| // SPDX-License-Identifier: GPL-2.0 OR MIT |
| /* |
| * Copyright (C) 2016-2017 INRIA and Microsoft Corporation. |
| * Copyright (C) 2018-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. |
| * |
| * This is a machine-generated formally verified implementation of Curve25519 |
| * ECDH from: <https://github.com/mitls/hacl-star>. Though originally machine |
| * generated, it has been tweaked to be suitable for use in the kernel. It is |
| * optimized for 64-bit machines that can efficiently work with 128-bit |
| * integer types. |
| */ |
| |
| typedef __uint128_t u128; |
| |
| static __always_inline u64 u64_eq_mask(u64 a, u64 b) |
| { |
| u64 x = a ^ b; |
| u64 minus_x = ~x + (u64)1U; |
| u64 x_or_minus_x = x | minus_x; |
| u64 xnx = x_or_minus_x >> (u32)63U; |
| u64 c = xnx - (u64)1U; |
| return c; |
| } |
| |
| static __always_inline u64 u64_gte_mask(u64 a, u64 b) |
| { |
| u64 x = a; |
| u64 y = b; |
| u64 x_xor_y = x ^ y; |
| u64 x_sub_y = x - y; |
| u64 x_sub_y_xor_y = x_sub_y ^ y; |
| u64 q = x_xor_y | x_sub_y_xor_y; |
| u64 x_xor_q = x ^ q; |
| u64 x_xor_q_ = x_xor_q >> (u32)63U; |
| u64 c = x_xor_q_ - (u64)1U; |
| return c; |
| } |
| |
| static __always_inline void modulo_carry_top(u64 *b) |
| { |
| u64 b4 = b[4]; |
| u64 b0 = b[0]; |
| u64 b4_ = b4 & 0x7ffffffffffffLLU; |
| u64 b0_ = b0 + 19 * (b4 >> 51); |
| b[4] = b4_; |
| b[0] = b0_; |
| } |
| |
| static __always_inline void fproduct_copy_from_wide_(u64 *output, u128 *input) |
| { |
| { |
| u128 xi = input[0]; |
| output[0] = ((u64)(xi)); |
| } |
| { |
| u128 xi = input[1]; |
| output[1] = ((u64)(xi)); |
| } |
| { |
| u128 xi = input[2]; |
| output[2] = ((u64)(xi)); |
| } |
| { |
| u128 xi = input[3]; |
| output[3] = ((u64)(xi)); |
| } |
| { |
| u128 xi = input[4]; |
| output[4] = ((u64)(xi)); |
| } |
| } |
| |
| static __always_inline void |
| fproduct_sum_scalar_multiplication_(u128 *output, u64 *input, u64 s) |
| { |
| output[0] += (u128)input[0] * s; |
| output[1] += (u128)input[1] * s; |
| output[2] += (u128)input[2] * s; |
| output[3] += (u128)input[3] * s; |
| output[4] += (u128)input[4] * s; |
| } |
| |
| static __always_inline void fproduct_carry_wide_(u128 *tmp) |
| { |
| { |
| u32 ctr = 0; |
| u128 tctr = tmp[ctr]; |
| u128 tctrp1 = tmp[ctr + 1]; |
| u64 r0 = ((u64)(tctr)) & 0x7ffffffffffffLLU; |
| u128 c = ((tctr) >> (51)); |
| tmp[ctr] = ((u128)(r0)); |
| tmp[ctr + 1] = ((tctrp1) + (c)); |
| } |
| { |
| u32 ctr = 1; |
| u128 tctr = tmp[ctr]; |
| u128 tctrp1 = tmp[ctr + 1]; |
| u64 r0 = ((u64)(tctr)) & 0x7ffffffffffffLLU; |
| u128 c = ((tctr) >> (51)); |
| tmp[ctr] = ((u128)(r0)); |
| tmp[ctr + 1] = ((tctrp1) + (c)); |
| } |
| |
| { |
| u32 ctr = 2; |
| u128 tctr = tmp[ctr]; |
| u128 tctrp1 = tmp[ctr + 1]; |
| u64 r0 = ((u64)(tctr)) & 0x7ffffffffffffLLU; |
| u128 c = ((tctr) >> (51)); |
| tmp[ctr] = ((u128)(r0)); |
