tachtig.c

   1 // Copyright 2007,2008  Segher Boessenkool  <segher@kernel.crashing.org>
   2 // Licensed under the terms of the GNU GPL, version 2
   3 // http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
   4
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <unistd.h>
   8 #include <string.h>
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11
  12 #include "tools.h"
  13
  14 #define ERROR(s) do { fprintf(stderr, s "\n"); exit(1); } while (0)
  15
  16 static u8 sd_key[16];
  17 static u8 sd_iv[16];
  18 static u8 md5_blanker[16];
  19
  20 static FILE *fp;
  21 static u32 n_files;
  22 static u32 files_size;
  23 static u32 total_size;
  24
  25 static void output_image(u8 *data, u32 w, u32 h, const char *name)
  26 {
  27         FILE *fp;
  28         u32 x, y;
  29
  30         fp = fopen(name, "wb");
  31         if (!fp)
  32                 fatal("open %s", name);
  33
  34         fprintf(fp, "P6 %d %d 255\n", w, h);
  35
  36         for (y = 0; y < h; y++)
  37                 for (x = 0; x < w; x++) {
  38                         u8 pix[3];
  39                         u16 raw;
  40                         u32 x0, x1, y0, y1, off;
  41
  42                         x0 = x & 3;
  43                         x1 = x >> 2;
  44                         y0 = y & 3;
  45                         y1 = y >> 2;
  46                         off = x0 + 4 * y0 + 16 * x1 + 4 * w * y1;
  47
  48                         raw = be16(data + 2*off);
  49
  50                         // RGB5A3
  51                         if (raw & 0x8000) {
  52                                 pix[0] = (raw >> 7) & 0xf8;
  53                                 pix[1] = (raw >> 2) & 0xf8;
  54                                 pix[2] = (raw << 3) & 0xf8;
  55                         } else {
  56                                 pix[0] = (raw >> 4) & 0xf0;
  57                                 pix[1] =  raw       & 0xf0;
  58                                 pix[2] = (raw << 4) & 0xf0;
  59                         }
  60
  61                         if (fwrite(pix, 3, 1, fp) != 1)
  62                                 fatal("write %s", name);
  63                 }
  64
  65         fclose(fp);
  66 }
  67
  68 static void do_file_header(void)
  69 {
  70         u8 header[0xf0c0];
  71         u8 md5_file[16];
  72         u8 md5_calc[16];
  73         u32 header_size;
  74         char name[256];
  75         FILE *out;
  76         u32 i;
  77
  78         if (fread(header, sizeof header, 1, fp) != 1)
  79                 fatal("read file header");
  80
  81         aes_cbc_dec(sd_key, sd_iv, header, sizeof header, header);
  82
  83         memcpy(md5_file, header + 0x0e, 16);
  84         memcpy(header + 0x0e, md5_blanker, 16);
  85         md5(header, sizeof header, md5_calc);
  86
  87         if (memcmp(md5_file, md5_calc, 0x10))
  88                 ERROR("MD5 mismatch");
  89
  90         header_size = be32(header + 8);
  91         if (header_size != 0x72a0 && header_size != 0xf0a0)
  92                 ERROR("unknown file header size");
  93
  94         out = fopen("###title###", "wb");
  95         if (!out)
  96                 fatal("open ###title###");
  97         if (fwrite(header + 0x40, 0x80, 1, out) != 1)
  98                 fatal("write ###title###");
  99         fclose(out);
 100
 101         output_image(header + 0xc0, 192, 64, "###banner###.ppm");
 102         if (header_size == 0x72a0)
 103                 output_image(header + 0x60c0, 48, 48, "###icon###.ppm");
 104         else
 105                 for (i = 0; i < 8; i++) {
 106                         snprintf(name, sizeof name, "###icon%d###.ppm", i);
 107                         output_image(header + 0x60c0 + 0x1200*i, 48, 48, name);
 108                 }
 109 }
 110
 111 static void do_backup_header(void)
 112 {
 113         u8 header[0x80];
 114
 115         if (fread(header, sizeof header, 1, fp) != 1)
 116                 fatal("read backup header");
 117
 118         if (be32(header + 4) != 0x426b0001)
 119                 ERROR("no Bk header");
 120         if (be32(header) != 0x70)
 121                 ERROR("wrong Bk header size");
 122
 123         fprintf(stderr, "NG id: %08x\n", be32(header + 8));
 124
 125         n_files = be32(header + 0x0c);
 126         files_size = be32(header + 0x10);
 127         total_size = be32(header + 0x1c);
 128
 129         fprintf(stderr, "%d files\n", n_files);
 130 }
 131
