mirror of
https://github.com/jedisct1/libsodium.git
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Shrink x25519_donna_c64; reuse functions from core
This commit is contained in:
Frank Denis
@@ -29,16 +29,13 @@
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#include "../scalarmult_curve25519.h"
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#include "curve25519_donna_c64.h"
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#include "private/curve25519_ref10.h"
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#include "private/common.h"
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#include "utils.h"
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typedef uint8_t u8;
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typedef uint64_t limb;
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typedef limb felem[5];
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/* Sum two numbers: output += in */
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static inline void
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fsum(limb *output, const limb *in)
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fe_add_self(fe output, const fe in)
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{
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output[0] += in[0];
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output[1] += in[1];
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@@ -54,41 +51,38 @@ fsum(limb *output, const limb *in)
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* On return, out[i] < 2**55
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*/
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static inline void
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fdifference_backwards(felem out, const felem in)
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fe_sub_backwards(fe out, const fe in)
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{
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/* 152 is 19 << 3 */
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static const limb two54m152 = (((limb)1) << 54) - 152;
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static const limb two54m8 = (((limb)1) << 54) - 8;
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static const uint64_t two54m152 = (((uint64_t) 1) << 54) - 152;
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static const uint64_t two54m8 = (((uint64_t) 1) << 54) - 8;
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out[0] = in[0] + two54m152 - out[0];
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out[1] = in[1] + two54m8 - out[1];
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out[2] = in[2] + two54m8 - out[2];
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out[3] = in[3] + two54m8 - out[3];
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out[4] = in[4] + two54m8 - out[4];
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out[1] = in[1] + two54m8 - out[1];
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out[2] = in[2] + two54m8 - out[2];
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out[3] = in[3] + two54m8 - out[3];
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out[4] = in[4] + two54m8 - out[4];
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}
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/* Multiply a number by a scalar: output = in * scalar */
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static inline void
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fscalar_product(felem output, const felem in, const limb scalar)
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fe_scalar_product(fe output, const fe in, const uint64_t scalar)
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{
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const uint64_t mask = 0x7ffffffffffffULL;
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uint128_t a;
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a = in[0] * (uint128_t)scalar;
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output[0] = ((limb)a) & 0x7ffffffffffff;
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a = in[0] * (uint128_t) scalar;
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output[0] = ((uint64_t) a) & mask;
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a = in[1] * (uint128_t) scalar + ((uint64_t) (a >> 51));
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output[1] = ((uint64_t) a) & mask;
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a = in[2] * (uint128_t) scalar + ((uint64_t) (a >> 51));
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output[2] = ((uint64_t) a) & mask;
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a = in[3] * (uint128_t) scalar + ((uint64_t) (a >> 51));
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output[3] = ((uint64_t) a) & mask;
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a = in[4] * (uint128_t) scalar + ((uint64_t) (a >> 51));
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output[4] = ((uint64_t) a) & mask;
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a = in[1] * (uint128_t)scalar + ((limb)(a >> 51));
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output[1] = ((limb)a) & 0x7ffffffffffff;
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a = in[2] * (uint128_t)scalar + ((limb)(a >> 51));
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output[2] = ((limb)a) & 0x7ffffffffffff;
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a = in[3] * (uint128_t)scalar + ((limb)(a >> 51));
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output[3] = ((limb)a) & 0x7ffffffffffff;
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a = in[4] * (uint128_t)scalar + ((limb)(a >> 51));
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output[4] = ((limb)a) & 0x7ffffffffffff;
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output[0] += (a >> 51) * 19;
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output[0] += (a >> 51) * 19ULL;
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}
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/* Multiply two numbers: output = in2 * in
