72 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			72 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include <tommath_private.h>
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| #ifdef BN_MP_FREAD_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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| #ifndef LTM_NO_FILE
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| /* read a bigint from a file stream in ASCII */
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| int mp_fread(mp_int *a, int radix, FILE *stream)
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| {
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|    int err, ch, neg, y;
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|    unsigned pos;
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| 
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|    /* clear a */
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|    mp_zero(a);
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| 
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|    /* if first digit is - then set negative */
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|    ch = fgetc(stream);
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|    if (ch == (int)'-') {
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|       neg = MP_NEG;
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|       ch = fgetc(stream);
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|    } else {
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|       neg = MP_ZPOS;
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|    }
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| 
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|    for (;;) {
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|       pos = (unsigned)(ch - (int)'(');
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|       if (mp_s_rmap_reverse_sz < pos) {
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|          break;
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|       }
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| 
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|       y = (int)mp_s_rmap_reverse[pos];
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| 
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|       if ((y == 0xff) || (y >= radix)) {
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|          break;
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|       }
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| 
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|       /* shift up and add */
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|       if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {
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|          return err;
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|       }
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|       if ((err = mp_add_d(a, (mp_digit)y, a)) != MP_OKAY) {
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|          return err;
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|       }
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| 
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|       ch = fgetc(stream);
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|    }
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|    if (mp_cmp_d(a, 0uL) != MP_EQ) {
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|       a->sign = neg;
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|    }
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| 
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|    return MP_OKAY;
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| }
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| #endif
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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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