| tmp[ctr + 1] = ((tctrp1) + (c)); |
| } |
| { |
| u32 ctr = 3; |
| u128 tctr = tmp[ctr]; |
| u128 tctrp1 = tmp[ctr + 1]; |
| u64 r0 = ((u64)(tctr)) & 0x7ffffffffffffLLU; |
| u128 c = ((tctr) >> (51)); |
| tmp[ctr] = ((u128)(r0)); |
| tmp[ctr + 1] = ((tctrp1) + (c)); |
| } |
| } |
| |
| static __always_inline void fmul_shift_reduce(u64 *output) |
| { |
| u64 tmp = output[4]; |
| u64 b0; |
| { |
| u32 ctr = 5 - 0 - 1; |
| u64 z = output[ctr - 1]; |
| output[ctr] = z; |
| } |
| { |
| u32 ctr = 5 - 1 - 1; |
| u64 z = output[ctr - 1]; |
| output[ctr] = z; |
| } |
| { |
| u32 ctr = 5 - 2 - 1; |
| u64 z = output[ctr - 1]; |
| output[ctr] = z; |
| } |
| { |
| u32 ctr = 5 - 3 - 1; |
| u64 z = output[ctr - 1]; |
| output[ctr] = z; |
| } |
| output[0] = tmp; |
| b0 = output[0]; |
| output[0] = 19 * b0; |
| } |
| |
| static __always_inline void fmul_mul_shift_reduce_(u128 *output, u64 *input, |
| u64 *input21) |
| { |
| u32 i; |
| u64 input2i; |
| { |
| u64 input2i = input21[0]; |
| fproduct_sum_scalar_multiplication_(output, input, input2i); |
| fmul_shift_reduce(input); |
| } |
| { |
| u64 input2i = input21[1]; |
| fproduct_sum_scalar_multiplication_(output, input, input2i); |
| fmul_shift_reduce(input); |
| } |
| { |
| u64 input2i = input21[2]; |
| fproduct_sum_scalar_multiplication_(output, input, input2i); |
| fmul_shift_reduce(input); |
| } |
| { |
| u64 input2i = input21[3]; |
| fproduct_sum_scalar_multiplication_(output, input, input2i); |
| fmul_shift_reduce(input); |
| } |
| i = 4; |
| input2i = input21[i]; |
| fproduct_sum_scalar_multiplication_(output, input, input2i); |
| } |
| |
| static __always_inline void fmul_fmul(u64 *output, u64 *input, u64 *input21) |
| { |
| u64 tmp[5] = { input[0], input[1], input[2], input[3], input[4] }; |
| { |
| u128 b4; |
| u128 b0; |
| u128 b4_; |
| u128 b0_; |
| u64 i0; |
| u64 i1; |
| u64 i0_; |
| u64 i1_; |
| u128 t[5] = { 0 }; |
| fmul_mul_shift_reduce_(t, tmp, input21); |
| fproduct_carry_wide_(t); |
| b4 = t[4]; |
| b0 = t[0]; |
| b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU)))); |
| b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51)))))))); |
| t[4] = b4_; |
| t[0] = b0_; |
| fproduct_copy_from_wide_(output, t); |
| i0 = output[0]; |
| i1 = output[1]; |
| i0_ = i0 & 0x7ffffffffffffLLU; |
| i1_ = i1 + (i0 >> 51); |
| output[0] = i0_; |
| output[1] = i1_; |
| } |
| } |
| |
| static __always_inline void fsquare_fsquare__(u128 *tmp, u64 *output) |
| { |
| u64 r0 = output[0]; |
| u64 r1 = output[1]; |
| u64 r2 = output[2]; |
| u64 r3 = output[3]; |
| u64 r4 = output[4]; |
| u64 d0 = r0 * 2; |
| u64 d1 = r1 * 2; |
| u64 d2 = r2 * 2 * 19; |
| u64 d419 = r4 * 19; |
| u64 d4 = d419 * 2; |
| u128 s0 = ((((((u128)(r0) * (r0))) + (((u128)(d4) * (r1))))) + |
| (((u128)(d2) * (r3)))); |
| u128 s1 = ((((((u128)(d0) * (r1))) + (((u128)(d4) * (r2))))) + |