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@@ -100,10 +94,11 @@ fscalar_product(felem output, const felem in, const limb scalar)
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* On return, output[i] < 2**52
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*/
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static inline void
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fmul(felem output, const felem in2, const felem in)
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fe_mul_restrict(fe output, const fe in2, const fe in)
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{
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const uint64_t mask = 0x7ffffffffffffULL;
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uint128_t t[5];
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limb r0, r1, r2, r3, r4, s0, s1, s2, s3, s4, c;
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uint64_t r0, r1, r2, r3, r4, s0, s1, s2, s3, s4, c;
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r0 = in[0];
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r1 = in[1];
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@@ -117,45 +112,45 @@ fmul(felem output, const felem in2, const felem in)
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s3 = in2[3];
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s4 = in2[4];
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t[0] = ((uint128_t)r0) * s0;
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t[1] = ((uint128_t)r0) * s1 + ((uint128_t)r1) * s0;
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t[2] = ((uint128_t)r0) * s2 + ((uint128_t)r2) * s0 + ((uint128_t)r1) * s1;
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t[3] = ((uint128_t)r0) * s3 + ((uint128_t)r3) * s0 + ((uint128_t)r1) * s2
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+ ((uint128_t)r2) * s1;
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t[4] = ((uint128_t)r0) * s4 + ((uint128_t)r4) * s0 + ((uint128_t)r3) * s1
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+ ((uint128_t)r1) * s3 + ((uint128_t)r2) * s2;
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t[0] = ((uint128_t) r0) * s0;
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t[1] = ((uint128_t) r0) * s1 + ((uint128_t) r1) * s0;
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t[2] = ((uint128_t) r0) * s2 + ((uint128_t) r2) * s0 + ((uint128_t) r1) * s1;
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t[3] = ((uint128_t) r0) * s3 + ((uint128_t) r3) * s0 + ((uint128_t) r1) * s2
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+ ((uint128_t) r2) * s1;
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t[4] = ((uint128_t) r0) * s4 + ((uint128_t) r4) * s0 + ((uint128_t) r3) * s1
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+ ((uint128_t) r1) * s3 + ((uint128_t) r2) * s2;
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r4 *= 19;
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r1 *= 19;
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r2 *= 19;
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r3 *= 19;
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r4 *= 19ULL;
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r1 *= 19ULL;
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r2 *= 19ULL;
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r3 *= 19ULL;
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t[0] += ((uint128_t)r4) * s1 + ((uint128_t)r1) * s4 + ((uint128_t)r2) * s3
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+ ((uint128_t)r3) * s2;
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t[1] += ((uint128_t)r4) * s2 + ((uint128_t)r2) * s4 + ((uint128_t)r3) * s3;
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t[2] += ((uint128_t)r4) * s3 + ((uint128_t)r3) * s4;
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t[3] += ((uint128_t)r4) * s4;
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t[0] += ((uint128_t) r4) * s1 + ((uint128_t) r1) * s4 + ((uint128_t) r2) * s3
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+ ((uint128_t) r3) * s2;
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t[1] += ((uint128_t) r4) * s2 + ((uint128_t) r2) * s4 + ((uint128_t) r3) * s3;
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t[2] += ((uint128_t) r4) * s3 + ((uint128_t) r3) * s4;
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t[3] += ((uint128_t) r4) * s4;
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r0 = (limb)t[0] & 0x7ffffffffffff;
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c = (limb)(t[0] >> 51);
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r0 = (uint64_t) t[0] & mask;
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c = (uint64_t) (t[0] >> 51);
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t[1] += c;
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r1 = (limb)t[1] & 0x7ffffffffffff;
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c = (limb)(t[1] >> 51);
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r1 = (uint64_t) t[1] & mask;
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c = (uint64_t) (t[1] >> 51);
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t[2] += c;
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r2 = (limb)t[2] & 0x7ffffffffffff;
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c = (limb)(t[2] >> 51);
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r2 = (uint64_t) t[2] & mask;
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c = (uint64_t) (t[2] >> 51);
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t[3] += c;
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r3 = (limb)t[3] & 0x7ffffffffffff;
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c = (limb)(t[3] >> 51);
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r3 = (uint64_t) t[3] & mask;
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c = (uint64_t) (t[3] >> 51);
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t[4] += c;
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r4 = (limb)t[4] & 0x7ffffffffffff;
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c = (limb)(t[4] >> 51);
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r0 += c * 19;
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r4 = (uint64_t) t[4] & mask;
