/**
 *  Copyright 2004-2005 Paul Querna
 *
 *  Licensed 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.
 *
 */

#include "mod_gnutls.h"

static int load_datum_from_file(apr_pool_t* pool, 
                                const char* file,
                                gnutls_datum_t* data)
{
    apr_file_t* fp;
    apr_finfo_t finfo;
    apr_status_t rv;
    apr_size_t br = 0;
    
    rv = apr_file_open(&fp, file, APR_READ|APR_BINARY, APR_OS_DEFAULT, 
                       pool);
    if (rv != APR_SUCCESS) {
        return rv;
    }
    
    rv = apr_file_info_get(&finfo, APR_FINFO_SIZE, fp);
    
    if (rv != APR_SUCCESS) {
        return rv;
    }
    
    data->data = apr_palloc(pool, finfo.size+1);
    rv = apr_file_read_full(fp, data->data, finfo.size, &br);
    
    if (rv != APR_SUCCESS) {
        return rv;
    }
    apr_file_close(fp);
    
    data->data[br] = '\0';
    data->size = br;
    
    return 0;
}

const char *mgs_set_cert_file(cmd_parms * parms, void *dummy,
                                        const char *arg)
{
    int ret;
    gnutls_datum_t data;
    const char* file;
    apr_pool_t* spool;
    mgs_srvconf_rec *sc =
        (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);
    apr_pool_create(&spool, parms->pool);
    
    file = ap_server_root_relative(spool, arg);

    if (load_datum_from_file(spool, file, &data) != 0) {
        return apr_psprintf(parms->pool, "GnuTLS: Error Reading "
                            "Certificate '%s'", file);
    }
    
    gnutls_x509_crt_init(&sc->cert_x509);
    ret = gnutls_x509_crt_import(sc->cert_x509, &data, GNUTLS_X509_FMT_PEM);
    if (ret != 0) {
        return apr_psprintf(parms->pool, "GnuTLS: Failed to Import "
                            "Certificate'%s': (%d) %s", file, ret, 
                            gnutls_strerror(ret));
    }
    
    apr_pool_destroy(spool);
    return NULL;
}

const char *mgs_set_key_file(cmd_parms * parms, void *dummy,
                                       const char *arg)
{
    int ret;
    gnutls_datum_t data;
    const char* file;
    apr_pool_t* spool;
    mgs_srvconf_rec *sc =
        (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);
    apr_pool_create(&spool, parms->pool);
    
    file = ap_server_root_relative(spool, arg);
    
    if (load_datum_from_file(spool, file, &data) != 0) {
        return apr_psprintf(parms->pool, "GnuTLS: Error Reading "
                            "Private Key '%s'", file);
    }
    
    gnutls_x509_privkey_init(&sc->privkey_x509);
    ret = gnutls_x509_privkey_import(sc->privkey_x509, &data, GNUTLS_X509_FMT_PEM);
    if (ret != 0) {
        return apr_psprintf(parms->pool, "GnuTLS: Failed to Import "
                            "Private Key '%s': (%d) %s", file, ret, 
                            gnutls_strerror(ret));
    }
    apr_pool_destroy(spool);
    return NULL;
}

const char *mgs_set_cache(cmd_parms * parms, void *dummy,
                                       const char *type, const char* arg)
{
    const char* err;
    mgs_srvconf_rec *sc = ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);
    if ((err = ap_check_cmd_context(parms, GLOBAL_ONLY))) {
        return err;
    }

    if (strcasecmp("none", type) == 0) {
        sc->cache_type = mgs_cache_none;
    }
    else if (strcasecmp("dbm", type) == 0) {
        sc->cache_type = mgs_cache_dbm;
    }
#if HAVE_APR_MEMCACHE
    else if (strcasecmp("memcache", type) == 0) {
        sc->cache_type = mgs_cache_memcache;
    }
#endif
    else {
        return "Invalid Type for GnuTLSCache!";
    }

    if (sc->cache_type == mgs_cache_dbm) {
        sc->cache_config = ap_server_root_relative(parms->pool, arg);
    }
    else {
        sc->cache_config = apr_pstrdup(parms->pool, arg);
    }

    return NULL;
}

const char *mgs_set_cache_timeout(cmd_parms * parms, void *dummy,
                                            const char *arg)
{
    int argint;
    mgs_srvconf_rec *sc =
    (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                    module_config,
                                                    &gnutls_module);
    
    argint = atoi(arg);
    
    if (argint < 0) {
        return "GnuTLSCacheTimeout: Invalid argument";
    }
    else if (argint == 0) {
        sc->cache_timeout = 0;
    }
    else {
        sc->cache_timeout = apr_time_from_sec(argint);
    }
    
    return NULL;
}

const char *mgs_set_client_verify(cmd_parms * parms, void *dummy,
                                            const char *arg)
{
    int mode;

    if (strcasecmp("none", arg) == 0 || strcasecmp("ignore", arg) == 0) {
        mode = GNUTLS_CERT_IGNORE;
    }
    else if (strcasecmp("optional", arg) == 0 || strcasecmp("request", arg) == 0) {
        mode = GNUTLS_CERT_REQUEST;
    }
    else if (strcasecmp("require", arg) == 0) {
        mode = GNUTLS_CERT_REQUIRE;
    }
    else {
        return "GnuTLSClientVerify: Invalid argument";
    }
    
