Lines Matching defs:P1
831 * Point addition (Jacobian coordinates): P1 is replaced with P1+P2.
834 * - If P1 == 0 but P2 != 0
835 * - If P1 != 0 but P2 == 0
836 * - If P1 == P2
838 * In all three cases, P1 is set to the point at infinity.
842 * - P1 and P2 have the same Y coordinate.
843 * - P1 == 0 and P2 == 0.
851 * Therefore, assuming that P1 != 0 and P2 != 0 on input, then the caller
856 * P1+P2 == 0, so the result is indeed the point at infinity.
857 * - Otherwise, P1 == P2, so a "double" operation should have been
861 * e.g. if P1 and P2 have the same Y coordinate, but distinct X coordinates.
864 p256_add(p256_jacobian *P1, const p256_jacobian *P2)
886 f256_montymul(t1, P1->x, t3);
888 f256_montymul(t3, P1->y, t4);
893 f256_montysquare(t4, P1->z);
895 f256_montymul(t5, P1->z, t4);
920 f256_montysquare(P1->x, t4);
921 f256_sub(P1->x, P1->x, t5);
922 f256_sub(P1->x, P1->x, t6);
923 f256_sub(P1->x, P1->x, t6);
928 f256_sub(t6, t6, P1->x);
929 f256_montymul(P1->y, t4, t6);
931 f256_sub(P1->y, P1->y, t1);
936 f256_montymul(t1, P1->z, P2->z);
937 f256_montymul(P1->z, t1, t2);
943 * Point addition (mixed coordinates): P1 is replaced with P1+P2.
949 * - If P1 == 0
950 * - If P1 == P2
952 * In both cases, P1 is set to the point at infinity.
956 * - P1 and P2 have the same Y (affine) coordinate.
957 * - The Y coordinate of P2 is 0 and P1 is the point at infinity.
963 * Therefore, assuming that P1 != 0 on input, then the caller
968 * P1+P2 == 0, so the result is indeed the point at infinity.
969 * - Otherwise, P1 == P2, so a "double" operation should have been
976 p256_add_mixed(p256_jacobian *P1, const p256_affine *P2)
997 memcpy(t1, P1->x, sizeof t1);
998 memcpy(t3, P1->y, sizeof t3);
1003 f256_montysquare(t4, P1->z);
1005 f256_montymul(t5, P1->z, t4);
1030 f256_montysquare(P1->x, t4);
1031 f256_sub(P1->x, P1->x, t5);
1032 f256_sub(P1->x, P1->x, t6);
1033 f256_sub(P1->x, P1->x, t6);
1038 f256_sub(t6, t6, P1->x);
1039 f256_montymul(P1->y, t4, t6);
1041 f256_sub(P1->y, P1->y, t1);
1046 f256_montymul(P1->z, P1->z, t2);
1054 * Point addition (mixed coordinates, complete): P1 is replaced with P1+P2.
1061 p256_add_complete_mixed(p256_jacobian *P1, const p256_affine *P2)
1078 * - If P1 is the point-at-infinity (z1 = 0), then z3 is
1081 * - If P1 = P2, then u1 = u2 and s1 = s2, and x3, y3 and z3
1084 * However, if P1 + P2 = 0, then u1 = u2 but s1 != s2, and then
1087 * To fix the case P1 = 0, we perform at the end a copy of P2
1088 * over P1, conditional to z1 = 0.
1090 * For P1 = P2: in that case, both h and r are set to 0, and
1092 * occurrence to make a mask which will be all-one if P1 = P2,
1112 * Set zz to -1 if P1 is the point at infinity, 0 otherwise.
1114 zz = P1->z[0] | P1->z[1] | P1->z[2] | P1->z[3] | P1->z[4];
1120 memcpy(t1, P1->x, sizeof t1);
1121 memcpy(t3, P1->y, sizeof t3);
1126 f256_montysquare(t4, P1->z);
1128 f256_montymul(t5, P1->z, t4);
1139 * If both h = 0 and r = 0, then P1 = P2, and we want to set
1158 f256_montysquare(P1->x, t4);
1159 f256_sub(P1->x, P1->x, t5);
1160 f256_sub(P1->x, P1->x, t6);
1161 f256_sub(P1->x, P1->x, t6);
1166 f256_sub(t6, t6, P1->x);
1167 f256_montymul(P1->y, t4, t6);
1169 f256_sub(P1->y, P1->y, t1);
1174 f256_montymul(P1->z, P1->z, t2);
1177 * The "double" result, in case P1 = P2.
1223 P1->x[i] |= tt & t5[i];
1224 P1->y[i] |= tt & t6[i];
1225 P1->z[i] |= tt & t1[i];
1229 * If P1 = 0, then we get z3 = 0 (which is invalid); if z1 is 0,
1234 P1->x[i] ^= zz & (P1->x[i] ^ P2->x[i]);
1235 P1->y[i] ^= zz & (P1->y[i] ^ P2->y[i]);
1236 P1->z[i] ^= zz & (P1->z[i] ^ F256_R[i]);