add AES, fix a bunch of bugs

we're getting an error screen! wee

1 files changed, 303 insertions, 0 deletions

diff --git a/src/DSi_AES.cpp b/src/DSi_AES.cpp
index 6a524dd..8271e3e 100644
--- a/src/DSi_AES.cpp
+++ b/src/DSi_AES.cpp
@@ -15,3 +15,306 @@
     You should have received a copy of the GNU General Public License along
     with melonDS. If not, see http://www.gnu.org/licenses/.
 */
+
+#include <stdio.h>
+#include <string.h>
+#include "DSi.h"
+#include "DSi_AES.h"
+#include "FIFO.h"
+#include "tiny-AES-c/aes.hpp"
+
+
+namespace DSi_AES
+{
+
+u32 Cnt;
+
+u32 BlkCnt;
+u32 RemBlocks;
+
+u32 InputDMASize, OutputDMASize;
+u32 AESMode;
+
+FIFO<u32>* InputFIFO;
+FIFO<u32>* OutputFIFO;
+
+u8 IV[16];
+
+u8 KeyNormal[4][16];
+u8 KeyX[4][16];
+u8 KeyY[4][16];
+
+u8 CurKey[16];
+
+AES_ctx Ctx;
+
+
+void Swap16(u8* dst, u8* src)
+{
+    for (int i = 0; i < 16; i++)
+        dst[i] = src[15-i];
+}
+
+void ROL16(u8* val, u32 n)
+{
+    u32 n_coarse = n >> 3;
+    u32 n_fine = n & 7;
+    u8 tmp[16];
+
+    for (u32 i = 0; i < 16; i++)
+    {
+        tmp[i] = val[(i - n_coarse) & 0xF];
+    }
+
+    for (u32 i = 0; i < 16; i++)
+    {
+        val[i] = (tmp[i] << n_fine) | (tmp[(i - 1) & 0xF] >> (8-n_fine));
+    }
+}
+
+#define _printhex(str, size) { for (int z = 0; z < (size); z++) printf("%02X", (str)[z]); printf("\n"); }
+
+
+bool Init()
+{
+    InputFIFO = new FIFO<u32>(16);
+    OutputFIFO = new FIFO<u32>(16);
+
+    const u8 zero[16] = {0};
+    AES_init_ctx_iv(&Ctx, zero, zero);
+
+    return true;
+}
+
+void DeInit()
+{
+    delete InputFIFO;
+    delete OutputFIFO;
+}
+
+void Reset()
+{
+    Cnt = 0;
+
+    BlkCnt = 0;
+    RemBlocks = 0;
+
+    InputDMASize = 0;
+    OutputDMASize = 0;
+    AESMode = 0;
+
+    InputFIFO->Clear();
+    OutputFIFO->Clear();
+
+    memset(KeyNormal, 0, sizeof(KeyNormal));
+    memset(KeyX, 0, sizeof(KeyX));
+    memset(KeyY, 0, sizeof(KeyY));
+
+    memset(CurKey, 0, sizeof(CurKey));
+
+    // initialize keys, as per GBAtek
+
+    // slot 3: console-unique eMMC crypto
+    *(u32*)&KeyX[3][0] = (u32)DSi::ConsoleID;
+    *(u32*)&KeyX[3][4] = (u32)DSi::ConsoleID ^ 0x24EE6906;
+    *(u32*)&KeyX[3][8] = (u32)(DSi::ConsoleID >> 32) ^ 0xE65B601D;
+    *(u32*)&KeyX[3][12] = (u32)(DSi::ConsoleID >> 32);
+    *(u32*)&KeyY[3][0] = 0x0AB9DC76;
+    *(u32*)&KeyY[3][4] = 0xBD4DC4D3;
+    *(u32*)&KeyY[3][8] = 0x202DDD1D;
+}
+
+
+void ProcessBlock_CTR()
+{
+    u8 data[16];
+    u8 data_rev[16];
+
+    *(u32*)&data[0] = InputFIFO->Read();
+    *(u32*)&data[4] = InputFIFO->Read();
+    *(u32*)&data[8] = InputFIFO->Read();
+    *(u32*)&data[12] = InputFIFO->Read();
+
+    //printf("AES-CTR: INPUT: "); _printhex(data, 16);
+
+    Swap16(data_rev, data);
+    AES_CTR_xcrypt_buffer(&Ctx, data_rev, 16);
+    Swap16(data, data_rev);
+
+    //printf("AES-CTR: OUTPUT: "); _printhex(data, 16);
+
+    OutputFIFO->Write(*(u32*)&data[0]);
+    OutputFIFO->Write(*(u32*)&data[4]);
+    OutputFIFO->Write(*(u32*)&data[8]);
+    OutputFIFO->Write(*(u32*)&data[12]);
+}
+
+
+u32 ReadCnt()
+{
+    u32 ret = Cnt;
+
+    ret |= InputFIFO->Level();
+    ret |= (OutputFIFO->Level() << 5);
+
+    return ret;
+}
+
+void WriteCnt(u32 val)
+{
+    u32 oldcnt = Cnt;
+    Cnt = val & 0xFC1FF000;
+
+    if (val & (1<<10)) InputFIFO->Clear();
+    if (val & (1<<11)) OutputFIFO->Clear();
+
+    u32 dmasize[4] = {4, 8, 12, 16};
