diff -r 000000000000 -r 6474c204b198 security/nss/lib/freebl/ecl/ecp_192.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/security/nss/lib/freebl/ecl/ecp_192.c Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,483 @@ +/* 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 "ecp.h" +#include "mpi.h" +#include "mplogic.h" +#include "mpi-priv.h" + +#define ECP192_DIGITS ECL_CURVE_DIGITS(192) + +/* Fast modular reduction for p192 = 2^192 - 2^64 - 1. a can be r. Uses + * algorithm 7 from Brown, Hankerson, Lopez, Menezes. Software + * Implementation of the NIST Elliptic Curves over Prime Fields. */ +static mp_err +ec_GFp_nistp192_mod(const mp_int *a, mp_int *r, const GFMethod *meth) +{ + mp_err res = MP_OKAY; + mp_size a_used = MP_USED(a); + mp_digit r3; +#ifndef MPI_AMD64_ADD + mp_digit carry; +#endif +#ifdef ECL_THIRTY_TWO_BIT + mp_digit a5a = 0, a5b = 0, a4a = 0, a4b = 0, a3a = 0, a3b = 0; + mp_digit r0a, r0b, r1a, r1b, r2a, r2b; +#else + mp_digit a5 = 0, a4 = 0, a3 = 0; + mp_digit r0, r1, r2; +#endif + + /* reduction not needed if a is not larger than field size */ + if (a_used < ECP192_DIGITS) { + if (a == r) { + return MP_OKAY; + } + return mp_copy(a, r); + } + + /* for polynomials larger than twice the field size, use regular + * reduction */ + if (a_used > ECP192_DIGITS*2) { + MP_CHECKOK(mp_mod(a, &meth->irr, r)); + } else { + /* copy out upper words of a */ + +#ifdef ECL_THIRTY_TWO_BIT + + /* in all the math below, + * nXb is most signifiant, nXa is least significant */ + switch (a_used) { + case 12: + a5b = MP_DIGIT(a, 11); + case 11: + a5a = MP_DIGIT(a, 10); + case 10: + a4b = MP_DIGIT(a, 9); + case 9: + a4a = MP_DIGIT(a, 8); + case 8: + a3b = MP_DIGIT(a, 7); + case 7: + a3a = MP_DIGIT(a, 6); + } + + + r2b= MP_DIGIT(a, 5); + r2a= MP_DIGIT(a, 4); + r1b = MP_DIGIT(a, 3); + r1a = MP_DIGIT(a, 2); + r0b = MP_DIGIT(a, 1); + r0a = MP_DIGIT(a, 0); + + /* implement r = (a2,a1,a0)+(a5,a5,a5)+(a4,a4,0)+(0,a3,a3) */ + MP_ADD_CARRY(r0a, a3a, r0a, 0, carry); + MP_ADD_CARRY(r0b, a3b, r0b, carry, carry); + MP_ADD_CARRY(r1a, a3a, r1a, carry, carry); + MP_ADD_CARRY(r1b, a3b, r1b, carry, carry); + MP_ADD_CARRY(r2a, a4a, r2a, carry, carry); + MP_ADD_CARRY(r2b, a4b, r2b, carry, carry); + r3 = carry; carry = 0; + MP_ADD_CARRY(r0a, a5a, r0a, 0, carry); + MP_ADD_CARRY(r0b, a5b, r0b, carry, carry); + MP_ADD_CARRY(r1a, a5a, r1a, carry, carry); + MP_ADD_CARRY(r1b, a5b, r1b, carry, carry); + MP_ADD_CARRY(r2a, a5a, r2a, carry, carry); + MP_ADD_CARRY(r2b, a5b, r2b, carry, carry); + r3 += carry; + MP_ADD_CARRY(r1a, a4a, r1a, 0, carry); + MP_ADD_CARRY(r1b, a4b, r1b, carry, carry); + MP_ADD_CARRY(r2a, 0, r2a, carry, carry); + MP_ADD_CARRY(r2b, 0, r2b, carry, carry); + r3 += carry; + + /* reduce out the carry */ + while (r3) { + MP_ADD_CARRY(r0a, r3, r0a, 0, carry); + MP_ADD_CARRY(r0b, 0, r0b, carry, carry); + MP_ADD_CARRY(r1a, r3, r1a, carry, carry); + MP_ADD_CARRY(r1b, 0, r1b, carry, carry); + MP_ADD_CARRY(r2a, 0, r2a, carry, carry); + MP_ADD_CARRY(r2b, 0, r2b, carry, carry); + r3 = carry; + } + + /* check for final reduction */ + /* + * our field is 0xffffffffffffffff, 0xfffffffffffffffe, + * 0xffffffffffffffff. That means we can only be over and need + * one more reduction + * if r2 == 0xffffffffffffffffff (same as r2+1 == 0) + * and + * r1 == 0xffffffffffffffffff or + * r1 == 0xfffffffffffffffffe and r0 = 0xfffffffffffffffff + * In all cases, we subtract the field (or add the 2's + * complement value (1,1,0)). (r0, r1, r2) + */ + if (((r2b == 0xffffffff) && (r2a == 0xffffffff) + && (r1b == 0xffffffff) ) && + ((r1a == 0xffffffff) || + (r1a == 0xfffffffe) && (r0a == 0xffffffff) && + (r0b == 0xffffffff)) ) { + /* do a quick subtract */ + MP_ADD_CARRY(r0a, 1, r0a, 0, carry); + MP_ADD_CARRY(r0b, carry, r0a, 0, carry); + r1a += 1+carry; + r1b = r2a = r2b = 0; + } + + /* set the lower words of r */ + if (a != r) { + MP_CHECKOK(s_mp_pad(r, 6)); + } + MP_DIGIT(r, 5) = r2b; + MP_DIGIT(r, 4) = r2a; + MP_DIGIT(r, 3) = r1b; + MP_DIGIT(r, 2) = r1a; + MP_DIGIT(r, 1) = r0b; + MP_DIGIT(r, 0) = r0a; + MP_USED(r) = 6; +#else + switch (a_used) { + case 6: + a5 = MP_DIGIT(a, 5); + case 5: + a4 = MP_DIGIT(a, 4); + case 4: + a3 = MP_DIGIT(a, 3); + } + + r2 = MP_DIGIT(a, 2); + r1 = MP_DIGIT(a, 1); + r0 = MP_DIGIT(a, 0); + + /* implement r = (a2,a1,a0)+(a5,a5,a5)+(a4,a4,0)+(0,a3,a3) */ +#ifndef MPI_AMD64_ADD + MP_ADD_CARRY(r0, a3, r0, 0, carry); + MP_ADD_CARRY(r1, a3, r1, carry, carry); + MP_ADD_CARRY(r2, a4, r2, carry, carry); + r3 = carry; + MP_ADD_CARRY(r0, a5, r0, 0, carry); + MP_ADD_CARRY(r1, a5, r1, carry, carry); + MP_ADD_CARRY(r2, a5, r2, carry, carry); + r3 += carry; + MP_ADD_CARRY(r1, a4, r1, 0, carry); + MP_ADD_CARRY(r2, 0, r2, carry, carry); + r3 += carry; + +#else + r2 = MP_DIGIT(a, 2); + r1 = MP_DIGIT(a, 1); + r0 = MP_DIGIT(a, 0); + + /* set the lower words of r */ + __asm__ ( + "xorq %3,%3 \n\t" + "addq %4,%0 \n\t" + "adcq %4,%1 \n\t" + "adcq %5,%2 \n\t" + "adcq $0,%3 \n\t" + "addq %6,%0 \n\t" + "adcq %6,%1 \n\t" + "adcq %6,%2 \n\t" + "adcq $0,%3 \n\t" + "addq %5,%1 \n\t" + "adcq $0,%2 \n\t" + "adcq $0,%3 \n\t" + : "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3), "=r"(a3), + "=r"(a4), "=r"(a5) + : "0" (r0), "1" (r1), "2" (r2), "3" (r3), + "4" (a3), "5" (a4), "6"(a5) + : "%cc" ); +#endif + + /* reduce out the carry */ + while (r3) { +#ifndef MPI_AMD64_ADD + MP_ADD_CARRY(r0, r3, r0, 0, carry); + MP_ADD_CARRY(r1, r3, r1, carry, carry); + MP_ADD_CARRY(r2, 0, r2, carry, carry); + r3 = carry; +#else + a3=r3; + __asm__ ( + "xorq %3,%3 \n\t" + "addq %4,%0 \n\t" + "adcq %4,%1 \n\t" + "adcq $0,%2 \n\t" + "adcq $0,%3 \n\t" + : "=r"(r0), "=r"(r1), "=r"(r2), "=r"(r3), "=r"(a3) + : "0" (r0), "1" (r1), "2" (r2), "3" (r3), "4"(a3) + : "%cc" ); +#endif + } + + /* check for final reduction */ + /* + * our field is 0xffffffffffffffff, 0xfffffffffffffffe, + * 0xffffffffffffffff. That means we can only be over and need + * one more reduction + * if r2 == 0xffffffffffffffffff (same as r2+1 == 0) + * and + * r1 == 0xffffffffffffffffff or + * r1 == 0xfffffffffffffffffe and r0 = 0xfffffffffffffffff + * In all cases, we subtract the field (or add the 2's + * complement value (1,1,0)). (r0, r1, r2) + */ + if (r3 || ((r2 == MP_DIGIT_MAX) && + ((r1 == MP_DIGIT_MAX) || + ((r1 == (MP_DIGIT_MAX-1)) && (r0 == MP_DIGIT_MAX))))) { + /* do a quick subtract */ + MP_ADD_CARRY(r0, 1, r0, 0, carry); + r1 += 1+carry; + r2 = 0; + } + /* set the lower words of r */ + if (a != r) { + MP_CHECKOK(s_mp_pad(r, 3)); + } + MP_DIGIT(r, 2) = r2; + MP_DIGIT(r, 1) = r1; + MP_DIGIT(r, 0) = r0; + MP_USED(r) = 3; +#endif + } + s_mp_clamp(r); + CLEANUP: + return res; +} + +#ifndef ECL_THIRTY_TWO_BIT +/* Compute the sum of 192 bit curves. Do the work in-line since the + * number of words are so small, we don't want to overhead of mp function + * calls. Uses optimized modular reduction for p192. + */ +static mp_err +ec_GFp_nistp192_add(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 + + /* Do quick 'subract' if we've gone over + * (add the 2's complement of the curve field) */ + if (carry || ((r2 == MP_DIGIT_MAX) && + ((r1 == MP_DIGIT_MAX) || + ((r1 == (MP_DIGIT_MAX-1)) && (r0 == MP_DIGIT_MAX))))) { +#ifndef MPI_AMD64_ADD + MP_ADD_CARRY(r0, 1, r0, 0, carry); + MP_ADD_CARRY(r1, 1, r1, carry, carry); + MP_ADD_CARRY(r2, 0, r2, carry, carry); +#else + __asm__ ( + "addq $1,%0 \n\t" + "adcq $1,%1 \n\t" + "adcq $0,%2 \n\t" + : "=r"(r0), "=r"(r1), "=r"(r2) + : "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; + s_mp_clamp(r); + + + CLEANUP: + return res; +} + +/* Compute the diff of 192 bit curves. Do the work in-line since the + * number of words are so small, we don't want to overhead of mp function + * calls. Uses optimized modular reduction for p192. + */ +static mp_err +ec_GFp_nistp192_sub(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) { +#ifndef MPI_AMD64_ADD + MP_SUB_BORROW(r0, 1, r0, 0, borrow); + MP_SUB_BORROW(r1, 1, r1, borrow, borrow); + MP_SUB_BORROW(r2, 0, r2, borrow, borrow); +#else + __asm__ ( + "subq $1,%0 \n\t" + "sbbq $1,%1 \n\t" + "sbbq $0,%2 \n\t" + : "=r"(r0), "=r"(r1), "=r"(r2) + : "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; + s_mp_clamp(r); + + CLEANUP: + return res; +} + +#endif + +/* Compute the square of polynomial a, reduce modulo p192. Store the + * result in r. r could be a. Uses optimized modular reduction for p192. + */ +static mp_err +ec_GFp_nistp192_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_nistp192_mod(r, r, meth)); + CLEANUP: + return res; +} + +/* Compute the product of two polynomials a and b, reduce modulo p192. + * Store the result in r. r could be a or b; a could be b. Uses + * optimized modular reduction for p192. */ +static mp_err +ec_GFp_nistp192_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_nistp192_mod(r, r, meth)); + CLEANUP: + return res; +} + +/* Divides two field elements. If a is NULL, then returns the inverse of + * b. */ +static mp_err +ec_GFp_nistp192_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_mul(a, &t, r)); + MP_CHECKOK(ec_GFp_nistp192_mod(r, r, meth)); + CLEANUP: + mp_clear(&t); + return res; + } +} + +/* Wire in fast field arithmetic and precomputation of base point for + * named curves. */ +mp_err +ec_group_set_gfp192(ECGroup *group, ECCurveName name) +{ + if (name == ECCurve_NIST_P192) { + group->meth->field_mod = &ec_GFp_nistp192_mod; + group->meth->field_mul = &ec_GFp_nistp192_mul; + group->meth->field_sqr = &ec_GFp_nistp192_sqr; + group->meth->field_div = &ec_GFp_nistp192_div; +#ifndef ECL_THIRTY_TWO_BIT + group->meth->field_add = &ec_GFp_nistp192_add; + group->meth->field_sub = &ec_GFp_nistp192_sub; +#endif + } + return MP_OKAY; +}