56 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			56 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include <tommath_private.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, tstdenis82@gmail.com, http://libtom.org
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|  */
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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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| 
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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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| 
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|    /* zero the int */
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|    mp_zero(a);
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| 
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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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| 
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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++ >> 7) & 1u);
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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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| 
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| /* ref:         $Format:%D$ */
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| /* git commit:  $Format:%H$ */
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| /* commit time: $Format:%ai$ */
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