/* * ***** 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 using floating point operations. * * 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): * Stephen Fung , Sun Microsystems Laboratories * * 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 ***** */ /* This source file is meant to be included by other source files * (ecp_fp###.c, where ### is one of 160, 192, 224) and should not * constitute an independent compilation unit. It requires the following * preprocessor definitions be made: ECFP_BSIZE - the number of bits in * the field's prime * ECFP_NUMDOUBLES - the number of doubles to store one * multi-precision integer in floating point /* Adds a prefix to a given token to give a unique token name. Prefixes * with "ecfp" + ECFP_BSIZE + "_". e.g. if ECFP_BSIZE = 160, then * PREFIX(hello) = ecfp160_hello This optimization allows static function * linking and compiler loop unrolling without code duplication. */ #ifndef PREFIX #define PREFIX(b) PREFIX1(ECFP_BSIZE, b) #define PREFIX1(bsize, b) PREFIX2(bsize, b) #define PREFIX2(bsize, b) ecfp ## bsize ## _ ## b #endif /* Returns true iff every double in d is 0. (If d == 0 and it is tidied, * this will be true.) */ mp_err PREFIX(isZero) (const double *d) { int i; for (i = 0; i < ECFP_NUMDOUBLES; i++) { if (d[i] != 0) return MP_NO; } return MP_YES; } /* Sets the multi-precision floating point number at t = 0 */ void PREFIX(zero) (double *t) { int i; for (i = 0; i < ECFP_NUMDOUBLES; i++) { t[i] = 0; } } /* Sets the multi-precision floating point number at t = 1 */ void PREFIX(one) (double *t) { int i; t[0] = 1; for (i = 1; i < ECFP_NUMDOUBLES; i++) { t[i] = 0; } } /* Checks if point P(x, y, z) is at infinity. Uses Jacobian coordinates. */ mp_err PREFIX(pt_is_inf_jac) (const ecfp_jac_pt * p) { return PREFIX(isZero) (p->z); } /* Sets the Jacobian point P to be at infinity. */ void PREFIX(set_pt_inf_jac) (ecfp_jac_pt * p) { PREFIX(zero) (p->z); } /* Checks if point P(x, y) is at infinity. Uses Affine coordinates. */ mp_err PREFIX(pt_is_inf_aff) (const ecfp_aff_pt * p) { if (PREFIX(isZero) (p->x) == MP_YES && PREFIX(isZero) (p->y) == MP_YES) return MP_YES; return MP_NO; } /* Sets the affine point P to be at infinity. */ void PREFIX(set_pt_inf_aff) (ecfp_aff_pt * p) { PREFIX(zero) (p->x); PREFIX(zero) (p->y); } /* Checks if point P(x, y, z, a*z^4) is at infinity. Uses Modified * Jacobian coordinates. */ mp_err PREFIX(pt_is_inf_jm) (const ecfp_jm_pt * p) { return PREFIX(isZero) (p->z); } /* Sets the Modified Jacobian point P to be at infinity. */ void PREFIX(set_pt_inf_jm) (ecfp_jm_pt * p) { PREFIX(zero) (p->z); } /* Checks if point P(x, y, z, z^2, z^3) is at infinity. Uses Chudnovsky * Jacobian coordinates */ mp_err PREFIX(pt_is_inf_chud) (const ecfp_chud_pt * p) { return