/*
* Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <string.h>
#include <openssl/dtls1.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "helpers/ssltestlib.h"
#include "testutil.h"
/* for SSL_READ_ETM() */
#include "../ssl/ssl_local.h"
static int debug = 0;
static unsigned int clnt_psk_callback(SSL *ssl, const char *hint,
char *ident, unsigned int max_ident_len,
unsigned char *psk,
unsigned int max_psk_len)
{
BIO_snprintf(ident, max_ident_len, "psk");
if (max_psk_len > 20)
max_psk_len = 20;
memset(psk, 0x5a, max_psk_len);
return max_psk_len;
}
static unsigned int srvr_psk_callback(SSL *ssl, const char *identity,
unsigned char *psk,
unsigned int max_psk_len)
{
if (max_psk_len > 20)
max_psk_len = 20;
memset(psk, 0x5a, max_psk_len);
return max_psk_len;
}
static int mtu_test(SSL_CTX *ctx, const char *cs, int no_etm)
{
SSL *srvr_ssl = NULL, *clnt_ssl = NULL;
BIO *sc_bio = NULL;
int i;
size_t s;
size_t mtus[30];
unsigned char buf[600];
int rv = 0;
memset(buf, 0x5a, sizeof(buf));
if (!TEST_true(create_ssl_objects(ctx, ctx, &srvr_ssl, &clnt_ssl,
NULL, NULL)))
goto end;
if (no_etm)
SSL_set_options(srvr_ssl, SSL_OP_NO_ENCRYPT_THEN_MAC);
if (!TEST_true(SSL_set_cipher_list(srvr_ssl, cs))
|| !TEST_true(SSL_set_cipher_list(clnt_ssl, cs))
|| !TEST_ptr(sc_bio = SSL_get_rbio(srvr_ssl))
|| !TEST_true(create_ssl_connection(clnt_ssl, srvr_ssl,
SSL_ERROR_NONE)))
goto end;
if (debug)
TEST_info("Channel established");
/* For record MTU values between 500 and 539, call DTLS_get_data_mtu()
* to query the payload MTU which will fit. */
for (i = 0; i < 30; i++) {
SSL_set_mtu(clnt_ssl, 500 + i);
mtus[i] = DTLS_get_data_mtu(clnt_ssl);
if (debug)
TEST_info("%s%s MTU for record mtu %d = %lu",
cs, no_etm ? "-noEtM" : "",
500 + i, (unsigned long)mtus[i]);
if (!TEST_size_t_ne(mtus[i], 0)) {
TEST_info("Cipher %s MTU %d", cs, 500 + i);
goto end;
}
}
/* Now get out of the way */
SSL_set_mtu(clnt_ssl, 1000);
/*
* Now for all values in the range of payload MTUs, send a payload of
* that size and see what actual record size we end up with.
*/
for (s = mtus[0]; s <= mtus[29]; s++) {
size_t reclen;
if (!TEST_int_eq(SSL_write(clnt_ssl, buf, s), (int)s))
goto end;
reclen = BIO_read(sc_bio, buf, sizeof(buf));
if (debug)
TEST_info("record %zu for payload %zu", reclen, s);
for (i = 0; i < 30; i++) {
/* DTLS_get_data_mtu() with record MTU 500+i returned mtus[i] ... */
if (!TEST_false(s <= mtus[i] && reclen > (size_t)(500 + i))) {
/*
* We sent a packet smaller than or equal to mtus[j] and
* that made a record *larger* than the record MTU 500+j!
*/
TEST_error("%s: s=%lu, mtus[i]=%lu, reclen=%lu, i=%d",
cs, (unsigned long)s, (unsigned long)mtus[i],
(unsigned long)reclen, 500 + i);
goto end;
}
if (!TEST_false(s > mtus[i] && reclen <= (size_t)(500 + i))) {
/*
* We sent a *larger* packet than mtus[i] and that *still*
* fits within the record MTU 500+i, so DTLS_get_data_mtu()
* was overly pessimistic.
*/
TEST_error("%s: s=%lu, mtus[i]=%lu, reclen=%lu, i=%d",
cs, (unsigned long)s, (unsigned long)mtus[i],
(unsigned long)reclen, 500 + i);
goto end;
}
}
}
rv = 1;
if (SSL_READ_ETM(clnt_ssl))
rv = 2;
end:
SSL_free(clnt_ssl);
SSL_free(srvr_ssl);
return rv;
}
static int run_mtu_tests(void)
{
SSL_CTX *ctx = NULL;
STACK_OF(SSL_CIPHER) *ciphers;
int i, ret = 0;
if (!TEST_ptr(ctx = SSL_CTX_new(DTLS_method())))
goto end;
SSL_CTX_set_psk_server_callback(ctx, srvr_psk_callback);
SSL_CTX_set_psk_client_callback(ctx, clnt_psk_callback);
SSL_CTX_set_security_level(ctx, 0);
/*
* We only care about iterating over each enc/mac; we don't want to
* repeat the test for each auth/kx variant. So keep life simple and
* only do (non-DH) PSK.
*/
if (!TEST_true(SSL_CTX_set_cipher_list(ctx, "PSK")))
goto end;
ciphers = SSL_CTX_get_ciphers(ctx);
for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
const SSL_CIPHER *cipher = sk_SSL_CIPHER_value(ciphers, i);
const char *cipher_name = SSL_CIPHER_get_name(cipher);
/* As noted above, only one test for each enc/mac variant. */
if (strncmp(cipher_name, "PSK-", 4) != 0)
continue;
if (!TEST_int_gt(ret = mtu_test(ctx, cipher_name, 0), 0))
break;
TEST_info("%s OK", cipher_name);
if (ret == 1)
continue;
/* mtu_test() returns 2 if it used Encrypt-then-MAC */
if (!TEST_int_gt(ret = mtu_test(ctx, cipher_name, 1), 0))
break;
TEST_info("%s without EtM OK", cipher_name);
}
end:
SSL_CTX_free(ctx);
return ret;
}
static int test_server_mtu_larger_than_max_fragment_length(void)
{
SSL_CTX *ctx = NULL;
SSL *srvr_ssl = NULL, *clnt_ssl = NULL;
int rv = 0;
if (!TEST_ptr(ctx = SSL_CTX_new(DTLS_method())))
goto end;
SSL_CTX_set_psk_server_callback(ctx, srvr_psk_callback);
SSL_CTX_set_psk_client_callback(ctx, clnt_psk_callback);
#ifndef OPENSSL_NO_DH
if (!TEST_true(SSL_CTX_set_dh_auto(ctx, 1)))
goto end;
#endif
if (!TEST_true(create_ssl_objects(ctx, ctx, &srvr_ssl, &clnt_ssl,
NULL, NULL)))
goto end;
SSL_set_options(srvr_ssl, SSL_OP_NO_QUERY_MTU);
if (!TEST_true(DTLS_set_link_mtu(srvr_ssl, 1500)))
goto end;
SSL_set_tlsext_max_fragment_length(clnt_ssl,
TLSEXT_max_fragment_length_512);
if (!TEST_true(create_ssl_connection(srvr_ssl, clnt_ssl,
SSL_ERROR_NONE)))
goto end;
rv = 1;
end:
SSL_free(clnt_ssl);
SSL_free(srvr_ssl);
SSL_CTX_free(ctx);
return rv;
}
int setup_tests(void)
{
ADD_TEST(run_mtu_tests);
ADD_TEST(test_server_mtu_larger_than_max_fragment_length);
return 1;
}
void cleanup_tests(void)
{
bio_s_mempacket_test_free();
}