#include <sys/types.h>
#include <sys/stat.h>

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>

#include "plugin.h"
#include "http_auth.h"
#include "log.h"
#include "response.h"


/**
 * the basic and digest auth framework
 * 
 * - config handling
 * - protocol handling
 * 
 * http_auth.c 
 * http_auth_digest.c 
 * 
 * do the real work
 */

INIT_FUNC(mod_auth_init) {
	mod_auth_plugin_data *p;
	
	p = calloc(1, sizeof(*p));
	
	p->tmp_buf = buffer_init();
	
	p->auth_user = buffer_init();
#ifdef USE_LDAP
	p->ldap_filter = buffer_init();
#endif
	
	return p;
}

FREE_FUNC(mod_auth_free) {
	mod_auth_plugin_data *p = p_d;
	
	UNUSED(srv);

	if (!p) return HANDLER_GO_ON;
	
	buffer_free(p->tmp_buf);
	buffer_free(p->auth_user);
#ifdef USE_LDAP
	buffer_free(p->ldap_filter);
#endif
	
	if (p->config_storage) {
		size_t i;
		for (i = 0; i < srv->config_context->used; i++) {
			mod_auth_plugin_config *s = p->config_storage[i];
			
			if (!s) continue;
			
			array_free(s->auth_require);
			buffer_free(s->auth_plain_groupfile);
			buffer_free(s->auth_plain_userfile);
			buffer_free(s->auth_htdigest_userfile);
			buffer_free(s->auth_htpasswd_userfile);
			buffer_free(s->auth_backend_conf);
			
			buffer_free(s->auth_ldap_hostname);
			buffer_free(s->auth_ldap_basedn);
			buffer_free(s->auth_ldap_filter);
			buffer_free(s->auth_ldap_cafile);
			
#ifdef USE_LDAP
			buffer_free(s->ldap_filter_pre);
			buffer_free(s->ldap_filter_post);
			
			if (s->ldap) ldap_unbind_s(s->ldap);
#endif
			
			free(s);
		}
		free(p->config_storage);
	}
	
	free(p);
	
	return HANDLER_GO_ON;
}

#define PATCH(x) \
	p->conf.x = s->x;
static int mod_auth_patch_connection(server *srv, connection *con, mod_auth_plugin_data *p) {
	size_t i, j;
	mod_auth_plugin_config *s = p->config_storage[0];

	PATCH(auth_backend);
	PATCH(auth_plain_groupfile);
	PATCH(auth_plain_userfile);
	PATCH(auth_htdigest_userfile);
	PATCH(auth_htpasswd_userfile);
	PATCH(auth_require);
	PATCH(auth_debug);
	PATCH(auth_ldap_hostname);
	PATCH(auth_ldap_basedn);
	PATCH(auth_ldap_filter);
	PATCH(auth_ldap_cafile);
	PATCH(auth_ldap_starttls);
#ifdef USE_LDAP
	PATCH(ldap);
	PATCH(ldap_filter_pre);
	PATCH(ldap_filter_post);
#endif
	
	/* skip the first, the global context */
	for (i = 1; i < srv->config_context->used; i++) {
		data_config *dc = (data_config *)srv->config_context->data[i];
		s = p->config_storage[i];
		
		/* condition didn't match */
		if (!config_check_cond(srv, con, dc)) continue;
		
		/* merge config */
		for (j = 0; j < dc->value->used; j++) {
			data_unset *du = dc->value->data[j];
			
			if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend"))) {
				PATCH(auth_backend);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.plain.groupfile"))) {
				PATCH(auth_plain_groupfile);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.plain.userfile"))) {
				PATCH(auth_plain_userfile);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.htdigest.userfile"))) {
				PATCH(auth_htdigest_userfile);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.htpasswd.userfile"))) {
				PATCH(auth_htpasswd_userfile);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.require"))) {
				PATCH(auth_require);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.debug"))) {
				PATCH(auth_debug);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.hostname"))) {
				PATCH(auth_ldap_hostname);
#ifdef USE_LDAP
				PATCH(ldap);
				PATCH(ldap_filter_pre);
				PATCH(ldap_filter_post);
#endif
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.base-dn"))) {
				PATCH(auth_ldap_basedn);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.filter"))) {
				PATCH(auth_ldap_filter);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.ca-file"))) {
				PATCH(auth_ldap_cafile);
			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("auth.backend.ldap.starttls"))) {
				PATCH(auth_ldap_starttls);
			}
		}
	}
	
	return 0;
}
#undef PATCH

static handler_t mod_auth_uri_handler(server *srv, connection *con, void *p_d) {
	size_t k;
	int auth_required = 0, auth_satisfied = 0;
	char *http_authorization = NULL;
	data_string *ds;
	mod_auth_plugin_data *p = p_d;
	array *req;
	size_t i;
	
