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NetBSD/dist/wpa_supplicant/tls_gnutls.c

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/*
* WPA Supplicant / SSL/TLS interface functions for openssl
* Copyright (c) 2004-2006, Jouni Malinen <jkmaline@cc.hut.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 48
typedef 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 (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 0
static 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 0
static 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;
}
#endif
int 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;
}
/* TODO: gnutls_certificate_set_verify_flags(xcred, flags);
* to force peer validation(?) */
if (params->ca_cert) {
conn->verify_peer = 1;
ret = gnutls_certificate_set_x509_trust_file(
conn->xcred, params->ca_cert, GNUTLS_X509_FMT_PEM);
if (ret < 0) {
wpa_printf(MSG_DEBUG, "Failed to read CA cert '%s' "
"in PEM format: %s", params->ca_cert,
gnutls_strerror(ret));
ret = gnutls_certificate_set_x509_trust_file(
conn->xcred, params->ca_cert,
GNUTLS_X509_FMT_DER);
if (ret < 0) {
wpa_printf(MSG_DEBUG, "Failed to read CA cert "
"'%s' in DER format: %s",
params->ca_cert,
gnutls_strerror(ret));
}
}
}
if (params->client_cert && params->private_key) {
/* TODO: private_key_passwd? */
ret = gnutls_certificate_set_x509_key_file(
conn->xcred, params->client_cert, params->private_key,
GNUTLS_X509_FMT_PEM);
if (ret < 0) {
wpa_printf(MSG_DEBUG, "Failed to read client cert/key "
"in PEM format: %s", gnutls_strerror(ret));
ret = gnutls_certificate_set_x509_key_file(
conn->xcred, params->client_cert,
params->private_key, GNUTLS_X509_FMT_DER);
if (ret < 0) {
wpa_printf(MSG_DEBUG, "Failed to read client "
"cert/key in DER format: %s",
gnutls_strerror(ret));
return ret;
}
}
}
ret = gnutls_credentials_set(conn->session, GNUTLS_CRD_CERTIFICATE,
conn->xcred);
if (ret < 0) {
wpa_printf(MSG_INFO, "Failed to configure credentials: %s",
gnutls_strerror(ret));
}
return ret;
}
int tls_global_ca_cert(void *_ssl_ctx, const char *ca_cert)
{
/* TODO */
return -1;
}
int tls_global_set_verify(void *ssl_ctx, int check_crl)
{
/* TODO */
return -1;
}
int tls_connection_set_verify(void *ssl_ctx, struct tls_connection *conn,
int verify_peer)
{
if (conn == NULL)
return -1;
/* TODO */
return 1;
}
int tls_global_client_cert(void *_ssl_ctx, const char *client_cert)
{
/* TODO */
return -1;
}
int tls_global_private_key(void *_ssl_ctx, const char *private_key,
const char *private_key_passwd)
{
/* TODO */
return -1;
}
int tls_connection_get_keys(void *ssl_ctx, struct tls_connection *conn,
struct tls_keys *keys)
{
security_parameters_st *sec;
if (conn == NULL || conn->session == NULL || keys == NULL)
return -1;
memset(keys, 0, sizeof(*keys));
sec = &conn->session->security_parameters;
keys->master_key = sec->master_secret;
keys->master_key_len = TLS_MASTER_SIZE;
keys->client_random = sec->client_random;
keys->client_random_len = TLS_RANDOM_SIZE;
keys->server_random = sec->server_random;
keys->server_random_len = TLS_RANDOM_SIZE;
return 0;
}
static int tls_connection_verify_peer(struct tls_connection *conn)
{
unsigned int status, num_certs, i;
time_t now;
const gnutls_datum_t *certs;
gnutls_x509_crt_t cert;
if (gnutls_certificate_verify_peers2(conn->session, &status) < 0) {
wpa_printf(MSG_INFO, "TLS: Failed to verify peer "
"certificate chain");
return -1;
}
if (conn->verify_peer && (status & GNUTLS_CERT_INVALID)) {
wpa_printf(MSG_INFO, "TLS: Peer certificate not trusted");
return -1;
}
if (status & GNUTLS_CERT_SIGNER_NOT_FOUND) {
wpa_printf(MSG_INFO, "TLS: Peer certificate does not have a "
"known issuer");
return -1;
}
if (status & GNUTLS_CERT_REVOKED) {
wpa_printf(MSG_INFO, "TLS: Peer certificate has been revoked");
return -1;
}
now = time(NULL);
certs = gnutls_certificate_get_peers(conn->session, &num_certs);
if (certs == NULL) {
wpa_printf(MSG_INFO, "TLS: No peer certificate chain "
"received");
return -1;
}
for (i = 0; i < num_certs; i++) {
char *buf;
size_t len;
if (gnutls_x509_crt_init(&cert) < 0) {
wpa_printf(MSG_INFO, "TLS: Certificate initialization "
"failed");
return -1;
}
if (gnutls_x509_crt_import(cert, &certs[i],
GNUTLS_X509_FMT_DER) < 0) {
wpa_printf(MSG_INFO, "TLS: Could not parse peer "
"certificate %d/%d", i + 1, num_certs);
gnutls_x509_crt_deinit(cert);
return -1;
}
gnutls_x509_crt_get_dn(cert, NULL, &len);
len++;
buf = malloc(len + 1);
if (buf) {
buf[0] = buf[len] = '\0';
gnutls_x509_crt_get_dn(cert, buf, &len);
}
