ACNL-7DD6-Fix.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "ACNL-7DD6-Fix.h"

#define SAVE_SIZE 0x89B00

void wait_to_exit(void)
{
    printf("\nPress Enter To Exit.\n");
    getchar(); 
    return;
}

void help_text(void)
{
    printf("ACNL-7DD6-Fix By Slattz\n");
    printf("Checksum code based on ACRehash by WulfyStylez/WemI0\n");
    printf("Usage: 'ACNL-7DD6-Fix filename', or drag-and-drop a file\n\n");
}

u32 GetAnimalCrossingChecksum(u8* data, u32 length)
{
    u32 table[0x100] = { 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4, 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB, 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B, 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24, 0x105EC76F, 0xE235446C, 0xF165B798, 0x30E349B, 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384, 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54, 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B, 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A, 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35, 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5, 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA, 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45, 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A, 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A, 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595, 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48, 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957, 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687, 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198, 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927, 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38, 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8, 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7, 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096, 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789, 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859, 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46, 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9, 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6, 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36, 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829, 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C, 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93, 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043, 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C, 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3, 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC, 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C, 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033, 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652, 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D, 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D, 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982, 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D, 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622, 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2, 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED, 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530, 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F, 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF, 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0, 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F, 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540, 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90, 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F, 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE, 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1, 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321, 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E, 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81, 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E, 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E, 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351 };
    u32 checksum = 0xFFFFFFFF;
    u32 i;
    
    if (length > 0)
    {
        int ofs = -1;
        if (length % 2 == 1)
        {
            ofs++;
            checksum = table[(u8)(data[ofs] ^ (checksum & 0xFF))] ^ (checksum >> 8);
        }
        int v10 = 0;
        u32 v12 = 0;
        for (i = length >> 1; i > 0; checksum = table[(u8)(data[ofs] ^ (v12 & 0xFF))] ^ (v12 >> 8))
        {
            i--;
            v10 = (u8)(data[ofs + 1] ^ (checksum & 0xFF));
            ofs += 2;
            v12 = table[v10] ^ (checksum >> 8);
        }
    }
    return ~checksum;
}

void hash_region(FILE *f, u32 offset, u32 len)
{
    u8 *buf = malloc(len);
    
    fseek(f, offset + 4, SEEK_SET);
    fread(buf, 1, len, f);
    u32 hash = GetAnimalCrossingChecksum(buf, len);
    fseek(f, offset, SEEK_SET);
    fwrite(&hash, 1, 4, f);
    free(buf);
}

void rehash_acnlwa(FILE *f)
{
    u32 i;
    hash_region(f, 0x80, 0x1C);
    for(i = 0; i < 4; i++)
    {
        hash_region(f, 0xA0 + (0xA480 * i), 0x6B84);
        hash_region(f, 0xA0 + (0xA480 * i) + 0x6B88, 0x38F4);
    }
    hash_region(f, 0x292A0, 0x22BC8);
    hash_region(f, 0x4BE80, 0x44B8);
    hash_region(f, 0x53424, 0x1E4D8);
    hash_region(f, 0x71900, 0x20);
    hash_region(f, 0x71924, 0xBE4);
    hash_region(f, 0x73954, 0x16188);
}

int main(int argc, char* argv[])
{
    help_text();
    if(argc < 2)
    {
        printf("Error: Specify a filename or drag-and-drop a file.\n");
        wait_to_exit();
        return 0;
    }

    FILE *save = fopen(argv[1], "r+b");
    if (save == NULL)
    {
        printf("Error opening file!\n");
        wait_to_exit();
        return 0;
    }
    
    fseek(save, 0, SEEK_END);
    u32 savesize = ftell(save);

    if (savesize != SAVE_SIZE)
    {
        printf("File isn't the correct size (0x%X)!\n", SAVE_SIZE);
        fclose(save);
        wait_to_exit();
        return 0;
    }

    u8 *buffer = malloc(0xE8);
    fseek(save, 0x04be88, SEEK_SET);
    fread(buffer, 1, 0xE8, save);

    int i;
    bool invalid = false;
    for (i = 0; i < 58; i++)
    {
        if ((buffer[i*4] >= 0x12 && buffer[i*4] <= 0x4B) || buffer[i*4] > 0xFC)
        {
            invalid = true;
            printf("Invalid Building Found: 0x%02X\n", buffer[i*4]);
            buffer[i*4] = 0xFC;
            buffer[(i*4)+1] = 0x00;
            buffer[(i*4)+2] = 0x00;
            buffer[(i*4)+3] = 0x00;
        }
    }

    if (invalid)
    {
        fseek(save, 0x04be88, SEEK_SET);
        fwrite(buffer, 1, 0xE8, save);
        rewind(save);
        rehash_acnlwa(save);
        printf("Save Fixed!\n");
    }

    else
    {
        printf("No Invalid Buildings Found!\n");
        printf("Save was not fixed!\n");
    }
        
    free(buffer);
    fclose(save);
    return 0;
}