text: 
  /*
   * This code implements the MD5 message-digest algorithm.
   * The algorithm is due to Ron Rivest.  This code was
   * written by Colin Plumb in 1993, no copyright is claimed.
   * This code is in the public domain; do with it what you wish.
   *
   * Equivalent code is available from RSA Data Security, Inc.
   * This code has been tested against that, and is equivalent,
   * except that you don't need to include two pages of legalese
   * with every copy.
   *
   * To compute the message digest of a chunk of bytes, declare an
   * MD5Context structure, pass it to MD5Init, call MD5Update as
   * needed on buffers full of bytes, and then call MD5Final, which
   * will fill a supplied 16-byte array with the digest.
   *
   * Changed so as no longer to depend on Colin Plumb's `usual.h' header
   * definitions; now uses stuff from dpkg's config.h.
   *  - Ian Jackson <ian@chiark.greenend.org.uk>.
   * Still in the public domain.
   */
  
  #ifndef __GPUTK_MD5_H__
  #define __GPUTK_MD5_H__
  
  #include <string.h>    /* for memcpy() */
  #include <sys/types.h> /* for stupid systems */
  
  #define UWORD32 unsigned int
  
  #define md5byte unsigned char
  
  struct MD5Context {
    UWORD32 buf[4];
    UWORD32 bytes[2];
    UWORD32 in[16];
  };
  
  static void MD5Transform(UWORD32 buf[4], UWORD32 const in[16]);
  
  static int g_bigEndian         = 0;
  static int g_endianessDetected = 0;
  
  static void detectEndianess() {
    int nl   = 0x12345678;
    short ns = 0x1234;
  
    unsigned char *p  = (unsigned char *)(&nl);
    unsigned char *sp = (unsigned char *)(&ns);
  
    if (g_endianessDetected)
      return;
    if (p[0] == 0x12 && p[1] == 0x34 && p[2] == 0x56 && p[3] == 0x78) {
      g_bigEndian = 1;
    } else if (p[0] == 0x78 && p[1] == 0x56 && p[2] == 0x34 &&
               p[3] == 0x12) {
      g_bigEndian = 0;
    } else {
      g_bigEndian = *sp != 0x12;
    }
  
    g_endianessDetected = 1;
  }
  
  static void byteSwap(UWORD32 *buf, unsigned words) {
    md5byte *p;
  
    if (!g_bigEndian)
      return;
  
    p = (md5byte *)buf;
  
    do {
      *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
               ((unsigned)p[1] << 8 | p[0]);
      p += 4;
    } while (--words);
  }
  
  /*
   * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
   * initialization constants.
   */
  static void MD5Init(struct MD5Context *ctx) {
    detectEndianess();
  
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;
  
    ctx->bytes[0] = 0;
    ctx->bytes[1] = 0;
  }
  
  /*
   * Update context to reflect the concatenation of another buffer full
   * of bytes.
   */
  static void MD5Update(struct MD5Context *ctx, md5byte const *buf,
                        unsigned len) {
    UWORD32 t;
  
    /* Update byte count */
  
    t = ctx->bytes[0];
    if ((ctx->bytes[0] = t + len) < t)
      ctx->bytes[1]++; /* Carry from low to high */
  
    t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
    if (t > len) {
      memcpy((md5byte *)ctx->in + 64 - t, buf, len);
      return;
    }
    /* First chunk is an odd size */
    memcpy((md5byte *)ctx->in + 64 - t, buf, t);
    byteSwap(ctx->in, 16);
    MD5Transform(ctx->buf, ctx->in);
    buf += t;
    len -= t;
  
    /* Process data in 64-byte chunks */
    while (len >= 64) {
      memcpy(ctx->in, buf, 64);
      byteSwap(ctx->in, 16);
      MD5Transform(ctx->buf, ctx->in);
      buf += 64;
      len -= 64;
    }
  
    /* Handle any remaining bytes of data. */
    memcpy(ctx->in, buf, len);
  }
  
  /*
   * Final wrapup - pad to 64-byte boundary with the bit pattern
   * 1 0* (64-bit count of bits processed, MSB-first)
   */
  static void MD5Final(md5byte digest[16], struct MD5Context *ctx) {
    int count  = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
    md5byte *p = (md5byte *)ctx->in + count;
  
    /* Set the first char of padding to 0x80.  There is always room. */
    *p++ = 0x80;
  
    /* Bytes of padding needed to make 56 bytes (-8..55) */
    count = 56 - 1 - count;
  
    if (count < 0) { /* Padding forces an extra block */
      memset(p, 0, count + 8);
      byteSwap(ctx->in, 16);
      MD5Transform(ctx->buf, ctx->in);
      p     = (md5byte *)ctx->in;
      count = 56;
    }
    memset(p, 0, count);
    byteSwap(ctx->in, 14);
  
    /* Append length in bits and transform */
    ctx->in[14] = ctx->bytes[0] << 3;
    ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
    MD5Transform(ctx->buf, ctx->in);
  
    byteSwap(ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset(&ctx, 0, sizeof(ctx)); /* In case it's sensitive */
  }
  
  #ifndef ASM_MD5
  
  /* The four core functions - F1 is optimized somewhat */
  
  /* #define F1(x, y, z) (x & y | ~x & z) */
  #define F1(x, y, z) (z ^ (x & (y ^ z)))
  #define F2(x, y, z) F1(z, x, y)
  #define F3(x, y, z) (x ^ y ^ z)
  #define F4(x, y, z) (y ^ (x | ~z))
  
  /* This is the central step in the MD5 algorithm. */
  #define MD5STEP(f, w, x, y, z, in, s)                                     \
    (w += f(x, y, z) + in, w = (w << s | w >> (32 - s)) + x)
  
  /*
   * The core of the MD5 algorithm, this alters an existing MD5 hash to
   * reflect the addition of 16 longwords of new data.  MD5Update blocks
   * the data and converts bytes into longwords for this routine.
   */
  static void MD5Transform(UWORD32 buf[4], UWORD32 const in[16]) {
    UWORD32 a, b, c, d;
  
    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];
  
    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
  
    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
  
    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
  
    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
  
    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
  }
  
  #endif
  
  static void MD5_buffer(const unsigned char *buf, unsigned int len,
                         unsigned char sig[16]) {
    struct MD5Context md5;
    MD5Init(&md5);
    MD5Update(&md5, buf, len);
    MD5Final(sig, &md5);
  }
  
  #define gpuTKMD5 MD5_buffer
  
  #define HEX_STRING "0123456789abcdef" /* to convert to hex */
  
  static void gpuTKMD5_sigToString(unsigned char signature[16], char *str,
                                int len) {
    unsigned char *sig_p;
    char *str_p, *max_p;
    unsigned int high, low;
  
    str_p = str;
    max_p = str + len;
  
    for (sig_p = (unsigned char *)signature;
         sig_p < (unsigned char *)signature + 16; sig_p++) {
      high = *sig_p / 16;
      low  = *sig_p % 16;
      /* account for 2 chars */
      if (str_p + 1 >= max_p) {
        break;
      }
      *str_p++ = HEX_STRING[high];
      *str_p++ = HEX_STRING[low];
    }
    /* account for 2 chars */
    if (str_p < max_p) {
      *str_p++ = '\0';
    }
  }
  
  #endif /* __GPUTK_MD5_H__ */
  