hostapd/src/tls/tlsv1_server.c

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/*
* TLSv1 server (RFC 2246)
* Copyright (c) 2006-2007, 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 "includes.h"
#include "common.h"
#include "sha1.h"
#include "tls.h"
#include "tlsv1_common.h"
#include "tlsv1_record.h"
#include "tlsv1_server.h"
#include "tlsv1_server_i.h"
/* TODO:
* Support for a message fragmented across several records (RFC 2246, 6.2.1)
*/
void tlsv1_server_alert(struct tlsv1_server *conn, u8 level, u8 description)
{
conn->alert_level = level;
conn->alert_description = description;
}
int tlsv1_server_derive_keys(struct tlsv1_server *conn,
const u8 *pre_master_secret,
size_t pre_master_secret_len)
{
u8 seed[2 * TLS_RANDOM_LEN];
u8 key_block[TLS_MAX_KEY_BLOCK_LEN];
u8 *pos;
size_t key_block_len;
if (pre_master_secret) {
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: pre_master_secret",
pre_master_secret, pre_master_secret_len);
os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
TLS_RANDOM_LEN);
if (tls_prf(pre_master_secret, pre_master_secret_len,
"master secret", seed, 2 * TLS_RANDOM_LEN,
conn->master_secret, TLS_MASTER_SECRET_LEN)) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive "
"master_secret");
return -1;
}
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: master_secret",
conn->master_secret, TLS_MASTER_SECRET_LEN);
}
os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random, TLS_RANDOM_LEN);
key_block_len = 2 * (conn->rl.hash_size + conn->rl.key_material_len +
conn->rl.iv_size);
if (tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
"key expansion", seed, 2 * TLS_RANDOM_LEN,
key_block, key_block_len)) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive key_block");
return -1;
}
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: key_block",
key_block, key_block_len);
pos = key_block;
/* client_write_MAC_secret */
os_memcpy(conn->rl.read_mac_secret, pos, conn->rl.hash_size);
pos += conn->rl.hash_size;
/* server_write_MAC_secret */
os_memcpy(conn->rl.write_mac_secret, pos, conn->rl.hash_size);
pos += conn->rl.hash_size;
/* client_write_key */
os_memcpy(conn->rl.read_key, pos, conn->rl.key_material_len);
pos += conn->rl.key_material_len;
/* server_write_key */
os_memcpy(conn->rl.write_key, pos, conn->rl.key_material_len);
pos += conn->rl.key_material_len;
/* client_write_IV */
os_memcpy(conn->rl.read_iv, pos, conn->rl.iv_size);
pos += conn->rl.iv_size;
/* server_write_IV */
os_memcpy(conn->rl.write_iv, pos, conn->rl.iv_size);
pos += conn->rl.iv_size;
return 0;
}
/**
* tlsv1_server_handshake - Process TLS handshake
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @in_data: Input data from TLS peer
* @in_len: Input data length
* @out_len: Length of the output buffer.
* Returns: Pointer to output data, %NULL on failure
*/
u8 * tlsv1_server_handshake(struct tlsv1_server *conn,
const u8 *in_data, size_t in_len,
size_t *out_len)
{
const u8 *pos, *end;
u8 *msg = NULL, *in_msg, *in_pos, *in_end, alert, ct;
size_t in_msg_len;
if (in_data == NULL || in_len == 0) {
wpa_printf(MSG_DEBUG, "TLSv1: No input data to server");
return NULL;
}
pos = in_data;
end = in_data + in_len;
in_msg = os_malloc(in_len);
if (in_msg == NULL)
return NULL;
/* Each received packet may include multiple records */
while (pos < end) {
in_msg_len = in_len;
if (tlsv1_record_receive(&conn->rl, pos, end - pos,
in_msg, &in_msg_len, &alert)) {
wpa_printf(MSG_DEBUG, "TLSv1: Processing received "
"record failed");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
goto failed;
}
ct = pos[0];
in_pos = in_msg;
in_end = in_msg + in_msg_len;
/* Each received record may include multiple messages of the
* same ContentType. */
while (in_pos < in_end) {
in_msg_len = in_end - in_pos;
if (tlsv1_server_process_handshake(conn, ct, in_pos,
&in_msg_len) < 0)
goto failed;
in_pos += in_msg_len;
}
pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
}
os_free(in_msg);
in_msg = NULL;
msg = tlsv1_server_handshake_write(conn, out_len);
failed:
os_free(in_msg);
if (conn->alert_level) {
if (conn->state == FAILED) {
/* Avoid alert loops */
wpa_printf(MSG_DEBUG, "TLSv1: Drop alert loop");
os_free(msg);
return NULL;
}
conn->state = FAILED;
os_free(msg);
msg = tlsv1_server_send_alert(conn, conn->alert_level,
conn->alert_description,
out_len);
}
return msg;
}
/**
* tlsv1_server_encrypt - Encrypt data into TLS tunnel
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @in_data: Pointer to plaintext data to be encrypted
* @in_len: Input buffer length
* @out_data: Pointer to output buffer (encrypted TLS data)
* @out_len: Maximum out_data length
* Returns: Number of bytes written to out_data, -1 on failure
*
* This function is used after TLS handshake has been completed successfully to
* send data in the encrypted tunnel.
