check_tls: better key generation.

GitOrigin-RevId: 090ac63afcac8a61df92f008f054cc0cfd559d36
This commit is contained in:
levlam 2019-08-22 22:26:12 +03:00
parent 85c64bb3da
commit 2e8ec529e9

View File

@ -4,6 +4,7 @@
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/BigNum.h"
#include "td/utils/common.h"
#include "td/utils/format.h"
#include "td/utils/logging.h"
@ -20,6 +21,25 @@
#include <map>
static bool is_quadratic_residue(const td::BigNum &a) {
// 2^255 - 19
td::BigNum mod =
td::BigNum::from_hex("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed").move_as_ok();
// (mod - 1) / 2 = 2^254 - 10
td::BigNum pow =
td::BigNum::from_hex("3ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff6").move_as_ok();
static td::BigNumContext context;
td::BigNum r;
td::BigNum::mod_exp(r, a, pow, mod, context);
td::BigNum one = td::BigNum::from_decimal("1").move_as_ok();
td::BigNum::mod_add(r, r, one, mod, context);
std::string result = r.to_decimal();
CHECK(result == "0" || result == "1" || result == "2");
return result == "2";
}
struct TlsInfo {
td::vector<size_t> extension_list;
td::vector<size_t> encrypted_application_data_length;
@ -42,6 +62,33 @@ td::Result<TlsInfo> test_tls(const td::string &url) {
request += static_cast<char>(length / 256);
request += static_cast<char>(length % 256);
};
auto add_key = [&] {
td::string key(32, '\0');
td::BigNumContext context;
td::BigNum mod =
td::BigNum::from_hex("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed").move_as_ok();
while (true) {
td::Random::secure_bytes(key);
key[31] = static_cast<char>(key[31] & 127);
td::BigNum x = td::BigNum::from_le_binary(key);
if (!is_quadratic_residue(x)) {
continue;
}
td::BigNum y = x.clone();
td::BigNum coef = td::BigNum::from_decimal("486662").move_as_ok();
td::BigNum::mod_add(y, y, coef, mod, context);
td::BigNum::mod_mul(y, y, x, mod, context);
td::BigNum one = td::BigNum::from_decimal("1").move_as_ok();
td::BigNum::mod_add(y, y, one, mod, context);
td::BigNum::mod_mul(y, y, x, mod, context);
// y = x^3 + 486662 * x^2 + x
if (is_quadratic_residue(y)) {
break;
}
}
request += key;
};
const size_t MAX_GREASE = 7;
char greases[MAX_GREASE];
@ -84,7 +131,7 @@ td::Result<TlsInfo> test_tls(const td::string &url) {
"\x01\x05\x03\x08\x05\x05\x01\x08\x06\x06\x01\x02\x01\x00\x12\x00\x00\x00\x33\x00\x2b\x00\x29");
add_grease(4);
add_string("\x00\x01\x00\x00\x1d\x00\x20");
add_random(32);
add_key();
add_string("\x00\x2d\x00\x02\x01\x01\x00\x2b\x00\x0b\x0a");
add_grease(6);
add_string("\x03\x04\x03\x03\x03\x02\x03\x01\x00\x1b\x00\x03\x02\x00\x02");