Mercurial > dropbear
diff bn_mp_exptmod_fast.c @ 190:d8254fc979e9 libtommath-orig LTM_0.35
Initial import of libtommath 0.35
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Fri, 06 May 2005 08:59:30 +0000 |
parents | d29b64170cf0 |
children |
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--- a/bn_mp_exptmod_fast.c Sun Dec 19 11:33:56 2004 +0000 +++ b/bn_mp_exptmod_fast.c Fri May 06 08:59:30 2005 +0000 @@ -29,8 +29,7 @@ #define TAB_SIZE 256 #endif -int -mp_exptmod_fast (mp_int * G, mp_int * X, mp_int * P, mp_int * Y, int redmode) +int mp_exptmod_fast (mp_int * G, mp_int * X, mp_int * P, mp_int * Y, int redmode) { mp_int M[TAB_SIZE], res; mp_digit buf, mp; @@ -88,11 +87,11 @@ #ifdef BN_MP_MONTGOMERY_SETUP_C /* now setup montgomery */ if ((err = mp_montgomery_setup (P, &mp)) != MP_OKAY) { - goto __M; + goto LBL_M; } #else err = MP_VAL; - goto __M; + goto LBL_M; #endif /* automatically pick the comba one if available (saves quite a few calls/ifs) */ @@ -108,7 +107,7 @@ redux = mp_montgomery_reduce; #else err = MP_VAL; - goto __M; + goto LBL_M; #endif } } else if (redmode == 1) { @@ -118,24 +117,24 @@ redux = mp_dr_reduce; #else err = MP_VAL; - goto __M; + goto LBL_M; #endif } else { #if defined(BN_MP_REDUCE_2K_SETUP_C) && defined(BN_MP_REDUCE_2K_C) /* setup DR reduction for moduli of the form 2**k - b */ if ((err = mp_reduce_2k_setup(P, &mp)) != MP_OKAY) { - goto __M; + goto LBL_M; } redux = mp_reduce_2k; #else err = MP_VAL; - goto __M; + goto LBL_M; #endif } /* setup result */ if ((err = mp_init (&res)) != MP_OKAY) { - goto __M; + goto LBL_M; } /* create M table @@ -149,45 +148,45 @@ #ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C /* now we need R mod m */ if ((err = mp_montgomery_calc_normalization (&res, P)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } #else err = MP_VAL; - goto __RES; + goto LBL_RES; #endif /* now set M[1] to G * R mod m */ if ((err = mp_mulmod (G, &res, P, &M[1])) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } else { mp_set(&res, 1); if ((err = mp_mod(G, P, &M[1])) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } /* compute the value at M[1<<(winsize-1)] by squaring M[1] (winsize-1) times */ if ((err = mp_copy (&M[1], &M[1 << (winsize - 1)])) != MP_OKAY) { - goto __RES; + goto LBL_RES; } for (x = 0; x < (winsize - 1); x++) { if ((err = mp_sqr (&M[1 << (winsize - 1)], &M[1 << (winsize - 1)])) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&M[1 << (winsize - 1)], P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } /* create upper table */ for (x = (1 << (winsize - 1)) + 1; x < (1 << winsize); x++) { if ((err = mp_mul (&M[x - 1], &M[1], &M[x])) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&M[x], P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } @@ -227,10 +226,10 @@ /* if the bit is zero and mode == 1 then we square */ if (mode == 1 && y == 0) { if ((err = mp_sqr (&res, &res)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } continue; } @@ -244,19 +243,19 @@ /* square first */ for (x = 0; x < winsize; x++) { if ((err = mp_sqr (&res, &res)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } /* then multiply */ if ((err = mp_mul (&res, &M[bitbuf], &res)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } /* empty window and reset */ @@ -271,10 +270,10 @@ /* square then multiply if the bit is set */ for (x = 0; x < bitcpy; x++) { if ((err = mp_sqr (&res, &res)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } /* get next bit of the window */ @@ -282,10 +281,10 @@ if ((bitbuf & (1 << winsize)) != 0) { /* then multiply */ if ((err = mp_mul (&res, &M[1], &res)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } if ((err = redux (&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } } @@ -299,15 +298,15 @@ * of R. */ if ((err = redux(&res, P, mp)) != MP_OKAY) { - goto __RES; + goto LBL_RES; } } /* swap res with Y */ mp_exch (&res, Y); err = MP_OKAY; -__RES:mp_clear (&res); -__M: +LBL_RES:mp_clear (&res); +LBL_M: mp_clear(&M[1]); for (x = 1<<(winsize-1); x < (1 << winsize); x++) { mp_clear (&M[x]);