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-rw-r--r--lib/nes/app/CMakeLists.txt3
-rw-r--r--lib/nes/app/action.hh13
-rw-r--r--lib/nes/app/application.cc16
-rw-r--r--lib/nes/app/application.hh2
-rw-r--r--lib/nes/app/crypto/CMakeLists.txt7
-rw-r--r--lib/nes/app/crypto/aes256.cc610
-rw-r--r--lib/nes/app/crypto/aes256.hh12
-rw-r--r--lib/nes/app/crypto/sha256.cc156
-rw-r--r--lib/nes/app/crypto/sha256.hh28
-rw-r--r--lib/nes/app/ui/CMakeLists.txt4
-rw-r--r--lib/nes/app/ui/screen-browser.cc8
-rw-r--r--lib/nes/app/ui/screen-prompt-key.cc66
-rw-r--r--lib/nes/app/ui/screen-prompt-key.hh28
-rw-r--r--lib/nes/common/containers/string-builder.cc13
-rw-r--r--lib/nes/common/containers/string-builder.hh3
15 files changed, 966 insertions, 3 deletions
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<u8 const*>(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<u8 const>{ 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<state_t*>(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<u8> 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<u8> 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<u8 const, 256 / 8>;
+
+ auto encrypt(span<u8>, key) -> void;
+ auto decrypt(span<u8>, 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<u32>(
+ (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<u8>((value >> 24) & 0xFF);
+ data_[offset + 1] = static_cast<u8>((value >> 16) & 0xFF);
+ data_[offset + 2] = static_cast<u8>((value >> 8) & 0xFF);
+ data_[offset + 3] = static_cast<u8>((value >> 0) & 0xFF);
+ }
+
+ auto sha256::hash(span<u8 const> 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<block_size>(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<u64>(message.get_length()) * 8;
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 56) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 48) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 40) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 32) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 24) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 16) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((length >> 8) & 0xFF);
+ last_blocks[last_block_length++] = static_cast<u8>((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<u8 const>(last_blocks).subspan<block_size>(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<u8 const, block_size> 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<u32>(
+ (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<u8 const>) -> sha256;
+
+ auto get_data() const -> span<u8 const, length> { return data_; }
+
+ private:
+ explicit sha256();
+
+ auto combine(span<u8 const, block_size>) -> 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<max_key_length> 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
diff --git a/lib/nes/common/containers/string-builder.cc b/lib/nes/common/containers/string-builder.cc
index ad2f97f..8182955 100644
--- a/lib/nes/common/containers/string-builder.cc
+++ b/lib/nes/common/containers/string-builder.cc
@@ -253,4 +253,17 @@ namespace nes
return status::error_invalid_format_string;
}
+
+ auto string_builder::remove_last() -> status
+ {
+ if (length_ == 0) { return status::error_buffer_overflow; }
+
+ length_ -= 1;
+ return status::success;
+ }
+
+ auto string_builder::clear() -> void
+ {
+ length_ = 0;
+ }
} // namespace nes \ No newline at end of file
diff --git a/lib/nes/common/containers/string-builder.hh b/lib/nes/common/containers/string-builder.hh
index 7dcbb34..a533461 100644
--- a/lib/nes/common/containers/string-builder.hh
+++ b/lib/nes/common/containers/string-builder.hh
@@ -92,6 +92,9 @@ namespace nes
return append_format(fmt, arg_wrappers, arg_count);
}
+ auto remove_last() -> status;
+ auto clear() -> void;
+
private:
auto append_format(string_view fmt, format_arg const* args, u32 arg_count) -> status;
auto append_format_arg(format_arg, string_view params) -> status;
generated by cgit v1.3.1 (git 2.54.0) at 2026-11-10 14:48:24 +0000