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c = (uint64_t) (t[4] >> 51);
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r0 += c * 19ULL;
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c = r0 >> 51;
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r0 = r0 & 0x7ffffffffffff;
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r0 = r0 & mask;
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r1 += c;
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c = r1 >> 51;
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r1 = r1 & 0x7ffffffffffff;
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r1 = r1 & mask;
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r2 += c;
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output[0] = r0;
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@@ -166,11 +161,12 @@ fmul(felem output, const felem in2, const felem in)
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}
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static inline void
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fsquare_times(felem output, const felem in, limb count)
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fe_square_times(fe output, const fe in, uint64_t count)
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{
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const uint64_t mask = 0x7ffffffffffffULL;
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uint128_t t[5];
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limb r0, r1, r2, r3, r4, c;
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limb d0, d1, d2, d4, d419;
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uint64_t r0, r1, r2, r3, r4, c;
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uint64_t d0, d1, d2, d4, d419;
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r0 = in[0];
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r1 = in[1];
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@@ -181,41 +177,41 @@ fsquare_times(felem output, const felem in, limb count)
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do {
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d0 = r0 * 2;
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d1 = r1 * 2;
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d2 = r2 * 2 * 19;
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d419 = r4 * 19;
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d2 = r2 * 2 * 19ULL;
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d419 = r4 * 19ULL;
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d4 = d419 * 2;
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t[0] = ((uint128_t)r0) * r0 + ((uint128_t)d4) * r1
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+ (((uint128_t)d2) * (r3));
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t[1] = ((uint128_t)d0) * r1 + ((uint128_t)d4) * r2
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+ (((uint128_t)r3) * (r3 * 19));
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t[2] = ((uint128_t)d0) * r2 + ((uint128_t)r1) * r1
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+ (((uint128_t)d4) * (r3));
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t[3] = ((uint128_t)d0) * r3 + ((uint128_t)d1) * r2
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+ (((uint128_t)r4) * (d419));
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t[4] = ((uint128_t)d0) * r4 + ((uint128_t)d1) * r3
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+ (((uint128_t)r2) * (r2));
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t[0] = ((uint128_t) r0) * r0 + ((uint128_t) d4) * r1
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+ (((uint128_t) d2) * (r3));
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t[1] = ((uint128_t) d0) * r1 + ((uint128_t) d4) * r2
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+ (((uint128_t) r3) * (r3 * 19ULL));
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t[2] = ((uint128_t) d0) * r2 + ((uint128_t) r1) * r1
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+ (((uint128_t) d4) * (r3));
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t[3] = ((uint128_t) d0) * r3 + ((uint128_t) d1) * r2
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+ (((uint128_t) r4) * (d419));
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t[4] = ((uint128_t) d0) * r4 + ((uint128_t) d1) * r3
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+ (((uint128_t) r2) * (r2));
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r0 = (limb)t[0] & 0x7ffffffffffff;
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c = (limb)(t[0] >> 51);
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r0 = (uint64_t) t[0] & mask;
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c = (uint64_t) (t[0] >> 51);
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t[1] += c;
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r1 = (limb)t[1] & 0x7ffffffffffff;
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c = (limb)(t[1] >> 51);
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r1 = (uint64_t) t[1] & mask;
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c = (uint64_t) (t[1] >> 51);
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t[2] += c;
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r2 = (limb)t[2] & 0x7ffffffffffff;
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c = (limb)(t[2] >> 51);
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r2 = (uint64_t) t[2] & mask;
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c = (uint64_t) (t[2] >> 51);
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t[3] += c;
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r3 = (limb)t[3] & 0x7ffffffffffff;
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c = (limb)(t[3] >> 51);
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r3 = (uint64_t) t[3] & mask;
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c = (uint64_t) (t[3] >> 51);
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t[4] += c;
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r4 = (limb)t[4] & 0x7ffffffffffff;
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c = (limb)(t[4] >> 51);
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r0 += c * 19;
