                result->reason = "LDAP: ldapssl_clientauth_init() failed.";
                result->msg = ldap_err2string(result->rc);
            }
        }
        else {
            result->rc = ldapssl_client_init(cert7db, NULL);
            if (result->rc != LDAP_SUCCESS) {
                result->reason = "LDAP: ldapssl_client_init() failed.";
                result->msg = ldap_err2string(result->rc);
            }
        }
    }
#else
    result->reason = "LDAP: SSL/TLS ldapssl_client_init() function not "
                     "supported by this Netscape/Mozilla/Solaris SDK. "
                     "Certificate authority file not set";
    result->rc = -1;
#endif
#endif

    /* Novell SDK */
#if APR_HAS_NOVELL_LDAPSDK
#if APR_HAS_LDAPSSL_CLIENT_INIT && APR_HAS_LDAPSSL_ADD_TRUSTED_CERT && APR_HAS_LDAPSSL_CLIENT_DEINIT
    /* The Novell library cannot support per connection certificates. Error
     * out if the ldap handle is provided.
     */
    if (ldap) {
        result->rc = -1;
        result->reason = "LDAP: The Novell LDAP SDK cannot support the setting "
                         "of certificates or keys on a per connection basis.";
    }
    /* Novell's library needs to be initialised first */
    else {
        result->rc = ldapssl_client_init(NULL, NULL);
        if (result->rc != LDAP_SUCCESS) {
            result->msg = ldap_err2string(result-> rc);
            result->reason = apr_pstrdup(pool, "LDAP: Could not "
                                         "initialize SSL");
        }
    }
    /* set one or more certificates */
    for (i = 0; LDAP_SUCCESS == result->rc && i < certs->nelts; i++) {
        /* Novell SDK supports DER or BASE64 files. */
        switch (ents[i].type) {
        case APR_LDAP_CA_TYPE_DER:
            result->rc = ldapssl_add_trusted_cert((void *)ents[i].path,
                                                  LDAPSSL_CERT_FILETYPE_DER);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_CA_TYPE_BASE64:
            result->rc = ldapssl_add_trusted_cert((void *)ents[i].path,
                                                  LDAPSSL_CERT_FILETYPE_B64);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_CERT_TYPE_DER:
            result->rc = ldapssl_set_client_cert((void *)ents[i].path,
                                                 LDAPSSL_CERT_FILETYPE_DER,
                                                 (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_CERT_TYPE_BASE64: 
            result->rc = ldapssl_set_client_cert((void *)ents[i].path,
                                                 LDAPSSL_CERT_FILETYPE_B64,
                                                 (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_CERT_TYPE_PFX: 
            result->rc = ldapssl_set_client_cert((void *)ents[i].path,
                                                 LDAPSSL_FILETYPE_P12,
                                                 (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_KEY_TYPE_DER:
            result->rc = ldapssl_set_client_private_key((void *)ents[i].path,
                                                        LDAPSSL_CERT_FILETYPE_DER,
                                                        (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_KEY_TYPE_BASE64:
            result->rc = ldapssl_set_client_private_key((void *)ents[i].path,
                                                        LDAPSSL_CERT_FILETYPE_B64,
                                                        (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_KEY_TYPE_PFX:
            result->rc = ldapssl_set_client_private_key((void *)ents[i].path,
                                                        LDAPSSL_FILETYPE_P12,
                                                        (void*)ents[i].password);
            result->msg = ldap_err2string(result->rc);
            break;
        default:
            result->rc = -1;
            result->reason = "LDAP: The Novell LDAP SDK only understands the "
                "DER and PEM (BASE64) file types.";
            break;
        }
        if (result->rc != LDAP_SUCCESS) {
            break;
        }
    }
#else
    result->reason = "LDAP: ldapssl_client_init(), "
                     "ldapssl_add_trusted_cert() or "
                     "ldapssl_client_deinit() functions not supported "
                     "by this Novell SDK. Certificate authority file "
                     "not set";
    result->rc = -1;
#endif
#endif

    /* OpenLDAP SDK */
#if APR_HAS_OPENLDAP_LDAPSDK
#ifdef LDAP_OPT_X_TLS_CACERTFILE
    /* set one or more certificates */
    /* FIXME: make it support setting directories as well as files */
    for (i = 0; i < certs->nelts; i++) {
        /* OpenLDAP SDK supports BASE64 files. */
        switch (ents[i].type) {
        case APR_LDAP_CA_TYPE_BASE64:
            result->rc = ldap_set_option(ldap, LDAP_OPT_X_TLS_CACERTFILE,
                                         (void *)ents[i].path);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_CERT_TYPE_BASE64:
            result->rc = ldap_set_option(ldap, LDAP_OPT_X_TLS_CERTFILE,
                                         (void *)ents[i].path);
            result->msg = ldap_err2string(result->rc);
            break;
        case APR_LDAP_KEY_TYPE_BASE64:
            result->rc = ldap_set_option(ldap, LDAP_OPT_X_TLS_KEYFILE,
                                         (void *)ents[i].path);
            result->msg = ldap_err2string(result->rc);
            break;
#ifdef LDAP_OPT_X_TLS_CACERTDIR
        case APR_LDAP_CA_TYPE_CACERTDIR_BASE64:
            result->rc = ldap_set_option(ldap, LDAP_OPT_X_TLS_CACERTDIR,
                                         (void *)ents[i].path);
            result->msg = ldap_err2string(result->rc);
            break;
#endif
        default:
            result->rc = -1;
            result->reason = "LDAP: The OpenLDAP SDK only understands the "
                "PEM (BASE64) file type.";
            break;
        }
        if (result->rc != LDAP_SUCCESS) {
            break;
        }
    }
#else
    result->reason = "LDAP: LDAP_OPT_X_TLS_CACERTFILE not "
                     "defined by this OpenLDAP SDK. Certificate "
                     "authority file not set";
    result->rc = -1;
#endif
#endif

    /* Microsoft SDK */
#if APR_HAS_MICROSOFT_LDAPSDK
    /* Microsoft SDK use the registry certificate store - error out
     * here with a message explaining this. */
    result->reason = "LDAP: CA certificates cannot be set using this method, "
                     "as they are stored in the registry instead.";
    result->rc = -1;
#endif

    /* SDK not recognised */
#if APR_HAS_OTHER_LDAPSDK
    result->reason = "LDAP: LDAP_OPT_X_TLS_CACERTFILE not "
                     "defined by this LDAP SDK. Certificate "
                     "authority file not set";
    result->rc = -1;
#endif

#else  /* not compiled with SSL Support */
    result->reason = "LDAP: Attempt to set certificate(s) failed. "
                     "Not built with SSL support";
    result->rc = -1;
#endif /* APR_HAS_LDAP_SSL */

}

#endif /* APR_HAS_LDAP */