/*
* wpa_supplicant/hostapd: TLSv1 common routines
* Copyright (c) 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 "includes.h"
#include "common.h"
#include "md5.h"
#include "sha1.h"
#include "crypto.h"
#include "x509v3.h"
#include "tlsv1_common.h"
/*
* TODO:
* RFC 2246 Section 9: Mandatory to implement TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
* Add support for commonly used cipher suites; don't bother with exportable
* suites.
*/
static const struct tls_cipher_suite tls_cipher_suites[] = {
{ TLS_NULL_WITH_NULL_NULL, TLS_KEY_X_NULL, TLS_CIPHER_NULL,
TLS_HASH_NULL },
{ TLS_RSA_WITH_RC4_128_MD5, TLS_KEY_X_RSA, TLS_CIPHER_RC4_128,
TLS_HASH_MD5 },
{ TLS_RSA_WITH_RC4_128_SHA, TLS_KEY_X_RSA, TLS_CIPHER_RC4_128,
TLS_HASH_SHA },
{ TLS_RSA_WITH_DES_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_DES_CBC,
TLS_HASH_SHA },
{ TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_KEY_X_RSA,
TLS_CIPHER_3DES_EDE_CBC, TLS_HASH_SHA },
{ TLS_DH_anon_WITH_RC4_128_MD5, TLS_KEY_X_DH_anon,
TLS_CIPHER_RC4_128, TLS_HASH_MD5 },
{ TLS_DH_anon_WITH_DES_CBC_SHA, TLS_KEY_X_DH_anon,
TLS_CIPHER_DES_CBC, TLS_HASH_SHA },
{ TLS_DH_anon_WITH_3DES_EDE_CBC_SHA, TLS_KEY_X_DH_anon,
TLS_CIPHER_3DES_EDE_CBC, TLS_HASH_SHA },
{ TLS_RSA_WITH_AES_128_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_AES_128_CBC,
TLS_HASH_SHA },
{ TLS_DH_anon_WITH_AES_128_CBC_SHA, TLS_KEY_X_DH_anon,
TLS_CIPHER_AES_128_CBC, TLS_HASH_SHA },
{ TLS_RSA_WITH_AES_256_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_AES_256_CBC,
TLS_HASH_SHA },
{ TLS_DH_anon_WITH_AES_256_CBC_SHA, TLS_KEY_X_DH_anon,
TLS_CIPHER_AES_256_CBC, TLS_HASH_SHA }
};
#define NUM_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
#define NUM_TLS_CIPHER_SUITES NUM_ELEMS(tls_cipher_suites)
static const struct tls_cipher_data tls_ciphers[] = {
{ TLS_CIPHER_NULL, TLS_CIPHER_STREAM, 0, 0, 0,
CRYPTO_CIPHER_NULL },
{ TLS_CIPHER_IDEA_CBC, TLS_CIPHER_BLOCK, 16, 16, 8,
CRYPTO_CIPHER_NULL },
{ TLS_CIPHER_RC2_CBC_40, TLS_CIPHER_BLOCK, 5, 16, 0,
CRYPTO_CIPHER_ALG_RC2 },
{ TLS_CIPHER_RC4_40, TLS_CIPHER_STREAM, 5, 16, 0,
CRYPTO_CIPHER_ALG_RC4 },
{ TLS_CIPHER_RC4_128, TLS_CIPHER_STREAM, 16, 16, 0,
CRYPTO_CIPHER_ALG_RC4 },
{ TLS_CIPHER_DES40_CBC, TLS_CIPHER_BLOCK, 5, 8, 8,
CRYPTO_CIPHER_ALG_DES },
{ TLS_CIPHER_DES_CBC, TLS_CIPHER_BLOCK, 8, 8, 8,
CRYPTO_CIPHER_ALG_DES },
{ TLS_CIPHER_3DES_EDE_CBC, TLS_CIPHER_BLOCK, 24, 24, 8,
CRYPTO_CIPHER_ALG_3DES },
{ TLS_CIPHER_AES_128_CBC, TLS_CIPHER_BLOCK, 16, 16, 16,
CRYPTO_CIPHER_ALG_AES },
{ TLS_CIPHER_AES_256_CBC, TLS_CIPHER_BLOCK, 32, 32, 16,
CRYPTO_CIPHER_ALG_AES }
