Botan::GF2m_Field Class Reference

#include <gf2m_small_m.h>

Public Member Functions
gf2m	get_cardinality () const
gf2m	get_extension_degree () const
	GF2m_Field (size_t extdeg)
gf2m	gf_div (gf2m x, gf2m y) const
gf2m	gf_div_nrr (gf2m a, gf2m b) const
gf2m	gf_div_rnn (gf2m x, gf2m y) const
gf2m	gf_div_rnr (gf2m x, gf2m b) const
gf2m	gf_div_zzr (gf2m x, gf2m b) const
gf2m	gf_exp (gf2m i) const
gf2m	gf_inv (gf2m x) const
gf2m	gf_inv_rn (gf2m x) const
gf2m	gf_l_from_n (gf2m x) const
gf2m	gf_log (gf2m i) const
gf2m	gf_mul (gf2m x, gf2m y) const
gf2m	gf_mul_fast (gf2m x, gf2m y) const
gf2m	gf_mul_lll (gf2m a, gf2m b) const
gf2m	gf_mul_lnn (gf2m x, gf2m y) const
gf2m	gf_mul_nnr (gf2m y, gf2m a) const
gf2m	gf_mul_nrn (gf2m a, gf2m y) const
gf2m	gf_mul_nrr (gf2m a, gf2m b) const
gf2m	gf_mul_rnn (gf2m x, gf2m y) const
gf2m	gf_mul_rnr (gf2m y, gf2m a) const
gf2m	gf_mul_rrn (gf2m a, gf2m y) const
gf2m	gf_mul_rrr (gf2m a, gf2m b) const
gf2m	gf_mul_zrz (gf2m a, gf2m y) const
gf2m	gf_mul_zzr (gf2m a, gf2m y) const
gf2m	gf_ord () const
gf2m	gf_pow (gf2m x, int i) const
gf2m	gf_sqrt (gf2m x) const
gf2m	gf_square (gf2m x) const
gf2m	gf_square_ln (gf2m x) const
gf2m	gf_square_rr (gf2m a) const
gf2m	square_rr (gf2m x) const

Detailed Description

GF(2^m) field for m = [2...16]

Definition at line 25 of file gf2m_small_m.h.

Constructor & Destructor Documentation

GF2m_Field()

Botan::GF2m_Field::GF2m_Field ( size_t  extdeg )

explicit

Definition at line 112 of file gf2m_small_m.cpp.

                                    : m_gf_extension_degree(extdeg),
                                        m_gf_multiplicative_order((1 << extdeg) - 1),
                                        m_gf_log_table(log_table(m_gf_extension_degree)),
                                        m_gf_exp_table(exp_table(m_gf_extension_degree))
   {
   }

Member Function Documentation

get_cardinality()

gf2m Botan::GF2m_Field::get_cardinality ( ) const

inline

Definition at line 193 of file gf2m_small_m.h.

         {
         return static_cast<gf2m>(1 << get_extension_degree());
         }

get_extension_degree()

gf2m Botan::GF2m_Field::get_extension_degree ( ) const

inline

Definition at line 188 of file gf2m_small_m.h.

Referenced by gf_pow().

         {
         return m_gf_extension_degree;
         }

gf_div()

gf2m Botan::GF2m_Field::gf_div	(	gf2m	x,
		gf2m	y
	)		const

Definition at line 119 of file gf2m_small_m.cpp.

References gf_exp(), and gf_log().

   {
   const int32_t sub_res = static_cast<int32_t>(gf_log(x) - static_cast<int32_t>(gf_log(y)));
   const int32_t modq_res = static_cast<int32_t>(_gf_modq_1(sub_res));
   const int32_t div_res = static_cast<int32_t>(x) ? static_cast<int32_t>(gf_exp(modq_res)) : 0;
   return static_cast<gf2m>(div_res);
   }

gf_div_nrr()

gf2m Botan::GF2m_Field::gf_div_nrr ( gf2m  a, gf2m  b  ) const

inline

Definition at line 134 of file gf2m_small_m.h.