PREFIX(isZero) (p->z); } /* Sets the Chudnovsky Jacobian point P to be at infinity. */ void PREFIX(set_pt_inf_chud) (ecfp_chud_pt * p) { PREFIX(zero) (p->z); } /* Copies a multi-precision floating point number, Setting dest = src */ void PREFIX(copy) (double *dest, const double *src) { int i; for (i = 0; i < ECFP_NUMDOUBLES; i++) { dest[i] = src[i]; } } /* Sets dest = -src */ void PREFIX(negLong) (double *dest, const double *src) { int i; for (i = 0; i < 2 * ECFP_NUMDOUBLES; i++) { dest[i] = -src[i]; } } /* Sets r = -p p = (x, y, z, z2, z3) r = (x, -y, z, z2, z3) Uses * Chudnovsky Jacobian coordinates. */ /* TODO reverse order */ void PREFIX(pt_neg_chud) (const ecfp_chud_pt * p, ecfp_chud_pt * r) { int i; PREFIX(copy) (r->x, p->x); PREFIX(copy) (r->z, p->z); PREFIX(copy) (r->z2, p->z2); PREFIX(copy) (r->z3, p->z3); for (i = 0; i < ECFP_NUMDOUBLES; i++) { r->y[i] = -p->y[i]; } } /* Computes r = x + y. Does not tidy or reduce. Any combinations of r, x, * y can point to the same data. Componentwise adds first ECFP_NUMDOUBLES * doubles of x and y and stores the result in r. */ void PREFIX(addShort) (double *r, const double *x, const double *y) { int i; for (i = 0; i < ECFP_NUMDOUBLES; i++) { *r++ = *x++ + *y++; } } /* Computes r = x + y. Does not tidy or reduce. Any combinations of r, x, * y can point to the same data. Componentwise adds first * 2*ECFP_NUMDOUBLES doubles of x and y and stores the result in r. */ void PREFIX(addLong) (double *r, const double *x, const double *y) { int i; for (i = 0; i < 2 * ECFP_NUMDOUBLES; i++) { *r++ = *x++ + *y++; } } /* Computes r = x - y. Does not tidy or reduce. Any combinations of r, x, * y can point to the same data. Componentwise subtracts first * ECFP_NUMDOUBLES doubles of x and y and stores the result in r. */ void PREFIX(subtractShort) (double *r, const double *x, const double *y) { int i; for (i = 0; i < ECFP_NUMDOUBLES; i++) { *r++ = *x++ - *y++; } } /* Computes r = x - y. Does not tidy or reduce. Any combinations of r, x, * y can point to the same data. Componentwise subtracts first * 2*ECFP_NUMDOUBLES doubles of x and y and stores the result in r. */ void PREFIX(subtractLong) (double *r, const double *x, const double *y) { int i; for (i = 0; i < 2 * ECFP_NUMDOUBLES; i++) { *r++ = *x++ - *y++; } } /* Computes r = x*y. Both x and y should be tidied and reduced, * r must be different (point to different memory) than x and y. * Does not tidy or reduce. */ void PREFIX(multiply)(double *r, const double *x, const double *y) { int i, j; for(j=0;jaIsM3) { /* When a = -3, M = 3(px - pz^2)(px + pz^2) */ PREFIX(square) (t1, dp->z); group->ecfp_reduce(t1, t1, group); /* 2^23 since the negative * rounding buys another bit */ PREFIX(addShort) (t0, dp->x, t1); /* 2*2^23 */ PREFIX(subtractShort) (t1, dp->x, t1); /* 