56 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			56 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#include <tommath.h>
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#ifdef BN_MP_READ_UNSIGNED_BIN_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis
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 *
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 * LibTomMath is a library that provides multiple-precision
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 * integer arithmetic as well as number theoretic functionality.
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 *
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 * The library was designed directly after the MPI library by
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 * Michael Fromberger but has been written from scratch with
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 * additional optimizations in place.
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 *
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 * The library is free for all purposes without any express
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 * guarantee it works.
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 *
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 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
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 */
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/* reads a unsigned char array, assumes the msb is stored first [big endian] */
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int mp_read_unsigned_bin (mp_int * a, const unsigned char *b, int c)
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{
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  int     res;
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  /* make sure there are at least two digits */
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  if (a->alloc < 2) {
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     if ((res = mp_grow(a, 2)) != MP_OKAY) {
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        return res;
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     }
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  }
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  /* zero the int */
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  mp_zero (a);
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  /* read the bytes in */
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  while (c-- > 0) {
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    if ((res = mp_mul_2d (a, 8, a)) != MP_OKAY) {
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      return res;
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    }
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#ifndef MP_8BIT
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      a->dp[0] |= *b++;
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      a->used += 1;
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#else
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      a->dp[0] = (*b & MP_MASK);
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      a->dp[1] |= ((*b++ >> 7U) & 1);
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      a->used += 2;
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#endif
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  }
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  mp_clamp (a);
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  return MP_OKAY;
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}
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#endif
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/* $Source: /cvs/libtom/libtommath/bn_mp_read_unsigned_bin.c,v $ */
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/* $Revision: 1.5 $ */
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/* $Date: 2006/12/28 01:25:13 $ */
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