The Tor Browser: security/nss/lib/freebl/ecl/ecl

security/nss/lib/freebl/ecl/ecl_gf.c@6474c204b198 (annotated)

security/nss/lib/freebl/ecl/ecl_gf.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "mpi.h"
 #include "mp_gf2m.h"
 #include "ecl-priv.h"
 #include "mpi-priv.h"
 #include <stdlib.h>
 /* Allocate memory for a new GFMethod object. */
 GFMethod *
 GFMethod_new()
 {
 	mp_err res = MP_OKAY;
 	GFMethod *meth;
 	meth = (GFMethod *) malloc(sizeof(GFMethod));
 	if (meth == NULL)
 		return NULL;
 	meth->constructed = MP_YES;
 	MP_DIGITS(&meth->irr) = 0;
 	meth->extra_free = NULL;
 	MP_CHECKOK(mp_init(&meth->irr));
   CLEANUP:
 	if (res != MP_OKAY) {
 		GFMethod_free(meth);
 		return NULL;
 	}
 	return meth;
 }
 /* Construct a generic GFMethod for arithmetic over prime fields with
  * irreducible irr. */
 GFMethod *
 GFMethod_consGFp(const mp_int *irr)
 {
 	mp_err res = MP_OKAY;
 	GFMethod *meth = NULL;
 	meth = GFMethod_new();
 	if (meth == NULL)
 		return NULL;
 	MP_CHECKOK(mp_copy(irr, &meth->irr));
 	meth->irr_arr[0] = mpl_significant_bits(irr);
 	meth->irr_arr[1] = meth->irr_arr[2] = meth->irr_arr[3] =
 		meth->irr_arr[4] = 0;
 	switch(MP_USED(&meth->irr)) {
 	/* maybe we need 1 and 2 words here as well?*/
 	case 3:
 		meth->field_add = &ec_GFp_add_3;
 		meth->field_sub = &ec_GFp_sub_3;
 		break;
 	case 4:
 		meth->field_add = &ec_GFp_add_4;
 		meth->field_sub = &ec_GFp_sub_4;
 		break;
 	case 5:
 		meth->field_add = &ec_GFp_add_5;
 		meth->field_sub = &ec_GFp_sub_5;
 		break;
 	case 6:
 		meth->field_add = &ec_GFp_add_6;
 		meth->field_sub = &ec_GFp_sub_6;
 		break;
 	default:
 		meth->field_add = &ec_GFp_add;
 		meth->field_sub = &ec_GFp_sub;
 	}
 	meth->field_neg = &ec_GFp_neg;
 	meth->field_mod = &ec_GFp_mod;
 	meth->field_mul = &ec_GFp_mul;
 	meth->field_sqr = &ec_GFp_sqr;
 	meth->field_div = &ec_GFp_div;
 	meth->field_enc = NULL;
 	meth->field_dec = NULL;
 	meth->extra1 = NULL;
 	meth->extra2 = NULL;
 	meth->extra_free = NULL;
   CLEANUP:
 	if (res != MP_OKAY) {
 		GFMethod_free(meth);
 		return NULL;
 	}
 	return meth;
 }
 /* Construct a generic GFMethod for arithmetic over binary polynomial
  * fields with irreducible irr that has array representation irr_arr (see
  * ecl-priv.h for description of the representation).  If irr_arr is NULL,
  * then it is constructed from the bitstring representation. */
 GFMethod *
 GFMethod_consGF2m(const mp_int *irr, const unsigned int irr_arr[5])
 {
 	mp_err res = MP_OKAY;
 	int ret;
 	GFMethod *meth = NULL;
 	meth = GFMethod_new();
 	if (meth == NULL)
 		return NULL;
 	MP_CHECKOK(mp_copy(irr, &meth->irr));
 	if (irr_arr != NULL) {