};
#define NUM_TLS_CIPHER_DATA NUM_ELEMS(tls_ciphers)
/**
* tls_get_cipher_suite - Get TLS cipher suite
* @suite: Cipher suite identifier
* Returns: Pointer to the cipher data or %NULL if not found
*/
const struct tls_cipher_suite * tls_get_cipher_suite(u16 suite)
{
size_t i;
for (i = 0; i < NUM_TLS_CIPHER_SUITES; i++)
if (tls_cipher_suites[i].suite == suite)
return &tls_cipher_suites[i];
return NULL;
}
static const struct tls_cipher_data * tls_get_cipher_data(tls_cipher cipher)
{
size_t i;
for (i = 0; i < NUM_TLS_CIPHER_DATA; i++)
if (tls_ciphers[i].cipher == cipher)
return &tls_ciphers[i];
return NULL;
}
/**
* tls_parse_cert - Parse DER encoded X.509 certificate and get public key
* @buf: ASN.1 DER encoded certificate
* @len: Length of the buffer
* @pk: Buffer for returning the allocated public key
* Returns: 0 on success, -1 on failure
*
* This functions parses an ASN.1 DER encoded X.509 certificate and retrieves
* the public key from it. The caller is responsible for freeing the public key
* by calling crypto_public_key_free().
*/
int tls_parse_cert(const u8 *buf, size_t len, struct crypto_public_key **pk)
{
struct x509_certificate *cert;
wpa_hexdump(MSG_MSGDUMP, "TLSv1: Parse ASN.1 DER certificate",
buf, len);
*pk = crypto_public_key_from_cert(buf, len);
if (*pk)
return 0;
cert = x509_certificate_parse(buf, len);
if (cert == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to parse X.509 "
"certificate");
return -1;
}
/* TODO
* verify key usage (must allow encryption)
*
* All certificate profiles, key and cryptographic formats are
* defined by the IETF PKIX working group [PKIX]. When a key
* usage extension is present, the digitalSignature bit must be
* set for the key to be eligible for signing, as described
* above, and the keyEncipherment bit must be present to allow
* encryption, as described above. The keyAgreement bit must be
* set on Diffie-Hellman certificates. (PKIX: RFC 3280)
*/
*pk = crypto_public_key_import(cert->public_key, cert->public_key_len);
x509_certificate_free(cert);
if (*pk == NULL) {
wpa_printf(MSG_ERROR, "TLSv1: Failed to import "
"server public key");
return -1;
}
return 0;
}
/**
* tlsv1_record_set_cipher_suite - TLS record layer: Set cipher suite
* @rl: Pointer to TLS record layer data
* @cipher_suite: New cipher suite
* Returns: 0 on success, -1 on failure
*
* This function is used to prepare TLS record layer for cipher suite change.
* tlsv1_record_change_write_cipher() and
* tlsv1_record_change_read_cipher() functions can then be used to change the
* currently used ciphers.
