The Tor Browser: security/nss/lib/freebl/ecl/ec2

security/nss/lib/freebl/ecl/ec2_233.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/ecl/ec2_233.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* 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 "ec2.h"
 #include "mp_gf2m.h"
 #include "mp_gf2m-priv.h"
 #include "mpi.h"
 #include "mpi-priv.h"
 #include <stdlib.h>
 /* Fast reduction for polynomials over a 233-bit curve. Assumes reduction
  * polynomial with terms {233, 74, 0}. */
 mp_err
 ec_GF2m_233_mod(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit *u, z;
 	if (a != r) {
 		MP_CHECKOK(mp_copy(a, r));
 	}
 #ifdef ECL_SIXTY_FOUR_BIT
 	if (MP_USED(r) < 8) {
 		MP_CHECKOK(s_mp_pad(r, 8));
 	}
 	u = MP_DIGITS(r);
 	MP_USED(r) = 8;
 	/* u[7] only has 18 significant bits */
 	z = u[7];
 	u[4] ^= (z << 33) ^ (z >> 41);
 	u[3] ^= (z << 23);
 	z = u[6];
 	u[4] ^= (z >> 31);
 	u[3] ^= (z << 33) ^ (z >> 41);
 	u[2] ^= (z << 23);
 	z = u[5];
 	u[3] ^= (z >> 31);
 	u[2] ^= (z << 33) ^ (z >> 41);
 	u[1] ^= (z << 23);
 	z = u[4];
 	u[2] ^= (z >> 31);
 	u[1] ^= (z << 33) ^ (z >> 41);
 	u[0] ^= (z << 23);
 	z = u[3] >> 41;				/* z only has 23 significant bits */
 	u[1] ^= (z << 10);
 	u[0] ^= z;
 	/* clear bits above 233 */
 	u[7] = u[6] = u[5] = u[4] = 0;
 	u[3] ^= z << 41;
 #else
 	if (MP_USED(r) < 15) {
 		MP_CHECKOK(s_mp_pad(r, 15));
 	}
 	u = MP_DIGITS(r);
 	MP_USED(r) = 15;
 	/* u[14] only has 18 significant bits */
 	z = u[14];
 	u[9] ^= (z << 1);
 	u[7] ^= (z >> 9);
 	u[6] ^= (z << 23);
 	z = u[13];
 	u[9] ^= (z >> 31);
 	u[8] ^= (z << 1);
 	u[6] ^= (z >> 9);
 	u[5] ^= (z << 23);
 	z = u[12];
 	u[8] ^= (z >> 31);
 	u[7] ^= (z << 1);
 	u[5] ^= (z >> 9);
 	u[4] ^= (z << 23);
 	z = u[11];
 	u[7] ^= (z >> 31);
 	u[6] ^= (z << 1);
 	u[4] ^= (z >> 9);
 	u[3] ^= (z << 23);
 	z = u[10];
 	u[6] ^= (z >> 31);
 	u[5] ^= (z << 1);
 	u[3] ^= (z >> 9);
 	u[2] ^= (z << 23);
 	z = u[9];
 	u[5] ^= (z >> 31);
 	u[4] ^= (z << 1);
 	u[2] ^= (z >> 9);
 	u[1] ^= (z << 23);
 	z = u[8];
 	u[4] ^= (z >> 31);
 	u[3] ^= (z << 1);
 	u[1] ^= (z >> 9);
 	u[0] ^= (z << 23);
 	z = u[7] >> 9;				/* z only has 23 significant bits */
 	u[3] ^= (z >> 22);
 	u[2] ^= (z << 10);
 	u[0] ^= z;
 	/* clear bits above 233 */
 	u[14] = u[13] = u[12] = u[11] = u[10] = u[9] = u[8] = 0;
 	u[7] ^= z << 9;
 #endif
 	s_mp_clamp(r);
   CLEANUP:
 	return res;
 }
 /* Fast squaring for polynomials over a 233-bit curve. Assumes reduction
  * polynomial with terms {233, 74, 0}. */
 mp_err
 ec_GF2m_233_sqr(const mp_int *a, mp_int *r, const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit *u, *v;
 	v = MP_DIGITS(a);
 #ifdef ECL_SIXTY_FOUR_BIT
 	if (MP_USED(a) < 4) {
 		return mp_bsqrmod(a, meth->irr_arr, r);
 	}
 	if (MP_USED(r) < 8) {
 		MP_CHECKOK(s_mp_pad(r, 8));
 	}
 	MP_USED(r) = 8;
 #else
 	if (MP_USED(a) < 8) {
 		return mp_bsqrmod(a, meth->irr_arr, r);
 	}
 	if (MP_USED(r) < 15) {
 		MP_CHECKOK(s_mp_pad(r, 15));
 	}
 	MP_USED(r) = 15;
 #endif
 	u = MP_DIGITS(r);
 #ifdef ECL_THIRTY_TWO_BIT
 	u[14] = gf2m_SQR0(v[7]);
 	u[13] = gf2m_SQR1(v[6]);
 	u[12] = gf2m_SQR0(v[6]);
 	u[11] = gf2m_SQR1(v[5]);
 	u[10] = gf2m_SQR0(v[5]);
 	u[9] = gf2m_SQR1(v[4]);