 		/* Irreducible polynomials are either trinomials or pentanomials. */
 		meth->irr_arr[0] = irr_arr[0];
 		meth->irr_arr[1] = irr_arr[1];
 		meth->irr_arr[2] = irr_arr[2];
 		if (irr_arr[2] > 0) {
 			meth->irr_arr[3] = irr_arr[3];
 			meth->irr_arr[4] = irr_arr[4];
 		} else {
 			meth->irr_arr[3] = meth->irr_arr[4] = 0;
 		}
 	} else {
 		ret = mp_bpoly2arr(irr, meth->irr_arr, 5);
 		/* Irreducible polynomials are either trinomials or pentanomials. */
 		if ((ret != 5) && (ret != 3)) {
 			res = MP_UNDEF;
 			goto CLEANUP;
 		}
 	}
 	meth->field_add = &ec_GF2m_add;
 	meth->field_neg = &ec_GF2m_neg;
 	meth->field_sub = &ec_GF2m_add;
 	meth->field_mod = &ec_GF2m_mod;
 	meth->field_mul = &ec_GF2m_mul;
 	meth->field_sqr = &ec_GF2m_sqr;
 	meth->field_div = &ec_GF2m_div;
 	meth->field_enc = NULL;
 	meth->field_dec = NULL;
 	meth->extra1 = NULL;
 	meth->extra2 = NULL;
 	meth->extra_free = NULL;
   CLEANUP:
 	if (res != MP_OKAY) {
 		GFMethod_free(meth);
 		return NULL;
 	}
 	return meth;
 }
 /* Free the memory allocated (if any) to a GFMethod object. */
 void
 GFMethod_free(GFMethod *meth)
 {
 	if (meth == NULL)
 		return;
 	if (meth->constructed == MP_NO)
 		return;
 	mp_clear(&meth->irr);
 	if (meth->extra_free != NULL)
 		meth->extra_free(meth);
 	free(meth);
 }
 /* Wrapper functions for generic prime field arithmetic. */
 /* Add two field elements.  Assumes that 0 <= a, b < meth->irr */
 mp_err
 ec_GFp_add(const mp_int *a, const mp_int *b, mp_int *r,
 		   const GFMethod *meth)
 {
 	/* PRE: 0 <= a, b < p = meth->irr POST: 0 <= r < p, r = a + b (mod p) */
 	mp_err res;
 	if ((res = mp_add(a, b, r)) != MP_OKAY) {
 		return res;
 	}
 	if (mp_cmp(r, &meth->irr) >= 0) {
 		return mp_sub(r, &meth->irr, r);
 	}
 	return res;
 }
 /* Negates a field element.  Assumes that 0 <= a < meth->irr */
 mp_err
 ec_GFp_neg(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	/* PRE: 0 <= a < p = meth->irr POST: 0 <= r < p, r = -a (mod p) */
 	if (mp_cmp_z(a) == 0) {
 		mp_zero(r);
 		return MP_OKAY;
 	}
 	return mp_sub(&meth->irr, a, r);
 }
 /* Subtracts two field elements.  Assumes that 0 <= a, b < meth->irr */
 mp_err
 ec_GFp_sub(const mp_int *a, const mp_int *b, mp_int *r,
 		   const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	/* PRE: 0 <= a, b < p = meth->irr POST: 0 <= r < p, r = a - b (mod p) */
 	res = mp_sub(a, b, r);
 	if (res == MP_RANGE) {
 		MP_CHECKOK(mp_sub(b, a, r));
 		if (mp_cmp_z(r) < 0) {
 			MP_CHECKOK(mp_add(r, &meth->irr, r));
 		}
 		MP_CHECKOK(ec_GFp_neg(r, r, meth));
 	}
 	if (mp_cmp_z(r) < 0) {
 		MP_CHECKOK(mp_add(r, &meth->irr, r));
 	}
   CLEANUP:
 	return res;
 }
 /*
  * Inline adds for small curve lengths.