+    InputDMASize = dmasize[3 - ((val >> 12) & 0x3)];
+    OutputDMASize = dmasize[(val >> 14) & 0x3];
+
+    AESMode = (val >> 28) & 0x3;
+    if (AESMode < 2) printf("AES-CCM TODO\n");
+
+    if (val & (1<<24))
+    {
+        u32 slot = (val >> 26) & 0x3;
+        memcpy(CurKey, KeyNormal[slot], 16);
+
+        //printf("AES: key(%d): ", slot); _printhex(CurKey, 16);
+
+        u8 tmp[16];
+        Swap16(tmp, CurKey);
+        AES_init_ctx(&Ctx, tmp);
+    }
+
+    if (!(oldcnt & (1<<31)) && (val & (1<<31)))
+    {
+        // transfer start (checkme)
+        RemBlocks = BlkCnt >> 16;
+    }
+
+    printf("AES CNT: %08X / mode=%d inDMA=%d outDMA=%d blocks=%d\n",
+           val, AESMode, InputDMASize, OutputDMASize, RemBlocks);
+}
+
+void WriteBlkCnt(u32 val)
+{
+    BlkCnt = val;
+}
+
+u32 ReadOutputFIFO()
+{
+    return OutputFIFO->Read();
+}
+
+void WriteInputFIFO(u32 val)
+{
+    // TODO: add some delay to processing
+
+    InputFIFO->Write(val);
+
+    if (!(Cnt & (1<<31))) return;
+
+    while (InputFIFO->Level() >= 4 && RemBlocks > 0)
+    {
+        switch (AESMode)
+        {
+        case 2:
+        case 3: ProcessBlock_CTR(); break;
+        default:
+            // dorp
+            OutputFIFO->Write(InputFIFO->Read());
+            OutputFIFO->Write(InputFIFO->Read());
+            OutputFIFO->Write(InputFIFO->Read());
+            OutputFIFO->Write(InputFIFO->Read());
+        }
+
+        RemBlocks--;
+    }
+
+    if (OutputFIFO->Level() >= OutputDMASize)
+    {
+        // trigger DMA
+        DSi::CheckNDMAs(1, 0x2B);
+    }
+    // TODO: DMA the other way around
+
+    if (RemBlocks == 0)
+    {
+        Cnt &= ~(1<<31);
+        if (Cnt & (1<<30)) NDS::SetIRQ2(NDS::IRQ2_DSi_AES);
+    }
+}
+
+
+void WriteIV(u32 offset, u32 val, u32 mask)
+{
+    u32 old = *(u32*)&IV[offset];
+
+    *(u32*)&IV[offset] = (old & ~mask) | (val & mask);
+
+    //printf("AES: IV: "); _printhex(IV, 16);
+
+    u8 tmp[16];
+    Swap16(tmp, IV);
+    AES_ctx_set_iv(&Ctx, tmp);
+}
+
+void WriteMAC(u32 offset, u32 val, u32 mask)
+{
+    //
+}
+
+void DeriveNormalKey(u32 slot)
+{
+    const u8 key_const[16] = {0xFF, 0xFE, 0xFB, 0x4E, 0x29, 0x59, 0x02, 0x58, 0x2A, 0x68, 0x0F, 0x5F, 0x1A, 0x4F, 0x3E, 0x79};
+    u8 tmp[16];
+
+    //printf("keyX: "); _printhex(KeyX[slot], 16);
+    //printf("keyY: "); _printhex(KeyY[slot], 16);
+
+    for (int i = 0; i < 16; i++)
+        tmp[i] = KeyX[slot][i] ^ KeyY[slot][i];
+
+    u32 carry = 0;
+    for (int i = 0; i < 16; i++)
+    {
+        u32 res = tmp[i] + key_const[15-i] + carry;
+        tmp[i] = res & 0xFF;
+        carry = res >> 8;
+    }
+
+    ROL16(tmp, 42);
+
+    //printf("derive normalkey %d\n", slot); _printhex(tmp, 16);
+
+    memcpy(KeyNormal[slot], tmp, 16);
+}
+
+void WriteKeyNormal(u32 slot, u32 offset, u32 val, u32 mask)
+{
+    u32 old = *(u32*)&KeyNormal[slot][offset];
+
+    *(u32*)&KeyNormal[slot][offset] = (old & ~mask) | (val & mask);
+}
+
+void WriteKeyX(u32 slot, u32 offset, u32 val, u32 mask)
+{
+    u32 old = *(u32*)&KeyX[slot][offset];
+
+    *(u32*)&KeyX[slot][offset] = (old & ~mask) | (val & mask);
+}
+
+void WriteKeyY(u32 slot, u32 offset, u32 val, u32 mask)
+{
+    u32 old = *(u32*)&KeyY[slot][offset];
+
+    *(u32*)&KeyY[slot][offset] = (old & ~mask) | (val & mask);
+
+    if (offset >= 0xC)
+    {
+        DeriveNormalKey(slot);
+    }
+}
+
+}