mirror of
https://github.com/bsnes-emu/bsnes.git
synced 2025-02-24 07:02:27 +01:00
f3e67da937
byuu says:
Changelog:
- added \~130 new PAL games to icarus (courtesy of Smarthuman
and aquaman)
- added all three Korean-localized games to icarus
- sfc: removed SuperDisc emulation (it was going nowhere)
- sfc: fixed MSU1 regression where the play/repeat flags were not
being cleared on track select
- nall: cryptography support added; will be used to sign future
databases (validation will always be optional)
- minor shims to fix compilation issues due to nall changes
The real magic is that we now have 25-30% of the PAL SNES library in
icarus!
Signing will be tricky. Obviously if I put the public key inside the
higan archive, then all anyone has to do is change that public key for
their own releases. And if you download from my site (which is now over
HTTPS), then you don't need the signing to verify integrity. I may just
put the public key on my site on my site and leave it at that, we'll
see.
80 lines
1.9 KiB
C++
80 lines
1.9 KiB
C++
#pragma once
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#include <nall/arithmetic/barrett.hpp>
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namespace nall { namespace EllipticCurve {
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static const uint256_t P = (1_u256 << 255) - 19;
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static const uint256_t L = (1_u256 << 252) + 27742317777372353535851937790883648493_u256;
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static BarrettReduction modP{P};
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static BarrettReduction modL{L};
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struct Modulo25519 : uint256_t {
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using type = Modulo25519;
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using uint256_t::uint256_t;
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alwaysinline auto operator()() const -> uint256_t {
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return *this;
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}
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alwaysinline auto operator-() const -> type {
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return P.operator-(*this);
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}
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template<typename T> alwaysinline auto operator+(const T& rhs) const -> type {
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auto lhs = (uint512_t)*this + rhs;
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if(lhs >= P) lhs -= P;
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return lhs;
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}
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template<typename T> alwaysinline auto operator-(const T& rhs) const -> type {
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auto lhs = (uint512_t)*this;
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if(lhs < rhs) lhs += P;
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return lhs - rhs;
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}
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template<typename T> alwaysinline auto operator*(const T& rhs) const -> type {
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uint256_t hi, lo;
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nall::mul(*this, rhs, hi, lo);
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return modP(uint512_t{hi, lo});
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}
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alwaysinline auto square() const -> type {
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uint256_t hi, lo;
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nall::square(*this, hi, lo);
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return modP(uint512_t{hi, lo});
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}
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inline auto expmod(uint256_t e) const -> type {
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type x = 1;
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for(auto n : rrange(256)) {
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x = x.square();
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if(e >> n & 1) x = operator*(x);
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}
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return x;
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}
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inline auto reciprocal() const -> type {
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return expmod(P - 2);
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}
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inline auto squareRoot() const -> type {
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static const type i = type(2).expmod((P - 1) >> 2); //i = sqrt(-1)
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type x = expmod((P + 3) >> 3);
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if(operator!=(x.square())) x = x * i;
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if(x & 1) x = -x;
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return x;
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}
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};
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inline auto cmove(bool bit, Modulo25519& lhs, const Modulo25519& rhs) -> void {
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if(bit) lhs = rhs;
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}
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inline auto cswap(bool bit, Modulo25519& lhs, Modulo25519& rhs) -> void {
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if(bit) swap(lhs, rhs);
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}
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}}
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