  */
 /* 3 words */
 mp_err
 ec_GFp_add_3(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit a0 = 0, a1 = 0, a2 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0;
 	mp_digit carry;
 	switch(MP_USED(a)) {
 	case 3:
 		a2 = MP_DIGIT(a,2);
 	case 2:
 		a1 = MP_DIGIT(a,1);
 	case 1:
 		a0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 3:
 		r2 = MP_DIGIT(b,2);
 	case 2:
 		r1 = MP_DIGIT(b,1);
 	case 1:
 		r0 = MP_DIGIT(b,0);
 	}
 #ifndef MPI_AMD64_ADD
 	MP_ADD_CARRY(a0, r0, r0, 0,     carry);
 	MP_ADD_CARRY(a1, r1, r1, carry, carry);
 	MP_ADD_CARRY(a2, r2, r2, carry, carry);
 #else
 	__asm__ (
                 "xorq   %3,%3           \n\t"
                 "addq   %4,%0           \n\t"
                 "adcq   %5,%1           \n\t"
                 "adcq   %6,%2           \n\t"
                 "adcq   $0,%3           \n\t"
                 : "=r"(r0), "=r"(r1), "=r"(r2), "=r"(carry)
                 : "r" (a0), "r" (a1), "r" (a2),
 		  "0" (r0), "1" (r1), "2" (r2)
                 : "%cc" );
 #endif
 	MP_CHECKOK(s_mp_pad(r, 3));
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 3;
 	/* Do quick 'subract' if we've gone over
 	 * (add the 2's complement of the curve field) */
 	 a2 = MP_DIGIT(&meth->irr,2);
 	if (carry ||  r2 >  a2 ||
 		((r2 == a2) && mp_cmp(r,&meth->irr) != MP_LT)) {
 		a1 = MP_DIGIT(&meth->irr,1);
 		a0 = MP_DIGIT(&meth->irr,0);
 #ifndef MPI_AMD64_ADD
 		MP_SUB_BORROW(r0, a0, r0, 0,     carry);
 		MP_SUB_BORROW(r1, a1, r1, carry, carry);
 		MP_SUB_BORROW(r2, a2, r2, carry, carry);
 #else
 		__asm__ (
 			"subq   %3,%0           \n\t"
 			"sbbq   %4,%1           \n\t"
 			"sbbq   %5,%2           \n\t"
 			: "=r"(r0), "=r"(r1), "=r"(r2)
 			: "r" (a0), "r" (a1), "r" (a2),
 			  "0" (r0), "1" (r1), "2" (r2)
 			: "%cc" );
 #endif
 		MP_DIGIT(r, 2) = r2;
 		MP_DIGIT(r, 1) = r1;
 		MP_DIGIT(r, 0) = r0;
 	}
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 4 words */
 mp_err
 ec_GFp_add_4(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit a0 = 0, a1 = 0, a2 = 0, a3 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0;
 	mp_digit carry;
 	switch(MP_USED(a)) {
 	case 4:
 		a3 = MP_DIGIT(a,3);
 	case 3:
 		a2 = MP_DIGIT(a,2);
 	case 2:
 		a1 = MP_DIGIT(a,1);
 	case 1:
 		a0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 4:
 		r3 = MP_DIGIT(b,3);
 	case 3:
 		r2 = MP_DIGIT(b,2);
 	case 2:
 		r1 = MP_DIGIT(b,1);
 	case 1:
 		r0 = MP_DIGIT(b,0);
 	}
 #ifndef MPI_AMD64_ADD
 	MP_ADD_CARRY(a0, r0, r0, 0,     carry);
 	MP_ADD_CARRY(a1, r1, r1, carry, carry);
 	MP_ADD_CARRY(a2, r2, r2, carry, carry);
 	MP_ADD_CARRY(a3, r3, r3, carry, carry);
 #else
 	__asm__ (
                 "xorq   %4,%4           \n\t"
                 "addq   %5,%0           \n\t"
                 "adcq   %6,%1           \n\t"
                 "adcq   %7,%2           \n\t"
                 "adcq   %8,%3           \n\t"
                 "adcq   $0,%4           \n\t"
                 : "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3), "=r"(carry)