	/* select the right config */
	mod_auth_patch_connection(srv, con, p);
	
	if (p->conf.auth_require == NULL) return HANDLER_GO_ON;
	
	/*
	 * AUTH
	 *  
	 */
	
	/* do we have to ask for auth ? */
	
	auth_required = 0;
	auth_satisfied = 0;
	
	/* search auth-directives for path */
	for (k = 0; k < p->conf.auth_require->used; k++) {
		if (p->conf.auth_require->data[k]->key->used == 0) continue;
		
		if (0 == strncmp(con->uri.path->ptr, p->conf.auth_require->data[k]->key->ptr, p->conf.auth_require->data[k]->key->used - 1)) {
			auth_required = 1;
			break;
		}
	}
	
	/* nothing to do for us */
	if (auth_required == 0) return HANDLER_GO_ON;
	
	req = ((data_array *)(p->conf.auth_require->data[k]))->value;
	
	/* try to get Authorization-header */
		
	if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Authorization"))) {
		http_authorization = ds->value->ptr;
	}
	
	if (ds && ds->value && ds->value->used) {
		char *auth_realm;
		data_string *method;
		
		method = (data_string *)array_get_element(req, "method");
		
		/* parse auth-header */
		if (NULL != (auth_realm = strchr(http_authorization, ' '))) {
			int auth_type_len = auth_realm - http_authorization;
			
			if ((auth_type_len == 5) &&
			    (0 == strncmp(http_authorization, "Basic", auth_type_len))) {
				
				if (0 == strcmp(method->value->ptr, "basic")) {
					auth_satisfied = http_auth_basic_check(srv, con, p, req, con->uri.path, auth_realm+1);
				}
			} else if ((auth_type_len == 6) &&
				   (0 == strncmp(http_authorization, "Digest", auth_type_len))) {
				if (0 == strcmp(method->value->ptr, "digest")) {
					if (-1 == (auth_satisfied = http_auth_digest_check(srv, con, p, req, con->uri.path, auth_realm+1))) {
						con->http_status = 400;
						
						/* a field was missing */
						
						return HANDLER_FINISHED;
					}
				}
			} else {
				log_error_write(srv, __FILE__, __LINE__, "ss", 
						"unknown authentification type:",
						http_authorization);
			}
		}
	}
	
	if (!auth_satisfied) {
		data_string *method, *realm;
		method = (data_string *)array_get_element(req, "method");
		realm = (data_string *)array_get_element(req, "realm");
		
		con->http_status = 401;
			
		if (0 == strcmp(method->value->ptr, "basic")) {
			buffer_copy_string(p->tmp_buf, "Basic realm=\"");
			buffer_append_string_buffer(p->tmp_buf, realm->value);
			buffer_append_string(p->tmp_buf, "\"");
			
			response_header_insert(srv, con, CONST_STR_LEN("WWW-Authenticate"), CONST_BUF_LEN(p->tmp_buf));
		} else if (0 == strcmp(method->value->ptr, "digest")) {
			char hh[33];
			http_auth_digest_generate_nonce(srv, p, srv->tmp_buf, hh);
			
			buffer_copy_string(p->tmp_buf, "Digest realm=\"");
			buffer_append_string_buffer(p->tmp_buf, realm->value);
			buffer_append_string(p->tmp_buf, "\", nonce=\"");
			buffer_append_string(p->tmp_buf, hh);
			buffer_append_string(p->tmp_buf, "\", qop=\"auth\"");
			
