From dd22e1ab7ab7b5bac841dae2b62bfa200b36c4d8 Mon Sep 17 00:00:00 2001 From: Hannes Schulze Date: Wed, 12 Feb 2025 23:57:32 +0100 Subject: add encryption/decryption --- lib/nes/app/CMakeLists.txt | 3 +- lib/nes/app/action.hh | 13 +- lib/nes/app/application.cc | 16 + lib/nes/app/application.hh | 2 + lib/nes/app/crypto/CMakeLists.txt | 7 + lib/nes/app/crypto/aes256.cc | 610 ++++++++++++++++++++++++++++++++++++ lib/nes/app/crypto/aes256.hh | 12 + lib/nes/app/crypto/sha256.cc | 156 +++++++++ lib/nes/app/crypto/sha256.hh | 28 ++ lib/nes/app/ui/CMakeLists.txt | 4 +- lib/nes/app/ui/screen-browser.cc | 8 + lib/nes/app/ui/screen-prompt-key.cc | 66 ++++ lib/nes/app/ui/screen-prompt-key.hh | 28 ++ 13 files changed, 950 insertions(+), 3 deletions(-) create mode 100644 lib/nes/app/crypto/CMakeLists.txt create mode 100644 lib/nes/app/crypto/aes256.cc create mode 100644 lib/nes/app/crypto/aes256.hh create mode 100644 lib/nes/app/crypto/sha256.cc create mode 100644 lib/nes/app/crypto/sha256.hh create mode 100644 lib/nes/app/ui/screen-prompt-key.cc create mode 100644 lib/nes/app/ui/screen-prompt-key.hh (limited to 'lib/nes/app') diff --git a/lib/nes/app/CMakeLists.txt b/lib/nes/app/CMakeLists.txt index df0769e..fbb13d9 100644 --- a/lib/nes/app/CMakeLists.txt +++ b/lib/nes/app/CMakeLists.txt @@ -9,4 +9,5 @@ target_sources( add_subdirectory(input) add_subdirectory(graphics) -add_subdirectory(ui) \ No newline at end of file +add_subdirectory(ui) +add_subdirectory(crypto) \ No newline at end of file diff --git a/lib/nes/app/action.hh b/lib/nes/app/action.hh index ed879f3..c88a5f1 100644 --- a/lib/nes/app/action.hh +++ b/lib/nes/app/action.hh @@ -21,11 +21,13 @@ namespace nes::app confirm_quit, launch_game, show_error, + prompt_key, }; private: type type_{ type::none }; string_view file_name_; + string_view key_; string_view message_; status error_{ status::success }; @@ -40,10 +42,11 @@ namespace nes::app static auto cancel_quit() -> action { return action{ type::cancel_quit }; } static auto confirm_quit() -> action { return action{ type::confirm_quit }; } - static auto launch_game(string_view const file_name) -> action + static auto launch_game(string_view const file_name, string_view const key = "") -> action { auto res = action{ type::launch_game }; res.file_name_ = file_name; + res.key_ = key; return res; } @@ -55,8 +58,16 @@ namespace nes::app return res; } + static auto prompt_key(string_view const file_name) -> action + { + auto res = action{ type::prompt_key }; + res.file_name_ = file_name; + return res; + } + auto get_type() const -> type { return type_; } auto get_file_name() const -> string_view { return file_name_; } + auto get_key() const -> string_view { return key_; } auto get_message() const -> string_view { return message_; } auto get_error() const -> status { return error_; } diff --git a/lib/nes/app/application.cc b/lib/nes/app/application.cc index 09c9f34..5646fa9 100644 --- a/lib/nes/app/application.cc +++ b/lib/nes/app/application.cc @@ -4,6 +4,8 @@ #include "nes/app/ui/screen.hh" #include "nes/app/graphics/renderer.hh" #include "nes/app/action.hh" +#include "nes/app/crypto/aes256.hh" +#include "nes/app/crypto/sha256.hh" namespace nes::app { @@ -54,6 +56,7 @@ namespace nes::app , screen_settings_{ input_manager_, preferences_ } , screen_error_{ keyboard } , screen_confirm_quit_{ keyboard } + , screen_prompt_key_{ keyboard } { display_.visible_screen = &screen_title_; } @@ -153,6 +156,12 @@ namespace nes::app display_.visible_screen = nullptr; break; } + case action::type::prompt_key: + { + screen_prompt_key_.reset(a.get_file_name()); + display_.visible_popup = &screen_prompt_key_; + break; + } case action::type::launch_game: { u8 buffer[sys::cartridge::max_file_size]; @@ -163,6 +172,13 @@ namespace nes::app break; } + if (!a.get_key().is_empty()) + { + auto const key = span{ reinterpret_cast(a.get_key().get_data()), a.get_key().get_length() }; + auto const key_hash = sha256::hash(key); + aes256::decrypt(span{ buffer, length }, key_hash.get_data()); + } + console_.emplace(display_, span{ buffer, length }); if (console_->get_status() != status::success) { diff --git a/lib/nes/app/application.hh b/lib/nes/app/application.hh index 960b022..5ed7413 100644 --- a/lib/nes/app/application.hh +++ b/lib/nes/app/application.hh @@ -7,6 +7,7 @@ #include "nes/app/ui/screen-freeze.hh" #include "nes/app/ui/screen-error.hh" #include "nes/app/ui/screen-confirm-quit.hh" +#include "nes/app/ui/screen-prompt-key.hh" #include "nes/app/preferences.hh" #include "nes/sys/nes.hh" #include "nes/common/containers/box.hh" @@ -64,6 +65,7 @@ namespace nes::app screen_freeze screen_freeze_; screen_error screen_error_; screen_confirm_quit screen_confirm_quit_; + screen_prompt_key screen_prompt_key_; public: explicit application(display&, input_device_keyboard&, file_browser&); diff --git a/lib/nes/app/crypto/CMakeLists.txt b/lib/nes/app/crypto/CMakeLists.txt new file mode 100644 index 0000000..75b8f09 --- /dev/null +++ b/lib/nes/app/crypto/CMakeLists.txt @@ -0,0 +1,7 @@ +target_sources( + nes + PRIVATE + sha256.hh + sha256.cc + aes256.hh + aes256.cc) \ No newline at end of file diff --git a/lib/nes/app/crypto/aes256.cc b/lib/nes/app/crypto/aes256.cc new file mode 100644 index 0000000..1fcaf9d --- /dev/null +++ b/lib/nes/app/crypto/aes256.cc @@ -0,0 +1,610 @@ +#include "nes/app/crypto/aes256.hh" + +#include "nes/common/utils.hh" + +namespace nes::app +{ + // Implementation copied from: https://github.com/kokke/tiny-AES-c/tree/master + + namespace + { +#define CTR 1 +#define AES256 1 +#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only + +#if defined(AES256) && (AES256 == 1) +#define AES_KEYLEN 32 +#define AES_keyExpSize 240 +#elif defined(AES192) && (AES192 == 1) +#define AES_KEYLEN 24 +#define AES_keyExpSize 208 +#else +#define AES_KEYLEN 16 // Key length in bytes +#define AES_keyExpSize 176 +#endif + + struct AES_ctx + { + u8 RoundKey[AES_keyExpSize]; +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) + u8 Iv[AES_BLOCKLEN]; +#endif + }; + + void AES_init_ctx(AES_ctx* ctx, u8 const* key); + +#if defined(ECB) && (ECB == 1) + // buffer size is exactly AES_BLOCKLEN bytes; + // you need only AES_init_ctx as IV is not used in ECB + // NB: ECB is considered insecure for most uses + void AES_ECB_encrypt(const AES_ctx* ctx, u8* buf); + void AES_ECB_decrypt(const AES_ctx* ctx, u8* buf); +#endif // #if defined(ECB) && (ECB == !) + +#if defined(CBC) && (CBC == 1) + // buffer size MUST be mutile of AES_BLOCKLEN; + // Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme + // NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv() + // no IV should ever be reused with the same key + void AES_CBC_encrypt_buffer(AES_ctx* ctx, u8* buf, u32 length); + void AES_CBC_decrypt_buffer(AES_ctx* ctx, u8* buf, u32 length); +#endif // #if defined(CBC) && (CBC == 1) + +#if defined(CTR) && (CTR == 1) + // Same function for encrypting as for decrypting. + // IV is incremented for every block, and used after encryption as XOR-compliment for output + // Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme + // NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv() + // no IV should ever be reused with the same key + void AES_CTR_xcrypt_buffer(AES_ctx* ctx, u8* buf, u32 length); +#endif // #if defined(CTR) && (CTR == 1) + +/* + +This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode. +Block size can be chosen in aes.h - available choices are AES128, AES192, AES256. + +The implementation is verified against the test vectors in: + National Institute of Standards and Technology Special Publication 800-38A 2001 ED + +ECB-AES128 +---------- + + plain-text: + 6bc1bee22e409f96e93d7e117393172a + ae2d8a571e03ac9c9eb76fac45af8e51 + 30c81c46a35ce411e5fbc1191a0a52ef + f69f2445df4f9b17ad2b417be66c3710 + + key: + 2b7e151628aed2a6abf7158809cf4f3c + + resulting cipher + 3ad77bb40d7a3660a89ecaf32466ef97 + f5d3d58503b9699de785895a96fdbaaf + 43b1cd7f598ece23881b00e3ed030688 + 7b0c785e27e8ad3f8223207104725dd4 + + +NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0) + You should pad the end of the string with zeros if this is not the case. + For AES192/256 the key size is proportionally larger. + +*/ + +/*****************************************************************************/ +/* Defines: */ +/*****************************************************************************/ +// The number of columns comprising a state in AES. This is a constant in AES. Value=4 +#define Nb 4 + +#if defined(AES256) && (AES256 == 1) +#define Nk 8 +#define Nr 14 +#elif defined(AES192) && (AES192 == 1) +#define Nk 6 +#define Nr 12 +#else +#define Nk 4 // The number of 32 bit words in a key. +#define Nr 10 // The number of rounds in AES Cipher. +#endif + +// jcallan@github points out that declaring Multiply as a function +// reduces code size considerably with the Keil ARM compiler. +// See this link for more information: https://github.com/kokke/tiny-AES-C/pull/3 +#ifndef MULTIPLY_AS_A_FUNCTION +#define MULTIPLY_AS_A_FUNCTION 0 +#endif + + /*****************************************************************************/ + /* Private variables: */ + /*****************************************************************************/ + // state - array holding the intermediate results during decryption. + using state_t = u8[4][4]; + + // The lookup-tables are marked const so they can be placed in read-only storage instead of RAM + // The numbers below can be computed dynamically trading ROM for RAM - + // This can be useful in (embedded) bootloader applications, where ROM is often limited. + u8 const sbox[256] = { + // 0 1 2 3 4 5 6 7 8 9 A B C D E F + 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, + 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, + 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, + 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, + 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, + 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, + 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, + 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, + 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, + 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, + 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, + 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, + 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, + 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, + 0xb0, 0x54, 0xbb, 0x16 + }; + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + const u8 rsbox[256] = { + 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, + 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, 0x54, 0x7b, 0x94, 0x32, + 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, + 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, + 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, + 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, + 0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, + 0x8a, 0x6b, 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, + 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, 0x47, 0xf1, + 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b, + 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, + 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, + 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, + 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, + 0x55, 0x21, 0x0c, 0x7d + }; +#endif + + // The round constant word array, Rcon[i], contains the values given by + // x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) + u8 const Rcon[11] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 }; + +/* + * Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12), + * that you can remove most of the elements in the Rcon array, because they are unused. + * + * From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon + * + * "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed), + * up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm." + */ + +/*****************************************************************************/ +/* Private functions: */ +/*****************************************************************************/ +/* +u8 getSBoxValue(u8 num) +{ + return sbox[num]; +} +*/ +#define getSBoxValue(num) (sbox[(num)]) + + // This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. + void KeyExpansion(u8* RoundKey, u8 const* Key) + { + unsigned i, j, k; + u8 tempa[4]; // Used for the column/row operations + + // The first round key is the key itself. + for (i = 0; i < Nk; ++i) + { + RoundKey[(i * 4) + 0] = Key[(i * 4) + 0]; + RoundKey[(i * 4) + 1] = Key[(i * 4) + 1]; + RoundKey[(i * 4) + 2] = Key[(i * 4) + 2]; + RoundKey[(i * 4) + 3] = Key[(i * 4) + 3]; + } + + // All other round keys are found from the previous round keys. + for (i = Nk; i < Nb * (Nr + 1); ++i) + { + { + k = (i - 1) * 4; + tempa[0] = RoundKey[k + 0]; + tempa[1] = RoundKey[k + 1]; + tempa[2] = RoundKey[k + 2]; + tempa[3] = RoundKey[k + 3]; + } + + if (i % Nk == 0) + { + // This function shifts the 4 bytes in a word to the left once. + // [a0,a1,a2,a3] becomes [a1,a2,a3,a0] + + // Function RotWord() + { + u8 const u8tmp = tempa[0]; + tempa[0] = tempa[1]; + tempa[1] = tempa[2]; + tempa[2] = tempa[3]; + tempa[3] = u8tmp; + } + + // SubWord() is a function that takes a four-byte input word and + // applies the S-box to each of the four bytes to produce an output word. + + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + + tempa[0] = tempa[0] ^ Rcon[i / Nk]; + } +#if defined(AES256) && (AES256 == 1) + if (i % Nk == 4) + { + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + } +#endif + j = i * 4; + k = (i - Nk) * 4; + RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0]; + RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1]; + RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2]; + RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3]; + } + } + + void AES_init_ctx(AES_ctx* ctx, u8 const* key) + { + KeyExpansion(ctx->RoundKey, key); + } + + // This function adds the round key to state. + // The round key is added to the state by an XOR function. + void AddRoundKey(u8 round, state_t* state, u8 const* RoundKey) + { + for (u8 i = 0; i < 4; ++i) + { + for (u8 j = 0; j < 4; ++j) + { + (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j]; + } + } + } + + // The SubBytes Function Substitutes the values in the + // state matrix with values in an S-box. + void SubBytes(state_t* state) + { + for (u8 i = 0; i < 4; ++i) + { + for (u8 j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxValue((*state)[j][i]); + } + } + } + + // The ShiftRows() function shifts the rows in the state to the left. + // Each row is shifted with different offset. + // Offset = Row number. So the first row is not shifted. + void ShiftRows(state_t* state) + { + // Rotate first row 1 columns to left + u8 temp = (*state)[0][1]; + (*state)[0][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[3][1]; + (*state)[3][1] = temp; + + // Rotate second row 2 columns to left + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to left + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[3][3]; + (*state)[3][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[1][3]; + (*state)[1][3] = temp; + } + + u8 xtime(u8 x) + { + return ((x << 1) ^ (((x >> 7) & 1) * 0x1b)); + } + + // MixColumns function mixes the columns of the state matrix + void MixColumns(state_t* state) + { + for (u8 i = 0; i < 4; ++i) + { + u8 t = (*state)[i][0]; + u8 Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3]; + u8 Tm = (*state)[i][0] ^ (*state)[i][1]; + Tm = xtime(Tm); + (*state)[i][0] ^= Tm ^ Tmp; + Tm = (*state)[i][1] ^ (*state)[i][2]; + Tm = xtime(Tm); + (*state)[i][1] ^= Tm ^ Tmp; + Tm = (*state)[i][2] ^ (*state)[i][3]; + Tm = xtime(Tm); + (*state)[i][2] ^= Tm ^ Tmp; + Tm = (*state)[i][3] ^ t; + Tm = xtime(Tm); + (*state)[i][3] ^= Tm ^ Tmp; + } + } + +// Multiply is used to multiply numbers