| (((u128)(r3 * 19) * (r3)))); |
| u128 s2 = ((((((u128)(d0) * (r2))) + (((u128)(r1) * (r1))))) + |
| (((u128)(d4) * (r3)))); |
| u128 s3 = ((((((u128)(d0) * (r3))) + (((u128)(d1) * (r2))))) + |
| (((u128)(r4) * (d419)))); |
| u128 s4 = ((((((u128)(d0) * (r4))) + (((u128)(d1) * (r3))))) + |
| (((u128)(r2) * (r2)))); |
| tmp[0] = s0; |
| tmp[1] = s1; |
| tmp[2] = s2; |
| tmp[3] = s3; |
| tmp[4] = s4; |
| } |
| |
| static __always_inline void fsquare_fsquare_(u128 *tmp, u64 *output) |
| { |
| u128 b4; |
| u128 b0; |
| u128 b4_; |
| u128 b0_; |
| u64 i0; |
| u64 i1; |
| u64 i0_; |
| u64 i1_; |
| fsquare_fsquare__(tmp, output); |
| fproduct_carry_wide_(tmp); |
| b4 = tmp[4]; |
| b0 = tmp[0]; |
| b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU)))); |
| b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51)))))))); |
| tmp[4] = b4_; |
| tmp[0] = b0_; |
| fproduct_copy_from_wide_(output, tmp); |
| i0 = output[0]; |
| i1 = output[1]; |
| i0_ = i0 & 0x7ffffffffffffLLU; |
| i1_ = i1 + (i0 >> 51); |
| output[0] = i0_; |
| output[1] = i1_; |
| } |
| |
| static __always_inline void fsquare_fsquare_times_(u64 *output, u128 *tmp, |
| u32 count1) |
| { |
| u32 i; |
| fsquare_fsquare_(tmp, output); |
| for (i = 1; i < count1; ++i) |
| fsquare_fsquare_(tmp, output); |
| } |
| |
| static __always_inline void fsquare_fsquare_times(u64 *output, u64 *input, |
| u32 count1) |
| { |
| u128 t[5]; |
| memcpy(output, input, 5 * sizeof(*input)); |
| fsquare_fsquare_times_(output, t, count1); |
| } |
| |
| static __always_inline void fsquare_fsquare_times_inplace(u64 *output, |
| u32 count1) |
| { |
| u128 t[5]; |
| fsquare_fsquare_times_(output, t, count1); |
| } |
| |
| static __always_inline void crecip_crecip(u64 *out, u64 *z) |
| { |
| u64 buf[20] = { 0 }; |
| u64 *a0 = buf; |
| u64 *t00 = buf + 5; |
| u64 *b0 = buf + 10; |
| u64 *t01; |
| u64 *b1; |
| u64 *c0; |
| u64 *a; |
| u64 *t0; |
| u64 *b; |
| u64 *c; |
| fsquare_fsquare_times(a0, z, 1); |
| fsquare_fsquare_times(t00, a0, 2); |
| fmul_fmul(b0, t00, z); |
| fmul_fmul(a0, b0, a0); |
| fsquare_fsquare_times(t00, a0, 1); |
| fmul_fmul(b0, t00, b0); |
| fsquare_fsquare_times(t00, b0, 5); |
| t01 = buf + 5; |
| b1 = buf + 10; |
| c0 = buf + 15; |
| fmul_fmul(b1, t01, b1); |
| fsquare_fsquare_times(t01, b1, 10); |
| fmul_fmul(c0, t01, b1); |
| fsquare_fsquare_times(t01, c0, 20); |
| fmul_fmul(t01, t01, c0); |
| fsquare_fsquare_times_inplace(t01, 10); |
| fmul_fmul(b1, t01, b1); |
| fsquare_fsquare_times(t01, b1, 50); |
| a = buf; |
| t0 = buf + 5; |
| b = buf + 10; |
| c = buf + 15; |
| fmul_fmul(c, t0, b); |
| fsquare_fsquare_times(t0, c, 100); |
| fmul_fmul(t0, t0, c); |
| fsquare_fsquare_times_inplace(t0, 50); |
| fmul_fmul(t0, t0, b); |
| fsquare_fsquare_times_inplace(t0, 5); |
| fmul_fmul(out, t0, a); |
| } |
| |
| static __always_inline void fsum(u64 *a, u64 *b) |