*/
int tlsv1_record_set_cipher_suite(struct tlsv1_record_layer *rl,
u16 cipher_suite)
{
const struct tls_cipher_suite *suite;
const struct tls_cipher_data *data;
wpa_printf(MSG_DEBUG, "TLSv1: Selected cipher suite: 0x%04x",
cipher_suite);
rl->cipher_suite = cipher_suite;
suite = tls_get_cipher_suite(cipher_suite);
if (suite == NULL)
return -1;
if (suite->hash == TLS_HASH_MD5) {
rl->hash_alg = CRYPTO_HASH_ALG_HMAC_MD5;
rl->hash_size = MD5_MAC_LEN;
} else if (suite->hash == TLS_HASH_SHA) {
rl->hash_alg = CRYPTO_HASH_ALG_HMAC_SHA1;
rl->hash_size = SHA1_MAC_LEN;
}
data = tls_get_cipher_data(suite->cipher);
if (data == NULL)
return -1;
rl->key_material_len = data->key_material;
rl->iv_size = data->block_size;
rl->cipher_alg = data->alg;
return 0;
}
/**
* tlsv1_record_change_write_cipher - TLS record layer: Change write cipher
* @rl: Pointer to TLS record layer data
* Returns: 0 on success (cipher changed), -1 on failure
*
* This function changes TLS record layer to use the new cipher suite
* configured with tlsv1_record_set_cipher_suite() for writing.
*/
int tlsv1_record_change_write_cipher(struct tlsv1_record_layer *rl)
{
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - New write cipher suite "
"0x%04x", rl->cipher_suite);
rl->write_cipher_suite = rl->cipher_suite;
os_memset(rl->write_seq_num, 0, TLS_SEQ_NUM_LEN);
if (rl->write_cbc) {
crypto_cipher_deinit(rl->write_cbc);
rl->write_cbc = NULL;
}
if (rl->cipher_alg != CRYPTO_CIPHER_NULL) {
rl->write_cbc = crypto_cipher_init(rl->cipher_alg,
rl->write_iv, rl->write_key,
rl->key_material_len);
if (rl->write_cbc == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize "
"cipher");
return -1;
}
}
return 0;
}
/**
* tlsv1_record_change_read_cipher - TLS record layer: Change read cipher
* @rl: Pointer to TLS record layer data
* Returns: 0 on success (cipher changed), -1 on failure
*
* This function changes TLS record layer to use the new cipher suite
* configured with tlsv1_record_set_cipher_suite() for reading.
*/
int tlsv1_record_change_read_cipher(struct tlsv1_record_layer *rl)
{
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - New read cipher suite "
"0x%04x", rl->cipher_suite);
rl->read_cipher_suite = rl->cipher_suite;
os_memset(rl->read_seq_num, 0, TLS_SEQ_NUM_LEN);
if (rl->read_cbc) {
crypto_cipher_deinit(rl->read_cbc);
rl->read_cbc = NULL;
}
if (rl->cipher_alg != CRYPTO_CIPHER_NULL) {
rl->read_cbc = crypto_cipher_init(rl->cipher_alg,
rl->read_iv, rl->read_key,
rl->key_material_len);
if (rl->read_cbc == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize "
"cipher");
return -1;
}
}
return 0;
}
/**
* tlsv1_record_send - TLS record layer: Send a message
* @rl: Pointer to TLS record layer data
* @content_type: Content type (TLS_CONTENT_TYPE_*)
* @buf: Buffer to send (with TLS_RECORD_HEADER_LEN octets reserved in the
* beginning for record layer to fill in; payload filled in after this and
* extra space in the end for HMAC).
* @buf_size: Maximum buf size
* @payload_len: Length of the payload
* @out_len: Buffer for returning the used buf length
* Returns: 0 on success, -1 on failure
*
* This function fills in the TLS record layer header, adds HMAC, and encrypts
* the data using the current write cipher.