in the field GF(2^8) +// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary +// The compiler seems to be able to vectorize the operation better this way. +// See https://github.com/kokke/tiny-AES-c/pull/34 +#if MULTIPLY_AS_A_FUNCTION + u8 Multiply(u8 x, u8 y) + { + return ( + ((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^ ((y >> 2 & 1) * xtime(xtime(x))) ^ + ((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^ + ((y >> 4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */ + } +#else +#define Multiply(x, y) \ + (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^ ((y >> 2 & 1) * xtime(xtime(x))) ^ \ + ((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^ ((y >> 4 & 1) * xtime(xtime(xtime(xtime(x)))))) + +#endif + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +/* +u8 getSBoxInvert(u8 num) +{ + return rsbox[num]; +} +*/ +#define getSBoxInvert(num) (rsbox[(num)]) + + // MixColumns function mixes the columns of the state matrix. + // The method used to multiply may be difficult to understand for the inexperienced. + // Please use the references to gain more information. + void InvMixColumns(state_t* state) + { + int i; + u8 a, b, c, d; + for (i = 0; i < 4; ++i) + { + a = (*state)[i][0]; + b = (*state)[i][1]; + c = (*state)[i][2]; + d = (*state)[i][3]; + + (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09); + (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d); + (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b); + (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e); + } + } + + // The SubBytes Function Substitutes the values in the + // state matrix with values in an S-box. + void InvSubBytes(state_t* state) + { + u8 i, j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxInvert((*state)[j][i]); + } + } + } + + void InvShiftRows(state_t* state) + { + u8 temp; + + // Rotate first row 1 columns to right + temp = (*state)[3][1]; + (*state)[3][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[0][1]; + (*state)[0][1] = temp; + + // Rotate second row 2 columns to right + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to right + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[1][3]; + (*state)[1][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[3][3]; + (*state)[3][3] = temp; + } +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + + // Cipher is the main function that encrypts the PlainText. + void Cipher(state_t* state, u8 const* RoundKey) + { + u8 round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(0, state, RoundKey); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr rounds are executed in the loop below. + // Last one without MixColumns() + for (round = 1;; ++round) + { + SubBytes(state); + ShiftRows(state); + if (round == Nr) + { + break; + } + MixColumns(state); + AddRoundKey(round, state, RoundKey); + } + // Add round key to last round + AddRoundKey(Nr, state, RoundKey); + } + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + void InvCipher(state_t* state, const u8* RoundKey) + { + u8 round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(Nr, state, RoundKey); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr rounds are executed in the loop below. + // Last one without InvMixColumn() + for (round = (Nr - 1);; --round) + { + InvShiftRows(state); + InvSubBytes(state); + AddRoundKey(round, state, RoundKey); + if (round == 0) + { + break; + } + InvMixColumns(state); + } + } +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ +#if defined(ECB) && (ECB == 1) + + void AES_ECB_encrypt(const AES_ctx* ctx, u8* buf) + { + // The next function call encrypts the PlainText with the Key using AES algorithm. + Cipher((state_t*)buf, ctx->RoundKey); + } + + void AES_ECB_decrypt(const AES_ctx* ctx, u8* buf) + { + // The next function call decrypts the PlainText with the Key using AES algorithm. + InvCipher((state_t*)buf, ctx->RoundKey); + } + +#endif // #if defined(ECB) && (ECB == 1) + +#if defined(CBC) && (CBC == 1) + + void