| { |
| a[0] += b[0]; |
| a[1] += b[1]; |
| a[2] += b[2]; |
| a[3] += b[3]; |
| a[4] += b[4]; |
| } |
| |
| static __always_inline void fdifference(u64 *a, u64 *b) |
| { |
| u64 tmp[5] = { 0 }; |
| u64 b0; |
| u64 b1; |
| u64 b2; |
| u64 b3; |
| u64 b4; |
| memcpy(tmp, b, 5 * sizeof(*b)); |
| b0 = tmp[0]; |
| b1 = tmp[1]; |
| b2 = tmp[2]; |
| b3 = tmp[3]; |
| b4 = tmp[4]; |
| tmp[0] = b0 + 0x3fffffffffff68LLU; |
| tmp[1] = b1 + 0x3ffffffffffff8LLU; |
| tmp[2] = b2 + 0x3ffffffffffff8LLU; |
| tmp[3] = b3 + 0x3ffffffffffff8LLU; |
| tmp[4] = b4 + 0x3ffffffffffff8LLU; |
| { |
| u64 xi = a[0]; |
| u64 yi = tmp[0]; |
| a[0] = yi - xi; |
| } |
| { |
| u64 xi = a[1]; |
| u64 yi = tmp[1]; |
| a[1] = yi - xi; |
| } |
| { |
| u64 xi = a[2]; |
| u64 yi = tmp[2]; |
| a[2] = yi - xi; |
| } |
| { |
| u64 xi = a[3]; |
| u64 yi = tmp[3]; |
| a[3] = yi - xi; |
| } |
| { |
| u64 xi = a[4]; |
| u64 yi = tmp[4]; |
| a[4] = yi - xi; |
| } |
| } |
| |
| static __always_inline void fscalar(u64 *output, u64 *b, u64 s) |
| { |
| u128 tmp[5]; |
| u128 b4; |
| u128 b0; |
| u128 b4_; |
| u128 b0_; |
| { |
| u64 xi = b[0]; |
| tmp[0] = ((u128)(xi) * (s)); |
| } |
| { |
| u64 xi = b[1]; |
| tmp[1] = ((u128)(xi) * (s)); |
| } |
| { |
| u64 xi = b[2]; |
| tmp[2] = ((u128)(xi) * (s)); |
| } |
| { |
| u64 xi = b[3]; |
| tmp[3] = ((u128)(xi) * (s)); |
| } |
| { |
| u64 xi = b[4]; |
| tmp[4] = ((u128)(xi) * (s)); |
| } |
| fproduct_carry_wide_(tmp); |
| b4 = tmp[4]; |
| b0 = tmp[0]; |
| b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU)))); |
| b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51)))))))); |
| tmp[4] = b4_; |
| tmp[0] = b0_; |
| fproduct_copy_from_wide_(output, tmp); |
| } |
| |
| static __always_inline void crecip(u64 *output, u64 *input) |
| { |
| crecip_crecip(output, input); |
| } |
| |
| static __always_inline void point_swap_conditional_step(u64 *a, u64 *b, |
| u64 swap1, u32 ctr) |
| { |
| u32 i = ctr - 1; |
| u64 ai = a[i]; |
| u64 bi = b[i]; |
| u64 x = swap1 & (ai ^ bi); |
| u64 ai1 = ai ^ x; |
| u64 bi1 = bi ^ x; |
| a[i] = ai1; |
| b[i] = bi1; |
| } |
| |
| static __always_inline void point_swap_conditional5(u64 *a, u64 *b, u64 swap1) |
| { |
| point_swap_conditional_step(a, b, swap1, 5); |
| point_swap_conditional_step(a, b, swap1, 4); |
| point_swap_conditional_step(a, b, swap1, 3); |
| point_swap_conditional_step(a, b, swap1, 2); |
| point_swap_conditional_step(a, b, swap1, 1); |
| } |
| |
| static __always_inline void point_swap_conditional(u64 *a, u64 *b, u64 iswap) |
| { |
| u64 swap1 = 0 - iswap; |
| point_swap_conditional5(a, b, swap1); |
| point_swap_conditional5(a + 5, b + 5, swap1); |
| } |
| |
| static __always_inline void point_copy(u64 *output, u64 *input) |
| { |
| memcpy(output, input, 5 * sizeof(*input)); |
| memcpy(output + 5, input + 5, 5 * sizeof(*input)); |