         {
         return gf_exp(_gf_modq_1(a - b));
         }

gf_div_rnn()

gf2m Botan::GF2m_Field::gf_div_rnn ( gf2m  x, gf2m  y  ) const

inline

Definition at line 124 of file gf2m_small_m.h.

         {
         return _gf_modq_1(gf_log(x) - gf_log(y));
         }

gf_div_rnr()

gf2m Botan::GF2m_Field::gf_div_rnr ( gf2m  x, gf2m  b  ) const

inline

Definition at line 129 of file gf2m_small_m.h.

         {
         return _gf_modq_1(gf_log(x) - b);
         }

gf_div_zzr()

gf2m Botan::GF2m_Field::gf_div_zzr ( gf2m  x, gf2m  b  ) const

inline

Definition at line 139 of file gf2m_small_m.h.

         {
         return ((x) ? gf_exp(_gf_modq_1(gf_log(x) - b)) : 0);
         }

gf_exp()

gf2m Botan::GF2m_Field::gf_exp ( gf2m  i ) const

inline

Definition at line 173 of file gf2m_small_m.h.

Referenced by gf_div(), and gf_pow().

         {
         return m_gf_exp_table.at(i); /* alpha^i */
         }

gf_inv()

gf2m Botan::GF2m_Field::gf_inv ( gf2m  x ) const

inline

Definition at line 144 of file gf2m_small_m.h.

         {
         return gf_exp(gf_ord() - gf_log(x));
         }

gf_inv_rn()

gf2m Botan::GF2m_Field::gf_inv_rn ( gf2m  x ) const

inline

Definition at line 149 of file gf2m_small_m.h.

         {
         return (gf_ord() - gf_log(x));
         }

gf_l_from_n()

gf2m Botan::GF2m_Field::gf_l_from_n ( gf2m  x ) const

inline

Definition at line 164 of file gf2m_small_m.h.

         {
         return gf_log(x);
         }

gf_log()

gf2m Botan::GF2m_Field::gf_log ( gf2m  i ) const

inline

Definition at line 178 of file gf2m_small_m.h.

Referenced by gf_div(), and gf_pow().

         {
         return m_gf_log_table.at(i); /* return i when x=alpha^i */
         }

gf_mul()

gf2m Botan::GF2m_Field::gf_mul ( gf2m  x, gf2m  y  ) const

inline

Definition at line 30 of file gf2m_small_m.h.

         {
         return ((x) ? gf_mul_fast(x, y) : 0);
         }

gf_mul_fast()

gf2m Botan::GF2m_Field::gf_mul_fast ( gf2m  x, gf2m  y  ) const

inline

Definition at line 45 of file gf2m_small_m.h.

         {
         return ((y) ? gf_exp(_gf_modq_1(gf_log(x) + gf_log(y))) : 0);
         }

gf_mul_lll()

gf2m Botan::GF2m_Field::gf_mul_lll ( gf2m  a, gf2m  b  ) const

inline

Definition at line 58 of file gf2m_small_m.h.

         {
         return (a + b);
         }

gf_mul_lnn()

gf2m Botan::GF2m_Field::gf_mul_lnn ( gf2m  x, gf2m  y  ) const

inline

Definition at line 83 of file gf2m_small_m.h.

         {
         return (gf_log(x) + gf_log(y));
         }

gf_mul_nnr()

gf2m Botan::GF2m_Field::gf_mul_nnr ( gf2m  y, gf2m  a  ) const

inline

non-zero operand

Definition at line 114 of file gf2m_small_m.h.

         {
         return gf_mul_nrn(a, y);
         }

gf_mul_nrn()

gf2m Botan::GF2m_Field::gf_mul_nrn ( gf2m  a, gf2m  y  ) const

inline

Definition at line 93 of file gf2m_small_m.h.

         {
         return gf_exp(_gf_modq_1((a) + gf_log(y)));
         }

gf_mul_nrr()

gf2m Botan::GF2m_Field::gf_mul_nrr ( gf2m  a, gf2m  b  ) const

inline

Definition at line 68 of file gf2m_small_m.h.