			response_header_insert(srv, con, CONST_STR_LEN("WWW-Authenticate"), CONST_BUF_LEN(p->tmp_buf));
		} else {
			/* evil */
		}
		return HANDLER_FINISHED;
	} else {
		/* the REMOTE_USER header */
		
		buffer_copy_string_buffer(con->authed_user, p->auth_user);
	}
	
	return HANDLER_GO_ON;
}

SETDEFAULTS_FUNC(mod_auth_set_defaults) {
	mod_auth_plugin_data *p = p_d;
	size_t i;
	
	config_values_t cv[] = { 
		{ "auth.backend",                   NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION }, /* 0 */
		{ "auth.backend.plain.groupfile",   NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.plain.userfile",    NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.require",                   NULL, T_CONFIG_LOCAL, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.ldap.hostname",     NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.ldap.base-dn",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.ldap.filter",       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.ldap.ca-file",       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.ldap.starttls",     NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.htdigest.userfile", NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.backend.htpasswd.userfile", NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },
		{ "auth.debug",                     NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION }, /* 11 */
		{ NULL,                             NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
	};
	
	p->config_storage = malloc(srv->config_context->used * sizeof(specific_config *));

	for (i = 0; i < srv->config_context->used; i++) {
		mod_auth_plugin_config *s;
		size_t n;
		data_array *da;
		array *ca;
		
		s = malloc(sizeof(mod_auth_plugin_config));
		s->auth_plain_groupfile = buffer_init();
		s->auth_plain_userfile = buffer_init();
		s->auth_htdigest_userfile = buffer_init();
		s->auth_htpasswd_userfile = buffer_init();
		s->auth_backend_conf = buffer_init();
		
		s->auth_ldap_hostname = buffer_init();
		s->auth_ldap_basedn = buffer_init();
		s->auth_ldap_filter = buffer_init();
		s->auth_ldap_cafile = buffer_init();
		s->auth_ldap_starttls = 0;
		s->auth_debug = 0;
		
		s->auth_require = array_init();
		
#ifdef USE_LDAP
		s->ldap_filter_pre = buffer_init();
		s->ldap_filter_post = buffer_init();
		s->ldap = NULL;
#endif
	
		cv[0].destination = s->auth_backend_conf;
		cv[1].destination = s->auth_plain_groupfile;
		cv[2].destination = s->auth_plain_userfile;
		cv[3].destination = s->auth_require;
		cv[4].destination = s->auth_ldap_hostname;
		cv[5].destination = s->auth_ldap_basedn;
		cv[6].destination = s->auth_ldap_filter;
		cv[7].destination = s->auth_ldap_cafile;
		cv[8].destination = &(s->auth_ldap_starttls);
		cv[9].destination = s->auth_htdigest_userfile;
		cv[10].destination = s->auth_htpasswd_userfile;
		cv[11].destination = &(s->auth_debug);
		
		p->config_storage[i] = s;
		ca = ((data_config *)srv->config_context->data[i])->value;
		
		if (0 != config_insert_values_global(srv, ca, cv)) {
			return HANDLER_ERROR;
		}
		
		if (s->auth_backend_conf->used) {
			if (0 == strcmp(s->auth_backend_conf->ptr, "htpasswd")) {
				s->auth_backend = AUTH_BACKEND_HTPASSWD;
			} else if (0 == strcmp(s->auth_backend_conf->ptr, "htdigest")) {
				s->auth_backend = AUTH_BACKEND_HTDIGEST;
			} else if (0 == strcmp(s->auth_backend_conf->ptr, "plain")) {
				s->auth_backend = AUTH_BACKEND_PLAIN;
			} else if (0 == strcmp(s->auth_backend_conf->ptr, "ldap")) {
				s->auth_backend = AUTH_BACKEND_LDAP;
			} else {
				log_error_write(srv, __FILE__, __LINE__, "sb", "auth.backend not supported:", s->auth_backend_conf);
				
				return HANDLER_ERROR;
			}
		}

		/* no auth.require for this section */
		if (NULL == (da = (data_array *)array_get_element(ca, "auth.require"))) continue;
		
		if (da->type != TYPE_ARRAY) continue;
		
		for (n = 0; n < da->value->used; n++) {
			size_t m;
			data_array *da_file = (data_array *)da->value->data[n];
			const char *method, *realm, *require;
			