*/
int tlsv1_record_send(struct tlsv1_record_layer *rl, u8 content_type, u8 *buf,
size_t buf_size, size_t payload_len, size_t *out_len)
{
u8 *pos, *ct_start, *length, *payload;
struct crypto_hash *hmac;
size_t clen;
pos = buf;
/* ContentType type */
ct_start = pos;
*pos++ = content_type;
/* ProtocolVersion version */
WPA_PUT_BE16(pos, TLS_VERSION);
pos += 2;
/* uint16 length */
length = pos;
WPA_PUT_BE16(length, payload_len);
pos += 2;
/* opaque fragment[TLSPlaintext.length] */
payload = pos;
pos += payload_len;
if (rl->write_cipher_suite != TLS_NULL_WITH_NULL_NULL) {
hmac = crypto_hash_init(rl->hash_alg, rl->write_mac_secret,
rl->hash_size);
if (hmac == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
"to initialize HMAC");
return -1;
}
crypto_hash_update(hmac, rl->write_seq_num, TLS_SEQ_NUM_LEN);
/* type + version + length + fragment */
crypto_hash_update(hmac, ct_start, pos - ct_start);
clen = buf + buf_size - pos;
if (clen < rl->hash_size) {
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Not "
"enough room for MAC");
crypto_hash_finish(hmac, NULL, NULL);
return -1;
}
if (crypto_hash_finish(hmac, pos, &clen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
"to calculate HMAC");
return -1;
}
wpa_hexdump(MSG_MSGDUMP, "TLSv1: Record Layer - Write HMAC",
pos, clen);
pos += clen;
if (rl->iv_size) {
size_t len = pos - payload;
size_t pad;
pad = (len + 1) % rl->iv_size;
if (pad)
pad = rl->iv_size - pad;
if (pos + pad + 1 > buf + buf_size) {
wpa_printf(MSG_DEBUG, "TLSv1: No room for "
"block cipher padding");
return -1;
}
os_memset(pos, pad, pad + 1);
pos += pad + 1;
}
if (crypto_cipher_encrypt(rl->write_cbc, payload,
payload, pos - payload) < 0)
return -1;
}
WPA_PUT_BE16(length, pos - length - 2);
inc_byte_array(rl->write_seq_num, TLS_SEQ_NUM_LEN);
*out_len = pos - buf;
return 0;
}
/**
* tlsv1_record_receive - TLS record layer: Process a received message
* @rl: Pointer to TLS record layer data
* @in_data: Received data
* @in_len: Length of the received data
* @out_data: Buffer for output data (must be at least as long as in_data)
* @out_len: Set to maximum out_data length by caller; used to return the
* length of the used data
* @alert: Buffer for returning an alert value on failure
* Returns: 0 on success, -1 on failure
*
* This function decrypts the received message, verifies HMAC and TLS record
* layer header.
*/
int tlsv1_record_receive(struct tlsv1_record_layer *rl,
const u8 *in_data, size_t in_len,
u8 *out_data, size_t *out_len, u8 *alert)
{
size_t i, rlen, hlen;
u8 padlen;
struct crypto_hash *hmac;
u8 len[2], hash[100];
wpa_hexdump(MSG_MSGDUMP, "TLSv1: Record Layer - Received",
in_data, in_len);
if (in_len < TLS_RECORD_HEADER_LEN) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short record (in_len=%lu)",
(unsigned long) in_len);
*alert = TLS_ALERT_DECODE_ERROR;
return -1;
}
wpa_printf(MSG_DEBUG, "TLSv1: Received content type %d version %d.%d "
"length %d", in_data[0], in_data[1], in_data[2],
WPA_GET_BE16(in_data + 3));
if (in_data[0] != TLS_CONTENT_TYPE_HANDSHAKE &&
in_data[0] != TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC &&
in_data[0] != TLS_CONTENT_TYPE_APPLICATION_DATA) {
wpa_printf(MSG_DEBUG, "TLSv1: Unexpected content type 0x%x",
in_data[0]);
*alert = TLS_ALERT_UNEXPECTED_MESSAGE;
return -1;
}