                 : "r" (a0), "r" (a1), "r" (a2), "r" (a3),
 		  "0" (r0), "1" (r1), "2" (r2), "3" (r3)
                 : "%cc" );
 #endif
 	MP_CHECKOK(s_mp_pad(r, 4));
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 4;
 	/* Do quick 'subract' if we've gone over
 	 * (add the 2's complement of the curve field) */
 	 a3 = MP_DIGIT(&meth->irr,3);
 	if (carry ||  r3 >  a3 ||
 		((r3 == a3) && mp_cmp(r,&meth->irr) != MP_LT)) {
 		a2 = MP_DIGIT(&meth->irr,2);
 		a1 = MP_DIGIT(&meth->irr,1);
 		a0 = MP_DIGIT(&meth->irr,0);
 #ifndef MPI_AMD64_ADD
 		MP_SUB_BORROW(r0, a0, r0, 0,     carry);
 		MP_SUB_BORROW(r1, a1, r1, carry, carry);
 		MP_SUB_BORROW(r2, a2, r2, carry, carry);
 		MP_SUB_BORROW(r3, a3, r3, carry, carry);
 #else
 		__asm__ (
 			"subq   %4,%0           \n\t"
 			"sbbq   %5,%1           \n\t"
 			"sbbq   %6,%2           \n\t"
 			"sbbq   %7,%3           \n\t"
 			: "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3)
 			: "r" (a0), "r" (a1), "r" (a2), "r" (a3),
 			  "0" (r0), "1" (r1), "2" (r2), "3" (r3)
 			: "%cc" );
 #endif
 		MP_DIGIT(r, 3) = r3;
 		MP_DIGIT(r, 2) = r2;
 		MP_DIGIT(r, 1) = r1;
 		MP_DIGIT(r, 0) = r0;
 	}
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 5 words */
 mp_err
 ec_GFp_add_5(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit a0 = 0, a1 = 0, a2 = 0, a3 = 0, a4 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0, r4 = 0;
 	mp_digit carry;
 	switch(MP_USED(a)) {
 	case 5:
 		a4 = MP_DIGIT(a,4);
 	case 4:
 		a3 = MP_DIGIT(a,3);
 	case 3:
 		a2 = MP_DIGIT(a,2);
 	case 2:
 		a1 = MP_DIGIT(a,1);
 	case 1:
 		a0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 5:
 		r4 = MP_DIGIT(b,4);
 	case 4:
 		r3 = MP_DIGIT(b,3);
 	case 3:
 		r2 = MP_DIGIT(b,2);
 	case 2:
 		r1 = MP_DIGIT(b,1);
 	case 1:
 		r0 = MP_DIGIT(b,0);
 	}
 	MP_ADD_CARRY(a0, r0, r0, 0,     carry);
 	MP_ADD_CARRY(a1, r1, r1, carry, carry);
 	MP_ADD_CARRY(a2, r2, r2, carry, carry);
 	MP_ADD_CARRY(a3, r3, r3, carry, carry);
 	MP_ADD_CARRY(a4, r4, r4, carry, carry);
 	MP_CHECKOK(s_mp_pad(r, 5));
 	MP_DIGIT(r, 4) = r4;
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 5;
 	/* Do quick 'subract' if we've gone over
 	 * (add the 2's complement of the curve field) */
 	 a4 = MP_DIGIT(&meth->irr,4);
 	if (carry ||  r4 >  a4 ||
 		((r4 == a4) && mp_cmp(r,&meth->irr) != MP_LT)) {
 		a3 = MP_DIGIT(&meth->irr,3);
 		a2 = MP_DIGIT(&meth->irr,2);
 		a1 = MP_DIGIT(&meth->irr,1);
 		a0 = MP_DIGIT(&meth->irr,0);
 		MP_SUB_BORROW(r0, a0, r0, 0,     carry);
 		MP_SUB_BORROW(r1, a1, r1, carry, carry);
 		MP_SUB_BORROW(r2, a2, r2, carry, carry);
 		MP_SUB_BORROW(r3, a3, r3, carry, carry);
 		MP_SUB_BORROW(r4, a4, r4, carry, carry);
 		MP_DIGIT(r, 4) = r4;
 		MP_DIGIT(r, 3) = r3;
 		MP_DIGIT(r, 2) = r2;
 		MP_DIGIT(r, 1) = r1;
 		MP_DIGIT(r, 0) = r0;
 	}
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 6 words */
 mp_err
 ec_GFp_add_6(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit a0 = 0, a1 = 0, a2 = 0, a3 = 0, a4 = 0, a5 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0, r4 = 0, r5 = 0;