| } |
| |
| static __always_inline void addanddouble_fmonty(u64 *pp, u64 *ppq, u64 *p, |
| u64 *pq, u64 *qmqp) |
| { |
| u64 *qx = qmqp; |
| u64 *x2 = pp; |
| u64 *z2 = pp + 5; |
| u64 *x3 = ppq; |
| u64 *z3 = ppq + 5; |
| u64 *x = p; |
| u64 *z = p + 5; |
| u64 *xprime = pq; |
| u64 *zprime = pq + 5; |
| u64 buf[40] = { 0 }; |
| u64 *origx = buf; |
| u64 *origxprime0 = buf + 5; |
| u64 *xxprime0; |
| u64 *zzprime0; |
| u64 *origxprime; |
| xxprime0 = buf + 25; |
| zzprime0 = buf + 30; |
| memcpy(origx, x, 5 * sizeof(*x)); |
| fsum(x, z); |
| fdifference(z, origx); |
| memcpy(origxprime0, xprime, 5 * sizeof(*xprime)); |
| fsum(xprime, zprime); |
| fdifference(zprime, origxprime0); |
| fmul_fmul(xxprime0, xprime, z); |
| fmul_fmul(zzprime0, x, zprime); |
| origxprime = buf + 5; |
| { |
| u64 *xx0; |
| u64 *zz0; |
| u64 *xxprime; |
| u64 *zzprime; |
| u64 *zzzprime; |
| xx0 = buf + 15; |
| zz0 = buf + 20; |
| xxprime = buf + 25; |
| zzprime = buf + 30; |
| zzzprime = buf + 35; |
| memcpy(origxprime, xxprime, 5 * sizeof(*xxprime)); |
| fsum(xxprime, zzprime); |
| fdifference(zzprime, origxprime); |
| fsquare_fsquare_times(x3, xxprime, 1); |
| fsquare_fsquare_times(zzzprime, zzprime, 1); |
| fmul_fmul(z3, zzzprime, qx); |
| fsquare_fsquare_times(xx0, x, 1); |
| fsquare_fsquare_times(zz0, z, 1); |
| { |
| u64 *zzz; |
| u64 *xx; |
| u64 *zz; |
| u64 scalar; |
| zzz = buf + 10; |
| xx = buf + 15; |
| zz = buf + 20; |
| fmul_fmul(x2, xx, zz); |
| fdifference(zz, xx); |
| scalar = 121665; |
| fscalar(zzz, zz, scalar); |
| fsum(zzz, xx); |
| fmul_fmul(z2, zzz, zz); |
| } |
| } |
| } |
| |
| static __always_inline void |
| ladder_smallloop_cmult_small_loop_step(u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, |
| u64 *q, u8 byt) |
| { |
| u64 bit0 = (u64)(byt >> 7); |
| u64 bit; |
| point_swap_conditional(nq, nqpq, bit0); |
| addanddouble_fmonty(nq2, nqpq2, nq, nqpq, q); |
| bit = (u64)(byt >> 7); |
| point_swap_conditional(nq2, nqpq2, bit); |
| } |
| |
| static __always_inline void |
| ladder_smallloop_cmult_small_loop_double_step(u64 *nq, u64 *nqpq, u64 *nq2, |
| u64 *nqpq2, u64 *q, u8 byt) |
| { |
| u8 byt1; |
| ladder_smallloop_cmult_small_loop_step(nq, nqpq, nq2, nqpq2, q, byt); |
| byt1 = byt << 1; |
| ladder_smallloop_cmult_small_loop_step(nq2, nqpq2, nq, nqpq, q, byt1); |
| } |
| |
| static __always_inline void |
| ladder_smallloop_cmult_small_loop(u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, |
| u64 *q, u8 byt, u32 i) |
| { |
| while (i--) { |
| ladder_smallloop_cmult_small_loop_double_step(nq, nqpq, nq2, |
| nqpq2, q, byt); |
| byt <<= 2; |
| } |
| } |
| |
| static __always_inline void ladder_bigloop_cmult_big_loop(u8 *n1, u64 *nq, |
| u64 *nqpq, u64 *nq2, |
| u64 *nqpq2, u64 *q, |
| u32 i) |
| { |
| while (i--) { |
| u8 byte = n1[i]; |
| ladder_smallloop_cmult_small_loop(nq, nqpq, nq2, nqpq2, q, |
