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Diffstat (limited to 'security/nss/lib/freebl/ecl/ecp_256.c')
| -rw-r--r-- | security/nss/lib/freebl/ecl/ecp_256.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/ecl/ecp_256.c b/security/nss/lib/freebl/ecl/ecp_256.c new file mode 100644 index 000000000..15d29ab6e --- /dev/null +++ b/security/nss/lib/freebl/ecl/ecp_256.c @@ -0,0 +1,429 @@ +/* + * ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is the elliptic curve math library for prime field curves. + * + * The Initial Developer of the Original Code is + * Sun Microsystems, Inc. + * Portions created by the Initial Developer are Copyright (C) 2003 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * Douglas Stebila <douglas@stebila.ca> + * + * Alternatively, the contents of this file may be used under the terms of + * either the GNU General Public License Version 2 or later (the "GPL"), or + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#include "ecp.h" +#include "mpi.h" +#include "mplogic.h" +#include "mpi-priv.h" +#include <stdlib.h> + +/* Fast modular reduction for p256 = 2^256 - 2^224 + 2^192+ 2^96 - 1. a can be r. + * Uses algorithm 2.29 from Hankerson, Menezes, Vanstone. Guide to + * Elliptic Curve Cryptography. */ +mp_err +ec_GFp_nistp256_mod(const mp_int *a, mp_int *r, const GFMethod *meth) +{ + mp_err res = MP_OKAY; + mp_size a_used = MP_USED(a); + int a_bits = mpl_significant_bits(a); + mp_digit carry; + +#ifdef ECL_THIRTY_TWO_BIT + mp_digit a8=0, a9=0, a10=0, a11=0, a12=0, a13=0, a14=0, a15=0; + mp_digit r0, r1, r2, r3, r4, r5, r6, r7; + int r8; /* must be a signed value ! */ +#else + mp_digit a4=0, a5=0, a6=0, a7=0; + mp_digit a4h, a4l, a5h, a5l, a6h, a6l, a7h, a7l; + mp_digit r0, r1, r2, r3; + int r4; /* must be a signed value ! */ +#endif + /* for polynomials larger than twice the field size + * use regular reduction */ + if (a_bits < 256) { + if (a == r) return MP_OKAY; + return mp_copy(a,r); + } + if (a_bits > 512) { + MP_CHECKOK(mp_mod(a, &meth->irr, r)); + } else { + +#ifdef ECL_THIRTY_TWO_BIT + switch (a_used) { + case 16: + a15 = MP_DIGIT(a,15); + case 15: + a14 = MP_DIGIT(a,14); + case 14: + a13 = MP_DIGIT(a,13); + case 13: + a12 = MP_DIGIT(a,12); + case 12: + a11 = MP_DIGIT(a,11); + case 11: + a10 = MP_DIGIT(a,10); + case 10: + a9 = MP_DIGIT(a,9); + case 9: + a8 = MP_DIGIT(a,8); + } + + r0 = MP_DIGIT(a,0); + r1 = MP_DIGIT(a,1); + r2 = MP_DIGIT(a,2); + r3 = MP_DIGIT(a,3); + r4 = MP_DIGIT(a,4); + r5 = MP_DIGIT(a,5); + r6 = MP_DIGIT(a,6); + r7 = MP_DIGIT(a,7); + + /* sum 1 */ + MP_ADD_CARRY(r3, a11, r3, 0, carry); + MP_ADD_CARRY(r4, a12, r4, carry, carry); + MP_ADD_CARRY(r5, a13, r5, carry, carry); + MP_ADD_CARRY(r6, a14, r6, carry, carry); + MP_ADD_CARRY(r7, a15, r7, carry, carry); + r8 = carry; + MP_ADD_CARRY(r3, a11, r3, 0, carry); + MP_ADD_CARRY(r4, a12, r4, carry, carry); + MP_ADD_CARRY(r5, a13, r5, carry, carry); + MP_ADD_CARRY(r6, a14, r6, carry, carry); + MP_ADD_CARRY(r7, a15, r7, carry, carry); + r8 += carry; + /* sum 2 */ + MP_ADD_CARRY(r3, a12, r3, 0, carry); + MP_ADD_CARRY(r4, a13, r4, carry, carry); + MP_ADD_CARRY(r5, a14, r5, carry, carry); + MP_ADD_CARRY(r6, a15, r6, carry, carry); + MP_ADD_CARRY(r7, 0, r7, carry, carry); + r8 += carry; + /* combine last bottom of sum 3 with second sum 2 */ + MP_ADD_CARRY(r0, a8, r0, 0, carry); + MP_ADD_CARRY(r1, a9, r1, carry, carry); + MP_ADD_CARRY(r2, a10, r2, carry, carry); + MP_ADD_CARRY(r3, a12, r3, carry, carry); + MP_ADD_CARRY(r4, a13, r4, carry, carry); + MP_ADD_CARRY(r5, a14, r5, carry, carry); + MP_ADD_CARRY(r6, a15, r6, carry, carry); + MP_ADD_CARRY(r7, a15, r7, carry, carry); /* from sum 3 */ + r8 += carry; + /* sum 3 (rest of it)*/ + MP_ADD_CARRY(r6, a14, r6, 0, carry); + MP_ADD_CARRY(r7, 0, r7, carry, carry); + r8 += carry; + /* sum 4 (rest of it)*/ + MP_ADD_CARRY(r0, a9, r0, 0, carry); + MP_ADD_CARRY(r1, a10, r1, carry, carry); + MP_ADD_CARRY(r2, a11, r2, carry, carry); + MP_ADD_CARRY(r3, a13, r3, carry, carry); + MP_ADD_CARRY(r4, a14, r4, carry, carry); + MP_ADD_CARRY(r5, a15, r5, carry, carry); + MP_ADD_CARRY(r6, a13, r6, carry, carry); + MP_ADD_CARRY(r7, a8, r7, carry, carry); + r8 += carry; + /* diff 5 */ + MP_SUB_BORROW(r0, a11, r0, 0, carry); + MP_SUB_BORROW(r1, a12, r1, carry, carry); + MP_SUB_BORROW(r2, a13, r2, carry, carry); + MP_SUB_BORROW(r3, 0, r3, carry, carry); + MP_SUB_BORROW(r4, 0, r4, carry, carry); + MP_SUB_BORROW(r5, 0, r5, carry, carry); + MP_SUB_BORROW(r6, a8, r6, carry, carry); + MP_SUB_BORROW(r7, a10, r7, carry, carry); + r8 -= carry; + /* diff 6 */ + MP_SUB_BORROW(r0, a12, r0, 0, carry); + MP_SUB_BORROW(r1, a13, r1, carry, carry); + MP_SUB_BORROW(r2, a14, r2, carry, carry); + MP_SUB_BORROW(r3, a15, r3, carry, carry); + MP_SUB_BORROW(r4, 0, r4, carry, carry); + MP_SUB_BORROW(r5, 0, r5, carry, carry); + MP_SUB_BORROW(r6, a9, r6, carry, carry); + MP_SUB_BORROW(r7, a11, r7, carry, carry); + r8 -= carry; + /* diff 7 */ + MP_SUB_BORROW(r0, a13, r0, 0, carry); + MP_SUB_BORROW(r1, a14, r1, carry, carry); + MP_SUB_BORROW(r2, a15, r2, carry, carry); + MP_SUB_BORROW(r3, a8, r3, carry, carry); + MP_SUB_BORROW(r4, a9, r4, carry, carry); + MP_SUB_BORROW(r5, a10, r5, carry, carry); + MP_SUB_BORROW(r6, 0, r6, carry, carry); + MP_SUB_BORROW(r7, a12, r7, carry, carry); + r8 -= carry; + /* diff 8 */ + MP_SUB_BORROW(r0, a14, r0, 0, carry); + MP_SUB_BORROW(r1, a15, r1, carry, carry); + MP_SUB_BORROW(r2, 0, r2, carry, carry); + MP_SUB_BORROW(r3, a9, r3, carry, carry); + MP_SUB_BORROW(r4, a10, r4, carry, carry); + MP_SUB_BORROW(r5, a11, r5, carry, carry); + MP_SUB_BORROW(r6, 0, r6, carry, carry); + MP_SUB_BORROW(r7, a13, r7, carry, carry); + r8 -= carry; + + /* reduce the overflows */ + while (r8 > 0) { + mp_digit r8_d = r8; + MP_ADD_CARRY(r0, r8_d, r0, 0, carry); + MP_ADD_CARRY(r1, 0, r1, carry, carry); + MP_ADD_CARRY(r2, 