*/
int tlsv1_server_encrypt(struct tlsv1_server *conn,
const u8 *in_data, size_t in_len,
u8 *out_data, size_t out_len)
{
size_t rlen;
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Plaintext AppData",
in_data, in_len);
os_memcpy(out_data + TLS_RECORD_HEADER_LEN, in_data, in_len);
if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_APPLICATION_DATA,
out_data, out_len, in_len, &rlen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
return rlen;
}
/**
* tlsv1_server_decrypt - Decrypt data from TLS tunnel
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @in_data: Pointer to input buffer (encrypted TLS data)
* @in_len: Input buffer length
* @out_data: Pointer to output buffer (decrypted data from TLS tunnel)
* @out_len: Maximum out_data length
* Returns: Number of bytes written to out_data, -1 on failure
*
* This function is used after TLS handshake has been completed successfully to
* receive data from the encrypted tunnel.
*/
int tlsv1_server_decrypt(struct tlsv1_server *conn,
const u8 *in_data, size_t in_len,
u8 *out_data, size_t out_len)
{
const u8 *in_end, *pos;
int res;
u8 alert, *out_end, *out_pos;
size_t olen;
pos = in_data;
in_end = in_data + in_len;
out_pos = out_data;
out_end = out_data + out_len;
while (pos < in_end) {
if (pos[0] != TLS_CONTENT_TYPE_APPLICATION_DATA) {
wpa_printf(MSG_DEBUG, "TLSv1: Unexpected content type "
"0x%x", pos[0]);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
olen = out_end - out_pos;
res = tlsv1_record_receive(&conn->rl, pos, in_end - pos,
out_pos, &olen, &alert);
if (res < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Record layer processing "
"failed");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
return -1;
}
out_pos += olen;
if (out_pos > out_end) {
wpa_printf(MSG_DEBUG, "TLSv1: Buffer not large enough "
"for processing the received record");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
}
return out_pos - out_data;
}
/**
* tlsv1_server_global_init - Initialize TLSv1 server
* Returns: 0 on success, -1 on failure
*
* This function must be called before using any other TLSv1 server functions.
*/
int tlsv1_server_global_init(void)
{
return crypto_global_init();
}
/**
* tlsv1_server_global_deinit - Deinitialize TLSv1 server
*
* This function can be used to deinitialize the TLSv1 server that was
* initialized by calling tlsv1_server_global_init(). No TLSv1 server functions
* can be called after this before calling tlsv1_server_global_init() again.