 	mp_digit carry;
 	switch(MP_USED(a)) {
 	case 6:
 		a5 = MP_DIGIT(a,5);
 	case 5:
 		a4 = MP_DIGIT(a,4);
 	case 4:
 		a3 = MP_DIGIT(a,3);
 	case 3:
 		a2 = MP_DIGIT(a,2);
 	case 2:
 		a1 = MP_DIGIT(a,1);
 	case 1:
 		a0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 6:
 		r5 = MP_DIGIT(b,5);
 	case 5:
 		r4 = MP_DIGIT(b,4);
 	case 4:
 		r3 = MP_DIGIT(b,3);
 	case 3:
 		r2 = MP_DIGIT(b,2);
 	case 2:
 		r1 = MP_DIGIT(b,1);
 	case 1:
 		r0 = MP_DIGIT(b,0);
 	}
 	MP_ADD_CARRY(a0, r0, r0, 0,     carry);
 	MP_ADD_CARRY(a1, r1, r1, carry, carry);
 	MP_ADD_CARRY(a2, r2, r2, carry, carry);
 	MP_ADD_CARRY(a3, r3, r3, carry, carry);
 	MP_ADD_CARRY(a4, r4, r4, carry, carry);
 	MP_ADD_CARRY(a5, r5, r5, carry, carry);
 	MP_CHECKOK(s_mp_pad(r, 6));
 	MP_DIGIT(r, 5) = r5;
 	MP_DIGIT(r, 4) = r4;
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 6;
 	/* Do quick 'subract' if we've gone over
 	 * (add the 2's complement of the curve field) */
 	a5 = MP_DIGIT(&meth->irr,5);
 	if (carry ||  r5 >  a5 ||
 		((r5 == a5) && mp_cmp(r,&meth->irr) != MP_LT)) {
 		a4 = MP_DIGIT(&meth->irr,4);
 		a3 = MP_DIGIT(&meth->irr,3);
 		a2 = MP_DIGIT(&meth->irr,2);
 		a1 = MP_DIGIT(&meth->irr,1);
 		a0 = MP_DIGIT(&meth->irr,0);
 		MP_SUB_BORROW(r0, a0, r0, 0,     carry);
 		MP_SUB_BORROW(r1, a1, r1, carry, carry);
 		MP_SUB_BORROW(r2, a2, r2, carry, carry);
 		MP_SUB_BORROW(r3, a3, r3, carry, carry);
 		MP_SUB_BORROW(r4, a4, r4, carry, carry);
 		MP_SUB_BORROW(r5, a5, r5, carry, carry);
 		MP_DIGIT(r, 5) = r5;
 		MP_DIGIT(r, 4) = r4;
 		MP_DIGIT(r, 3) = r3;
 		MP_DIGIT(r, 2) = r2;
 		MP_DIGIT(r, 1) = r1;
 		MP_DIGIT(r, 0) = r0;
 	}
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /*
  * The following subraction functions do in-line subractions based
  * on our curve size.
  *
  * ... 3 words
  */
 mp_err
 ec_GFp_sub_3(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit b0 = 0, b1 = 0, b2 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0;
 	mp_digit borrow;
 	switch(MP_USED(a)) {
 	case 3:
 		r2 = MP_DIGIT(a,2);
 	case 2:
 		r1 = MP_DIGIT(a,1);
 	case 1:
 		r0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 3:
 		b2 = MP_DIGIT(b,2);
 	case 2:
 		b1 = MP_DIGIT(b,1);
 	case 1:
 		b0 = MP_DIGIT(b,0);
 	}
 #ifndef MPI_AMD64_ADD
 	MP_SUB_BORROW(r0, b0, r0, 0,     borrow);
 	MP_SUB_BORROW(r1, b1, r1, borrow, borrow);
 	MP_SUB_BORROW(r2, b2, r2, borrow, borrow);
 #else
 	__asm__ (
                 "xorq   %3,%3           \n\t"
                 "subq   %4,%0           \n\t"
                 "sbbq   %5,%1           \n\t"
                 "sbbq   %6,%2           \n\t"
                 "adcq   $0,%3           \n\t"
                 : "=r"(r0), "=r"(r1), "=r"(r2), "=r" (borrow)
                 : "r" (b0), "r" (b1), "r" (b2),
 		  "0" (r0), "1" (r1), "2" (r2)
                 : "%cc" );
 #endif
 	/* Do quick 'add' if we've gone under 0
 	 * (subtract the 2's complement of the curve field) */
 	if (borrow) {
 	 	b2 = MP_DIGIT(&meth->irr,2);
 		b1 = MP_DIGIT(&meth->irr,1);