0, r2, carry, carry); + MP_ADD_CARRY(r3, -r8_d, r3, carry, carry); + MP_ADD_CARRY(r4, MP_DIGIT_MAX, r4, carry, carry); + MP_ADD_CARRY(r5, MP_DIGIT_MAX, r5, carry, carry); + MP_ADD_CARRY(r6, -(r8_d+1), r6, carry, carry); + MP_ADD_CARRY(r7, (r8_d-1), r7, carry, carry); + r8 = carry; + } + + /* reduce the underflows */ + while (r8 < 0) { + mp_digit r8_d = -r8; + MP_SUB_BORROW(r0, r8_d, r0, 0, carry); + MP_SUB_BORROW(r1, 0, r1, carry, carry); + MP_SUB_BORROW(r2, 0, r2, carry, carry); + MP_SUB_BORROW(r3, -r8_d, r3, carry, carry); + MP_SUB_BORROW(r4, MP_DIGIT_MAX, r4, carry, carry); + MP_SUB_BORROW(r5, MP_DIGIT_MAX, r5, carry, carry); + MP_SUB_BORROW(r6, -(r8_d+1), r6, carry, carry); + MP_SUB_BORROW(r7, (r8_d-1), r7, carry, carry); + r8 = -carry; + } + if (a != r) { + MP_CHECKOK(s_mp_pad(r,8)); + } + MP_SIGN(r) = MP_ZPOS; + MP_USED(r) = 8; + + MP_DIGIT(r,7) = r7; + MP_DIGIT(r,6) = r6; + 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; + + /* final reduction if necessary */ + if ((r7 == MP_DIGIT_MAX) && + ((r6 > 1) || ((r6 == 1) && + (r5 || r4 || r3 || + ((r2 == MP_DIGIT_MAX) && (r1 == MP_DIGIT_MAX) + && (r0 == MP_DIGIT_MAX)))))) { + MP_CHECKOK(mp_sub(r, &meth->irr, r)); + } +#ifdef notdef + + + /* smooth the negatives */ + while (MP_SIGN(r) != MP_ZPOS) { + MP_CHECKOK(mp_add(r, &meth->irr, r)); + } + while (MP_USED(r) > 8) { + MP_CHECKOK(mp_sub(r, &meth->irr, r)); + } + + /* final reduction if necessary */ + if (MP_DIGIT(r,7) >= MP_DIGIT(&meth->irr,7)) { + if (mp_cmp(r,&meth->irr) != MP_LT) { + MP_CHECKOK(mp_sub(r, &meth->irr, r)); + } + } +#endif + s_mp_clamp(r); +#else + switch (a_used) { + 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); + } + a7l = a7 << 32; + a7h = a7 >> 32; + a6l = a6 << 32; + a6h = a6 >> 32; + a5l = a5 << 32; + a5h = a5 >> 32; + a4l = a4 << 32; + a4h = a4 >> 32; + r3 = MP_DIGIT(a,3); + r2 = MP_DIGIT(a,2); + r1 = MP_DIGIT(a,1); + r0 = MP_DIGIT(a,0); + + /* sum 1 */ + MP_ADD_CARRY(r1, a5h << 32, r1, 0, carry); + MP_ADD_CARRY(r2, a6, r2, carry, carry); + MP_ADD_CARRY(r3, a7, r3, carry, carry); + r4 = carry; + MP_ADD_CARRY(r1, a5h << 32, r1, 0, carry); + MP_ADD_CARRY(r2, a6, r2, carry, carry); + MP_ADD_CARRY(r3, a7, r3, carry, carry); + r4 += carry; + /* sum 2 */ + MP_ADD_CARRY(r1, a6l, r1, 0, carry); + MP_ADD_CARRY(r2, a6h | a7l, r2, carry, carry); + MP_ADD_CARRY(r3, a7h, r3, carry, carry); + r4 += carry; + MP_ADD_CARRY(r1, a6l, r1, 0, carry); + MP_ADD_CARRY(r2, a6h | a7l, r2, carry, carry); + MP_ADD_CARRY(r3, a7h, r3, carry, carry); + r4 += carry; + + /* sum 3 */ + MP_ADD_CARRY(r0, a4, r0, 0, carry); + MP_ADD_CARRY(r1, a5l >> 32, r1, carry, carry); + MP_ADD_CARRY(r2, 0, r2, carry, carry); + MP_ADD_CARRY(r3, a7, r3, carry, carry); + r4 += carry; + /* sum 4 */ + MP_ADD_CARRY(r0, a4h | a5l, r0, 0, carry); + MP_ADD_CARRY(r1, a5h|(a6h<<32), r1, carry, carry); + MP_ADD_CARRY(r2, a7, r2, carry, carry); + MP_ADD_CARRY(r3, a6h | a4l, r3, carry, carry); + r4 += carry; + /* diff 5 */ + MP_SUB_BORROW(r0, a5h | a6l, r0, 0, carry); + MP_SUB_BORROW(r1, a6h, r1, carry, carry); + MP_SUB_BORROW(r2, 