 132 static mode_t perm_to_mode(u8 perm)
 133 {
 134         mode_t mode;
 135         u32 i;
 136
 137         mode = 0;
 138         for (i = 0; i < 3; i++) {
 139                 mode <<= 3;
 140                 if (perm & 0x20)
 141                         mode |= 2;
 142                 if (perm & 0x10)
 143                         mode |= 4;
 144                 perm <<= 2;
 145         }
 146
 147         return mode;
 148 }
 149
 150 static void do_file(void)
 151 {
 152         u8 header[0x80];
 153         u32 size;
 154         u32 rounded_size;
 155         u8 perm, attr, type;
 156         char *name;
 157         u8 *data;
 158         FILE *out;
 159         mode_t mode;
 160
 161         if (fread(header, sizeof header, 1, fp) != 1)
 162                 fatal("read file header");
 163
 164         if (be32(header) != 0x03adf17e)
 165                 ERROR("bad file header");
 166
 167         size = be32(header + 4);
 168         perm = header[8];
 169         attr = header[9];
 170         type = header[10];
 171         name = header + 11;
 172
 173         fprintf(stderr, "file: size=%08x perm=%02x attr=%02x type=%02x name=%s\n", size, perm, attr, type, name);
 174
 175         mode = perm_to_mode(perm);
 176
 177         switch (type) {
 178         case 1:
 179                 rounded_size = (size + 63) & ~63;
 180                 data = malloc(rounded_size);
 181                 if (!data)
 182                         fatal("malloc");
 183                 if (fread(data, rounded_size, 1, fp) != 1)
 184                         fatal("read file data for %s", name);
 185
 186                 aes_cbc_dec(sd_key, header + 0x50, data, rounded_size, data);
 187
 188                 out = fopen(name, "wb");
 189                 if (!out)
 190                         fatal("open %s", name);
 191                 if (fwrite(data, size, 1, out) != 1)
 192                         fatal("write %s", name);
 193                 fclose(out);
 194
 195                 free(data);
 196                 break;
 197
 198         case 2:
 199                 if (mkdir(name, 0777))
 200                         fatal("mkdir %s", name);
 201                 mode |= 0111;
 202                 break;
 203
 204         default:
 205                 ERROR("unhandled file type");
 206         }
 207
 208         if (chmod(name, mode))
 209                 fatal("chmod %s", name);
 210 }
 211
 212 static void do_sig(void)
 213 {
 214         u8 sig[0x40];
 215         u8 ng_cert[0x180];
 216         u8 ap_cert[0x180];
 217         u8 hash[0x14];
 218         u8 *data;
 219         u32 data_size;
 220         int ok;
 221
 222         if (fread(sig, sizeof sig, 1, fp) != 1)
 223                 fatal("read signature");
 224         if (fread(ng_cert, sizeof ng_cert, 1, fp) != 1)
 225                 fatal("read NG cert");
 226         if (fread(ap_cert, sizeof ap_cert, 1, fp) != 1)
 227                 fatal("read AP cert");
 228
 229         data_size = total_size - 0x340;
 230
 231         data = malloc(data_size);
 232         if (!data)
 233                 fatal("malloc");
 234         fseek(fp, 0xf0c0, SEEK_SET);
 235         if (fread(data, data_size, 1, fp) != 1)
 236                 fatal("read data for sig check");
 237         sha(data, data_size, hash);
 238         sha(hash, 20, hash);
 239         free(data);
 240
 241         ok = check_ec(ng_cert, ap_cert, sig, hash);
 242         printf("ok: %d\n", ok);
 243 }
 244
 245 int main(int argc, char **argv)
 246 {
 247         u32 i;
 248
 249         if (argc != 3) {
 250                 fprintf(stderr, "Usage: %s <data.bin> <destdir>\n", argv[0]);
 251                 return 1;
 252         }
 253
 254         get_key("sd-key", sd_key, 16);
 255         get_key("sd-iv", sd_iv, 16);
 256         get_key("md5-blanker", md5_blanker, 16);
 257
 258         fp = fopen(argv[1], "rb");
 259         if (!fp)
 260                 fatal("open %s", argv[1]);
 261
 262         if (mkdir(argv[2], 0777))
 263                 fatal("mkdir %s", argv[2]);
 264         if (chdir(argv[2]))
 265                 fatal("chdir %s", argv[2]);
 266
 267         do_file_header();
 268         do_backup_header();
 269
 270         for (i = 0; i < n_files; i++)
 271                 do_file();
 272
 273         if (chdir(".."))
 274                 fatal("chdir ..");
 275
 276         do_sig();
 277
 278         fclose(fp);
 279
 280         return 0;
 281 }