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r4 = (uint64_t) t[4] & mask;
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c = (uint64_t) (t[4] >> 51);
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r0 += c * 19ULL;
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c = r0 >> 51;
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r0 = r0 & 0x7ffffffffffff;
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r0 = r0 & mask;
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r1 += c;
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c = r1 >> 51;
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r1 = r1 & 0x7ffffffffffff;
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r1 = r1 & mask;
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r2 += c;
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} while (--count);
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@@ -226,133 +222,6 @@ fsquare_times(felem output, const felem in, limb count)
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output[4] = r4;
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}
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#ifdef NATIVE_LITTLE_ENDIAN
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static inline limb
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load_limb(const u8 *in)
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{
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limb out;
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memcpy(&out, in, sizeof(limb));
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return out;
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}
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static inline void
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store_limb(u8 *out, limb in)
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{
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memcpy(out, &in, sizeof(limb));
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}
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#else
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static inline limb
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load_limb(const u8 *in)
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{
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return ((limb)in[0]) | (((limb)in[1]) << 8) | (((limb)in[2]) << 16)
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| (((limb)in[3]) << 24) | (((limb)in[4]) << 32)
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| (((limb)in[5]) << 40) | (((limb)in[6]) << 48)
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| (((limb)in[7]) << 56);
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}
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static inline void
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store_limb(u8 *out, limb in)
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{
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out[0] = in & 0xff;
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out[1] = (in >> 8) & 0xff;
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out[2] = (in >> 16) & 0xff;
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out[3] = (in >> 24) & 0xff;
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out[4] = (in >> 32) & 0xff;
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out[5] = (in >> 40) & 0xff;
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out[6] = (in >> 48) & 0xff;
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out[7] = (in >> 56) & 0xff;
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}
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#endif
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/* Take a little-endian, 32-byte number and expand it into polynomial form */
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static void
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fexpand(limb *output, const u8 *in)
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{
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output[0] = load_limb(in) & 0x7ffffffffffff;
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output[1] = (load_limb(in + 6) >> 3) & 0x7ffffffffffff;
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output[2] = (load_limb(in + 12) >> 6) & 0x7ffffffffffff;
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output[3] = (load_limb(in + 19) >> 1) & 0x7ffffffffffff;
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output[4] = (load_limb(in + 24) >> 12) & 0x7ffffffffffff;
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}
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/* Take a fully reduced polynomial form number and contract it into a
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* little-endian, 32-byte array
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*/
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static void
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fcontract(u8 *output, const felem input)
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{
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uint128_t t[5];
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t[0] = input[0];
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t[1] = input[1];
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t[2] = input[2];
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t[3] = input[3];
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t[4] = input[4];
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t[1] += t[0] >> 51;
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t[0] &= 0x7ffffffffffff;
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t[2] += t[1] >> 51;
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t[1] &= 0x7ffffffffffff;
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t[3] += t[2] >> 51;
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t[2] &= 0x7ffffffffffff;
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t[4] += t[3] >> 51;
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t[3] &= 0x7ffffffffffff;
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t[0] += 19 * (t[4] >> 51);
