Idstorage Keys (0×0004-0×0008) – Generating hash

The idstorage area stores low level info on the PSP. Keys 4-8 are used for config data for various components (the battery, clock generator, LCD, etc.) and are in a different format to all the other keys.

Here is the code to generate the hash for these particular keys:

view plain
C:
  1. /*
  2. Idstorage Leaf Hash Gen Sample – SilverSpring 2007
  3.  
  4. The idstorage area stores low level info on the PSP.
  5. Keys 4-8 are used for config data for various components
  6. (the battery, clock generator, LCD, etc.)
  7. and are in a different format to all the other keys.
  8.  
  9. Specifically the format is as follows:
  10.  
  11. typedef struct
  12. {
  13.     u32 signature;
  14.     int type;
  15.     int datalen;
  16.     u32 hash;
  17.     u8 databuf[0x1F0];
  18.  
  19. } SceIdStorageLeaf;
  20.  
  21. Here’s the code to regenerate the hash for those keys.
  22. */
  23.  
  24. #include <stdio.h>
  25.  
  26. #define POLY (0xEDB88320)
  27.  
  28. #define LEAF_0x0004_HASH    (0x1FAB01BB)
  29. #define LEAF_DATA_SIZE  (0x1F0)
  30.  
  31. unsigned int gen_hash(unsigned int seed, unsigned char buf[], int size);
  32. void gen_table(void);
  33.  
  34.  
  35. unsigned int table[256];
  36.  
  37.  
  38. unsigned char leaf_0x0004_data[LEAF_DATA_SIZE] =
  39. {
  40.     0xD8, 0×00, 0×24, 0×00, 0×14, 0×31, 0×14, 0×00, 0×94, 0×01, 0×48, 0×00, 0xD8, 0×00, 0×00, 0×00,
  41.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  42.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  43.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  44.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  45.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  46.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  47.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  48.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  49.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  50.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  51.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  52.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  53.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  54.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  55.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  56.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  57.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  58.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  59.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  60.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  61.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  62.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  63.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  64.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  65.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  66.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  67.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  68.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  69.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  70.     0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00, 0×00,
  71. };
  72.  
  73.  
  74. int main()
  75. {
  76.     unsigned int hash;
  77.  
  78.     gen_table();
  79.     hash = gen_hash(0xFFFFFFFF, leaf_0x0004_data, LEAF_DATA_SIZE);
  80.  
  81.     if (hash != LEAF_0x0004_HASH)
  82.         printf("error: hash not match \n");
  83.  
  84.     printf("leaf_0x0004 hash: 0x%08X", hash);
  85.  
  86.     return 0;
  87. }
  88.  
  89.  
  90. unsigned int gen_hash(unsigned int seed, unsigned char buf[], int size)
  91. {
  92.     unsigned int hash = ~seed;
  93.     unsigned char index;
  94.     int i;
  95.  
  96.     for (i=0; i!=size; i++)
  97.     {
  98.         index = buf[i] ^ hash;
  99.         hash>>= 8;
  100.         hash ^= table[index];
  101.     }
  102.  
  103.     return(~hash);
  104. }
  105.  
  106. void gen_table(void)
  107. {
  108.     unsigned int i, j, x;
  109.  
  110.     for (i=0; i<256; i++)
  111.     {
  112.         x = i;
  113.  
  114.         for (j=0; j<8; j++)
  115.         {
  116.             if (x & 1)
  117.                 x = (x>>1) ^ POLY;
  118.             else
  119.                 x = (x>>1);
  120.         }
  121.  
  122.         table[i] = x;
  123.     }
  124. }

Note: this is a PC app (though you could run it on the PSP as well if you wanted).

This entry was posted on Monday, November 5th, 2007 at 4:43 pm and is filed under Code Snippets. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

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