 		b0 = MP_DIGIT(&meth->irr,0);
 #ifndef MPI_AMD64_ADD
 		MP_ADD_CARRY(b0, r0, r0, 0,      borrow);
 		MP_ADD_CARRY(b1, r1, r1, borrow, borrow);
 		MP_ADD_CARRY(b2, r2, r2, borrow, borrow);
 #else
 		__asm__ (
 			"addq   %3,%0           \n\t"
 			"adcq   %4,%1           \n\t"
 			"adcq   %5,%2           \n\t"
 			: "=r"(r0), "=r"(r1), "=r"(r2)
 			: "r" (b0), "r" (b1), "r" (b2),
   			  "0" (r0), "1" (r1), "2" (r2)
 			: "%cc" );
 #endif
 	}
 #ifdef MPI_AMD64_ADD
 	/* compiler fakeout? */
 	if ((r2 == b0) && (r1 == b0) && (r0 == b0)) {
 		MP_CHECKOK(s_mp_pad(r, 4));
 	}
 #endif
 	MP_CHECKOK(s_mp_pad(r, 3));
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 3;
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 4 words */
 mp_err
 ec_GFp_sub_4(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit b0 = 0, b1 = 0, b2 = 0, b3 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0;
 	mp_digit borrow;
 	switch(MP_USED(a)) {
 	case 4:
 		r3 = MP_DIGIT(a,3);
 	case 3:
 		r2 = MP_DIGIT(a,2);
 	case 2:
 		r1 = MP_DIGIT(a,1);
 	case 1:
 		r0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 4:
 		b3 = MP_DIGIT(b,3);
 	case 3:
 		b2 = MP_DIGIT(b,2);
 	case 2:
 		b1 = MP_DIGIT(b,1);
 	case 1:
 		b0 = MP_DIGIT(b,0);
 	}
 #ifndef MPI_AMD64_ADD
 	MP_SUB_BORROW(r0, b0, r0, 0,     borrow);
 	MP_SUB_BORROW(r1, b1, r1, borrow, borrow);
 	MP_SUB_BORROW(r2, b2, r2, borrow, borrow);
 	MP_SUB_BORROW(r3, b3, r3, borrow, borrow);
 #else
 	__asm__ (
                 "xorq   %4,%4           \n\t"
                 "subq   %5,%0           \n\t"
                 "sbbq   %6,%1           \n\t"
                 "sbbq   %7,%2           \n\t"
                 "sbbq   %8,%3           \n\t"
                 "adcq   $0,%4           \n\t"
                 : "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3), "=r" (borrow)
                 : "r" (b0), "r" (b1), "r" (b2), "r" (b3),
 		  "0" (r0), "1" (r1), "2" (r2), "3" (r3)
                 : "%cc" );
 #endif
 	/* Do quick 'add' if we've gone under 0
 	 * (subtract the 2's complement of the curve field) */
 	if (borrow) {
 	 	b3 = MP_DIGIT(&meth->irr,3);
 	 	b2 = MP_DIGIT(&meth->irr,2);
 		b1 = MP_DIGIT(&meth->irr,1);
 		b0 = MP_DIGIT(&meth->irr,0);
 #ifndef MPI_AMD64_ADD
 		MP_ADD_CARRY(b0, r0, r0, 0,      borrow);
 		MP_ADD_CARRY(b1, r1, r1, borrow, borrow);
 		MP_ADD_CARRY(b2, r2, r2, borrow, borrow);
 		MP_ADD_CARRY(b3, r3, r3, borrow, borrow);
 #else
 		__asm__ (
 			"addq   %4,%0           \n\t"
 			"adcq   %5,%1           \n\t"
 			"adcq   %6,%2           \n\t"
 			"adcq   %7,%3           \n\t"
 			: "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3)
 			: "r" (b0), "r" (b1), "r" (b2), "r" (b3),
   			  "0" (r0), "1" (r1), "2" (r2), "3" (r3)
 			: "%cc" );
 #endif
 	}
 #ifdef MPI_AMD64_ADD
 	/* compiler fakeout? */
 	if ((r3 == b0) && (r1 == b0) && (r0 == b0)) {
 		MP_CHECKOK(s_mp_pad(r, 4));
 	}
 #endif
 	MP_CHECKOK(s_mp_pad(r, 4));
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 4;
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 5 words */
