From 15660bd8570735139d91d0165a2614747f570202 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Mon, 3 Aug 2020 14:14:39 -0400
Subject: [PATCH] aes_util: Allow SetIV to be non-allocating
In a few places, the data to be set as the IV is already within an array.
We shouldn't require this data to be heap-allocated if it doesn't need
to be. This allows certain callers to reduce heap churn.
---
src/core/crypto/aes_util.cpp | 21 ++++++++++++---------
src/core/crypto/aes_util.h | 9 ++++++---
src/core/crypto/ctr_encryption_layer.cpp | 9 ++++-----
src/core/crypto/ctr_encryption_layer.h | 9 ++++++---
src/core/crypto/partition_data_manager.cpp | 5 ++---
src/core/file_sys/content_archive.cpp | 7 ++++---
src/core/file_sys/nca_patch.cpp | 3 ++-
7 files changed, 36 insertions(+), 27 deletions(-)
diff --git a/src/core/crypto/aes_util.cpp b/src/core/crypto/aes_util.cpp
index 4be76bb43..330996b24 100644
--- a/src/core/crypto/aes_util.cpp
+++ b/src/core/crypto/aes_util.cpp
@@ -2,6 +2,7 @@
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
+#include <array>
#include <mbedtls/cipher.h>
#include "common/assert.h"
#include "common/logging/log.h"
@@ -10,8 +11,10 @@
namespace Core::Crypto {
namespace {
-std::vector<u8> CalculateNintendoTweak(std::size_t sector_id) {
- std::vector<u8> out(0x10);
+using NintendoTweak = std::array<u8, 16>;
+
+NintendoTweak CalculateNintendoTweak(std::size_t sector_id) {
+ NintendoTweak out{};
for (std::size_t i = 0xF; i <= 0xF; --i) {
out[i] = sector_id & 0xFF;
sector_id >>= 8;
@@ -63,13 +66,6 @@ AESCipher<Key, KeySize>::~AESCipher() {
mbedtls_cipher_free(&ctx->decryption_context);
}
-template <typename Key, std::size_t KeySize>
-void AESCipher<Key, KeySize>::SetIV(std::vector<u8> iv) {
- ASSERT_MSG((mbedtls_cipher_set_iv(&ctx->encryption_context, iv.data(), iv.size()) ||
- mbedtls_cipher_set_iv(&ctx->decryption_context, iv.data(), iv.size())) == 0,
- "Failed to set IV on mbedtls ciphers.");
-}
-
template <typename Key, std::size_t KeySize>
void AESCipher<Key, KeySize>::Transcode(const u8* src, std::size_t size, u8* dest, Op op) const {
auto* const context = op == Op::Encrypt ? &ctx->encryption_context : &ctx->decryption_context;
@@ -124,6 +120,13 @@ void AESCipher<Key, KeySize>::XTSTranscode(const u8* src, std::size_t size, u8*
}
}
+template <typename Key, std::size_t KeySize>
+void AESCipher<Key, KeySize>::SetIVImpl(const u8* data, std::size_t size) {
+ ASSERT_MSG((mbedtls_cipher_set_iv(&ctx->encryption_context, data, size) ||
+ mbedtls_cipher_set_iv(&ctx->decryption_context, data, size)) == 0,
+ "Failed to set IV on mbedtls ciphers.");
+}
+
template class AESCipher<Key128>;
template class AESCipher<Key256>;
} // namespace Core::Crypto
diff --git a/src/core/crypto/aes_util.h b/src/core/crypto/aes_util.h
index edc4ab910..e2a304186 100644
--- a/src/core/crypto/aes_util.h
+++ b/src/core/crypto/aes_util.h
@@ -6,7 +6,6 @@
#include <memory>
#include <type_traits>
-#include <vector>
#include "common/common_types.h"
#include "core/file_sys/vfs.h"
@@ -32,10 +31,12 @@ class AESCipher {
public:
AESCipher(Key key, Mode mode);
-
~AESCipher();
- void SetIV(std::vector<u8> iv);
+ template <typename ContiguousContainer>
+ void SetIV(const ContiguousContainer& container) {
+ SetIVImpl(std::data(container), std::size(container));
+ }
template <typename Source, typename Dest>
void Transcode(const Source* src, std::size_t size, Dest* dest, Op op) const {
@@ -59,6 +60,8 @@ public:
std::size_t sector_size, Op op);
private:
+ void SetIVImpl(const u8* data, std::size_t size);
+
std::unique_ptr<CipherContext> ctx;
};
} // namespace Core::Crypto
diff --git a/src/core/crypto/ctr_encryption_layer.cpp b/src/core/crypto/ctr_encryption_layer.cpp
index 902841c77..5c84bb0a4 100644
--- a/src/core/crypto/ctr_encryption_layer.cpp
+++ b/src/core/crypto/ctr_encryption_layer.cpp
@@ -2,6 +2,7 @@
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
+#include <algorithm>
#include <cstring>
#include "common/assert.h"
#include "core/crypto/ctr_encryption_layer.h"
@@ -10,8 +11,7 @@ namespace Core::Crypto {
CTREncryptionLayer::CTREncryptionLayer(FileSys::VirtualFile base_, Key128 key_,
std::size_t base_offset)
- : EncryptionLayer(std::move(base_)), base_offset(base_offset), cipher(key_, Mode::CTR),
- iv(16, 0) {}
+ : EncryptionLayer(std::move(base_)), base_offset(base_offset), cipher(key_, Mode::CTR) {}
std::size_t CTREncryptionLayer::Read(u8* data, std::size_t length, std::size_t offset) const {
if (length == 0)
@@ -39,9 +39,8 @@ std::size_t CTREncryptionLayer::Read(u8* data, std::size_t length, std::size_t o
return read + Read(data + read, length - read, offset + read);
}
-void CTREncryptionLayer::SetIV(const std::vector<u8>& iv_) {
- const auto length = std::min(iv_.size(), iv.size());
- iv.assign(iv_.cbegin(), iv_.cbegin() + length);
+void CTREncryptionLayer::SetIV(const IVData& iv_) {
+ iv = iv_;
}
void CTREncryptionLayer::UpdateIV(std::size_t offset) const {
diff --git a/src/core/crypto/ctr_encryption_layer.h b/src/core/crypto/ctr_encryption_layer.h
index a7bf810f4..a2429f001 100644
--- a/src/core/crypto/ctr_encryption_layer.h
+++ b/src/core/crypto/ctr_encryption_layer.h
@@ -4,7 +4,8 @@
#pragma once
-#include <vector>
+#include <array>
+
#include "core/crypto/aes_util.h"
#include "core/crypto/encryption_layer.h"
#include "core/crypto/key_manager.h"
@@ -14,18 +15,20 @@ namespace Core::Crypto {
// Sits on top of a VirtualFile and provides CTR-mode AES decription.
