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tetex-bin  3.0
Functions | Variables
Decrypt.cc File Reference
#include <aconf.h>
#include "gmem.h"
#include "Decrypt.h"

Go to the source code of this file.

Functions

static void rc4InitKey (Guchar *key, int keyLen, Guchar *state)
static Guchar rc4DecryptByte (Guchar *state, Guchar *x, Guchar *y, Guchar c)
static void md5 (Guchar *msg, int msgLen, Guchar *digest)
static Gulong rotateLeft (Gulong x, int r)
static Gulong md5Round1 (Gulong a, Gulong b, Gulong c, Gulong d, Gulong Xk, Gulong s, Gulong Ti)
static Gulong md5Round2 (Gulong a, Gulong b, Gulong c, Gulong d, Gulong Xk, Gulong s, Gulong Ti)
static Gulong md5Round3 (Gulong a, Gulong b, Gulong c, Gulong d, Gulong Xk, Gulong s, Gulong Ti)
static Gulong md5Round4 (Gulong a, Gulong b, Gulong c, Gulong d, Gulong Xk, Gulong s, Gulong Ti)

Variables

static Guchar passwordPad [32]

Function Documentation

static void md5 ( Guchar msg,
int  msgLen,
Guchar digest 
) [static]

Definition at line 259 of file Decrypt.cc.

                                                         {
  Gulong x[16];
  Gulong a, b, c, d, aa, bb, cc, dd;
  int n64;
  int i, j, k;

  // compute number of 64-byte blocks
  // (length + pad byte (0x80) + 8 bytes for length)
  n64 = (msgLen + 1 + 8 + 63) / 64;

  // initialize a, b, c, d
  a = 0x67452301;
  b = 0xefcdab89;
  c = 0x98badcfe;
  d = 0x10325476;

  // loop through blocks
  k = 0;
  for (i = 0; i < n64; ++i) {

    // grab a 64-byte block
    for (j = 0; j < 16 && k < msgLen - 3; ++j, k += 4)
      x[j] = (((((msg[k+3] << 8) + msg[k+2]) << 8) + msg[k+1]) << 8) + msg[k];
    if (i == n64 - 1) {
      if (k == msgLen - 3)
       x[j] = 0x80000000 + (((msg[k+2] << 8) + msg[k+1]) << 8) + msg[k];
      else if (k == msgLen - 2)
       x[j] = 0x800000 + (msg[k+1] << 8) + msg[k];
      else if (k == msgLen - 1)
       x[j] = 0x8000 + msg[k];
      else
       x[j] = 0x80;
      ++j;
      while (j < 16)
       x[j++] = 0;
      x[14] = msgLen << 3;
    }

    // save a, b, c, d
    aa = a;
    bb = b;
    cc = c;
    dd = d;

    // round 1
    a = md5Round1(a, b, c, d, x[0],   7, 0xd76aa478);
    d = md5Round1(d, a, b, c, x[1],  12, 0xe8c7b756);
    c = md5Round1(c, d, a, b, x[2],  17, 0x242070db);
    b = md5Round1(b, c, d, a, x[3],  22, 0xc1bdceee);
    a = md5Round1(a, b, c, d, x[4],   7, 0xf57c0faf);
    d = md5Round1(d, a, b, c, x[5],  12, 0x4787c62a);
    c = md5Round1(c, d, a, b, x[6],  17, 0xa8304613);
    b = md5Round1(b, c, d, a, x[7],  22, 0xfd469501);
    a = md5Round1(a, b, c, d, x[8],   7, 0x698098d8);
    d = md5Round1(d, a, b, c, x[9],  12, 0x8b44f7af);
    c = md5Round1(c, d, a, b, x[10], 17, 0xffff5bb1);
    b = md5Round1(b, c, d, a, x[11], 22, 0x895cd7be);
    a = md5Round1(a, b, c, d, x[12],  7, 0x6b901122);
    d = md5Round1(d, a, b, c, x[13], 12, 0xfd987193);
    c = md5Round1(c, d, a, b, x[14], 17, 0xa679438e);
    b = md5Round1(b, c, d, a, x[15], 22, 0x49b40821);

