public static void ge_montx_to_p2(Ge_p2 p, int[] u, byte ed_sign_bit) { int[] x = new int[10]; int[] y = new int[10]; int[] A = new int[10]; int[] v = new int[10]; int[] v2 = new int[10]; int[] iv = new int[10]; int[] nx = new int[10]; Fe_frombytes.fe_frombytes(A, A_bytes); /* given u, recover edwards y */ /* given u, recover v */ /* given u and v, recover edwards x */ Fe_montx_to_edy.fe_montx_to_edy(y, u); /* y = (u - 1) / (u + 1) */ Fe_mont_rhs.fe_mont_rhs(v2, u); /* v^2 = u(u^2 + Au + 1) */ Fe_sqrt.fe_sqrt(v, v2); /* v = sqrt(v^2) */ Fe_mul.fe_mul(x, u, A); /* x = u * sqrt(-(A+2)) */ Fe_invert.fe_invert(iv, v); /* 1/v */ Fe_mul.fe_mul(x, x, iv); /* x = (u/v) * sqrt(-(A+2)) */ Fe_neg.fe_neg(nx, x); /* negate x to match sign bit */ Fe_cmov.fe_cmov(x, nx, Fe_isnegative.fe_isnegative(x) ^ ed_sign_bit); Fe_copy.fe_copy(p.X, x); Fe_copy.fe_copy(p.Y, y); Fe_1.fe_1(p.Z); /* POSTCONDITION: check that p->X and p->Y satisfy the Ed curve equation */ /* -x^2 + y^2 = 1 + dx^2y^2 */ //#ifndef NDEBUG //{ //fe one, d, x2, y2, x2y2, dx2y2; // //unsigned char dbytes[32] = { //0xa3, 0x78, 0x59, 0x13, 0xca, 0x4d, 0xeb, 0x75, //0xab, 0xd8, 0x41, 0x41, 0x4d, 0x0a, 0x70, 0x00, //0x98, 0xe8, 0x79, 0x77, 0x79, 0x40, 0xc7, 0x8c, //0x73, 0xfe, 0x6f, 0x2b, 0xee, 0x6c, 0x03, 0x52 //}; // //fe_frombytes(d, dbytes); //fe_1(one); //fe_sq(x2, p->X); /* x^2 */ //fe_sq(y2, p->Y); /* y^2 */ // //fe_mul(dx2y2, x2, y2); /* x^2y^2 */ //fe_mul(dx2y2, dx2y2, d); /* dx^2y^2 */ //fe_add(dx2y2, dx2y2, one); /* dx^2y^2 + 1 */ //fe_neg(x2y2, x2); /* -x^2 */ //fe_add(x2y2, x2y2, y2); /* -x^2 + y^2 */ // //assert(fe_isequal(x2y2, dx2y2)); //} //#endif }
//CONVERT #include "ge.h" public static void ge_p3_tobytes(byte[] s, Ge_p3 h) { int[] recip = new int[10]; int[] x = new int[10]; int[] y = new int[10]; Fe_invert.fe_invert(recip, h.Z); Fe_mul.fe_mul(x, h.X, recip); Fe_mul.fe_mul(y, h.Y, recip); Fe_tobytes.fe_tobytes(s, y); s[31] ^= (byte)(Fe_isnegative.fe_isnegative(x) << 7); }
public static void fe_montx_to_edy(int[] y, int[] u) { /* * y = (u - 1) / (u + 1) * * NOTE: u=-1 is converted to y=0 since fe_invert is mod-exp */ int[] one = new int[10]; int[] um1 = new int[10]; int[] up1 = new int[10]; Fe_1.fe_1(one); Fe_sub.fe_sub(um1, u, one); Fe_add.fe_add(up1, u, one); Fe_invert.fe_invert(up1, up1); Fe_mul.fe_mul(y, um1, up1); }
