/**
* 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;
}
static int tls_write_client_key_exchange(struct tlsv1_client *conn,
u8 **msgpos, u8 *end)
{
u8 *pos, *rhdr, *hs_start, *hs_length;
size_t rlen;
tls_key_exchange keyx;
const struct tls_cipher_suite *suite;
suite = tls_get_cipher_suite(conn->rl.cipher_suite);
if (suite == NULL)
keyx = TLS_KEY_X_NULL;
else
keyx = suite->key_exchange;
pos = *msgpos;
wpa_printf(MSG_DEBUG, "TLSv1: Send ClientKeyExchange");
rhdr = pos;
pos += TLS_RECORD_HEADER_LEN;
/* opaque fragment[TLSPlaintext.length] */
/* Handshake */
hs_start = pos;
/* HandshakeType msg_type */
*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE;
/* uint24 length (to be filled) */
hs_length = pos;
pos += 3;
/* body - ClientKeyExchange */
if (keyx == TLS_KEY_X_DH_anon) {
if (tlsv1_key_x_anon_dh(conn, &pos, end) < 0)
return -1;
} else {
if (tlsv1_key_x_rsa(conn, &pos, end) < 0)
return -1;
}
WPA_PUT_BE24(hs_length, pos - hs_length - 3);
if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
rhdr, end - rhdr, hs_start, pos - hs_start,
&rlen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
pos = rhdr + rlen;
tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
*msgpos = pos;
return 0;
}
int tls_server_key_exchange_allowed(tls_cipher cipher)
{
const struct tls_cipher_suite *suite;
/* RFC 2246, Section 7.4.3 */
suite = tls_get_cipher_suite(cipher);
if (suite == NULL)
return 0;
switch (suite->key_exchange) {
case TLS_KEY_X_DHE_DSS:
case TLS_KEY_X_DHE_DSS_EXPORT:
case TLS_KEY_X_DHE_RSA:
case TLS_KEY_X_DHE_RSA_EXPORT:
case TLS_KEY_X_DH_anon_EXPORT:
case TLS_KEY_X_DH_anon:
return 1;
case TLS_KEY_X_RSA_EXPORT:
return 1 /* FIX: public key len > 512 bits */;
default:
return 0;
}
}
static int tls_write_server_key_exchange(struct tlsv1_server *conn,
u8 **msgpos, u8 *end)
{
tls_key_exchange keyx;
const struct tls_cipher_suite *suite;
#ifdef EAP_FAST
u8 *pos, *rhdr, *hs_start, *hs_length;
size_t rlen;
u8 *dh_ys;
size_t dh_ys_len;
#endif /* EAP_FAST */
suite = tls_get_cipher_suite(conn->rl.cipher_suite);
if (suite == NULL)
keyx = TLS_KEY_X_NULL;
else
keyx = suite->key_exchange;
if (!tls_server_key_exchange_allowed(conn->rl.cipher_suite)) {
wpa_printf(MSG_DEBUG, "TLSv1: No ServerKeyExchange needed");
return 0;
}
if (keyx != TLS_KEY_X_DH_anon) {
/* TODO? */
wpa_printf(MSG_DEBUG, "TLSv1: ServerKeyExchange not yet "
"supported with key exchange type %d", keyx);
return -1;
}
#ifdef EAP_FAST
if (conn->cred == NULL || conn->cred->dh_p == NULL ||
conn->cred->dh_g == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: No DH parameters available for "
"ServerKeyExhcange");
return -1;
}
os_free(conn->dh_secret);
conn->dh_secret_len = conn->cred->dh_p_len;
conn->dh_secret = os_malloc(conn->dh_secret_len);
if (conn->dh_secret == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
"memory for secret (Diffie-Hellman)");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
if (os_get_random(conn->dh_secret, conn->dh_secret_len)) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
"data for Diffie-Hellman");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
os_free(conn->dh_secret);
conn->dh_secret = NULL;
return -1;
}
if (os_memcmp(conn->dh_secret, conn->cred->dh_p, conn->dh_secret_len) >
0)
conn->dh_secret[0] = 0; /* make sure secret < p */
pos = conn->dh_secret;
while (pos + 1 < conn->dh_secret + conn->dh_secret_len && *pos == 0)
pos++;
if (pos != conn->dh_secret) {
os_memmove(conn->dh_secret, pos,
conn->dh_secret_len - (pos - conn->dh_secret));
conn->dh_secret_len -= pos - conn->dh_secret;
}
wpa_hexdump_key(MSG_DEBUG, "TLSv1: DH server's secret value",
conn->dh_secret, conn->dh_secret_len);
/* Ys = g^secret mod p */
dh_ys_len = conn->cred->dh_p_len;
dh_ys = os_malloc(dh_ys_len);
if (dh_ys == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate memory for "
"Diffie-Hellman");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
if (crypto_mod_exp(conn->cred->dh_g, conn->cred->dh_g_len,