 	u[8] = gf2m_SQR0(v[4]);
 #endif
 	u[7] = gf2m_SQR1(v[3]);
 	u[6] = gf2m_SQR0(v[3]);
 	u[5] = gf2m_SQR1(v[2]);
 	u[4] = gf2m_SQR0(v[2]);
 	u[3] = gf2m_SQR1(v[1]);
 	u[2] = gf2m_SQR0(v[1]);
 	u[1] = gf2m_SQR1(v[0]);
 	u[0] = gf2m_SQR0(v[0]);
 	return ec_GF2m_233_mod(r, r, meth);
   CLEANUP:
 	return res;
 }
 /* Fast multiplication for polynomials over a 233-bit curve. Assumes
  * reduction polynomial with terms {233, 74, 0}. */
 mp_err
 ec_GF2m_233_mul(const mp_int *a, const mp_int *b, mp_int *r,
 				const GFMethod *meth)
 {
 	mp_err res = MP_OKAY;
 	mp_digit a3 = 0, a2 = 0, a1 = 0, a0, b3 = 0, b2 = 0, b1 = 0, b0;
 #ifdef ECL_THIRTY_TWO_BIT
 	mp_digit a7 = 0, a6 = 0, a5 = 0, a4 = 0, b7 = 0, b6 = 0, b5 = 0, b4 =
 ;
 	mp_digit rm[8];
 #endif
 	if (a == b) {
 		return ec_GF2m_233_sqr(a, r, meth);
 	} else {
 		switch (MP_USED(a)) {
 #ifdef ECL_THIRTY_TWO_BIT
 		case 8:
 			a7 = MP_DIGIT(a, 7);
 		case 7:
 			a6 = MP_DIGIT(a, 6);
 		case 6:
 			a5 = MP_DIGIT(a, 5);
 		case 5:
 			a4 = MP_DIGIT(a, 4);
 #endif
 		case 4:
 			a3 = MP_DIGIT(a, 3);
 		case 3:
 			a2 = MP_DIGIT(a, 2);
 		case 2:
 			a1 = MP_DIGIT(a, 1);
 		default:
 			a0 = MP_DIGIT(a, 0);
 		}
 		switch (MP_USED(b)) {
 #ifdef ECL_THIRTY_TWO_BIT
 		case 8:
 			b7 = MP_DIGIT(b, 7);
 		case 7:
 			b6 = MP_DIGIT(b, 6);
 		case 6:
 			b5 = MP_DIGIT(b, 5);
 		case 5:
 			b4 = MP_DIGIT(b, 4);
 #endif
 		case 4:
 			b3 = MP_DIGIT(b, 3);
 		case 3:
 			b2 = MP_DIGIT(b, 2);
 		case 2:
 			b1 = MP_DIGIT(b, 1);
 		default:
 			b0 = MP_DIGIT(b, 0);
 		}
 #ifdef ECL_SIXTY_FOUR_BIT
 		MP_CHECKOK(s_mp_pad(r, 8));
 		s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0);
 		MP_USED(r) = 8;
 		s_mp_clamp(r);
 #else
 		MP_CHECKOK(s_mp_pad(r, 16));
 		s_bmul_4x4(MP_DIGITS(r) + 8, a7, a6, a5, a4, b7, b6, b5, b4);
 		s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0);
 		s_bmul_4x4(rm, a7 ^ a3, a6 ^ a2, a5 ^ a1, a4 ^ a0, b7 ^ b3,
 				   b6 ^ b2, b5 ^ b1, b4 ^ b0);
 		rm[7] ^= MP_DIGIT(r, 7) ^ MP_DIGIT(r, 15);
 		rm[6] ^= MP_DIGIT(r, 6) ^ MP_DIGIT(r, 14);
 		rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 13);
 		rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 12);
 		rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 11);
 		rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 10);
 		rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 9);
 		rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 8);
 		MP_DIGIT(r, 11) ^= rm[7];
 		MP_DIGIT(r, 10) ^= rm[6];
 		MP_DIGIT(r, 9) ^= rm[5];
 		MP_DIGIT(r, 8) ^= rm[4];
 		MP_DIGIT(r, 7) ^= rm[3];
 		MP_DIGIT(r, 6) ^= rm[2];
 		MP_DIGIT(r, 5) ^= rm[1];
 		MP_DIGIT(r, 4) ^= rm[0];
 		MP_USED(r) = 16;
 		s_mp_clamp(r);
 #endif
 		return ec_GF2m_233_mod(r, r, meth);
 	}
   CLEANUP:
 	return res;
 }
 /* Wire in fast field arithmetic for 233-bit curves. */
 mp_err
 ec_group_set_gf2m233(ECGroup *group, ECCurveName name)
 {
 	group->meth->field_mod = &ec_GF2m_233_mod;
 	group->meth->field_mul = &ec_GF2m_233_mul;
 	group->meth->field_sqr = &ec_GF2m_233_sqr;
 	return MP_OKAY;
 }

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security/nss/lib/freebl/ecl/ec2_233.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/ecl/ec2_233.c