wpa_printf(MSG_DEBUG, "TLS: Peer cert chain %d/%d: %s",
i + 1, num_certs, buf);
if (i == 0) {
/* TODO: validate subject_match and altsubject_match */
}
free(buf);
if (gnutls_x509_crt_get_expiration_time(cert) < now ||
gnutls_x509_crt_get_activation_time(cert) > now) {
wpa_printf(MSG_INFO, "TLS: Peer certificate %d/%d is "
"not valid at this time",
i + 1, num_certs);
gnutls_x509_crt_deinit(cert);
return -1;
}
gnutls_x509_crt_deinit(cert);
}
return 0;
}
u8 * tls_connection_handshake(void *ssl_ctx, struct tls_connection *conn,
const u8 *in_data, size_t in_len,
size_t *out_len)
{
u8 *out_data;
int ret;
if (in_data && in_len) {
if (conn->pull_buf) {
wpa_printf(MSG_DEBUG, "%s - %d bytes remaining in "
"pull_buf", __func__, conn->pull_buf_len);
free(conn->pull_buf);
}
conn->pull_buf = malloc(in_len);
if (conn->pull_buf == NULL)
return NULL;
memcpy(conn->pull_buf, in_data, in_len);
conn->pull_buf_offset = conn->pull_buf;
conn->pull_buf_len = in_len;
}
ret = gnutls_handshake(conn->session);
if (ret < 0) {
switch (ret) {
case GNUTLS_E_AGAIN:
break;
case GNUTLS_E_FATAL_ALERT_RECEIVED:
wpa_printf(MSG_DEBUG, "%s - received fatal '%s' alert",
__func__, gnutls_alert_get_name(
gnutls_alert_get(conn->session)));
conn->read_alerts++;
/* continue */
default:
wpa_printf(MSG_DEBUG, "%s - gnutls_handshake failed "
"-> %s", __func__, gnutls_strerror(ret));
conn->failed++;
}
} else {
wpa_printf(MSG_DEBUG, "TLS: Handshake completed successfully");
if (conn->verify_peer && tls_connection_verify_peer(conn)) {
wpa_printf(MSG_INFO, "TLS: Peer certificate chain "
"failed validation");
conn->failed++;
return NULL;
}
conn->established = 1;
if (conn->push_buf == NULL) {
/* Need to return something to get final TLS ACK. */
conn->push_buf = malloc(1);
}
}
out_data = conn->push_buf;
*out_len = conn->push_buf_len;
conn->push_buf = NULL;
conn->push_buf_len = 0;
return out_data;
}
u8 * tls_connection_server_handshake(void *ssl_ctx,
struct tls_connection *conn,
const u8 *in_data, size_t in_len,
size_t *out_len)
{
/* TODO */
return NULL;
}
int tls_connection_encrypt(void *ssl_ctx, struct tls_connection *conn,
const u8 *in_data, size_t in_len,
u8 *out_data, size_t out_len)
{
ssize_t res;
res = gnutls_record_send(conn->session, in_data, in_len);
if (conn->push_buf == NULL)
return -1;
if (conn->push_buf_len < out_len)
out_len = conn->push_buf_len;
memcpy(out_data, conn->push_buf, out_len);
free(conn->push_buf);
conn->push_buf = NULL;
conn->push_buf_len = 0;
return out_len;
}
int tls_connection_decrypt(void *ssl_ctx, struct tls_connection *conn,
const u8 *in_data, size_t in_len,
u8 *out_data, size_t out_len)
{
ssize_t res;
if (conn->pull_buf) {
wpa_printf(MSG_DEBUG, "%s - %d bytes remaining in "
"pull_buf", __func__, conn->pull_buf_len);
free(conn->pull_buf);
}
conn->pull_buf = malloc(in_len);
if (conn->pull_buf == NULL)
return -1;
memcpy(conn->pull_buf, in_data, in_len);
conn->pull_buf_offset = conn->pull_buf;
conn->pull_buf_len = in_len;
res = gnutls_record_recv(conn->session, out_data, out_len);
if (res < 0) {
wpa_printf(MSG_DEBUG, "%s - gnutls_record_recv failed: %d "
"(%s)", __func__, res, gnutls_strerror(res));
}
return res;
}
int tls_connection_resumed(void *ssl_ctx, struct tls_connection *conn)
{
if (conn == NULL)
return 0;
return gnutls_session_is_resumed(conn->session);
}
#ifdef EAP_FAST
int tls_connection_set_master_key(void *ssl_ctx, struct tls_connection *conn,
const u8 *key, size_t key_len)
{
/* TODO */
return -1;
}
#endif /* EAP_FAST */
int tls_connection_set_anon_dh(void *ssl_ctx, struct tls_connection *conn)
{
/* TODO: set ADH-AES128-SHA cipher */
return -1;
}
int tls_get_cipher(void *ssl_ctx, struct tls_connection *conn,
char *buf, size_t buflen)
{
/* TODO */
buf[0] = '\0';
return 0;
}
int tls_connection_enable_workaround(void *ssl_ctx,
struct tls_connection *conn)
{
/* TODO: set SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS */
return 0;
}
#ifdef EAP_FAST
int tls_connection_client_hello_ext(void *ssl_ctx, struct tls_connection *conn,
int ext_type, const u8 *data,
size_t data_len)
{
/* TODO */
return -1;
}
#endif /* EAP_FAST */
int tls_connection_get_failed(void *ssl_ctx, struct tls_connection *conn)
{
if (conn == NULL)
return -1;
return conn->failed;
}
int tls_connection_get_read_alerts(void *ssl_ctx, struct tls_connection *conn)
{
if (conn == NULL)
return -1;
return conn->read_alerts;
}
int tls_connection_get_write_alerts(void *ssl_ctx, struct tls_connection *conn)
{
if (conn == NULL)
return -1;
return conn->write_alerts;
}
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