| byte, 4); |
| } |
| } |
| |
| static void ladder_cmult(u64 *result, u8 *n1, u64 *q) |
| { |
| u64 point_buf[40] = { 0 }; |
| u64 *nq = point_buf; |
| u64 *nqpq = point_buf + 10; |
| u64 *nq2 = point_buf + 20; |
| u64 *nqpq2 = point_buf + 30; |
| point_copy(nqpq, q); |
| nq[0] = 1; |
| ladder_bigloop_cmult_big_loop(n1, nq, nqpq, nq2, nqpq2, q, 32); |
| point_copy(result, nq); |
| } |
| |
| static __always_inline void format_fexpand(u64 *output, const u8 *input) |
| { |
| const u8 *x00 = input + 6; |
| const u8 *x01 = input + 12; |
| const u8 *x02 = input + 19; |
| const u8 *x0 = input + 24; |
| u64 i0, i1, i2, i3, i4, output0, output1, output2, output3, output4; |
| i0 = get_unaligned_le64(input); |
| i1 = get_unaligned_le64(x00); |
| i2 = get_unaligned_le64(x01); |
| i3 = get_unaligned_le64(x02); |
| i4 = get_unaligned_le64(x0); |
| output0 = i0 & 0x7ffffffffffffLLU; |
| output1 = i1 >> 3 & 0x7ffffffffffffLLU; |
| output2 = i2 >> 6 & 0x7ffffffffffffLLU; |
| output3 = i3 >> 1 & 0x7ffffffffffffLLU; |
| output4 = i4 >> 12 & 0x7ffffffffffffLLU; |
| output[0] = output0; |
| output[1] = output1; |
| output[2] = output2; |
| output[3] = output3; |
| output[4] = output4; |
| } |
| |
| static __always_inline void format_fcontract_first_carry_pass(u64 *input) |
| { |
| u64 t0 = input[0]; |
| u64 t1 = input[1]; |
| u64 t2 = input[2]; |
| u64 t3 = input[3]; |
| u64 t4 = input[4]; |
| u64 t1_ = t1 + (t0 >> 51); |
| u64 t0_ = t0 & 0x7ffffffffffffLLU; |
| u64 t2_ = t2 + (t1_ >> 51); |
| u64 t1__ = t1_ & 0x7ffffffffffffLLU; |
| u64 t3_ = t3 + (t2_ >> 51); |
| u64 t2__ = t2_ & 0x7ffffffffffffLLU; |
| u64 t4_ = t4 + (t3_ >> 51); |
| u64 t3__ = t3_ & 0x7ffffffffffffLLU; |
| input[0] = t0_; |
| input[1] = t1__; |
| input[2] = t2__; |
| input[3] = t3__; |
| input[4] = t4_; |
| } |
| |
| static __always_inline void format_fcontract_first_carry_full(u64 *input) |
| { |
| format_fcontract_first_carry_pass(input); |
| modulo_carry_top(input); |
| } |
| |
| static __always_inline void format_fcontract_second_carry_pass(u64 *input) |
| { |
| u64 t0 = input[0]; |
| u64 t1 = input[1]; |
| u64 t2 = input[2]; |
| u64 t3 = input[3]; |
| u64 t4 = input[4]; |
| u64 t1_ = t1 + (t0 >> 51); |
| u64 t0_ = t0 & 0x7ffffffffffffLLU; |
| u64 t2_ = t2 + (t1_ >> 51); |
| u64 t1__ = t1_ & 0x7ffffffffffffLLU; |
| u64 t3_ = t3 + (t2_ >> 51); |
| u64 t2__ = t2_ & 0x7ffffffffffffLLU; |
| u64 t4_ = t4 + (t3_ >> 51); |
| u64 t3__ = t3_ & 0x7ffffffffffffLLU; |
| input[0] = t0_; |
| input[1] = t1__; |
| input[2] = t2__; |
| input[3] = t3__; |
| input[4] = t4_; |
| } |
| |
| static __always_inline void format_fcontract_second_carry_full(u64 *input) |
| { |
| u64 i0; |
| u64 i1; |
| u64 i0_; |
| u64 i1_; |
| format_fcontract_second_carry_pass(input); |
| modulo_carry_top(input); |
| i0 = input[0]; |
| i1 = input[1]; |