         {
         return (gf_exp(gf_mul_rrr(a, b)));
         }

gf_mul_rnn()

gf2m Botan::GF2m_Field::gf_mul_rnn ( gf2m  x, gf2m  y  ) const

inline

Definition at line 88 of file gf2m_small_m.h.

         {
         return _gf_modq_1(gf_mul_lnn(x, y));
         }

gf_mul_rnr()

gf2m Botan::GF2m_Field::gf_mul_rnr ( gf2m  y, gf2m  a  ) const

inline

Definition at line 78 of file gf2m_small_m.h.

         {
         return gf_mul_rrn(a, y);
         }

gf_mul_rrn()

gf2m Botan::GF2m_Field::gf_mul_rrn ( gf2m  a, gf2m  y  ) const

inline

Definition at line 73 of file gf2m_small_m.h.

         {
         return _gf_modq_1(gf_mul_lll(a, gf_log(y)));
         }

gf_mul_rrr()

gf2m Botan::GF2m_Field::gf_mul_rrr ( gf2m  a, gf2m  b  ) const

inline

Definition at line 63 of file gf2m_small_m.h.

         {
         return (_gf_modq_1(gf_mul_lll(a, b)));
         }

gf_mul_zrz()

gf2m Botan::GF2m_Field::gf_mul_zrz ( gf2m  a, gf2m  y  ) const

inline

zero operand allowed

Definition at line 101 of file gf2m_small_m.h.

         {
         return ( (y == 0) ? 0 : gf_mul_nrn(a, y) );
         }

gf_mul_zzr()

gf2m Botan::GF2m_Field::gf_mul_zzr ( gf2m  a, gf2m  y  ) const

inline

Definition at line 106 of file gf2m_small_m.h.

         {
         return gf_mul_zrz(y, a);
         }

gf_ord()

gf2m Botan::GF2m_Field::gf_ord ( ) const

inline

Definition at line 183 of file gf2m_small_m.h.

Referenced by gf_pow().

         {
         return m_gf_multiplicative_order;
         }

gf_pow()

gf2m Botan::GF2m_Field::gf_pow	(	gf2m	x,
		int	i
	)		const

Definition at line 128 of file gf2m_small_m.cpp.

References get_extension_degree(), gf_exp(), gf_log(), and gf_ord().

   {
   if (i == 0)
      return 1;
   else if (x == 0)
      return 0;
   else
      {
      // i mod (q-1)
      while (i >> get_extension_degree())
         i = (i & (gf_ord())) + (i >> get_extension_degree());
      i *= gf_log(x);
      while (i >> get_extension_degree())
         i = (i & (gf_ord())) + (i >> get_extension_degree());
      return gf_exp(i);
      }
   }

gf_sqrt()

gf2m Botan::GF2m_Field::gf_sqrt ( gf2m  x ) const

inline

Definition at line 119 of file gf2m_small_m.h.

         {
         return ((x) ? gf_exp(_gf_modq_1(gf_log(x) << (get_extension_degree()-1))) : 0);
         }

gf_square()

gf2m Botan::GF2m_Field::gf_square ( gf2m  x ) const

inline

Definition at line 35 of file gf2m_small_m.h.

         {
         return ((x) ? gf_exp(_gf_modq_1(gf_log(x) << 1)) : 0);
         }

gf_square_ln()

gf2m Botan::GF2m_Field::gf_square_ln ( gf2m  x ) const

inline

Definition at line 154 of file gf2m_small_m.h.

         {
         return gf_log(x) << 1;
         }

gf_square_rr()

gf2m Botan::GF2m_Field::gf_square_rr ( gf2m  a ) const

inline

Definition at line 159 of file gf2m_small_m.h.

         {
         return a << 1;
         }

square_rr()

gf2m Botan::GF2m_Field::square_rr ( gf2m  x ) const

inline

Definition at line 40 of file gf2m_small_m.h.

         {
         return _gf_modq_1(x << 1);
         }

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The documentation for this class was generated from the following files:

• src/lib/pubkey/mce/gf2m_small_m.h
• src/lib/pubkey/mce/gf2m_small_m.cpp