 mp_err
 ec_GFp_sub_5(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit b0 = 0, b1 = 0, b2 = 0, b3 = 0, b4 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0, r4 = 0;
 	mp_digit borrow;
 	switch(MP_USED(a)) {
 	case 5:
 		r4 = MP_DIGIT(a,4);
 	case 4:
 		r3 = MP_DIGIT(a,3);
 	case 3:
 		r2 = MP_DIGIT(a,2);
 	case 2:
 		r1 = MP_DIGIT(a,1);
 	case 1:
 		r0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 5:
 		b4 = MP_DIGIT(b,4);
 	case 4:
 		b3 = MP_DIGIT(b,3);
 	case 3:
 		b2 = MP_DIGIT(b,2);
 	case 2:
 		b1 = MP_DIGIT(b,1);
 	case 1:
 		b0 = MP_DIGIT(b,0);
 	}
 	MP_SUB_BORROW(r0, b0, r0, 0,     borrow);
 	MP_SUB_BORROW(r1, b1, r1, borrow, borrow);
 	MP_SUB_BORROW(r2, b2, r2, borrow, borrow);
 	MP_SUB_BORROW(r3, b3, r3, borrow, borrow);
 	MP_SUB_BORROW(r4, b4, r4, borrow, borrow);
 	/* Do quick 'add' if we've gone under 0
 	 * (subtract the 2's complement of the curve field) */
 	if (borrow) {
 	 	b4 = MP_DIGIT(&meth->irr,4);
 	 	b3 = MP_DIGIT(&meth->irr,3);
 	 	b2 = MP_DIGIT(&meth->irr,2);
 		b1 = MP_DIGIT(&meth->irr,1);
 		b0 = MP_DIGIT(&meth->irr,0);
 		MP_ADD_CARRY(b0, r0, r0, 0,      borrow);
 		MP_ADD_CARRY(b1, r1, r1, borrow, borrow);
 		MP_ADD_CARRY(b2, r2, r2, borrow, borrow);
 		MP_ADD_CARRY(b3, r3, r3, borrow, borrow);
 	}
 	MP_CHECKOK(s_mp_pad(r, 5));
 	MP_DIGIT(r, 4) = r4;
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 5;
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* 6 words */
 mp_err
 ec_GFp_sub_6(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit b0 = 0, b1 = 0, b2 = 0, b3 = 0, b4 = 0, b5 = 0;
 	mp_digit r0 = 0, r1 = 0, r2 = 0, r3 = 0, r4 = 0, r5 = 0;
 	mp_digit borrow;
 	switch(MP_USED(a)) {
 	case 6:
 		r5 = MP_DIGIT(a,5);
 	case 5:
 		r4 = MP_DIGIT(a,4);
 	case 4:
 		r3 = MP_DIGIT(a,3);
 	case 3:
 		r2 = MP_DIGIT(a,2);
 	case 2:
 		r1 = MP_DIGIT(a,1);
 	case 1:
 		r0 = MP_DIGIT(a,0);
 	}
 	switch(MP_USED(b)) {
 	case 6:
 		b5 = MP_DIGIT(b,5);
 	case 5:
 		b4 = MP_DIGIT(b,4);
 	case 4:
 		b3 = MP_DIGIT(b,3);
 	case 3:
 		b2 = MP_DIGIT(b,2);
 	case 2:
 		b1 = MP_DIGIT(b,1);
 	case 1:
 		b0 = MP_DIGIT(b,0);
 	}
 	MP_SUB_BORROW(r0, b0, r0, 0,     borrow);
 	MP_SUB_BORROW(r1, b1, r1, borrow, borrow);
 	MP_SUB_BORROW(r2, b2, r2, borrow, borrow);
 	MP_SUB_BORROW(r3, b3, r3, borrow, borrow);
 	MP_SUB_BORROW(r4, b4, r4, borrow, borrow);
 	MP_SUB_BORROW(r5, b5, r5, borrow, borrow);
 	/* Do quick 'add' if we've gone under 0
 	 * (subtract the 2's complement of the curve field) */
 	if (borrow) {
 	 	b5 = MP_DIGIT(&meth->irr,5);
 	 	b4 = MP_DIGIT(&meth->irr,4);
 	 	b3 = MP_DIGIT(&meth->irr,3);
 	 	b2 = MP_DIGIT(&meth->irr,2);
 		b1 = MP_DIGIT(&meth->irr,1);
 		b0 = MP_DIGIT(&meth->irr,0);
 		MP_ADD_CARRY(b0, r0, r0, 0,      borrow);
 		MP_ADD_CARRY(b1, r1, r1, borrow, borrow);
 		MP_ADD_CARRY(b2, r2, r2, borrow, borrow);
 		MP_ADD_CARRY(b3, r3, r3, borrow, borrow);
 		MP_ADD_CARRY(b4, r4, r4, borrow, borrow);
 	}
 	MP_CHECKOK(s_mp_pad(r, 6));
 	MP_DIGIT(r, 5) = r5;
 	MP_DIGIT(r, 4) = r4;
 	MP_DIGIT(r, 3) = r3;