    // round 2
    a = md5Round2(a, b, c, d, x[1],   5, 0xf61e2562);
    d = md5Round2(d, a, b, c, x[6],   9, 0xc040b340);
    c = md5Round2(c, d, a, b, x[11], 14, 0x265e5a51);
    b = md5Round2(b, c, d, a, x[0],  20, 0xe9b6c7aa);
    a = md5Round2(a, b, c, d, x[5],   5, 0xd62f105d);
    d = md5Round2(d, a, b, c, x[10],  9, 0x02441453);
    c = md5Round2(c, d, a, b, x[15], 14, 0xd8a1e681);
    b = md5Round2(b, c, d, a, x[4],  20, 0xe7d3fbc8);
    a = md5Round2(a, b, c, d, x[9],   5, 0x21e1cde6);
    d = md5Round2(d, a, b, c, x[14],  9, 0xc33707d6);
    c = md5Round2(c, d, a, b, x[3],  14, 0xf4d50d87);
    b = md5Round2(b, c, d, a, x[8],  20, 0x455a14ed);
    a = md5Round2(a, b, c, d, x[13],  5, 0xa9e3e905);
    d = md5Round2(d, a, b, c, x[2],   9, 0xfcefa3f8);
    c = md5Round2(c, d, a, b, x[7],  14, 0x676f02d9);
    b = md5Round2(b, c, d, a, x[12], 20, 0x8d2a4c8a);

    // round 3
    a = md5Round3(a, b, c, d, x[5],   4, 0xfffa3942);
    d = md5Round3(d, a, b, c, x[8],  11, 0x8771f681);
    c = md5Round3(c, d, a, b, x[11], 16, 0x6d9d6122);
    b = md5Round3(b, c, d, a, x[14], 23, 0xfde5380c);
    a = md5Round3(a, b, c, d, x[1],   4, 0xa4beea44);
    d = md5Round3(d, a, b, c, x[4],  11, 0x4bdecfa9);
    c = md5Round3(c, d, a, b, x[7],  16, 0xf6bb4b60);
    b = md5Round3(b, c, d, a, x[10], 23, 0xbebfbc70);
    a = md5Round3(a, b, c, d, x[13],  4, 0x289b7ec6);
    d = md5Round3(d, a, b, c, x[0],  11, 0xeaa127fa);
    c = md5Round3(c, d, a, b, x[3],  16, 0xd4ef3085);
    b = md5Round3(b, c, d, a, x[6],  23, 0x04881d05);
    a = md5Round3(a, b, c, d, x[9],   4, 0xd9d4d039);
    d = md5Round3(d, a, b, c, x[12], 11, 0xe6db99e5);
    c = md5Round3(c, d, a, b, x[15], 16, 0x1fa27cf8);
    b = md5Round3(b, c, d, a, x[2],  23, 0xc4ac5665);

    // round 4
    a = md5Round4(a, b, c, d, x[0],   6, 0xf4292244);
    d = md5Round4(d, a, b, c, x[7],  10, 0x432aff97);
    c = md5Round4(c, d, a, b, x[14], 15, 0xab9423a7);
    b = md5Round4(b, c, d, a, x[5],  21, 0xfc93a039);
    a = md5Round4(a, b, c, d, x[12],  6, 0x655b59c3);
    d = md5Round4(d, a, b, c, x[3],  10, 0x8f0ccc92);
    c = md5Round4(c, d, a, b, x[10], 15, 0xffeff47d);
    b = md5Round4(b, c, d, a, x[1],  21, 0x85845dd1);
    a = md5Round4(a, b, c, d, x[8],   6, 0x6fa87e4f);
    d = md5Round4(d, a, b, c, x[15], 10, 0xfe2ce6e0);
    c = md5Round4(c, d, a, b, x[6],  15, 0xa3014314);
    b = md5Round4(b, c, d, a, x[13], 21, 0x4e0811a1);
    a = md5Round4(a, b, c, d, x[4],   6, 0xf7537e82);
    d = md5Round4(d, a, b, c, x[11], 10, 0xbd3af235);
    c = md5Round4(c, d, a, b, x[2],  15, 0x2ad7d2bb);
    b = md5Round4(b, c, d, a, x[9],  21, 0xeb86d391);