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t[4] &= 0x7ffffffffffff;
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t[1] += t[0] >> 51;
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t[0] &= 0x7ffffffffffff;
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t[2] += t[1] >> 51;
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t[1] &= 0x7ffffffffffff;
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t[3] += t[2] >> 51;
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t[2] &= 0x7ffffffffffff;
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t[4] += t[3] >> 51;
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t[3] &= 0x7ffffffffffff;
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t[0] += 19 * (t[4] >> 51);
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t[4] &= 0x7ffffffffffff;
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/* now t is between 0 and 2^255-1, properly carried. */
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/* case 1: between 0 and 2^255-20. case 2: between 2^255-19 and 2^255-1. */
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t[0] += 19;
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t[1] += t[0] >> 51;
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t[0] &= 0x7ffffffffffff;
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t[2] += t[1] >> 51;
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t[1] &= 0x7ffffffffffff;
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t[3] += t[2] >> 51;
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t[2] &= 0x7ffffffffffff;
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t[4] += t[3] >> 51;
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t[3] &= 0x7ffffffffffff;
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t[0] += 19 * (t[4] >> 51);
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t[4] &= 0x7ffffffffffff;
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/* now between 19 and 2^255-1 in both cases, and offset by 19. */
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t[0] += 0x8000000000000 - 19;
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t[1] += 0x8000000000000 - 1;
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t[2] += 0x8000000000000 - 1;
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t[3] += 0x8000000000000 - 1;
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t[4] += 0x8000000000000 - 1;
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/* now between 2^255 and 2^256-20, and offset by 2^255. */
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t[1] += t[0] >> 51;
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t[0] &= 0x7ffffffffffff;
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t[2] += t[1] >> 51;
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t[1] &= 0x7ffffffffffff;
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t[3] += t[2] >> 51;
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t[2] &= 0x7ffffffffffff;
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t[4] += t[3] >> 51;
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t[3] &= 0x7ffffffffffff;
|
||||
t[4] &= 0x7ffffffffffff;
|
||||
|
||||
store_limb(output, t[0] | (t[1] << 51));
|
||||
store_limb(output + 8, (t[1] >> 13) | (t[2] << 38));
|
||||
store_limb(output + 16, (t[2] >> 26) | (t[3] << 25));
|
||||
store_limb(output + 24, (t[3] >> 39) | (t[4] << 12));
|
||||
}
|
||||
|
||||
/* Input: Q, Q', Q-Q'
|
||||
* Output: 2Q, Q+Q'
|
||||
*
|
||||
@@ -363,42 +232,41 @@ fcontract(u8 *output, const felem input)
|
||||
* qmqp: short form, preserved
|
||||
*/
|
||||
static void
|
||||
fmonty(limb *x2, limb *z2, /* output 2Q */
|
||||
limb *x3, limb *z3, /* output Q + Q' */
|
||||
limb *x, limb *z, /* input Q */
|
||||
limb *xprime, limb *zprime, /* input Q' */
|
||||
const limb *qmqp /* input Q - Q' */)
|
||||
fe_mont_y(fe x2, fe z2, /* output 2Q */
|
||||
fe x3, fe z3, /* output Q + Q' */
|
||||
fe x, fe z, /* input Q */
|
||||
fe xprime, fe zprime, /* input Q' */
|
||||
const fe qmqp /* input Q - Q' */)
|
||||
{
|
||||
limb origx[5], origxprime[5], zzz[5], xx[5], zz[5], xxprime[5], zzprime[5],
|
||||
zzzprime[5];
|
||||
fe origx, origxprime, zzz, xx, zz, xxprime, zzprime, zzzprime;
|
||||
|
||||
memcpy(origx, x, 5 * sizeof(limb));
|
||||
fsum(x, z);
|
||||
fdifference_backwards(z, origx); /* does x - z */
|
||||
memcpy(origx, x, 5 * sizeof(uint64_t));
|
||||
fe_add_self(x, z);
|
||||
fe_sub_backwards(z, origx); /* does x - z */
|
||||
|
||||
memcpy(origxprime, xprime, sizeof(limb) * 5);
|
||||
fsum(xprime, zprime);
|
||||
fdifference_backwards(zprime, origxprime);
|
||||
fmul(xxprime, xprime, z);
|
||||
fmul(zzprime, x, zprime);
|
||||
memcpy(origxprime, xxprime, sizeof(limb) * 5);
|
||||
fsum(xxprime, zzprime);
|
||||
fdifference_backwards(zzprime, origxprime);
|
||||
fsquare_times(x3, xxprime, 1);
|
||||
fsquare_times(zzzprime, zzprime, 1);
|
||||
fmul(z3, zzzprime, qmqp);
|
||||
memcpy(origxprime, xprime, sizeof(uint64_t) * 5);
|
||||
fe_add_self(xprime, zprime);
|
||||
fe_sub_backwards(zprime, origxprime);
|
||||
fe_mul_restrict(xxprime, xprime, z);
|
||||
fe_mul_restrict(zzprime, x, zprime);
|
||||
memcpy(origxprime, xxprime, sizeof(uint64_t) * 5);
|
||||
fe_add_self(xxprime, zzprime);
|
||||
fe_sub_backwards(zzprime, origxprime);
|
||||
fe_square_times(x3, xxprime, 1);
|
||||
fe_square_times(zzzprime, zzprime, 1);
|
||||
fe_mul_restrict(z3, zzzprime, qmqp);
|
||||
|
||||
fsquare_times(xx, x, 1);
|
||||
fsquare_times(zz, z, 1);
|
||||
fmul(x2, xx, zz);
|
||||
fdifference_backwards(zz, xx); /* does zz = xx - zz */
|
||||
fscalar_product(zzz, zz, 121665);
|
||||
fsum(zzz, xx);
|
||||
fmul(z2, zz, zzz);
|
||||
fe_square_times(xx, x, 1);
|
||||
fe_square_times(zz, z, 1);
|
||||
fe_mul_restrict(x2, xx, zz);
|
||||
fe_sub_backwards(zz, xx); /* does zz = xx - zz */
|
||||
fe_scalar_product(zzz, zz, 121665);
|
||||
fe_add_self(zzz, xx);
|
||||
fe_mul_restrict(z2, zz, zzz);
|
||||
}
|
||||
|
||||
/* -----------------------------------------------------------------------------
|
||||
Maybe swap the contents of two limb arrays (@a and @b), each @len elements
|
||||
Maybe swap the contents of two uint64_t arrays (@a and @b), each @len elements
|
||||
long. Perform the swap iff @swap is non-zero.