conn->dh_secret, conn->dh_secret_len,
conn->cred->dh_p, conn->cred->dh_p_len,
dh_ys, &dh_ys_len)) {
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
os_free(dh_ys);
return -1;
}
wpa_hexdump(MSG_DEBUG, "TLSv1: DH Ys (server's public value)",
dh_ys, dh_ys_len);
/*
* struct {
* select (KeyExchangeAlgorithm) {
* case diffie_hellman:
* ServerDHParams params;
* Signature signed_params;
* case rsa:
* ServerRSAParams params;
* Signature signed_params;
* };
* } ServerKeyExchange;
*
* struct {
* opaque dh_p<1..2^16-1>;
* opaque dh_g<1..2^16-1>;
* opaque dh_Ys<1..2^16-1>;
* } ServerDHParams;
*/
pos = *msgpos;
wpa_printf(MSG_DEBUG, "TLSv1: Send ServerKeyExchange");
rhdr = pos;
pos += TLS_RECORD_HEADER_LEN;
/* opaque fragment[TLSPlaintext.length] */
/* Handshake */
hs_start = pos;
/* HandshakeType msg_type */
*pos++ = TLS_HANDSHAKE_TYPE_SERVER_KEY_EXCHANGE;
/* uint24 length (to be filled) */
hs_length = pos;
pos += 3;
/* body - ServerDHParams */
/* dh_p */
if (pos + 2 + conn->cred->dh_p_len > end) {
wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space for "
"dh_p");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
os_free(dh_ys);
return -1;
}
WPA_PUT_BE16(pos, conn->cred->dh_p_len);
pos += 2;
os_memcpy(pos, conn->cred->dh_p, conn->cred->dh_p_len);
pos += conn->cred->dh_p_len;
/* dh_g */
if (pos + 2 + conn->cred->dh_g_len > end) {
wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space for "
"dh_g");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
os_free(dh_ys);
return -1;
}
WPA_PUT_BE16(pos, conn->cred->dh_g_len);
pos += 2;
os_memcpy(pos, conn->cred->dh_g, conn->cred->dh_g_len);
pos += conn->cred->dh_g_len;
/* dh_Ys */
if (pos + 2 + dh_ys_len > end) {
wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space for "
"dh_Ys");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
os_free(dh_ys);
return -1;
}
WPA_PUT_BE16(pos, dh_ys_len);
pos += 2;
os_memcpy(pos, dh_ys, dh_ys_len);
pos += dh_ys_len;
os_free(dh_ys);
WPA_PUT_BE24(hs_length, pos - hs_length - 3);
if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
rhdr, end - rhdr, pos - hs_start, &rlen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
pos = rhdr + rlen;
tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
*msgpos = pos;
return 0;
#else /* EAP_FAST */
return -1;
#endif /* EAP_FAST */
}
static int tls_write_server_certificate(struct tlsv1_server *conn,
u8 **msgpos, u8 *end)
{
u8 *pos, *rhdr, *hs_start, *hs_length, *cert_start;
size_t rlen;
struct x509_certificate *cert;
const struct tls_cipher_suite *suite;
suite = tls_get_cipher_suite(conn->rl.cipher_suite);
if (suite && suite->key_exchange == TLS_KEY_X_DH_anon) {
wpa_printf(MSG_DEBUG, "TLSv1: Do not send Certificate when "
"using anonymous DH");
return 0;
}
pos = *msgpos;
wpa_printf(MSG_DEBUG, "TLSv1: Send Certificate");
rhdr = pos;
pos += TLS_RECORD_HEADER_LEN;
/* opaque fragment[TLSPlaintext.length] */
/* Handshake */
hs_start = pos;
/* HandshakeType msg_type */
*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE;
/* uint24 length (to be filled) */
hs_length = pos;
pos += 3;
/* body - Certificate */
/* uint24 length (to be filled) */
cert_start = pos;
pos += 3;
cert = conn->cred->cert;
while (cert) {
if (pos + 3 + cert->cert_len > end) {
wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space "
"for Certificate (cert_len=%lu left=%lu)",
(unsigned long) cert->cert_len,
(unsigned long) (end - pos));
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
WPA_PUT_BE24(pos, cert->cert_len);
pos += 3;
os_memcpy(pos, cert->cert_start, cert->cert_len);
pos += cert->cert_len;
if (x509_certificate_self_signed(cert))
break;
cert = x509_certificate_get_subject(conn->cred->trusted_certs,
&cert->issuer);
}
if (cert == conn->cred->cert || cert == NULL) {
/*
* Server was not configured with all the needed certificates
* to form a full certificate chain. The client may fail to
* validate the chain unless it is configured with all the
* missing CA certificates.