 	MP_DIGIT(r, 2) = r2;
 	MP_DIGIT(r, 1) = r1;
 	MP_DIGIT(r, 0) = r0;
 	MP_SIGN(r) = MP_ZPOS;
 	MP_USED(r) = 6;
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* Reduces an integer to a field element. */
 mp_err
 ec_GFp_mod(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	return mp_mod(a, &meth->irr, r);
 }
 /* Multiplies two field elements. */
 mp_err
 ec_GFp_mul(const mp_int *a, const mp_int *b, mp_int *r,
 		   const GFMethod *meth)
 {
 	return mp_mulmod(a, b, &meth->irr, r);
 }
 /* Squares a field element. */
 mp_err
 ec_GFp_sqr(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	return mp_sqrmod(a, &meth->irr, r);
 }
 /* Divides two field elements. If a is NULL, then returns the inverse of
  * b. */
 mp_err
 ec_GFp_div(const mp_int *a, const mp_int *b, mp_int *r,
 		   const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_int t;
 	/* If a is NULL, then return the inverse of b, otherwise return a/b. */
 	if (a == NULL) {
 		return mp_invmod(b, &meth->irr, r);
 	} else {
 		/* MPI doesn't support divmod, so we implement it using invmod and
 		 * mulmod. */
 		MP_CHECKOK(mp_init(&t));
 		MP_CHECKOK(mp_invmod(b, &meth->irr, &t));
 		MP_CHECKOK(mp_mulmod(a, &t, &meth->irr, r));
 	  CLEANUP:
 		mp_clear(&t);
 		return res;
 	}
 }
 /* Wrapper functions for generic binary polynomial field arithmetic. */
 /* Adds two field elements. */
 mp_err
 ec_GF2m_add(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	return mp_badd(a, b, r);
 }
 /* Negates a field element. Note that for binary polynomial fields, the
  * negation of a field element is the field element itself. */
 mp_err
 ec_GF2m_neg(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	if (a == r) {
 		return MP_OKAY;
 	} else {
 		return mp_copy(a, r);
 	}
 }
 /* Reduces a binary polynomial to a field element. */
 mp_err
 ec_GF2m_mod(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	return mp_bmod(a, meth->irr_arr, r);
 }
 /* Multiplies two field elements. */
 mp_err
 ec_GF2m_mul(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	return mp_bmulmod(a, b, meth->irr_arr, r);
 }
 /* Squares a field element. */
 mp_err
 ec_GF2m_sqr(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	return mp_bsqrmod(a, meth->irr_arr, r);
 }
 /* Divides two field elements. If a is NULL, then returns the inverse of
  * b. */
 mp_err
 ec_GF2m_div(const mp_int *a, const mp_int *b, mp_int *r,
 			const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_int t;
 	/* If a is NULL, then return the inverse of b, otherwise return a/b. */
 	if (a == NULL) {
 		/* The GF(2^m) portion of MPI doesn't support invmod, so we
 		 * compute 1/b. */
 		MP_CHECKOK(mp_init(&t));
 		MP_CHECKOK(mp_set_int(&t, 1));
 		MP_CHECKOK(mp_bdivmod(&t, b, &meth->irr, meth->irr_arr, r));
 	  CLEANUP:
 		mp_clear(&t);
 		return res;
 	} else {
 		return mp_bdivmod(a, b, &meth->irr, meth->irr_arr, r);
 	}
 }

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security/nss/lib/freebl/ecl/ecl_gf.c@6474c204b198 (annotated)

security/nss/lib/freebl/ecl/ecl_gf.c