0, r2, carry, carry); + MP_SUB_BORROW(r3, (a4l>>32)|a5l,r3, carry, carry); + r4 -= carry; + /* diff 6 */ + MP_SUB_BORROW(r0, a6, r0, 0, carry); + MP_SUB_BORROW(r1, a7, r1, carry, carry); + MP_SUB_BORROW(r2, 0, r2, carry, carry); + MP_SUB_BORROW(r3, a4h|(a5h<<32),r3, carry, carry); + r4 -= carry; + /* diff 7 */ + MP_SUB_BORROW(r0, a6h|a7l, r0, 0, carry); + MP_SUB_BORROW(r1, a7h|a4l, r1, carry, carry); + MP_SUB_BORROW(r2, a4h|a5l, r2, carry, carry); + MP_SUB_BORROW(r3, a6l, r3, carry, carry); + r4 -= carry; + /* diff 8 */ + MP_SUB_BORROW(r0, a7, r0, 0, carry); + MP_SUB_BORROW(r1, a4h<<32, r1, carry, carry); + MP_SUB_BORROW(r2, a5, r2, carry, carry); + MP_SUB_BORROW(r3, a6h<<32, r3, carry, carry); + r4 -= carry; + + /* reduce the overflows */ + while (r4 > 0) { + mp_digit r4_long = r4; + mp_digit r4l = (r4_long << 32); + MP_ADD_CARRY(r0, r4_long, r0, 0, carry); + MP_ADD_CARRY(r1, -r4l, r1, carry, carry); + MP_ADD_CARRY(r2, MP_DIGIT_MAX, r2, carry, carry); + MP_ADD_CARRY(r3, r4l-r4_long-1,r3, carry, carry); + r4 = carry; + } + + /* reduce the underflows */ + while (r4 < 0) { + mp_digit r4_long = -r4; + mp_digit r4l = (r4_long << 32); + MP_SUB_BORROW(r0, r4_long, r0, 0, carry); + MP_SUB_BORROW(r1, -r4l, r1, carry, carry); + MP_SUB_BORROW(r2, MP_DIGIT_MAX, r2, carry, carry); + MP_SUB_BORROW(r3, r4l-r4_long-1,r3, carry, carry); + r4 = -carry; + } + + if (a != r) { + MP_CHECKOK(s_mp_pad(r,4)); + } + MP_SIGN(r) = MP_ZPOS; + MP_USED(r) = 4; + + MP_DIGIT(r,3) = r3; + MP_DIGIT(r,2) = r2; + MP_DIGIT(r,1) = r1; + MP_DIGIT(r,0) = r0; + + /* final reduction if necessary */ + if ((r3 > 0xFFFFFFFF00000001ULL) || + ((r3 == 0xFFFFFFFF00000001ULL) && + (r2 || (r1 >> 32)|| + (r1 == 0xFFFFFFFFULL && r0 == MP_DIGIT_MAX)))) { + /* very rare, just use mp_sub */ + MP_CHECKOK(mp_sub(r, &meth->irr, r)); + } + + s_mp_clamp(r); +#endif + } + + CLEANUP: + return res; +} + +/* Compute the square of polynomial a, reduce modulo p256. Store the + * result in r. r could be a. Uses optimized modular reduction for p256. + */ +mp_err +ec_GFp_nistp256_sqr(const mp_int *a, mp_int *r, const GFMethod *meth) +{ + mp_err res = MP_OKAY; + + MP_CHECKOK(mp_sqr(a, r)); + MP_CHECKOK(ec_GFp_nistp256_mod(r, r, meth)); + CLEANUP: + return res; +} + +/* Compute the product of two polynomials a and b, reduce modulo p256. + * Store the result in r. r could be a or b; a could be b. Uses + * optimized modular reduction for p256. */ +mp_err +ec_GFp_nistp256_mul(const mp_int *a, const mp_int *b, mp_int *r, + const GFMethod *meth) +{ + mp_err res = MP_OKAY; + + MP_CHECKOK(mp_mul(a, b, r)); + MP_CHECKOK(ec_GFp_nistp256_mod(r, r, meth)); + CLEANUP: + return res; +} + +/* Wire in fast field arithmetic and precomputation of base point for + * named curves. */ +mp_err +ec_group_set_gfp256(ECGroup *group, ECCurveName name) +{ + if (name == ECCurve_NIST_P256) { + group->meth->field_mod = &ec_GFp_nistp256_mod; + group->meth->field_mul = &ec_GFp_nistp256_mul; + group->meth->field_sqr = &ec_GFp_nistp256_sqr; + } + return MP_OKAY; +} |