*/
wpa_printf(MSG_DEBUG, "TLSv1: Full server certificate chain "
"not configured - validation may fail");
}
WPA_PUT_BE24(cert_start, pos - cert_start - 3);
WPA_PUT_BE24(hs_length, pos - hs_length - 3);
if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
rhdr, end - rhdr, pos - hs_start, &rlen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
pos = rhdr + rlen;
tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
*msgpos = pos;
return 0;
}
static int tls_process_client_key_exchange(struct tlsv1_server *conn, u8 ct,
const u8 *in_data, size_t *in_len) {
const u8 *pos, *end;
size_t left, len;
u8 type;
tls_key_exchange keyx;
const struct tls_cipher_suite *suite;
if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
"received content type 0x%x", ct);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
pos = in_data;
left = *in_len;
if (left < 4) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short ClientKeyExchange "
"(Left=%lu)", (unsigned long) left);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
type = *pos++;
len = WPA_GET_BE24(pos);
pos += 3;
left -= 4;
if (len > left) {
wpa_printf(MSG_DEBUG, "TLSv1: Mismatch in ClientKeyExchange "
"length (len=%lu != left=%lu)",
(unsigned long) len, (unsigned long) left);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
end = pos + len;
if (type != TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE) {
wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
"message %d (expected ClientKeyExchange)", type);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
wpa_printf(MSG_DEBUG, "TLSv1: Received ClientKeyExchange");
wpa_hexdump(MSG_DEBUG, "TLSv1: ClientKeyExchange", pos, len);
suite = tls_get_cipher_suite(conn->rl.cipher_suite);
if (suite == NULL)
keyx = TLS_KEY_X_NULL;
else
keyx = suite->key_exchange;
if (keyx == TLS_KEY_X_DH_anon &&
tls_process_client_key_exchange_dh_anon(conn, pos, end) < 0)
return -1;
if (keyx != TLS_KEY_X_DH_anon &&
tls_process_client_key_exchange_rsa(conn, pos, end) < 0)
return -1;
*in_len = end - in_data;
conn->state = CERTIFICATE_VERIFY;
return 0;
}
static int tls_process_server_key_exchange(struct tlsv1_client *conn, u8 ct,
const u8 *in_data, size_t *in_len)
{
const u8 *pos, *end;
size_t left, len;
u8 type;
const struct tls_cipher_suite *suite;
if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
"received content type 0x%x", ct);
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
pos = in_data;
left = *in_len;
if (left < 4) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short ServerKeyExchange "
"(Left=%lu)", (unsigned long) left);
tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
return -1;
}
type = *pos++;
len = WPA_GET_BE24(pos);
pos += 3;
left -= 4;
if (len > left) {
wpa_printf(MSG_DEBUG, "TLSv1: Mismatch in ServerKeyExchange "
"length (len=%lu != left=%lu)",
(unsigned long) len, (unsigned long) left);
tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
return -1;
}
end = pos + len;
if (type == TLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST)
return tls_process_certificate_request(conn, ct, in_data,
in_len);
if (type == TLS_HANDSHAKE_TYPE_SERVER_HELLO_DONE)
return tls_process_server_hello_done(conn, ct, in_data,
in_len);
if (type != TLS_HANDSHAKE_TYPE_SERVER_KEY_EXCHANGE) {
wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
"message %d (expected ServerKeyExchange/"
"CertificateRequest/ServerHelloDone)", type);
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
wpa_printf(MSG_DEBUG, "TLSv1: Received ServerKeyExchange");
if (!tls_server_key_exchange_allowed(conn->rl.cipher_suite)) {
wpa_printf(MSG_DEBUG, "TLSv1: ServerKeyExchange not allowed "
"with the selected cipher suite");
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
wpa_hexdump(MSG_DEBUG, "TLSv1: ServerKeyExchange", pos, len);
suite = tls_get_cipher_suite(conn->rl.cipher_suite);
if (suite && (suite->key_exchange == TLS_KEY_X_DH_anon ||
suite->key_exchange == TLS_KEY_X_DHE_RSA)) {
if (tlsv1_process_diffie_hellman(conn, pos, len,
suite->key_exchange) < 0) {
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
} else {
wpa_printf(MSG_DEBUG, "TLSv1: UnexpectedServerKeyExchange");
tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
*in_len = end - in_data;
conn->state = SERVER_CERTIFICATE_REQUEST;
return 0;
}