class CTREncryptionLayer : public EncryptionLayer {
public:
+ using IVData = std::array<u8, 16>;
+
CTREncryptionLayer(FileSys::VirtualFile base, Key128 key, std::size_t base_offset);
std::size_t Read(u8* data, std::size_t length, std::size_t offset) const override;
- void SetIV(const std::vector<u8>& iv);
+ void SetIV(const IVData& iv);
private:
std::size_t base_offset;
// Must be mutable as operations modify cipher contexts.
mutable AESCipher<Key128> cipher;
- mutable std::vector<u8> iv;
+ mutable IVData iv{};
void UpdateIV(std::size_t offset) const;
};
diff --git a/src/core/crypto/partition_data_manager.cpp b/src/core/crypto/partition_data_manager.cpp
index 7ed71ac3a..b31a81560 100644
--- a/src/core/crypto/partition_data_manager.cpp
+++ b/src/core/crypto/partition_data_manager.cpp
@@ -346,10 +346,9 @@ FileSys::VirtualFile PartitionDataManager::GetPackage2Raw(Package2Type type) con
}
static bool AttemptDecrypt(const std::array<u8, 16>& key, Package2Header& header) {
- const std::vector<u8> iv(header.header_ctr.begin(), header.header_ctr.end());
Package2Header temp = header;
AESCipher<Key128> cipher(key, Mode::CTR);
- cipher.SetIV(iv);
+ cipher.SetIV(header.header_ctr);
cipher.Transcode(&temp.header_ctr, sizeof(Package2Header) - 0x100, &temp.header_ctr,
Op::Decrypt);
if (temp.magic == Common::MakeMagic('P', 'K', '2', '1')) {
@@ -388,7 +387,7 @@ void PartitionDataManager::DecryptPackage2(const std::array<Key128, 0x20>& packa
auto c = a->ReadAllBytes();
AESCipher<Key128> cipher(package2_keys[revision], Mode::CTR);
- cipher.SetIV({header.section_ctr[1].begin(), header.section_ctr[1].end()});
+ cipher.SetIV(header.section_ctr[1]);
cipher.Transcode(c.data(), c.size(), c.data(), Op::Decrypt);
const auto ini_file = std::make_shared<FileSys::VectorVfsFile>(c);
diff --git a/src/core/file_sys/content_archive.cpp b/src/core/file_sys/content_archive.cpp
index 473245d5a..5039341c7 100644
--- a/src/core/file_sys/content_archive.cpp
+++ b/src/core/file_sys/content_archive.cpp
@@ -495,9 +495,10 @@ VirtualFile NCA::Decrypt(const NCASectionHeader& s_header, VirtualFile in, u64 s
auto out = std::make_shared<Core::Crypto::CTREncryptionLayer>(std::move(in), *key,
starting_offset);
- std::vector<u8> iv(16);
- for (u8 i = 0; i < 8; ++i)
- iv[i] = s_header.raw.section_ctr[0x8 - i - 1];
+ Core::Crypto::CTREncryptionLayer::IVData iv{};
+ for (std::size_t i = 0; i < 8; ++i) {
+ iv[i] = s_header.raw.section_ctr[8 - i - 1];
+ }
out->SetIV(iv);
return std::static_pointer_cast<VfsFile>(out);
}
diff --git a/src/core/file_sys/nca_patch.cpp b/src/core/file_sys/nca_patch.cpp
index 0090cc6c4..fe7375e84 100644
--- a/src/core/file_sys/nca_patch.cpp
+++ b/src/core/file_sys/nca_patch.cpp
@@ -3,6 +3,7 @@
// Refer to the license.txt file included.
#include <algorithm>
+#include <array>
#include <cstddef>
#include <cstring>
@@ -66,7 +67,7 @@ std::size_t BKTR::Read(u8* data, std::size_t length, std::size_t offset) const {
Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(key, Core::Crypto::Mode::CTR);
// Calculate AES IV
- std::vector<u8> iv(16);
+ std::array<u8, 16> iv{};
auto subsection_ctr = subsection.ctr;
auto offset_iv = section_offset + base_offset;
for (std::size_t i = 0; i < section_ctr.size(); ++i)