			if (da->value->data[n]->type != TYPE_ARRAY) {
				log_error_write(srv, __FILE__, __LINE__, "sssbs", 
						"unexpected type for key: ", "auth.require", "[", da->value->data[n]->key, "](string)");
				
				return HANDLER_ERROR;
			}
					
			method = realm = require = NULL;
					
			for (m = 0; m < da_file->value->used; m++) {
				if (da_file->value->data[m]->type == TYPE_STRING) {
					if (0 == strcmp(da_file->value->data[m]->key->ptr, "method")) {
						method = ((data_string *)(da_file->value->data[m]))->value->ptr;
					} else if (0 == strcmp(da_file->value->data[m]->key->ptr, "realm")) {
						realm = ((data_string *)(da_file->value->data[m]))->value->ptr;
					} else if (0 == strcmp(da_file->value->data[m]->key->ptr, "require")) {
						require = ((data_string *)(da_file->value->data[m]))->value->ptr;
					} else {
						log_error_write(srv, __FILE__, __LINE__, "sssbs", "unexpected type for key: ", "auth.require", "[", da_file->value->data[m]->key, "](string)");
						return HANDLER_ERROR;
					}
				} else {
					log_error_write(srv, __FILE__, __LINE__, "sssbs", "unexpected type for key: ", "auth.require", "[", da_file->value->data[m]->key, "](string)");
					
					return HANDLER_ERROR;
				}
			}
					
			if (method == NULL) {
				log_error_write(srv, __FILE__, __LINE__, "sssss", "missing entry for key: ", "auth.require", "[", "method", "](string)");
				return HANDLER_ERROR;
			} else {
				if (0 != strcmp(method, "basic") &&
				    0 != strcmp(method, "digest")) {
					log_error_write(srv, __FILE__, __LINE__, "sssss", "auth.require->method has to be either 'basic' or 'digest'");
					return HANDLER_ERROR;
				}
			}
			
			if (realm == NULL) {
				log_error_write(srv, __FILE__, __LINE__, "sssss", "missing entry for key: ", "auth.require", "[", "realm", "](string)");
				return HANDLER_ERROR;
			}
			
			if (require == NULL) {
				log_error_write(srv, __FILE__, __LINE__, "sssss", "missing entry for key: ", "auth.require", "[", "require", "](string)");
				return HANDLER_ERROR;
			}
			
			if (method && realm && require) {
				data_string *ds;
				data_array *a;
				
				a = data_array_init();
				buffer_copy_string_buffer(a->key, da_file->key);
				
				ds = data_string_init();
				
				buffer_copy_string(ds->key, "method");
				buffer_copy_string(ds->value, method);
				
				array_insert_unique(a->value, (data_unset *)ds);
				
				ds = data_string_init();
				
				buffer_copy_string(ds->key, "realm");
				buffer_copy_string(ds->value, realm);
				
				array_insert_unique(a->value, (data_unset *)ds);
				
				ds = data_string_init();
				
				buffer_copy_string(ds->key, "require");
				buffer_copy_string(ds->value, require);
				
				array_insert_unique(a->value, (data_unset *)ds);
				
				array_insert_unique(s->auth_require, (data_unset *)a);
			}
		}
	
		switch(s->auth_backend) {
		case AUTH_BACKEND_PLAIN:
			if (s->auth_plain_userfile->used) {
				int fd;
				/* try to read */
				if (-1 == (fd = open(s->auth_plain_userfile->ptr, O_RDONLY))) {
					log_error_write(srv, __FILE__, __LINE__, "sbss", 
							"opening auth.backend.plain.userfile:", s->auth_plain_userfile,
							"failed:", strerror(errno));
					return HANDLER_ERROR;
				}
				close(fd);
			}
			break;
		case AUTH_BACKEND_HTPASSWD:
			if (s->auth_htpasswd_userfile->used) {
				int fd;
				/* try to read */
				if (-1 == (fd = open(s->auth_htpasswd_userfile->ptr, O_RDONLY))) {
					log_error_write(srv, __FILE__, __LINE__, "sbss", 
							"opening auth.backend.htpasswd.userfile:", s->auth_htpasswd_userfile,
							"failed:", strerror(errno));
					return HANDLER_ERROR;
				}
				close(fd);
			}
			break;
		case AUTH_BACKEND_HTDIGEST:
			if (s->auth_htdigest_userfile->used) {
				int fd;
				/* try to read */
				if (-1 == (fd = open(s->auth_htdigest_userfile->ptr, O_RDONLY))) {
					log_error_write(srv, __FILE__, __LINE__, "sbss", 
							"opening auth.backend.htdigest.userfile:", s->auth_htdigest_userfile,
							"failed:", strerror(errno));
					return HANDLER_ERROR;
				}
				close(fd);
			}
			break;
		case AUTH_BACKEND_LDAP: 
#ifdef USE_LDAP
#if 0			
			if (s->auth_ldap_basedn->used == 0) {
				log_error_write(srv, __FILE__, __LINE__, "s", "ldap: auth.backend.ldap.base-dn has to be set");
				
