diff options
| -rw-r--r-- | benchmark/check_tls.cpp | 6 | ||||
| -rw-r--r-- | td/mtproto/TlsInit.cpp | 53 |
2 files changed, 54 insertions, 5 deletions
diff --git a/benchmark/check_tls.cpp b/benchmark/check_tls.cpp index a7eb768e2..7ff1a1466 100644 --- a/benchmark/check_tls.cpp +++ b/benchmark/check_tls.cpp @@ -21,6 +21,8 @@ #include <map> +static td::BigNumContext context; + static bool is_quadratic_residue(const td::BigNum &a) { // 2^255 - 19 td::BigNum mod = @@ -29,13 +31,12 @@ static bool is_quadratic_residue(const td::BigNum &a) { 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(); + td::string result = r.to_decimal(); CHECK(result == "0" || result == "1" || result == "2"); return result == "2"; } @@ -64,7 +65,6 @@ td::Result<TlsInfo> test_tls(const td::string &url) { }; auto add_key = [&] { td::string key(32, '\0'); - td::BigNumContext context; td::BigNum mod = td::BigNum::from_hex("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed").move_as_ok(); while (true) { diff --git a/td/mtproto/TlsInit.cpp b/td/mtproto/TlsInit.cpp index fc66a8841..07d80fc13 100644 --- a/td/mtproto/TlsInit.cpp +++ b/td/mtproto/TlsInit.cpp @@ -7,6 +7,7 @@ #include "td/mtproto/TlsInit.h" #include "td/utils/as.h" +#include "td/utils/BigNum.h" #include "td/utils/common.h" #include "td/utils/crypto.h" #include "td/utils/logging.h" @@ -35,7 +36,7 @@ void Grease::init(MutableSlice res) { class TlsHello { public: struct Op { - enum class Type { String, Random, Zero, Domain, Grease, BeginScope, EndScope }; + enum class Type { String, Random, Zero, Domain, Grease, Key, BeginScope, EndScope }; Type type; int length; int seed; @@ -80,6 +81,11 @@ class TlsHello { res.type = Type::EndScope; return res; } + static Op key() { + Op res; + res.type = Type::Key; + return res; + } }; static const TlsHello &get_default() { @@ -112,7 +118,7 @@ class TlsHello { "\x04\x04\x01\x05\x03\x08\x05\x05\x01\x08\x06\x06\x01\x02\x01\x00\x12\x00\x00\x00\x33\x00\x2b\x00\x29"), Op::grease(4), Op::string("\x00\x01\x00\x00\x1d\x00\x20"), - Op::random(32), + Op::key(), Op::string("\x00\x2d\x00\x02\x01\x01\x00\x2b\x00\x0b\x0a"), Op::grease(6), Op::string("\x03\x04\x03\x03\x03\x02\x03\x01\x00\x1b\x00\x03\x02\x00\x02"), @@ -193,6 +199,9 @@ class TlsHelloCalcLength { } size_ += 2; break; + case Type::Key: + size_ += 32; + break; case Type::BeginScope: size_ += 2; scope_offset_.push_back(size_); @@ -280,6 +289,33 @@ class TlsHelloStore { dest_.remove_prefix(2); break; } + case Type::Key: { + BigNum mod = BigNum::from_hex("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed").move_as_ok(); + BigNumContext big_num_context; + auto key = dest_.substr(0, 32); + while (true) { + Random::secure_bytes(key); + key[31] = static_cast<char>(key[31] & 127); + BigNum x = BigNum::from_le_binary(key); + if (!is_quadratic_residue(x)) { + continue; + } + + BigNum y = x.clone(); + BigNum coef = BigNum::from_decimal("486662").move_as_ok(); + BigNum::mod_add(y, y, coef, mod, big_num_context); + BigNum::mod_mul(y, y, x, mod, big_num_context); + BigNum one = BigNum::from_decimal("1").move_as_ok(); + BigNum::mod_add(y, y, one, mod, big_num_context); + BigNum::mod_mul(y, y, x, mod, big_num_context); + // y = x^3 + 486662 * x^2 + x + if (is_quadratic_residue(y)) { + break; + } + } + dest_.remove_prefix(32); + break; + } case Type::BeginScope: scope_offset_.push_back(get_offset()); dest_.remove_prefix(2); @@ -319,6 +355,19 @@ class TlsHelloStore { MutableSlice dest_; std::vector<size_t> scope_offset_; + static bool is_quadratic_residue(const BigNum &a) { + // 2^255 - 19 + BigNum mod = BigNum::from_hex("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed").move_as_ok(); + // (mod - 1) / 2 = 2^254 - 10 + BigNum pow = BigNum::from_hex("3ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff6").move_as_ok(); + + BigNumContext context; + BigNum r; + BigNum::mod_exp(r, a, pow, mod, context); + + return r.to_decimal() == "1"; + } + size_t get_offset() const { return data_.size() - dest_.size(); } |