    // increment a, b, c, d
    a += aa;
    b += bb;
    c += cc;
    d += dd;
  }

  // break digest into bytes
  digest[0] = (Guchar)(a & 0xff);
  digest[1] = (Guchar)((a >>= 8) & 0xff);
  digest[2] = (Guchar)((a >>= 8) & 0xff);
  digest[3] = (Guchar)((a >>= 8) & 0xff);
  digest[4] = (Guchar)(b & 0xff);
  digest[5] = (Guchar)((b >>= 8) & 0xff);
  digest[6] = (Guchar)((b >>= 8) & 0xff);
  digest[7] = (Guchar)((b >>= 8) & 0xff);
  digest[8] = (Guchar)(c & 0xff);
  digest[9] = (Guchar)((c >>= 8) & 0xff);
  digest[10] = (Guchar)((c >>= 8) & 0xff);
  digest[11] = (Guchar)((c >>= 8) & 0xff);
  digest[12] = (Guchar)(d & 0xff);
  digest[13] = (Guchar)((d >>= 8) & 0xff);
  digest[14] = (Guchar)((d >>= 8) & 0xff);
  digest[15] = (Guchar)((d >>= 8) & 0xff);
}

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static Gulong md5Round1 ( Gulong  a,
Gulong  b,
Gulong  c,
Gulong  d,
Gulong  Xk,
Gulong  s,
Gulong  Ti 
) [inline, static]

Definition at line 239 of file Decrypt.cc.

                                                             {
  return b + rotateLeft((a + ((b & c) | (~b & d)) + Xk + Ti), s);
}

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static Gulong md5Round2 ( Gulong  a,
Gulong  b,
Gulong  c,
Gulong  d,
Gulong  Xk,
Gulong  s,
Gulong  Ti 
) [inline, static]

Definition at line 244 of file Decrypt.cc.

                                                             {
  return b + rotateLeft((a + ((b & d) | (c & ~d)) + Xk + Ti), s);
}

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static Gulong md5Round3 ( Gulong  a,
Gulong  b,
Gulong  c,
Gulong  d,
Gulong  Xk,
Gulong  s,
Gulong  Ti 
) [inline, static]

Definition at line 249 of file Decrypt.cc.

                                                             {
  return b + rotateLeft((a + (b ^ c ^ d) + Xk + Ti), s);
}

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static Gulong md5Round4 ( Gulong  a,
Gulong  b,
Gulong  c,
Gulong  d,
Gulong  Xk,
Gulong  s,
Gulong  Ti 
) [inline, static]

Definition at line 254 of file Decrypt.cc.

                                                             {
  return b + rotateLeft((a + (c ^ (b | ~d)) + Xk + Ti), s);
}

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static Guchar rc4DecryptByte ( Guchar state,
Guchar x,
Guchar y,
Guchar  c 
) [static]

Definition at line 217 of file Decrypt.cc.

                                                                            {
  Guchar x1, y1, tx, ty;

  x1 = *x = (*x + 1) % 256;
  y1 = *y = (state[*x] + *y) % 256;
  tx = state[x1];
  ty = state[y1];
  state[x1] = ty;
  state[y1] = tx;
  return c ^ state[(tx + ty) % 256];
}

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static void rc4InitKey ( Guchar key,
int  keyLen,
Guchar state 
) [static]

Definition at line 200 of file Decrypt.cc.

                                                               {
  Guchar index1, index2;
  Guchar t;
  int i;

  for (i = 0; i < 256; ++i)
    state[i] = i;
  index1 = index2 = 0;
  for (i = 0; i < 256; ++i) {
    index2 = (key[index1] + state[i] + index2) % 256;
    t = state[i];
    state[i] = state[index2];
    state[index2] = t;
    index1 = (index1 + 1) % keyLen;
  }
}

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static Gulong rotateLeft ( Gulong  x,
int  r 
) [inline, static]

Definition at line 234 of file Decrypt.cc.

                                                 {
  x &= 0xffffffff;
  return ((x << r) | (x >> (32 - r))) & 0xffffffff;
}

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Variable Documentation

Guchar passwordPad[32] [static]
Initial value:
 {
  0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41,
  0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08, 
  0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80, 
  0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a
}

Definition at line 22 of file Decrypt.cc.