if (WPA_GET_BE16(in_data + 1) != TLS_VERSION) {
wpa_printf(MSG_DEBUG, "TLSv1: Unexpected protocol version "
"%d.%d", in_data[1], in_data[2]);
*alert = TLS_ALERT_PROTOCOL_VERSION;
return -1;
}
rlen = WPA_GET_BE16(in_data + 3);
/* TLSCiphertext must not be more than 2^14+2048 bytes */
if (TLS_RECORD_HEADER_LEN + rlen > 18432) {
wpa_printf(MSG_DEBUG, "TLSv1: Record overflow (len=%lu)",
(unsigned long) (TLS_RECORD_HEADER_LEN + rlen));
*alert = TLS_ALERT_RECORD_OVERFLOW;
return -1;
}
in_data += TLS_RECORD_HEADER_LEN;
in_len -= TLS_RECORD_HEADER_LEN;
if (rlen > in_len) {
wpa_printf(MSG_DEBUG, "TLSv1: Not all record data included "
"(rlen=%lu > in_len=%lu)",
(unsigned long) rlen, (unsigned long) in_len);
*alert = TLS_ALERT_DECODE_ERROR;
return -1;
}
in_len = rlen;
if (*out_len < in_len) {
wpa_printf(MSG_DEBUG, "TLSv1: Not enough output buffer for "
"processing received record");
*alert = TLS_ALERT_INTERNAL_ERROR;
return -1;
}
os_memcpy(out_data, in_data, in_len);
*out_len = in_len;
if (rl->read_cipher_suite != TLS_NULL_WITH_NULL_NULL) {
if (crypto_cipher_decrypt(rl->read_cbc, out_data,
out_data, in_len) < 0) {
*alert = TLS_ALERT_DECRYPTION_FAILED;
return -1;
}
if (rl->iv_size) {
if (in_len == 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short record"
" (no pad)");
*alert = TLS_ALERT_DECODE_ERROR;
return -1;
}
padlen = out_data[in_len - 1];
if (padlen >= in_len) {
wpa_printf(MSG_DEBUG, "TLSv1: Incorrect pad "
"length (%u, in_len=%lu) in "
"received record",
padlen, (unsigned long) in_len);
*alert = TLS_ALERT_DECRYPTION_FAILED;
return -1;
}
for (i = in_len - padlen; i < in_len; i++) {
if (out_data[i] != padlen) {
wpa_hexdump(MSG_DEBUG,
"TLSv1: Invalid pad in "
"received record",
out_data + in_len - padlen,
padlen);
*alert = TLS_ALERT_DECRYPTION_FAILED;
return -1;
}
}
*out_len -= padlen + 1;
}
wpa_hexdump(MSG_MSGDUMP,
"TLSv1: Record Layer - Decrypted data",
out_data, in_len);
if (*out_len < rl->hash_size) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short record; no "
"hash value");
*alert = TLS_ALERT_INTERNAL_ERROR;
return -1;
}
*out_len -= rl->hash_size;
hmac = crypto_hash_init(rl->hash_alg, rl->read_mac_secret,
rl->hash_size);
if (hmac == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
"to initialize HMAC");
*alert = TLS_ALERT_INTERNAL_ERROR;
return -1;
}
crypto_hash_update(hmac, rl->read_seq_num, TLS_SEQ_NUM_LEN);
/* type + version + length + fragment */
crypto_hash_update(hmac, in_data - TLS_RECORD_HEADER_LEN, 3);
WPA_PUT_BE16(len, *out_len);
crypto_hash_update(hmac, len, 2);
crypto_hash_update(hmac, out_data, *out_len);
hlen = sizeof(hash);
if (crypto_hash_finish(hmac, hash, &hlen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Record Layer - Failed "
"to calculate HMAC");
return -1;
}
if (hlen != rl->hash_size ||
os_memcmp(hash, out_data + *out_len, hlen) != 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Invalid HMAC value in "
"received message");
*alert = TLS_ALERT_BAD_RECORD_MAC;
return -1;
}
}
/* TLSCompressed must not be more than 2^14+1024 bytes */
if (TLS_RECORD_HEADER_LEN + *out_len > 17408) {
wpa_printf(MSG_DEBUG, "TLSv1: Record overflow (len=%lu)",
(unsigned long) (TLS_RECORD_HEADER_LEN + *out_len));
*alert = TLS_ALERT_RECORD_OVERFLOW;
return -1;
}
inc_byte_array(rl->read_seq_num, TLS_SEQ_NUM_LEN);
return 0;
}