zestig.c

   1 #include <sys/types.h>
   2 #include <sys/stat.h>
   3 #include <sys/mman.h>
   4 #include <unistd.h>
   5 #include <fcntl.h>
   6 #include <string.h>
   7 #include <stdio.h>
   8
   9 #include "tools.h"
  10
  11 static const u8 *rom;
  12 static const u8 *super;
  13 static const u8 *fat;
  14 static const u8 *fst;
  15
  16 static u8 key[16];
  17
  18 static const u8 *map_rom(const char *name)
  19 {
  20         int fd = open(name, O_RDONLY);
  21         void *map = mmap(0, 0x20000000, PROT_READ, MAP_SHARED, fd, 0);
  22         close(fd);
  23         return map;
  24 }
  25
  26 static const u8 *find_super(void)
  27 {
  28         u32 newest = 0;
  29         const u8 *super = 0, *p;
  30
  31         for (p = rom + 0x1fc00000; p < rom + 0x20000000; p += 0x40000)
  32                 if (be32(p) == 0x53464653) {
  33                         u32 version = be32(p + 4);
  34                         if (super == 0 || version > newest) {
  35                                 super = p;
  36                                 newest = version;
  37                         }
  38                 }
  39
  40         return super;
  41 }
  42
  43 static void print_mode(u8 mode)
  44 {
  45         int i;
  46         const char dir[4] = "?-d?";
  47         const char perm[3] = "-rw";
  48
  49         fprintf(stderr, "%c", dir[mode & 3]);
  50         for (i = 0; i < 3; i++) {
  51                 fprintf(stderr, "%c", perm[(mode >> 6) & 1]);
  52                 fprintf(stderr, "%c", perm[(mode >> 6) & 2]);
  53                 mode <<= 2;
  54         }
  55 }
  56
  57 static void print_entry(const u8 *entry)
  58 {
  59         char name[13];
  60         u8 mode, attr;
  61         u16 sub, sib;
  62         u32 size;
  63         u16 x1, uid, gid;
  64         u32 x3;
  65
  66         memcpy(name, entry, 12);
  67         name[12] = 0;
  68         mode = entry[0x0c];
  69         attr = entry[0x0d];
  70         sub = be16(entry + 0x0e);
  71         sib = be16(entry + 0x10);
  72         size = be32(entry + 0x12);
  73         x1 = be16(entry + 0x16);
  74         uid = be16(entry + 0x18);
  75         gid = be16(entry + 0x1a);
  76         x3 = be32(entry + 0x1c);
  77
  78         print_mode(mode);
  79         fprintf(stderr, " %02x %04x %04x %08x (%04x %08x) %s\n",
  80                 attr, uid, gid, size, x1, x3, name);
  81 }
  82
  83 static u8 block[0x4000];
  84
  85 static void do_file(const u8 *entry, const char *parent_path)
  86 {
  87         char name[13];
  88         char path[256];
  89         u8 iv[16];
  90         u16 sub;
  91         u32 size, this_size;
  92         FILE *fp;
  93
  94         memcpy(name, entry, 12);
  95         name[12] = 0;
  96         sub = be16(entry + 0x0e);
  97         size = be32(entry + 0x12);
  98
  99         if (parent_path[strlen(parent_path) - 1] == '/' || name[0] == '/')
 100                 sprintf(path, "%s%s", parent_path, name);
 101         else
 102                 sprintf(path, "%s/%s", parent_path, name);
 103
 104         fp = fopen(path + 1, "wb");
 105
 106         while (size) {
 107                 this_size = size > 0x4000 ? 0x4000 : size;
 108
 109                 memset(iv, 0, sizeof iv);
 110                 aes_cbc_dec(key, iv, (u8 *)rom + 0x4000*sub, 0x4000, block);
 111
 112                 fwrite(block, 1, this_size, fp);
 113
 114                 size -= this_size;
 115                 sub = be16(fat + 2*sub);
 116         }
 117
 118         fclose(fp);
 119 }
 120
 121 static void do_entry(const u8 *entry, const char *parent_path);
 122
 123 static void print_dir_entries(const u8 *entry)
 124 {
 125         u16 sib;
 126
 127         sib = be16(entry + 0x10);
 128
 129         if (sib != 0xffff)
 130                 print_dir_entries(fst + 0x20*sib);
 131
 132         print_entry(entry);
 133 }
 134
 135 static void do_dir(const u8 *entry, const char *parent_path)
 136 {
 137         char name[13];
 138         char path[256];
 139         u16 sub, sib;
 140
 141         memcpy(name, entry, 12);
 142         name[12] = 0;
 143         sub = be16(entry + 0x0e);
 144         sib = be16(entry + 0x10);
 145
 146         if (parent_path[strlen(parent_path) - 1] == '/' || name[0] == '/')
 147                 sprintf(path, "%s%s", parent_path, name);
 148         else
 149                 sprintf(path, "%s/%s", parent_path, name);
 150         fprintf(stderr, "%s:\n", path);
 151         if (sub != 0xffff)
 152                 print_dir_entries(fst + 0x20*sub);
 153         fprintf(stderr, "\n");
 154
 155         if (path[1])
 156                 mkdir(path + 1, 0777);
 157
 158         if (sub != 0xffff)
 159                 do_entry(fst + 0x20*sub, path);
 160 }
 161
 162 static void do_entry(const u8 *entry, const char *parent_path)
 163 {
 164         u8 mode;
 165         u16 sib;
 166
 167         mode = entry[0x0c];
 168         sib = be16(entry + 0x10);
 169
 170         if (sib != 0xffff)
 171                 do_entry(fst + 0x20*sib, parent_path);
 172
 173         mode &= 3;
 174
 175         switch(mode) {
 176         case 1:
 177                 do_file(entry, parent_path);
 178                 break;
 179         case 2:
 180                 do_dir(entry, parent_path);
 181                 break;
 182         default:
 183                 fprintf(stderr, "unknown mode! (%d)\n", mode);
 184         }
 185 }
 186
 187 int main(int argc, char **argv)
 188 {
 189         get_key("default/nand-key", key, 16);
 190
 191         rom = map_rom(argv[1]);
 192         super = find_super();
 193         fat = super + 0x0c;
 194         fst = fat + 0x10000;
 195
 196         mkdir(argv[2], 0777);
 197         chdir(argv[2]);
 198         do_entry(fst, "");
 199         chdir("..");
 200
 201         return 0;
 202 }