2 * 2^23 */ PREFIX(multiply) (M, t0, t1); /* 40 * 2^46 */ PREFIX(addLong) (t0, M, M); /* 80 * 2^46 */ PREFIX(addLong) (M, t0, M); /* 120 * 2^46 < 2^53 */ group->ecfp_reduce(M, M, group); } else { /* Generic case */ /* M = 3 (px^2) + a*(pz^4) */ PREFIX(square) (t0, dp->x); PREFIX(addLong) (M, t0, t0); PREFIX(addLong) (t0, t0, M); /* t0 = 3(px^2) */ PREFIX(square) (M, dp->z); group->ecfp_reduce(M, M, group); PREFIX(square) (t1, M); group->ecfp_reduce(t1, t1, group); PREFIX(multiply) (M, t1, group->curvea); /* M = a(pz^4) */ PREFIX(addLong) (M, M, t0); group->ecfp_reduce(M, M, group); } /* rz = 2 * py * pz */ PREFIX(multiply) (t1, dp->y, dp->z); PREFIX(addLong) (t1, t1, t1); group->ecfp_reduce(dr->z, t1, group); /* t0 = 2y^2 */ PREFIX(square) (t0, dp->y); group->ecfp_reduce(t0, t0, group); PREFIX(addShort) (t0, t0, t0); /* S = 4 * px * py^2 = 2 * px * t0 */ PREFIX(multiply) (S, dp->x, t0); PREFIX(addLong) (S, S, S); group->ecfp_reduce(S, S, group); /* rx = M^2 - 2 * S */ PREFIX(square) (t1, M); PREFIX(subtractShort) (t1, t1, S); PREFIX(subtractShort) (t1, t1, S); group->ecfp_reduce(dr->x, t1, group); /* ry = M * (S - rx) - 8 * py^4 */ PREFIX(square) (t1, t0); /* t1 = 4y^4 */ PREFIX(subtractShort) (S, S, dr->x); PREFIX(multiply) (t0, M, S); PREFIX(subtractLong) (t0, t0, t1); PREFIX(subtractLong) (t0, t0, t1); group->ecfp_reduce(dr->y, t0, group); CLEANUP: return; } /* Perform a point addition using coordinate system Jacobian + Affine -> * Jacobian. Input and output should be multi-precision floating point * integers. */ void PREFIX(pt_add_jac_aff) (const ecfp_jac_pt * p, const ecfp_aff_pt * q, ecfp_jac_pt * r, const EC_group_fp * group) { /* Temporary storage */ double A[2 * ECFP_NUMDOUBLES], B[2 * ECFP_NUMDOUBLES], C[2 * ECFP_NUMDOUBLES], C2[2 * ECFP_NUMDOUBLES], D[2 * ECFP_NUMDOUBLES], C3[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity for p or q */ if (PREFIX(pt_is_inf_aff) (q) == MP_YES) { PREFIX(copy) (r->x, p->x); PREFIX(copy) (r->y, p->y); PREFIX(copy) (r->z, p->z); goto CLEANUP; } else if (PREFIX(pt_is_inf_jac) (p) == MP_YES) { PREFIX(copy) (r->x, q->x); PREFIX(copy) (r->y, q->y); /* Since the affine point is not infinity, we can set r->z = 1 */ PREFIX(one) (r->z); goto CLEANUP; } /* Calculates c = qx * pz^2 - px d = (qy * b - py) rx = d^2 - c^3 + 2 * (px * c^2) ry = d * (c-rx) - py*c^3 rz = c * pz */ /* A = pz^2, B = pz^3 */ PREFIX(square) (A, p->z); group->ecfp_reduce(A, A, group); PREFIX(multiply) (B, A, p->z); group->ecfp_reduce(B, B, group); /* C = qx * A - px */ PREFIX(multiply) (C, q->x, A); PREFIX(subtractShort) (C, C, p->x); group->ecfp_reduce(C, C, group); /* D = qy * B - py */ PREFIX(multiply) (D, q->y, B); PREFIX(subtractShort) (D, D, p->y); group->ecfp_reduce(D, D, group); /* C2 = C^2, C3 = C^3 */ PREFIX(square) (C2, C); group->ecfp_reduce(C2, C2, group); PREFIX(multiply) (C3, C2, C); group->ecfp_reduce(C3, C3, group); /* rz = A = pz * C */ PREFIX(multiply) (A, p->z, C); group->ecfp_reduce(r->z, A, group); /* C = px * C^2, untidied, unreduced */ PREFIX(multiply) (C, p->x, C2); /* A = D^2, untidied, unreduced */ PREFIX(square) (A, D); /* rx = B = A - C3 - C - C = D^2 - (C^3 + 2 * (px * C^2) */ PREFIX(subtractShort) (A, A, C3); PREFIX(subtractLong) (A, A, C); PREFIX(subtractLong) (A, A, C); group->ecfp_reduce(r->x, A, group); /* B = py * C3, untidied, unreduced */ PREFIX(multiply) (B, p->y, C3); /* C = px * C^2 - rx */ PREFIX(subtractShort) (C, C, r->x); group->ecfp_reduce(C, C, group); /* ry = A = D * C - py * C^3 */ PREFIX(multiply) (A, D, C); PREFIX(subtractLong) (A, A, B); group->ecfp_reduce(r->y, A, group); CLEANUP: return; } /* Perform a point addition using Jacobian coordinate system. Input and * output should be multi-precision floating point integers. */ void PREFIX(pt_add_jac) (const ecfp_jac_pt * p, const ecfp_jac_pt * q, ecfp_jac_pt * r, const EC_group_fp * group) { /* Temporary Storage */ double t0[2 * ECFP_NUMDOUBLES], t1[2 * ECFP_NUMDOUBLES], U[2 * ECFP_NUMDOUBLES], R[2 * ECFP_NUMDOUBLES], S[2 * ECFP_NUMDOUBLES], H[2 * ECFP_NUMDOUBLES], H3[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity for p, if so set r = q */ if (PREFIX(pt_is_inf_jac) (p) == MP_YES) { PREFIX(copy) (r->x, q->x); PREFIX(copy) (r->y, q->y); PREFIX(copy) (r->z, q->z); goto CLEANUP; } /* Check for point at infinity for p, if so set r = q */ if (PREFIX(pt_is_inf_jac) (q) == MP_YES) { PREFIX(copy) (r->x, p->x); PREFIX(copy) (r->y, p->y); PREFIX(copy) (r->z, p->z); goto CLEANUP; } /* U = px * qz^2 , S = py * qz^3 */ PREFIX(square) (t0, q->z); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (U, p->x, t0); group->ecfp_reduce(U, U, group); PREFIX(multiply) (t1, t0, q->z); group->ecfp_reduce(t1, t1, group); PREFIX(multiply) (t0, p->y, t1); group->ecfp_reduce(S, t0, group); /* H = qx*(pz)^2 - U , R = (qy * pz^3 - S) */ PREFIX(square) (t0, p->z); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (H, q->x, t0); PREFIX(subtractShort) (H, H, U); group->ecfp_reduce(H, H, group); PREFIX(multiply) (t1, t0, p->z); /* t1 = pz^3 */ group->ecfp_reduce(t1, t1, group); PREFIX(multiply) (t0, t1, q->y); /* t0 = qy * pz^3 */ PREFIX(subtractShort) (t0, t0, S); group->ecfp_reduce(R, t0, group); /* U = U*H^2, H3 = H^3 */ PREFIX(square) (t0, H); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, U, t0); group->ecfp_reduce(U, t1, group); PREFIX(multiply) (H3, t0, H); group->ecfp_reduce(H3, H3, group); /* rz = pz * qz * H */ PREFIX(multiply) (t0, q->z, H); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, t0, p->z); group->ecfp_reduce(r->z, t1, group); /* rx = R^2 - H^3 - 2 * U */ PREFIX(square) (t0, R); PREFIX(subtractShort) (t0, t0, H3); PREFIX(subtractShort) (t0, t0, U); PREFIX(subtractShort) (t0, t0, U); group->ecfp_reduce(r->x, t0, group); /* ry = R(U - rx) - S*H3 */ PREFIX(subtractShort) (t1, U, r->x); PREFIX(multiply) (t0, t1, R); PREFIX(multiply) (t1, S, H3); PREFIX(subtractLong) (t1, t0, t1); group->ecfp_reduce(r->y, t1, group); CLEANUP: return; } /* Perform a point doubling in Modified Jacobian coordinates. Input and * output should be multi-precision floating point integers. */ void PREFIX(pt_dbl_jm) (const ecfp_jm_pt * p, ecfp_jm_pt * r, const EC_group_fp * group) { /* Temporary storage */ double t0[2 * ECFP_NUMDOUBLES], t1[2 * ECFP_NUMDOUBLES], M[2 * ECFP_NUMDOUBLES], S[2 * ECFP_NUMDOUBLES], U[2 * ECFP_NUMDOUBLES], T[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity */ if (PREFIX(pt_is_inf_jm) (p) == MP_YES) { /* Set r = pt at infinity by setting rz = 0 */ PREFIX(set_pt_inf_jm) (r); goto CLEANUP; } /* M = 3 (px^2) + a*(pz^4) */ PREFIX(square) (t0, p->x); PREFIX(addLong) (M, t0, t0); PREFIX(addLong) (t0, t0, M); /* t0 = 3(px^2) */ PREFIX(addShort) (t0, t0, p->az4); group->ecfp_reduce(M, t0, group); /* rz = 2 * py * pz */ PREFIX(multiply) (t1, p->y, p->z); PREFIX(addLong) (t1, t1, t1); group->ecfp_reduce(r->z, t1, group); /* t0 = 2y^2, U = 8y^4 */ PREFIX(square) (t0, p->y); group->ecfp_reduce(t0, t0, group); PREFIX(addShort) (t0, t0, t0); PREFIX(square) (U, t0); group->ecfp_reduce(U, U, group); PREFIX(addShort) (U, U, U); /* S = 4 * px * py^2 = 2 * px * t0 */ PREFIX(multiply) (S, p->x, t0); group->ecfp_reduce(S, S, group); PREFIX(addShort) (S, S, S); /* rx = M^2 - 2S */ PREFIX(square) (T, M); PREFIX(subtractShort) (T, T, S); PREFIX(subtractShort) (T, T, S); group->ecfp_reduce(r->x, T, group); /* ry = M * (S - rx) - U */ PREFIX(subtractShort) (S, S, r->x); PREFIX(multiply) (t0, M, S); PREFIX(subtractShort) (t0, t0, U); group->ecfp_reduce(r->y, t0, group); /* ra*z^4 = 2*U*(apz4) */ PREFIX(multiply) (t1, U, p->az4); PREFIX(addLong) (t1, t1, t1); group->ecfp_reduce(r->az4, t1, group); CLEANUP: return; } /* Perform a point doubling using coordinates Affine -> Chudnovsky * Jacobian. Input and output should be multi-precision floating point * integers. */ void PREFIX(pt_dbl_aff2chud) (const ecfp_aff_pt * p, ecfp_chud_pt * r, const EC_group_fp * group) { double t0[2 * ECFP_NUMDOUBLES], t1[2 * ECFP_NUMDOUBLES], M[2 * ECFP_NUMDOUBLES], twoY2[2 * ECFP_NUMDOUBLES], S[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity for p, if so set r = O */ if (PREFIX(pt_is_inf_aff) (p) == MP_YES) { PREFIX(set_pt_inf_chud) (r); goto CLEANUP; } /* M = 3(px)^2 + a */ PREFIX(square) (t0, p->x); PREFIX(addLong) (t1, t0, t0); PREFIX(addLong) (t1, t1, t0); PREFIX(addShort) (t1, t1, group->curvea); group->ecfp_reduce(M, t1, group); /* twoY2 = 2*(py)^2, S = 4(px)(py)^2 */ PREFIX(square) (twoY2, p->y); PREFIX(addLong) (twoY2, twoY2, twoY2); group->ecfp_reduce(twoY2, twoY2, group); PREFIX(multiply) (S, p->x, twoY2); PREFIX(addLong) (S, S, S); group->ecfp_reduce(S, S, group); /* rx = M^2 - 2S */ PREFIX(square) (t0, M); PREFIX(subtractShort) (t0, t0, S); PREFIX(subtractShort) (t0, t0, S); group->ecfp_reduce(r->x, t0, group); /* ry = M(S-rx) - 8y^4 */ PREFIX(subtractShort) (t0, S, r->x); PREFIX(multiply) (t1, t0, M); PREFIX(square) (t0, twoY2); PREFIX(subtractLong) (t1, t1, t0); PREFIX(subtractLong) (t1, t1, t0); group->ecfp_reduce(r->y, t1, group); /* rz = 2py */ PREFIX(addShort) (r->z, p->y, p->y); /* rz2 = rz^2 */ PREFIX(square) (t0, r->z); group->ecfp_reduce(r->z2, t0, group); /* rz3 = rz^3 */ PREFIX(multiply) (t0, r->z, r->z2); group->ecfp_reduce(r->z3, t0, group); CLEANUP: return; } /* Perform a point addition using coordinates: Modified Jacobian + * Chudnovsky Jacobian -> Modified Jacobian. Input and output should be * multi-precision floating point integers. */ void PREFIX(pt_add_jm_chud) (ecfp_jm_pt * p, ecfp_chud_pt * q, ecfp_jm_pt * r, const EC_group_fp * group) { double t0[2 * ECFP_NUMDOUBLES], t1[2 * ECFP_NUMDOUBLES], U[2 * ECFP_NUMDOUBLES], R[2 * ECFP_NUMDOUBLES], S[2 * ECFP_NUMDOUBLES], H[2 * ECFP_NUMDOUBLES], H3[2 * ECFP_NUMDOUBLES], pz2[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity for p, if so set r = q need to convert * from Chudnovsky form to Modified Jacobian form */ if (PREFIX(pt_is_inf_jm) (p) == MP_YES) { PREFIX(copy) (r->x, q->x); PREFIX(copy) (r->y, q->y); PREFIX(copy) (r->z, q->z); PREFIX(square) (t0, q->z2); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, t0, group->curvea); group->ecfp_reduce(r->az4, t1, group); goto CLEANUP; } /* Check for point at infinity for q, if so set r = p */ if (PREFIX(pt_is_inf_chud) (q) == MP_YES) { PREFIX(copy) (r->x, p->x); PREFIX(copy) (r->y, p->y); PREFIX(copy) (r->z, p->z); PREFIX(copy) (r->az4, p->az4); goto CLEANUP; } /* U = px * qz^2 */ PREFIX(multiply) (U, p->x, q->z2); group->ecfp_reduce(U, U, group); /* H = qx*(pz)^2 - U */ PREFIX(square) (t0, p->z); group->ecfp_reduce(pz2, t0, group); PREFIX(multiply) (H, pz2, q->x); group->ecfp_reduce(H, H, group); PREFIX(subtractShort) (H, H, U); /* U = U*H^2, H3 = H^3 */ PREFIX(square) (t0, H); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, U, t0); group->ecfp_reduce(U, t1, group); PREFIX(multiply) (H3, t0, H); group->ecfp_reduce(H3, H3, group); /* S = py * qz^3 */ PREFIX(multiply) (S, p->y, q->z3); group->ecfp_reduce(S, S, group); /* R = (qy * z1^3 - s) */ PREFIX(multiply) (t0, pz2, p->z); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (R, t0, q->y); PREFIX(subtractShort) (R, R, S); group->ecfp_reduce(R, R, group); /* rz = pz * qz * H */ PREFIX(multiply) (t1, q->z, H); group->ecfp_reduce(t1, t1, group); PREFIX(multiply) (t0, p->z, t1); group->ecfp_reduce(r->z, t0, group); /* rx = R^2 - H^3 - 2 * U */ PREFIX(square) (t0, R); PREFIX(subtractShort) (t0, t0, H3); PREFIX(subtractShort) (t0, t0, U); PREFIX(subtractShort) (t0, t0, U); group->ecfp_reduce(r->x, t0, group); /* ry = R(U - rx) - S*H3 */ PREFIX(subtractShort) (t1, U, r->x); PREFIX(multiply) (t0, t1, R); PREFIX(multiply) (t1, S, H3); PREFIX(subtractLong) (t1, t0, t1); group->ecfp_reduce(r->y, t1, group); if (group->aIsM3) { /* a == -3 */ /* a(rz^4) = -3 * ((rz^2)^2) */ PREFIX(square) (t0, r->z); group->ecfp_reduce(t0, t0, group); PREFIX(square) (t1, t0); PREFIX(addLong) (t0, t1, t1); PREFIX(addLong) (t0, t0, t1); PREFIX(negLong) (t0, t0); group->ecfp_reduce(r->az4, t0, group); } else { /* Generic case */ /* a(rz^4) = a * ((rz^2)^2) */ PREFIX(square) (t0, r->z); group->ecfp_reduce(t0, t0, group); PREFIX(square) (t1, t0); group->ecfp_reduce(t1, t1, group); PREFIX(multiply) (t0, group->curvea, t1); group->ecfp_reduce(r->az4, t0, group); } CLEANUP: return; } /* Perform a point addition using Chudnovsky Jacobian coordinates. Input * and output should be multi-precision floating point integers. */ void PREFIX(pt_add_chud) (const ecfp_chud_pt * p, const ecfp_chud_pt * q, ecfp_chud_pt * r, const EC_group_fp * group) { /* Temporary Storage */ double t0[2 * ECFP_NUMDOUBLES], t1[2 * ECFP_NUMDOUBLES], U[2 * ECFP_NUMDOUBLES], R[2 * ECFP_NUMDOUBLES], S[2 * ECFP_NUMDOUBLES], H[2 * ECFP_NUMDOUBLES], H3[2 * ECFP_NUMDOUBLES]; /* Check for point at infinity for p, if so set r = q */ if (PREFIX(pt_is_inf_chud) (p) == MP_YES) { PREFIX(copy) (r->x, q->x); PREFIX(copy) (r->y, q->y); PREFIX(copy) (r->z, q->z); PREFIX(copy) (r->z2, q->z2); PREFIX(copy) (r->z3, q->z3); goto CLEANUP; } /* Check for point at infinity for p, if so set r = q */ if (PREFIX(pt_is_inf_chud) (q) == MP_YES) { PREFIX(copy) (r->x, p->x); PREFIX(copy) (r->y, p->y); PREFIX(copy) (r->z, p->z); PREFIX(copy) (r->z2, p->z2); PREFIX(copy) (r->z3, p->z3); goto CLEANUP; } /* U = px * qz^2 */ PREFIX(multiply) (U, p->x, q->z2); group->ecfp_reduce(U, U, group); /* H = qx*(pz)^2 - U */ PREFIX(multiply) (H, q->x, p->z2); PREFIX(subtractShort) (H, H, U); group->ecfp_reduce(H, H, group); /* U = U*H^2, H3 = H^3 */ PREFIX(square) (t0, H); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, U, t0); group->ecfp_reduce(U, t1, group); PREFIX(multiply) (H3, t0, H); group->ecfp_reduce(H3, H3, group); /* S = py * qz^3 */ PREFIX(multiply) (S, p->y, q->z3); group->ecfp_reduce(S, S, group); /* rz = pz * qz * H */ PREFIX(multiply) (t0, q->z, H); group->ecfp_reduce(t0, t0, group); PREFIX(multiply) (t1, t0, p->z); group->ecfp_reduce(r->z, t1, group); /* R = (qy * z1^3 - s) */ PREFIX(multiply) (t0, q->y, p->z3); PREFIX(subtractShort) (t0, t0, S); group->ecfp_reduce(R, t0, group); /* rx = R^2 - H^3 - 2 * U */ PREFIX(square) (t0, R); PREFIX(subtractShort) (t0, t0, H3); PREFIX(subtractShort) (t0, t0, U); PREFIX(subtractShort) (t0, t0, U); group->ecfp_reduce(r->x, t0, group); /* ry = R(U - rx) - S*H3 */ PREFIX(subtractShort) (t1, U, r->x); PREFIX(multiply) (t0, t1, R); PREFIX(multiply) (t1, S, H3); PREFIX(subtractLong) (t1, t0, t1); group->ecfp_reduce(r->y, t1, group); /* rz2 = rz^2 */ PREFIX(square) (t0, r->z); group->ecfp_reduce(r->z2, t0, group); /* rz3 = rz^3 */ PREFIX(multiply) (t0, r->z, r->z2); group->ecfp_reduce(r->z3, t0, group); CLEANUP: return; } /* Expects out to be an array of size 16 of Chudnovsky Jacobian points. * Fills in Chudnovsky Jacobian form (x, y, z, z^2, z^3), for -15P, -13P, * -11P, -9P, -7P, -5P, -3P, -P, P, 3P, 5P, 7P, 9P, 11P, 13P, 15P */ void PREFIX(precompute_chud) (ecfp_chud_pt * out, const ecfp_aff_pt * p, const EC_group_fp * group) { ecfp_chud_pt p2; /* Set out[8] = P */ PREFIX(copy) (out[8].x, p->x); PREFIX(copy) (out[8].y, p->y); PREFIX(one) (out[8].z); PREFIX(one) (out[8].z2); PREFIX(one) (out[8].z3); /* Set p2 = 2P */ PREFIX(pt_dbl_aff2chud) (p, &p2, group); /* Set 3P, 5P, ..., 15P */ PREFIX(pt_add_chud) (&out[8], &p2, &out[9], group); PREFIX(pt_add_chud) (&out[9], &p2, &out[10], group); PREFIX(pt_add_chud) (&out[10], &p2, &out[11], group); PREFIX(pt_add_chud) (&out[11], &p2, &out[12], group); PREFIX(pt_add_chud) (&out[12], &p2, &out[13], group); PREFIX(pt_add_chud) (&out[13], &p2, &out[14], group); PREFIX(pt_add_chud) (&out[14], &p2, &out[15], group); /* Set -15P, -13P, ..., -P */ PREFIX(pt_neg_chud) (&out[8], &out[7]); PREFIX(pt_neg_chud) (&out[9], &out[6]); PREFIX(pt_neg_chud) (&out[10], &out[5]); PREFIX(pt_neg_chud) (&out[11], &out[4]); PREFIX(pt_neg_chud) (&out[12], &out[3]); PREFIX(pt_neg_chud) (&out[13], &out[2]); PREFIX(pt_neg_chud) (&out[14], &out[1]); PREFIX(pt_neg_chud) (&out[15], &out[0]); } /* Expects out to be an array of size 16 of Jacobian points. Fills in * Jacobian form (x, y, z), for O, P, 2P, ... 15P */ void PREFIX(precompute_jac) (ecfp_jac_pt * precomp, const ecfp_aff_pt * p, const EC_group_fp * group) { int i; /* fill precomputation table */ /* set precomp[0] */ PREFIX(set_pt_inf_jac) (&precomp[0]); /* set precomp[1] */ PREFIX(copy) (precomp[1].x, p->x); PREFIX(copy) (precomp[1].y, p->y); if (PREFIX(pt_is_inf_aff) (p) == MP_YES) { PREFIX(zero) (precomp[1].z); } else { PREFIX(one) (precomp[1].z); } /* set precomp[2] */ group->pt_dbl_jac(&precomp[1], &precomp[2], group); /* set rest of precomp */ for (i = 3; i < 16; i++) { group->pt_add_jac_aff(&precomp[i - 1], p, &precomp[i], group); } }