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iof-bird-daemon / lib / md5.c @ 18c8241a

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/*
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 * This code implements the MD5 message-digest algorithm.
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 * The algorithm is due to Ron Rivest.  This code was
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 * written by Colin Plumb in 1993, no copyright is claimed.
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 * This code is in the public domain; do with it what you wish.
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 *
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 * Equivalent code is available from RSA Data Security, Inc.
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 * This code has been tested against that, and is equivalent,
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 * except that you don't need to include two pages of legalese
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 * with every copy.
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 *
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 * To compute the message digest of a chunk of bytes, declare an
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 * MD5Context structure, pass it to MD5Init, call MD5Update as
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 * needed on buffers full of bytes, and then call MD5Final, which
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 * will fill a supplied 16-byte array with the digest.
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 */
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/*
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 * Adapted for BIRD by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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 */
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#include <string.h>                /* for memcpy() */
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#include "nest/bird.h"
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#include "md5.h"
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#ifdef CPU_LITTLE_ENDIAN
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#define byteReverse(buf, len)        /* Nothing */
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#else
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void byteReverse(unsigned char *buf, unsigned longs);
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/*
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 * Note: this code is harmless on little-endian machines.
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 */
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void byteReverse(unsigned char *buf, unsigned longs)
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{
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    u32 t;
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    do {
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        t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
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            ((unsigned) buf[1] << 8 | buf[0]);
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        *(u32 *) buf = t;
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        buf += 4;
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    } while (--longs);
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}
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#endif
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/*
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 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
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 * initialization constants.
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 */
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void MD5Init(struct MD5Context *ctx)
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{
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    ctx->buf[0] = 0x67452301;
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    ctx->buf[1] = 0xefcdab89;
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    ctx->buf[2] = 0x98badcfe;
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    ctx->buf[3] = 0x10325476;
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    ctx->bits[0] = 0;
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    ctx->bits[1] = 0;
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}
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/*
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 * Update context to reflect the concatenation of another buffer full
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 * of bytes.
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 */
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void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
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{
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    u32 t;
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    /* Update bitcount */
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    t = ctx->bits[0];
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    if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
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        ctx->bits[1]++;                /* Carry from low to high */
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    ctx->bits[1] += len >> 29;
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    t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
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    /* Handle any leading odd-sized chunks */
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    if (t) {
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        unsigned char *p = (unsigned char *) ctx->in + t;
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        t = 64 - t;
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        if (len < t) {
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            memcpy(p, buf, len);
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            return;
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        }
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        memcpy(p, buf, t);
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        byteReverse(ctx->in, 16);
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        MD5Transform(ctx->buf, (u32 *) ctx->in);
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        buf += t;
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        len -= t;
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    }
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    /* Process data in 64-byte chunks */
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    while (len >= 64) {
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        memcpy(ctx->in, buf, 64);
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        byteReverse(ctx->in, 16);
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        MD5Transform(ctx->buf, (u32 *) ctx->in);
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        buf += 64;
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        len -= 64;
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    }
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    /* Handle any remaining bytes of data. */
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    memcpy(ctx->in, buf, len);
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}
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/*
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 * Final wrapup - pad to 64-byte boundary with the bit pattern 
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 * 1 0* (64-bit count of bits processed, MSB-first)
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 */
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void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
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{
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    unsigned count;
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    unsigned char *p;
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    /* Compute number of bytes mod 64 */
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    count = (ctx->bits[0] >> 3) & 0x3F;
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    /* Set the first char of padding to 0x80.  This is safe since there is
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       always at least one byte free */
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    p = ctx->in + count;
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    *p++ = 0x80;
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    /* Bytes of padding needed to make 64 bytes */
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    count = 64 - 1 - count;
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    /* Pad out to 56 mod 64 */
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    if (count < 8) {
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        /* Two lots of padding:  Pad the first block to 64 bytes */
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        memset(p, 0, count);
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        byteReverse(ctx->in, 16);
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        MD5Transform(ctx->buf, (u32 *) ctx->in);
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        /* Now fill the next block with 56 bytes */
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        memset(ctx->in, 0, 56);
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    } else {
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        /* Pad block to 56 bytes */
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        memset(p, 0, count - 8);
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    }
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    byteReverse(ctx->in, 14);
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    /* Append length in bits and transform */
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    ((u32 *) ctx->in)[14] = ctx->bits[0];
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    ((u32 *) ctx->in)[15] = ctx->bits[1];
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    MD5Transform(ctx->buf, (u32 *) ctx->in);
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    byteReverse((unsigned char *) ctx->buf, 4);
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    memcpy(digest, ctx->buf, 16);
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    memset((char *) ctx, 0, sizeof(ctx));        /* In case it's sensitive */
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}
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/* The four core functions - F1 is optimized somewhat */
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/* #define F1(x, y, z) (x & y | ~x & z) */
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#define F1(x, y, z) (z ^ (x & (y ^ z)))
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#define F2(x, y, z) F1(z, x, y)
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#define F3(x, y, z) (x ^ y ^ z)
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#define F4(x, y, z) (y ^ (x | ~z))
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/* This is the central step in the MD5 algorithm. */
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#define MD5STEP(f, w, x, y, z, data, s) \
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        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
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/*
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 * The core of the MD5 algorithm, this alters an existing MD5 hash to
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 * reflect the addition of 16 longwords of new data.  MD5Update blocks
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 * the data and converts bytes into longwords for this routine.
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 */
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void MD5Transform(u32 buf[4], u32 const in[16])
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{
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    register u32 a, b, c, d;
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    a = buf[0];
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    b = buf[1];
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    c = buf[2];
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    d = buf[3];
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    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
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    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
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    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
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    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
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    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
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    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
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    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
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    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
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    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
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    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
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    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
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    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
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    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
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    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
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    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
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    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
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    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
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    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
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    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
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    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
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    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
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    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
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    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
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    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
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    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
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    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
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    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
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    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
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    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
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    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
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    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
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    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
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    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
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    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
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    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
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    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
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    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
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    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
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    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
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    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
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    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
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    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
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    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
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    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
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    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
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    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
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    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
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    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
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    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
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    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
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    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
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    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
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    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
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    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
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    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
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    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
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    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
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    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
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    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
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    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
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    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
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    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
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    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
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    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
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    buf[0] += a;
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    buf[1] += b;
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    buf[2] += c;
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    buf[3] += d;
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}