*/
void tlsv1_server_global_deinit(void)
{
crypto_global_deinit();
}
/**
* tlsv1_server_init - Initialize TLSv1 server connection
* @cred: Pointer to server credentials from tlsv1_server_cred_alloc()
* Returns: Pointer to TLSv1 server connection data or %NULL on failure
*/
struct tlsv1_server * tlsv1_server_init(struct tlsv1_credentials *cred)
{
struct tlsv1_server *conn;
size_t count;
u16 *suites;
conn = os_zalloc(sizeof(*conn));
if (conn == NULL)
return NULL;
conn->cred = cred;
conn->state = CLIENT_HELLO;
if (tls_verify_hash_init(&conn->verify) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize verify "
"hash");
os_free(conn);
return NULL;
}
count = 0;
suites = conn->cipher_suites;
#ifndef CONFIG_CRYPTO_INTERNAL
suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
#endif /* CONFIG_CRYPTO_INTERNAL */
suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
conn->num_cipher_suites = count;
return conn;
}
static void tlsv1_server_clear_data(struct tlsv1_server *conn)
{
tlsv1_record_set_cipher_suite(&conn->rl, TLS_NULL_WITH_NULL_NULL);
tlsv1_record_change_write_cipher(&conn->rl);
tlsv1_record_change_read_cipher(&conn->rl);
tls_verify_hash_free(&conn->verify);
crypto_public_key_free(conn->client_rsa_key);
conn->client_rsa_key = NULL;
os_free(conn->session_ticket);
conn->session_ticket = NULL;
conn->session_ticket_len = 0;
conn->use_session_ticket = 0;
os_free(conn->dh_secret);
conn->dh_secret = NULL;
conn->dh_secret_len = 0;
}
/**
* tlsv1_server_deinit - Deinitialize TLSv1 server connection
* @conn: TLSv1 server connection data from tlsv1_server_init()
*/
void tlsv1_server_deinit(struct tlsv1_server *conn)
{
tlsv1_server_clear_data(conn);
os_free(conn);
}
/**
* tlsv1_server_established - Check whether connection has been established
* @conn: TLSv1 server connection data from tlsv1_server_init()
* Returns: 1 if connection is established, 0 if not
*/
int tlsv1_server_established(struct tlsv1_server *conn)
{
return conn->state == ESTABLISHED;
}
/**
* tlsv1_server_prf - Use TLS-PRF to derive keying material
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @label: Label (e.g., description of the key) for PRF
* @server_random_first: seed is 0 = client_random|server_random,
* 1 = server_random|client_random
* @out: Buffer for output data from TLS-PRF
* @out_len: Length of the output buffer
* Returns: 0 on success, -1 on failure
*/
int tlsv1_server_prf(struct tlsv1_server *conn, const char *label,
int server_random_first, u8 *out, size_t out_len)
{
u8 seed[2 * TLS_RANDOM_LEN];
if (conn->state != ESTABLISHED)
return -1;
if (server_random_first) {
os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random,
TLS_RANDOM_LEN);
} else {
os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
TLS_RANDOM_LEN);
}
return tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
label, seed, 2 * TLS_RANDOM_LEN, out, out_len);
}
/**
* tlsv1_server_get_cipher - Get current cipher name
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @buf: Buffer for the cipher name
* @buflen: buf size
* Returns: 0 on success, -1 on failure
*
* Get the name of the currently used cipher.
