/* * WPA Supplicant / SSL/TLS interface functions for openssl * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Alternatively, this software may be distributed under the terms of BSD * license. * * See README and COPYING for more details. */#include <stdlib.h>#include <stdio.h>#include <string.h>#include <errno.h>#include <gnutls/gnutls.h>#include <gnutls/x509.h>#include "common.h"#include "tls.h"/* * It looks like gnutls does not provide access to client/server_random and * master_key. This is somewhat unfortunate since these are needed for key * derivation in EAP-{TLS,TTLS,PEAP,FAST}. Workaround for now is a horrible * hack that copies the gnutls_session_int definition from gnutls_int.h so that * we can get the needed information. */typedef u8 uint8;#define TLS_RANDOM_SIZE 32#define TLS_MASTER_SIZE 48typedef unsigned char opaque;typedef struct {    uint8 suite[2];} cipher_suite_st;typedef struct {	gnutls_connection_end_t entity;	gnutls_kx_algorithm_t kx_algorithm;	gnutls_cipher_algorithm_t read_bulk_cipher_algorithm;	gnutls_mac_algorithm_t read_mac_algorithm;	gnutls_compression_method_t read_compression_algorithm;	gnutls_cipher_algorithm_t write_bulk_cipher_algorithm;	gnutls_mac_algorithm_t write_mac_algorithm;	gnutls_compression_method_t write_compression_algorithm;	cipher_suite_st current_cipher_suite;	opaque master_secret[TLS_MASTER_SIZE];	opaque client_random[TLS_RANDOM_SIZE];	opaque server_random[TLS_RANDOM_SIZE];	/* followed by stuff we are not interested in */} security_parameters_st;struct gnutls_session_int {	security_parameters_st security_parameters;	/* followed by things we are not interested in */};static int tls_gnutls_ref_count = 0;struct tls_connection {	gnutls_session session;	char *subject_match, *altsubject_match;	int read_alerts, write_alerts, failed;	u8 *pre_shared_secret;	size_t pre_shared_secret_len;	int established;	int verify_peer;	u8 *push_buf, *pull_buf, *pull_buf_offset;	size_t push_buf_len, pull_buf_len;	gnutls_certificate_credentials_t xcred;};static void tls_log_func(int level, const char *msg){	char *s, *pos;	if (level == 6 || level == 7) {		/* These levels seem to be mostly I/O debug and msg dumps */		return;	}	s = strdup(msg);	if (s == NULL)		return;	pos = s;	while (*pos != '\0') {		if (*pos == '\n') {			*pos = '\0';			break;		}		pos++;	}	wpa_printf(level > 3 ? MSG_MSGDUMP : MSG_DEBUG,		   "gnutls<%d> %s", level, s);	free(s);}extern int wpa_debug_show_keys;void * tls_init(const struct tls_config *conf){	/* Because of the horrible hack to get master_secret and client/server	 * random, we need to make sure that the gnutls version is something	 * that is expected to have same structure definition for the session	 * data.. */	const char *ver;	const char *ok_ver[] = { "1.2.3", "1.2.4", "1.2.5", "1.2.6", NULL };	int i;	if (tls_gnutls_ref_count == 0 && gnutls_global_init() < 0)		return NULL;	tls_gnutls_ref_count++;	ver = gnutls_check_version(NULL);	if (ver == NULL)		return NULL;	wpa_printf(MSG_DEBUG, "%s - gnutls version %s", __func__, ver);	for (i = 0; ok_ver[i]; i++) {		if (strcmp(ok_ver[i], ver) == 0)			break;	}	if (ok_ver[i] == NULL) {		wpa_printf(MSG_INFO, "Untested gnutls version %s - this needs "			   "to be tested and enabled in tls_gnutls.c", ver);		return NULL;	}	gnutls_global_set_log_function(tls_log_func);	if (wpa_debug_show_keys)		gnutls_global_set_log_level(11);	return (void *) 1;}void tls_deinit(void *ssl_ctx){	tls_gnutls_ref_count--;	if (tls_gnutls_ref_count == 0)		gnutls_global_deinit();}int tls_get_errors(void *ssl_ctx){	return 0;}static ssize_t tls_pull_func(gnutls_transport_ptr ptr, void *buf,			     size_t len){	struct tls_connection *conn = (struct tls_connection *) ptr;	u8 *end;	if (conn->pull_buf == NULL) {		errno = EWOULDBLOCK;		return -1;	}	end = conn->pull_buf + conn->pull_buf_len;	if ((size_t) (end - conn->pull_buf_offset) < len)		len = end - conn->pull_buf_offset;	memcpy(buf, conn->pull_buf_offset, len);	conn->pull_buf_offset += len;	if (conn->pull_buf_offset == end) {		wpa_printf(MSG_DEBUG, "%s - pull_buf consumed", __func__);		free(conn->pull_buf);		conn->pull_buf = conn->pull_buf_offset = NULL;		conn->pull_buf_len = 0;	} else {		wpa_printf(MSG_DEBUG, "%s - %d bytes remaining in pull_buf",			   __func__, end - conn->pull_buf_offset);	}	return len;}static ssize_t tls_push_func(gnutls_transport_ptr ptr, const void *buf,			     size_t len){	struct tls_connection *conn = (struct tls_connection *) ptr;	u8 *nbuf;	nbuf = realloc(conn->push_buf, conn->push_buf_len + len);	if (nbuf == NULL) {		errno = ENOMEM;		return -1;	}	memcpy(nbuf + conn->push_buf_len, buf, len);	conn->push_buf = nbuf;	conn->push_buf_len += len;	return len;}struct