XorWithIv(u8* buf, const u8* Iv) + { + u8 i; + for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size + { + buf[i] ^= Iv[i]; + } + } + + void AES_CBC_encrypt_buffer(AES_ctx* ctx, u8* buf, u32 length) + { + u32 i; + u8* Iv = ctx->Iv; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + XorWithIv(buf, Iv); + Cipher((state_t*)buf, ctx->RoundKey); + Iv = buf; + buf += AES_BLOCKLEN; + } + /* store Iv in ctx for next call */ + copy(Iv, ctx->Iv, AES_BLOCKLEN); + } + + void AES_CBC_decrypt_buffer(AES_ctx* ctx, u8* buf, u32 length) + { + u32 i; + u8 storeNextIv[AES_BLOCKLEN]; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + copy(buf, storeNextIv, AES_BLOCKLEN); + InvCipher((state_t*)buf, ctx->RoundKey); + XorWithIv(buf, ctx->Iv); + copy(storeNextIv, ctx->Iv, AES_BLOCKLEN); + buf += AES_BLOCKLEN; + } + } + +#endif // #if defined(CBC) && (CBC == 1) + +#if defined(CTR) && (CTR == 1) + + /* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be + * reused with the same key */ + void AES_CTR_xcrypt_buffer(AES_ctx* ctx, u8* buf, u32 length) + { + u8 buffer[AES_BLOCKLEN]; + + u32 i; + int bi; + for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi) + { + if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */ + { + copy(ctx->Iv, buffer, AES_BLOCKLEN); + Cipher(reinterpret_cast(buffer), ctx->RoundKey); + + /* Increment Iv and handle overflow */ + for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) + { + /* inc will overflow */ + if (ctx->Iv[bi] == 255) + { + ctx->Iv[bi] = 0; + continue; + } + ctx->Iv[bi] += 1; + break; + } + bi = 0; + } + + buf[i] = (buf[i] ^ buffer[bi]); + } + } + +#endif // #if defined(CTR) && (CTR == 1) + } // namespace + + auto aes256::encrypt(span const buffer, key const key) -> void + { + auto ctx = AES_ctx{}; + AES_init_ctx(&ctx, key.get_data()); + AES_CTR_xcrypt_buffer(&ctx, buffer.get_data(), buffer.get_length()); + } + + auto aes256::decrypt(span const buffer, key const key) -> void + { + // For CTR: Encryption is same as decryption. + return encrypt(buffer, key); + } +} // namespace nes::app \ No newline at end of file diff --git a/lib/nes/app/crypto/aes256.hh b/lib/nes/app/crypto/aes256.hh new file mode 100644 index 0000000..1ce9d7a --- /dev/null +++ b/lib/nes/app/crypto/aes256.hh @@ -0,0 +1,12 @@ +#pragma once + +#include "nes/common/containers/span.hh" +#include "nes/common/types.hh" + +namespace nes::app::aes256 +{ + using key = span; + + auto encrypt(span, key) -> void; + auto decrypt(span, key) -> void; +} // namespace nes::app::aes256 \ No newline at end of file diff --git a/lib/nes/app/crypto/sha256.cc b/lib/nes/app/crypto/sha256.cc new file mode 100644 index 0000000..d8f8658 --- /dev/null +++ b/lib/nes/app/crypto/sha256.cc @@ -0,0 +1,156 @@ +#include "nes/app/crypto/sha256.hh" +#include "nes/common/utils.hh" + +namespace nes::app +{ + namespace + { + constexpr u32 round_constants[64] = + { + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, + 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, + 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, + 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, + 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, + 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2, + }; + + auto rightrotate(u32 input, u32 index) -> u32 + { + return (input >> index) | (input << (32 - index)); + } + } // namespace + + auto sha256::get(u32 const index) -> u32 + { + auto const offset = index * 4; + return static_cast( + (data_[offset + 0] << 24) | + (data_[offset + 1] << 16) | + (data_[offset + 2] << 8) | + (data_[offset + 3] << 0)); + } + + auto sha256::set(u32 const index, u32 const value) -> void + { + auto const offset = index * 4; + data_[offset + 0] = static_cast((value >> 24) & 0xFF); + data_[offset + 1] = static_cast((value >> 16) & 0xFF); + data_[offset + 2] = static_cast((value >> 8) & 0xFF); + data_[offset + 3] = static_cast((value >> 0) & 0xFF); + } + + auto sha256::hash(span const message) -> sha256 + { + // https://en.wikipedia.org/wiki/SHA-2#Pseudocode + + auto res = sha256{}; + + auto const blocks = message.get_length() / block_size; + auto const remainder = message.get_length() - blocks * block_size; + for (auto i = u32{ 0 }; i < blocks; ++i) + { + res.combine(message.subspan(i * block_size)); + } + + u8 last_blocks[block_size * 2]{}; + auto last_block_length = remainder; + copy(&message[blocks * block_size], last_blocks, remainder); + // Add a single 1 bit. + last_blocks[last_block_length++] = 0b10000000; + // Fill with 0 bits s.t. there's 8 bytes remaining in the last block. + auto zeroes = sizeof(last_blocks) - last_block_length - 8; + while (zeroes >= block_size) { zeroes -= block_size; } + last_block_length += zeroes; + // Add the length as big-endian. + auto const length = static_cast(message.get_length()) * 8; + last_blocks[last_block_length++] = static_cast((length >> 56) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 48) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 40) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 32) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 24) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 16) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 8) & 0xFF); + last_blocks[last_block_length++] = static_cast((length >> 0) & 0xFF); + auto const last_block_count = last_block_length / block_size; + for (auto i = u32{ 0 }; i < last_block_count; ++i) + { + res.combine(span(last_blocks).subspan(i * block_size)); + } + + return res; + } + + sha256::sha256() + { + set(0, 0x6a09e667); + set(1, 0xbb67ae85); + set(2, 0x3c6ef372); + set(3, 0xa54ff53a); + set(4, 0x510e527f); + set(5, 0x9b05688c); + set(6, 0x1f83d9ab); + set(7, 0x5be0cd19); + } + + auto sha256::combine(span const chunk) -> void + { + u32 w[64]{}; + + // copy chunk into first 16 words w[0..15] of the message schedule array + for (auto i = u32{ 0 }; i < 16; ++i) + { + auto const offset = i * 4; + w[i] = static_cast( + (chunk[offset + 0] << 24) | + (chunk[offset + 1] << 16) | + (chunk[offset + 2] << 8) | + (chunk[offset + 3] << 0)); + } + + for (auto i = u32{ 16 }; i < 64; i++) + { + auto s0 = rightrotate(w[i-15], 7) ^ rightrotate(w[i-15], 18) ^ (w[i-15] >> 3); + auto s1 = rightrotate(w[i-2], 17) ^ rightrotate(w[i-2], 19) ^ (w[i-2] >> 10); + w[i] = w[i-16] + s0 + w[i-7] + s1; + } + auto a = get(0); + auto b = get(1); + auto c = get(2); + auto d = get(3); + auto e = get(4); + auto f = get(5); + auto g = get(6); + auto h = get(7); + + for (auto i = u32{ 0 }; i < 64; i++) + { + auto s1 = rightrotate(e, 6) ^ rightrotate(e, 11) ^ rightrotate(e, 25); + auto ch = (e & f) ^ ((~e) & g); + auto tmp1 = h + s1 + ch + round_constants[i] + w[i]; + auto s0 = rightrotate(a, 2) ^ rightrotate(a, 13) ^ rightrotate(a, 22); + auto maj = (a & b) ^ (a & c) ^ (b & c); + auto tmp2 = s0 + maj; + + h = g; + g = f; + f = e; + e = d + tmp1; + d = c; + c = b; + b = a; + a = tmp1 + tmp2; + } + + set(0, get(0) + a); + set(1, get(1) + b); + set(2, get(2) + c); + set(3, get(3) + d); + set(4, get(4) + e); + set(5, get(5) + f); + set(6, get(6) + g); + set(7, get(7) + h); + } +} // namespace nes::app \ No newline at end of file diff --git a/lib/nes/app/crypto/sha256.hh b/lib/nes/app/crypto/sha256.hh new file mode 100644 index 0000000..55ba202 --- /dev/null +++ b/lib/nes/app/crypto/sha256.hh @@ -0,0 +1,28 @@ +#pragma once + +#include "nes/common/containers/span.hh" +#include "nes/common/types.hh" + +namespace nes::app +{ + class sha256 + { + static constexpr auto length = u32{ 256 / 8 }; + static constexpr auto block_size = u32{ 512 / 8 }; + + u8 data_[length]{}; + + public: + static auto hash(span) -> sha256; + + auto get_data() const -> span { return data_; } + + private: + explicit sha256(); + + auto combine(span) -> void; + + auto get(u32 index) -> u32; + auto set(u32 index, u32 value) -> void; + }; +} // namespace nes::app \ No newline at end of file diff --git a/lib/nes/app/ui/CMakeLists.txt b/lib/nes/app/ui/CMakeLists.txt index c43bb13..1f8d138 100644 --- a/lib/nes/app/ui/CMakeLists.txt +++ b/lib/nes/app/ui/CMakeLists.txt @@ -14,4 +14,6 @@ target_sources( screen-error.hh screen-error.cc screen-confirm-quit.hh - screen-confirm-quit.cc) \ No newline at end of file + screen-confirm-quit.cc + screen-prompt-key.hh + screen-prompt-key.cc) \ No newline at end of file diff --git a/lib/nes/app/ui/screen-browser.cc b/lib/nes/app/ui/screen-browser.cc index 50b0060..84fb647 100644 --- a/lib/nes/app/ui/screen-browser.cc +++ b/lib/nes/app/ui/screen-browser.cc @@ -111,6 +111,14 @@ namespace nes::app return action::go_to_title(); } } + else if (event == input_event::key_down(key::letter_d)) + { + auto const selected = selection_.get_selected(); + if (selected && selected->entry.get_type() == file_browser::entry_type::file) + { + return action::prompt_key(selected->entry.get_name()); + } + } else if (event == input_event::key_down(key::enter)) { auto const selected = selection_.get_selected(); diff --git a/lib/nes/app/ui/screen-prompt-key.cc b/lib/nes/app/ui/screen-prompt-key.cc new file mode 100644 index 0000000..e15d724 --- /dev/null +++ b/lib/nes/app/ui/screen-prompt-key.cc @@ -0,0 +1,66 @@ +#include "nes/app/ui/screen-prompt-key.hh" +#include "nes/app/graphics/renderer.hh" +#include "nes/app/graphics/color.hh" +#include "nes/app/input/input-device-keyboard.hh" + +namespace nes::app +{ + screen_prompt_key::screen_prompt_key(input_device_keyboard& keyboard) + : keyboard_{ keyboard } + { + } + + auto screen_prompt_key::reset(string_view const file_name) -> void + { + file_name_ = file_name; + key_.clear(); + } + + auto screen_prompt_key::render(renderer& renderer) -> void + { + renderer.render_rect(2, 8, 28, 10, color::background_secondary); + renderer.render_border(2, 8, 28, 10, color::foreground_primary); + renderer.render_rect(4, 12, 24, 1, color::background_primary); + + auto const attrs = text_attributes{} + .set_alignment(text_alignment::center) + .set_ellipsize_mode(ellipsize_mode::end) + .set_max_width(26); + renderer.render_text(16, 10, "Key:", color::foreground_primary, attrs); + auto const key_attrs = text_attributes{} + .set_alignment(text_alignment::left) + .set_ellipsize_mode(ellipsize_mode::clip) + .set_max_width(24); + renderer.render_text_format(4, 12, color::foreground_primary, key_attrs, "{}_", key_.get_result()); + renderer.render_text(16, 15, "> OK <", color::accent_primary, attrs); + } + + auto screen_prompt_key::process_events() -> action + { + while (auto const event = keyboard_.poll_event()) + { + if (event == input_event::key_down(key::escape)) + { + return action::close_popup(); + } + else if (event == input_event::key_down(key::enter)) + { + return action::launch_game(file_name_, key_.get_result()); + } + else if (event == input_event::key_down(key::backspace)) + { + key_.remove_last(); + } + else if (event.get_type() == input_event::type::key_down) + { + auto const symbol = to_ascii(event.get_key(), keyboard_.read_modifiers()); + if (symbol != 0) + { + key_.append_char(symbol); + } + } + } + + return action{}; + } +} // namespace nes::app \ No newline at end of file diff --git a/lib/nes/app/ui/screen-prompt-key.hh b/lib/nes/app/ui/screen-prompt-key.hh new file mode 100644 index 0000000..337e1b6 --- /dev/null +++ b/lib/nes/app/ui/screen-prompt-key.hh @@ -0,0 +1,28 @@ +#pragma once + +#include "nes/app/ui/screen.hh" +#include "nes/common/containers/string-builder.hh" +#include "nes/common/containers/string-view.hh" + +namespace nes::app +{ + class input_device_keyboard; + + /// Prompts the user for a decryption key. + class screen_prompt_key final : public screen + { + static constexpr auto max_key_length = u32{ 23 }; + + input_device_keyboard& keyboard_; + string_view file_name_; + string_buffer key_; + + public: + explicit screen_prompt_key(input_device_keyboard&); + + auto reset(string_view file_name) -> void; + + auto render(renderer&) -> void override; + auto process_events() -> action override; + }; +} // namespace nes::app \ No newline at end of file -- cgit v1.3.1