*/
int tlsv1_server_get_cipher(struct tlsv1_server *conn, char *buf,
size_t buflen)
{
char *cipher;
switch (conn->rl.cipher_suite) {
case TLS_RSA_WITH_RC4_128_MD5:
cipher = "RC4-MD5";
break;
case TLS_RSA_WITH_RC4_128_SHA:
cipher = "RC4-SHA";
break;
case TLS_RSA_WITH_DES_CBC_SHA:
cipher = "DES-CBC-SHA";
break;
case TLS_RSA_WITH_3DES_EDE_CBC_SHA:
cipher = "DES-CBC3-SHA";
break;
case TLS_DH_anon_WITH_AES_128_CBC_SHA:
cipher = "ADH-AES-128-SHA";
break;
case TLS_RSA_WITH_AES_256_CBC_SHA:
cipher = "AES-256-SHA";
break;
case TLS_RSA_WITH_AES_128_CBC_SHA:
cipher = "AES-128-SHA";
break;
default:
return -1;
}
if (os_strlcpy(buf, cipher, buflen) >= buflen)
return -1;
return 0;
}
/**
* tlsv1_server_shutdown - Shutdown TLS connection
* @conn: TLSv1 server connection data from tlsv1_server_init()
* Returns: 0 on success, -1 on failure
*/
int tlsv1_server_shutdown(struct tlsv1_server *conn)
{
conn->state = CLIENT_HELLO;
if (tls_verify_hash_init(&conn->verify) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to re-initialize verify "
"hash");
return -1;
}
tlsv1_server_clear_data(conn);
return 0;
}
/**
* tlsv1_server_resumed - Was session resumption used
* @conn: TLSv1 server connection data from tlsv1_server_init()
* Returns: 1 if current session used session resumption, 0 if not
*/
int tlsv1_server_resumed(struct tlsv1_server *conn)
{
return 0;
}
/**
* tlsv1_server_get_keys - Get master key and random data from TLS connection
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @keys: Structure of key/random data (filled on success)
* Returns: 0 on success, -1 on failure
*/
int tlsv1_server_get_keys(struct tlsv1_server *conn, struct tls_keys *keys)
{
os_memset(keys, 0, sizeof(*keys));
if (conn->state == CLIENT_HELLO)
return -1;
keys->client_random = conn->client_random;
keys->client_random_len = TLS_RANDOM_LEN;
if (conn->state != SERVER_HELLO) {
keys->server_random = conn->server_random;
keys->server_random_len = TLS_RANDOM_LEN;
keys->master_key = conn->master_secret;
keys->master_key_len = TLS_MASTER_SECRET_LEN;
}
return 0;
}
/**
* tlsv1_server_get_keyblock_size - Get TLS key_block size
* @conn: TLSv1 server connection data from tlsv1_server_init()
* Returns: Size of the key_block for the negotiated cipher suite or -1 on
* failure
*/
int tlsv1_server_get_keyblock_size(struct tlsv1_server *conn)
{
if (conn->state == CLIENT_HELLO || conn->state == SERVER_HELLO)
return -1;
return 2 * (conn->rl.hash_size + conn->rl.key_material_len +
conn->rl.iv_size);
}
/**
* tlsv1_server_set_cipher_list - Configure acceptable cipher suites
* @conn: TLSv1 server connection data from tlsv1_server_init()
* @ciphers: Zero (TLS_CIPHER_NONE) terminated list of allowed ciphers
* (TLS_CIPHER_*).
* Returns: 0 on success, -1 on failure
*/
int tlsv1_server_set_cipher_list(struct tlsv1_server *conn, u8 *ciphers)
{
#ifdef EAP_SERVER_FAST
size_t count;
u16 *suites;
/* TODO: implement proper configuration of cipher suites */
if (ciphers[0] == TLS_CIPHER_ANON_DH_AES128_SHA) {
count = 0;
suites = conn->cipher_suites;
#ifndef CONFIG_CRYPTO_INTERNAL
suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
#endif /* CONFIG_CRYPTO_INTERNAL */
suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
#ifndef CONFIG_CRYPTO_INTERNAL
suites[count++] = TLS_DH_anon_WITH_AES_256_CBC_SHA;
#endif /* CONFIG_CRYPTO_INTERNAL */
suites[count++] = TLS_DH_anon_WITH_AES_128_CBC_SHA;
suites[count++] = TLS_DH_anon_WITH_3DES_EDE_CBC_SHA;
suites[count++] = TLS_DH_anon_WITH_RC4_128_MD5;
suites[count++] = TLS_DH_anon_WITH_DES_CBC_SHA;
conn->num_cipher_suites = count;
}
return 0;
#else /* EAP_SERVER_FAST */
return -1;
#endif /* EAP_SERVER_FAST */
}
int tlsv1_server_set_verify(struct tlsv1_server *conn, int verify_peer)
{
conn->verify_peer = verify_peer;
return 0;
}
void tlsv1_server_set_session_ticket_cb(struct tlsv1_server *conn,
tlsv1_server_session_ticket_cb cb,
void *ctx)
{
wpa_printf(MSG_DEBUG, "TLSv1: SessionTicket callback set %p (ctx %p)",
cb, ctx);
conn->session_ticket_cb = cb;
conn->session_ticket_cb_ctx = ctx;
}