| i0_ = i0 & 0x7ffffffffffffLLU; |
| i1_ = i1 + (i0 >> 51); |
| input[0] = i0_; |
| input[1] = i1_; |
| } |
| |
| static __always_inline void format_fcontract_trim(u64 *input) |
| { |
| u64 a0 = input[0]; |
| u64 a1 = input[1]; |
| u64 a2 = input[2]; |
| u64 a3 = input[3]; |
| u64 a4 = input[4]; |
| u64 mask0 = u64_gte_mask(a0, 0x7ffffffffffedLLU); |
| u64 mask1 = u64_eq_mask(a1, 0x7ffffffffffffLLU); |
| u64 mask2 = u64_eq_mask(a2, 0x7ffffffffffffLLU); |
| u64 mask3 = u64_eq_mask(a3, 0x7ffffffffffffLLU); |
| u64 mask4 = u64_eq_mask(a4, 0x7ffffffffffffLLU); |
| u64 mask = (((mask0 & mask1) & mask2) & mask3) & mask4; |
| u64 a0_ = a0 - (0x7ffffffffffedLLU & mask); |
| u64 a1_ = a1 - (0x7ffffffffffffLLU & mask); |
| u64 a2_ = a2 - (0x7ffffffffffffLLU & mask); |
| u64 a3_ = a3 - (0x7ffffffffffffLLU & mask); |
| u64 a4_ = a4 - (0x7ffffffffffffLLU & mask); |
| input[0] = a0_; |
| input[1] = a1_; |
| input[2] = a2_; |
| input[3] = a3_; |
| input[4] = a4_; |
| } |
| |
| static __always_inline void format_fcontract_store(u8 *output, u64 *input) |
| { |
| u64 t0 = input[0]; |
| u64 t1 = input[1]; |
| u64 t2 = input[2]; |
| u64 t3 = input[3]; |
| u64 t4 = input[4]; |
| u64 o0 = t1 << 51 | t0; |
| u64 o1 = t2 << 38 | t1 >> 13; |
| u64 o2 = t3 << 25 | t2 >> 26; |
| u64 o3 = t4 << 12 | t3 >> 39; |
| u8 *b0 = output; |
| u8 *b1 = output + 8; |
| u8 *b2 = output + 16; |
| u8 *b3 = output + 24; |
| put_unaligned_le64(o0, b0); |
| put_unaligned_le64(o1, b1); |
| put_unaligned_le64(o2, b2); |
| put_unaligned_le64(o3, b3); |
| } |
| |
| static __always_inline void format_fcontract(u8 *output, u64 *input) |
| { |
| format_fcontract_first_carry_full(input); |
| format_fcontract_second_carry_full(input); |
| format_fcontract_trim(input); |
| format_fcontract_store(output, input); |
| } |
| |
| static __always_inline void format_scalar_of_point(u8 *scalar, u64 *point) |
| { |
| u64 *x = point; |
| u64 *z = point + 5; |
| u64 buf[10] __aligned(32) = { 0 }; |
| u64 *zmone = buf; |
| u64 *sc = buf + 5; |
| crecip(zmone, z); |
| fmul_fmul(sc, x, zmone); |
| format_fcontract(scalar, sc); |
| } |
| |
| static void curve25519_generic(u8 mypublic[CURVE25519_KEY_SIZE], |
| const u8 secret[CURVE25519_KEY_SIZE], |
| const u8 basepoint[CURVE25519_KEY_SIZE]) |
| { |
| u64 buf0[10] __aligned(32) = { 0 }; |
| u64 *x0 = buf0; |
| u64 *z = buf0 + 5; |
| u64 *q; |
| format_fexpand(x0, basepoint); |
| z[0] = 1; |
| q = buf0; |
| { |
| u8 e[32] __aligned(32) = { 0 }; |
| u8 *scalar; |
| memcpy(e, secret, 32); |
| curve25519_clamp_secret(e); |
| scalar = e; |
| { |
| u64 buf[15] = { 0 }; |
| u64 *nq = buf; |
| u64 *x = nq; |
| x[0] = 1; |
| ladder_cmult(nq, scalar, q); |
| format_scalar_of_point(mypublic, nq); |
| memzero_explicit(buf, sizeof(buf)); |
| } |
| memzero_explicit(e, sizeof(e)); |
| } |
| memzero_explicit(buf0, sizeof(buf0)); |
| } |