				return HANDLER_ERROR;
			}
#endif
			
			if (s->auth_ldap_filter->used) {
				char *dollar;
				
				/* parse filter */
			
				if (NULL == (dollar = strchr(s->auth_ldap_filter->ptr, '$'))) {
					log_error_write(srv, __FILE__, __LINE__, "s", "ldap: auth.backend.ldap.filter is missing a replace-operator '$'");
					
					return HANDLER_ERROR;
				}
				
				buffer_copy_string_len(s->ldap_filter_pre, s->auth_ldap_filter->ptr, dollar - s->auth_ldap_filter->ptr);
				buffer_copy_string(s->ldap_filter_post, dollar+1);
			}
			
			if (s->auth_ldap_hostname->used) {
				int ret;
				if (NULL == (s->ldap = ldap_init(s->auth_ldap_hostname->ptr, LDAP_PORT))) {
					log_error_write(srv, __FILE__, __LINE__, "ss", "ldap ...", strerror(errno));
					
					return HANDLER_ERROR;
				}
				
				ret = LDAP_VERSION3;
				if (LDAP_OPT_SUCCESS != (ret = ldap_set_option(s->ldap, LDAP_OPT_PROTOCOL_VERSION, &ret))) {
					log_error_write(srv, __FILE__, __LINE__, "ss", "ldap:", ldap_err2string(ret));
				
					return HANDLER_ERROR;
				}

				if (s->auth_ldap_starttls) {
					if (buffer_is_empty(s->auth_ldap_cafile)) {
						log_error_write(srv, __FILE__, __LINE__, "s", "CA file has to be set");
						
						return HANDLER_ERROR;
						
					}
			
					if (LDAP_OPT_SUCCESS != (ret = ldap_set_option(NULL, LDAP_OPT_X_TLS_CACERTFILE, s->auth_ldap_cafile->ptr))) {
						log_error_write(srv, __FILE__, __LINE__, "ss", "Loading CA certificate failed:", ldap_err2string(ret));
						
						return HANDLER_ERROR;
					}
	
					if (LDAP_OPT_SUCCESS != (ret = ldap_start_tls_s(s->ldap, NULL,  NULL))) {
						log_error_write(srv, __FILE__, __LINE__, "ss", "ldap startTLS failed:", ldap_err2string(ret));
						
						return HANDLER_ERROR;
					}
				}
				
				
				/* 1. */
				if (LDAP_SUCCESS != (ret = ldap_simple_bind_s(s->ldap, NULL, NULL))) {
					log_error_write(srv, __FILE__, __LINE__, "ss", "ldap:", ldap_err2string(ret));
					
					return HANDLER_ERROR;
				}
			}
#else
			log_error_write(srv, __FILE__, __LINE__, "s", "no ldap support available");
			return HANDLER_ERROR;
#endif
			break;
		default:
			break;
		}
	}
	
	return HANDLER_GO_ON;
}

int mod_auth_plugin_init(plugin *p) {
	p->version     = LIGHTTPD_VERSION_ID;
	p->name        = buffer_init_string("auth");
	p->init        = mod_auth_init;
	p->set_defaults = mod_auth_set_defaults;
	p->handle_uri_clean = mod_auth_uri_handler;
	p->cleanup     = mod_auth_free;
	
	p->data        = NULL;
	
	return 0;
}