    /* This was set from a directory context */
    if (parms->path) {
        mgs_dirconf_rec *dc = (mgs_dirconf_rec *)dummy;
        dc->client_verify_mode = mode;
    }
    else {
        mgs_srvconf_rec *sc =
        (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);        
        sc->client_verify_mode = mode;
    }

    return NULL;
}

const char *mgs_set_client_ca_file(cmd_parms * parms, void *dummy,
                                            const char *arg)
{
    int rv;
    const char* file;
    mgs_srvconf_rec *sc = 
        (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);        
    file = ap_server_root_relative(parms->pool, arg);
    rv = gnutls_certificate_set_x509_trust_file(sc->certs, 
                                                file, GNUTLS_X509_FMT_PEM);
    
    if (rv < 0) {
        return apr_psprintf(parms->pool, "GnuTLS: Failed to load "
                            "Client CA File '%s': (%d) %s", file, rv, 
                            gnutls_strerror(rv));   
    }
    return NULL;
}

const char *mgs_set_enabled(cmd_parms * parms, void *dummy,
                                      const char *arg)
{
    mgs_srvconf_rec *sc =
        (mgs_srvconf_rec *) ap_get_module_config(parms->server->
                                                        module_config,
                                                        &gnutls_module);
    if (!strcasecmp(arg, "On")) {
        sc->enabled = GNUTLS_ENABLED_TRUE;
    }
    else if (!strcasecmp(arg, "Off")) {
        sc->enabled = GNUTLS_ENABLED_FALSE;
    }
    else {
        return "GnuTLSEnable must be set to 'On' or 'Off'";
    }

    return NULL;
}

void *mgs_config_server_create(apr_pool_t * p, server_rec * s)
{
    int i;
    mgs_srvconf_rec *sc = apr_pcalloc(p, sizeof(*sc));
    
    sc->enabled = GNUTLS_ENABLED_FALSE;
    
    gnutls_certificate_allocate_credentials(&sc->certs);
    sc->privkey_x509 = NULL;
    sc->cert_x509 = NULL;
    sc->cache_timeout = apr_time_from_sec(300);
    sc->cache_type = mgs_cache_dbm;
    sc->cache_config = ap_server_root_relative(p, "conf/gnutls_cache");
    
    /* TODO: Make this Configurable. But it isn't configurable in mod_ssl? */
    sc->dh_params_file = ap_server_root_relative(p, "conf/dhfile");
    sc->rsa_params_file = ap_server_root_relative(p, "conf/rsafile");
    
    /* Finish SSL Client Certificate Support */
    sc->client_verify_mode = GNUTLS_CERT_IGNORE;
    
    /* TODO: Make this Configurable ! */
    /* mod_ssl uses a flex based parser for this part.. sigh */
    i = 0;
    sc->ciphers[i++] = GNUTLS_CIPHER_AES_256_CBC;
    sc->ciphers[i++] = GNUTLS_CIPHER_AES_128_CBC;
    sc->ciphers[i++] = GNUTLS_CIPHER_ARCFOUR_128;
    sc->ciphers[i++] = GNUTLS_CIPHER_3DES_CBC;
    sc->ciphers[i++] = GNUTLS_CIPHER_ARCFOUR_40;
    sc->ciphers[i] = 0;
    
    i = 0;
    sc->key_exchange[i++] = GNUTLS_KX_RSA;
    sc->key_exchange[i++] = GNUTLS_KX_RSA_EXPORT;
    sc->key_exchange[i++] = GNUTLS_KX_DHE_DSS;
    sc->key_exchange[i++] = GNUTLS_KX_DHE_RSA;
    sc->key_exchange[i++] = GNUTLS_KX_ANON_DH;
    sc->key_exchange[i++] = GNUTLS_KX_SRP;
    sc->key_exchange[i++] = GNUTLS_KX_SRP_RSA;
    sc->key_exchange[i++] = GNUTLS_KX_SRP_DSS;
    sc->key_exchange[i] = 0;
    
    i = 0;
    sc->macs[i++] = GNUTLS_MAC_SHA;
    sc->macs[i++] = GNUTLS_MAC_MD5;
    sc->macs[i++] = GNUTLS_MAC_RMD160;
    sc->macs[i] = 0;
    
    i = 0;
    sc->protocol[i++] = GNUTLS_TLS1_1;
    sc->protocol[i++] = GNUTLS_TLS1;
    sc->protocol[i++] = GNUTLS_SSL3;
    sc->protocol[i] = 0;
    
    i = 0;
    sc->compression[i++] = GNUTLS_COMP_NULL;
    sc->compression[i++] = GNUTLS_COMP_ZLIB;
    sc->compression[i++] = GNUTLS_COMP_LZO;
    sc->compression[i] = 0;
    
    i = 0;
    sc->cert_types[i++] = GNUTLS_CRT_X509;
    sc->cert_types[i] = 0;
    
    return sc;
}

void *mgs_config_dir_merge(apr_pool_t *p, void *basev, void *addv)
{
    mgs_dirconf_rec *new;
    mgs_dirconf_rec *base = (mgs_dirconf_rec *) basev;
    mgs_dirconf_rec *add = (mgs_dirconf_rec *) addv;
    
    new = (mgs_dirconf_rec *) apr_pcalloc(p, sizeof(mgs_dirconf_rec));
    new->lua_bytecode = apr_pstrmemdup(p, add->lua_bytecode,
                                       add->lua_bytecode_len);
    new->lua_bytecode_len = add->lua_bytecode_len;
    new->client_verify_mode = add->client_verify_mode;
    return new;
}

void *mgs_config_dir_create(apr_pool_t *p, char *dir)
{
    mgs_dirconf_rec *dc = apr_palloc(p, sizeof(*dc));
    
    dc->client_verify_mode = -1;
    dc->lua_bytecode = NULL;
    dc->lua_bytecode_len = 0;
    return dc;
}