tls_connection * tls_connection_init(void *ssl_ctx){	struct tls_connection *conn;	const int cert_types[2] = { GNUTLS_CRT_X509, 0 };	const int protos[2] = { GNUTLS_TLS1, 0 };	conn = malloc(sizeof(*conn));	if (conn == NULL)		return NULL;	memset(conn, 0, sizeof(*conn));	if (gnutls_init(&conn->session, GNUTLS_CLIENT) < 0) {		wpa_printf(MSG_INFO, "TLS: Failed to initialize new TLS "			   "connection");		free(conn);		return NULL;	}	gnutls_set_default_priority(conn->session);	gnutls_certificate_type_set_priority(conn->session, cert_types);	gnutls_protocol_set_priority(conn->session, protos);	gnutls_transport_set_pull_function(conn->session, tls_pull_func);	gnutls_transport_set_push_function(conn->session, tls_push_func);	gnutls_transport_set_ptr(conn->session, (gnutls_transport_ptr) conn);	gnutls_certificate_allocate_credentials(&conn->xcred);	return conn;}void tls_connection_deinit(void *ssl_ctx, struct tls_connection *conn){	if (conn == NULL)		return;	gnutls_certificate_free_credentials(conn->xcred);	gnutls_deinit(conn->session);	free(conn->pre_shared_secret);	free(conn->subject_match);	free(conn->altsubject_match);	free(conn->push_buf);	free(conn->pull_buf);	free(conn);}int tls_connection_established(void *ssl_ctx, struct tls_connection *conn){	return conn ? conn->established : 0;}int tls_connection_shutdown(void *ssl_ctx, struct tls_connection *conn){	if (conn == NULL)		return -1;	/* Shutdown previous TLS connection without notifying the peer	 * because the connection was already terminated in practice	 * and "close notify" shutdown alert would confuse AS. */	gnutls_bye(conn->session, GNUTLS_SHUT_RDWR);	free(conn->push_buf);	conn->push_buf = NULL;	conn->push_buf_len = 0;	conn->established = 0;	/* TODO: what to do trigger new handshake for re-auth? */	return 0;}#if 0static int tls_match_altsubject(X509 *cert, const char *match){	GENERAL_NAME *gen;	char *field, *tmp;	void *ext;	int i, found = 0;	size_t len;	ext = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);	for (i = 0; ext && i < sk_GENERAL_NAME_num(ext); i++) {		gen = sk_GENERAL_NAME_value(ext, i);		switch (gen->type) {		case GEN_EMAIL:			field = "EMAIL";			break;		case GEN_DNS:			field = "DNS";			break;		case GEN_URI:			field = "URI";			break;		default:			field = NULL;			wpa_printf(MSG_DEBUG, "TLS: altSubjectName: "				   "unsupported type=%d", gen->type);			break;		}		if (!field)			continue;		wpa_printf(MSG_DEBUG, "TLS: altSubjectName: %s:%s",			   field, gen->d.ia5->data);		len = strlen(field) + 1 + strlen((char *) gen->d.ia5->data) +			1;		tmp = malloc(len);		if (tmp == NULL)			continue;		snprintf(tmp, len, "%s:%s", field, gen->d.ia5->data);		if (strstr(tmp, match))			found++;		free(tmp);	}	return found;}#endif#if 0static int tls_verify_cb(int preverify_ok, X509_STORE_CTX *x509_ctx){	char buf[256];	X509 *err_cert;	int err, depth;	SSL *ssl;	struct tls_connection *conn;	char *match, *altmatch;	err_cert = X509_STORE_CTX_get_current_cert(x509_ctx);	err = X509_STORE_CTX_get_error(x509_ctx);	depth = X509_STORE_CTX_get_error_depth(x509_ctx);	ssl = X509_STORE_CTX_get_ex_data(x509_ctx,					 SSL_get_ex_data_X509_STORE_CTX_idx());	X509_NAME_oneline(X509_get_subject_name(err_cert), buf, sizeof(buf));	conn = SSL_get_app_data(ssl);	match = conn ? conn->subject_match : NULL;	altmatch = conn ? conn->altsubject_match : NULL;	if (!preverify_ok) {		wpa_printf(MSG_WARNING, "TLS: Certificate verification failed,"			   " error %d (%s) depth %d for '%s'", err,			   X509_verify_cert_error_string(err), depth, buf);	} else {		wpa_printf(MSG_DEBUG, "TLS: tls_verify_cb - "			   "preverify_ok=%d err=%d (%s) depth=%d buf='%s'",			   preverify_ok, err,			   X509_verify_cert_error_string(err), depth, buf);		if (depth == 0 && match && strstr(buf, match) == NULL) {			wpa_printf(MSG_WARNING, "TLS: Subject '%s' did not "				   "match with '%s'", buf, match);			preverify_ok = 0;		} else if (depth == 0 && altmatch &&			   !tls_match_altsubject(err_cert, altmatch)) {			wpa_printf(MSG_WARNING, "TLS: altSubjectName match "				   "'%s' not found", altmatch);			preverify_ok = 0;		}	}	return preverify_ok;}#endifint tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,			      const struct tls_connection_params *params){	int ret;	if (conn == NULL || params == NULL)		return -1;	free(conn->subject_match);	conn->subject_match = NULL;	if (params->subject_match) {		conn->subject_match = strdup(params->subject_match);		if (conn->subject_match == NULL)			return -1;	}	free(conn->altsubject_match);	conn->altsubject_match = NULL;	if (params->altsubject_match) {		conn->altsubject_match = strdup(params->altsubject_match);		if (conn->altsubject_match == NULL)			return -1;	}