public static void ge_p3_to_montx(int[] u, Ge_p3 ed) { /* * u = (y + 1) / (1 - y) * or * u = (y + z) / (z - y) * * NOTE: y=1 is converted to u=0 since fe_invert is mod-exp */ int[] y_plus_one = new int[10]; int[] one_minus_y = new int[10]; int[] inv_one_minus_y = new int[10]; Fe_add.fe_add(y_plus_one, ed.Y, ed.Z); Fe_sub.fe_sub(one_minus_y, ed.Z, ed.Y); Fe_invert.fe_invert(inv_one_minus_y, one_minus_y); Fe_mul.fe_mul(u, y_plus_one, inv_one_minus_y); }
//CONVERT #include "crypto_scalarmult.h" //CONVERT #include "fe.h" public static int crypto_scalarmult(byte[] q, byte[] n, byte[] p) { byte[] e = new byte[32]; int i; int[] x1 = new int[10]; int[] x2 = new int[10]; int[] z2 = new int[10]; int[] x3 = new int[10]; int[] z3 = new int[10]; int[] tmp0 = new int[10]; int[] tmp1 = new int[10]; int pos; int swap; int b; for (i = 0; i < 32; ++i) { e[i] = n[i]; } // e[0] &= 248; // e[31] &= 127; // e[31] |= 64; Fe_frombytes.fe_frombytes(x1, p); Fe_1.fe_1(x2); Fe_0.fe_0(z2); Fe_copy.fe_copy(x3, x1); Fe_1.fe_1(z3); swap = 0; for (pos = 254; pos >= 0; --pos) { b = (int)(((uint)e[pos / 8]) >> (pos & 7)); b &= 1; swap ^= b; Fe_cswap.fe_cswap(x2, x3, swap); Fe_cswap.fe_cswap(z2, z3, swap); swap = b; //CONVERT #include "montgomery.h" /* qhasm: fe X2 */ /* qhasm: fe Z2 */ /* qhasm: fe X3 */ /* qhasm: fe Z3 */ /* qhasm: fe X4 */ /* qhasm: fe Z4 */ /* qhasm: fe X5 */ /* qhasm: fe Z5 */ /* qhasm: fe A */ /* qhasm: fe B */ /* qhasm: fe C */ /* qhasm: fe D */ /* qhasm: fe E */ /* qhasm: fe AA */ /* qhasm: fe BB */ /* qhasm: fe DA */ /* qhasm: fe CB */ /* qhasm: fe t0 */ /* qhasm: fe t1 */ /* qhasm: fe t2 */ /* qhasm: fe t3 */ /* qhasm: fe t4 */ /* qhasm: enter ladder */ /* qhasm: D = X3-Z3 */ /* asm 1: fe_sub.fe_sub(>D=fe#5,<X3=fe#3,<Z3=fe#4); */ /* asm 2: fe_sub.fe_sub(>D=tmp0,<X3=x3,<Z3=z3); */ Fe_sub.fe_sub(tmp0, x3, z3); /* qhasm: B = X2-Z2 */ /* asm 1: fe_sub.fe_sub(>B=fe#6,<X2=fe#1,<Z2=fe#2); */ /* asm 2: fe_sub.fe_sub(>B=tmp1,<X2=x2,<Z2=z2); */ Fe_sub.fe_sub(tmp1, x2, z2); /* qhasm: A = X2+Z2 */ /* asm 1: fe_add.fe_add(>A=fe#1,<X2=fe#1,<Z2=fe#2); */ /* asm 2: fe_add.fe_add(>A=x2,<X2=x2,<Z2=z2); */ Fe_add.fe_add(x2, x2, z2); /* qhasm: C = X3+Z3 */ /* asm 1: fe_add.fe_add(>C=fe#2,<X3=fe#3,<Z3=fe#4); */ /* asm 2: fe_add.fe_add(>C=z2,<X3=x3,<Z3=z3); */ Fe_add.fe_add(z2, x3, z3); /* qhasm: DA = D*A */ /* asm 1: fe_mul.fe_mul(>DA=fe#4,<D=fe#5,<A=fe#1); */ /* asm 2: fe_mul.fe_mul(>DA=z3,<D=tmp0,<A=x2); */ Fe_mul.fe_mul(z3, tmp0, x2); /* qhasm: CB = C*B */ /* asm 1: fe_mul.fe_mul(>CB=fe#2,<C=fe#2,<B=fe#6); */ /* asm 2: fe_mul.fe_mul(>CB=z2,<C=z2,<B=tmp1); */ Fe_mul.fe_mul(z2, z2, tmp1); /* qhasm: BB = B^2 */ /* asm 1: fe_sq.fe_sq(>BB=fe#5,<B=fe#6); */ /* asm 2: fe_sq.fe_sq(>BB=tmp0,<B=tmp1); */ Fe_sq.fe_sq(tmp0, tmp1); /* qhasm: AA = A^2 */ /* asm 1: fe_sq.fe_sq(>AA=fe#6,<A=fe#1); */ /* asm 2: fe_sq.fe_sq(>AA=tmp1,<A=x2); */ Fe_sq.fe_sq(tmp1, x2); /* qhasm: t0 = DA+CB */ /* asm 1: fe_add.fe_add(>t0=fe#3,<DA=fe#4,<CB=fe#2); */ /* asm 2: fe_add.fe_add(>t0=x3,<DA=z3,<CB=z2); */ Fe_add.fe_add(x3, z3, z2); /* qhasm: assign x3 to t0 */ /* qhasm: t1 = DA-CB */ /* asm 1: fe_sub.fe_sub(>t1=fe#2,<DA=fe#4,<CB=fe#2); */ /* asm 2: fe_sub.fe_sub(>t1=z2,<DA=z3,<CB=z2); */ Fe_sub.fe_sub(z2, z3, z2); /* qhasm: X4 = AA*BB */ /* asm 1: fe_mul.fe_mul(>X4=fe#1,<AA=fe#6,<BB=fe#5); */ /* asm 2: fe_mul.fe_mul(>X4=x2,<AA=tmp1,<BB=tmp0); */ Fe_mul.fe_mul(x2, tmp1, tmp0); /* qhasm: E = AA-BB */ /* asm 1: fe_sub.fe_sub(>E=fe#6,<AA=fe#6,<BB=fe#5); */ /* asm 2: fe_sub.fe_sub(>E=tmp1,<AA=tmp1,<BB=tmp0); */ Fe_sub.fe_sub(tmp1, tmp1, tmp0); /* qhasm: t2 = t1^2 */ /* asm 1: fe_sq.fe_sq(>t2=fe#2,<t1=fe#2); */ /* asm 2: fe_sq.fe_sq(>t2=z2,<t1=z2); */ Fe_sq.fe_sq(z2, z2); /* qhasm: t3 = a24*E */ /* asm 1: fe_mul121666(>t3=fe#4,<E=fe#6); */ /* asm 2: fe_mul121666(>t3=z3,<E=tmp1); */ Fe_mul121666.fe_mul121666(z3, tmp1); /* qhasm: X5 = t0^2 */ /* asm 1: fe_sq.fe_sq(>X5=fe#3,<t0=fe#3); */ /* asm 2: fe_sq.fe_sq(>X5=x3,<t0=x3); */ Fe_sq.fe_sq(x3, x3); /* qhasm: t4 = BB+t3 */ /* asm 1: fe_add.fe_add(>t4=fe#5,<BB=fe#5,<t3=fe#4); */ /* asm 2: fe_add.fe_add(>t4=tmp0,<BB=tmp0,<t3=z3); */ Fe_add.fe_add(tmp0, tmp0, z3); /* qhasm: Z5 = X1*t2 */ /* asm 1: fe_mul.fe_mul(>Z5=fe#4,x1,<t2=fe#2); */ /* asm 2: fe_mul.fe_mul(>Z5=z3,x1,<t2=z2); */ Fe_mul.fe_mul(z3, x1, z2); /* qhasm: Z4 = E*t4 */ /* asm 1: fe_mul.fe_mul(>Z4=fe#2,<E=fe#6,<t4=fe#5); */ /* asm 2: fe_mul.fe_mul(>Z4=z2,<E=tmp1,<t4=tmp0); */ Fe_mul.fe_mul(z2, tmp1, tmp0); /* qhasm: return */ } Fe_cswap.fe_cswap(x2, x3, swap); Fe_cswap.fe_cswap(z2, z3, swap); Fe_invert.fe_invert(z2, z2); Fe_mul.fe_mul(x2, x2, z2); Fe_tobytes.fe_tobytes(q, x2); return(0); }