|
||||
|
||||
This function performs the swap without leaking any side-channel
|
||||
@@ -406,15 +274,15 @@ fmonty(limb *x2, limb *z2, /* output 2Q */
|
||||
-----------------------------------------------------------------------------
|
||||
*/
|
||||
static void
|
||||
swap_conditional(limb a[5], limb b[5], limb iswap)
|
||||
swap_conditional(fe f, fe g, unsigned int b)
|
||||
{
|
||||
const limb swap = -iswap;
|
||||
unsigned i;
|
||||
const uint64_t mask = (uint64_t) (-(int64_t) b);
|
||||
unsigned int i;
|
||||
|
||||
for (i = 0; i < 5; ++i) {
|
||||
const limb x = swap & (a[i] ^ b[i]);
|
||||
a[i] ^= x;
|
||||
b[i] ^= x;
|
||||
for (i = 0; i < 5; i++) {
|
||||
const uint64_t x = mask & (f[i] ^ g[i]);
|
||||
f[i] ^= x;
|
||||
g[i] ^= x;
|
||||
}
|
||||
}
|
||||
|
||||
@@ -425,25 +293,25 @@ swap_conditional(limb a[5], limb b[5], limb iswap)
|
||||
* q: a point of the curve (short form)
|
||||
*/
|
||||
static void
|
||||
cmult(limb *resultx, limb *resultz, const u8 *n, const limb *q)
|
||||
cmult(fe resultx, fe resultz, const uint8_t *n, const fe q)
|
||||
{
|
||||
limb a[5] = { 0 }, b[5] = { 1 }, c[5] = { 1 }, d[5] = { 0 };
|
||||
limb *nqpqx = a, *nqpqz = b, *nqx = c, *nqz = d, *t;
|
||||
limb e[5] = { 0 }, f[5] = { 1 }, g[5] = { 0 }, h[5] = { 1 };
|
||||
limb *nqpqx2 = e, *nqpqz2 = f, *nqx2 = g, *nqz2 = h;
|
||||
fe a = { 0 }, b = { 1 }, c = { 1 }, d = { 0 };
|
||||
uint64_t *nqpqx = a, *nqpqz = b, *nqx = c, *nqz = d, *t;
|
||||
fe e = { 0 }, f = { 1 }, g = { 0 }, h = { 1 };
|
||||
uint64_t *nqpqx2 = e, *nqpqz2 = f, *nqx2 = g, *nqz2 = h;
|
||||
|
||||
unsigned i, j;
|
||||
|
||||
memcpy(nqpqx, q, sizeof(limb) * 5);
|
||||
memcpy(nqpqx, q, sizeof(uint64_t) * 5);
|
||||
|
||||
for (i = 0; i < 32; ++i) {
|
||||
u8 byte = n[31 - i];
|
||||
uint8_t byte = n[31 - i];
|
||||
for (j = 0; j < 8; ++j) {
|
||||
const limb bit = byte >> 7;
|
||||
const unsigned int bit = byte >> 7;
|
||||
|
||||
swap_conditional(nqx, nqpqx, bit);
|
||||
swap_conditional(nqz, nqpqz, bit);
|
||||
fmonty(nqx2, nqz2, nqpqx2, nqpqz2, nqx, nqz, nqpqx, nqpqz, q);
|
||||
fe_mont_y(nqx2, nqz2, nqpqx2, nqpqz2, nqx, nqz, nqpqx, nqpqz, q);
|
||||
swap_conditional(nqx2, nqpqx2, bit);
|
||||
swap_conditional(nqz2, nqpqz2, bit);
|
||||
|
||||
@@ -464,8 +332,8 @@ cmult(limb *resultx, limb *resultz, const u8 *n, const limb *q)
|
||||
}
|
||||
}
|
||||
|
||||
memcpy(resultx, nqx, sizeof(limb) * 5);
|
||||
memcpy(resultz, nqz, sizeof(limb) * 5);
|
||||
memcpy(resultx, nqx, sizeof(uint64_t) * 5);
|
||||
memcpy(resultz, nqz, sizeof(uint64_t) * 5);
|
||||
}
|
||||
|
||||
/* -----------------------------------------------------------------------------
|
||||
@@ -473,32 +341,32 @@ cmult(limb *resultx, limb *resultz, const u8 *n, const limb *q)
|
||||
-----------------------------------------------------------------------------
|
||||
*/
|
||||
static void
|
||||
crecip(felem out, const felem z)
|
||||
crecip(fe out, const fe z)
|
||||
{
|
||||
felem a, t0, b, c;
|
||||
fe a, t0, b, c;
|
||||
|
||||
/* 2 */ fsquare_times(a, z, 1); /* a = 2 */
|
||||
/* 8 */ fsquare_times(t0, a, 2);
|
||||
/* 9 */ fmul(b, t0, z); /* b = 9 */
|
||||
/* 11 */ fmul(a, b, a); /* a = 11 */
|
||||
/* 22 */ fsquare_times(t0, a, 1);
|
||||
/* 2^5 - 2^0 = 31 */ fmul(b, t0, b);
|
||||
/* 2^10 - 2^5 */ fsquare_times(t0, b, 5);
|
||||
/* 2^10 - 2^0 */ fmul(b, t0, b);
|
||||
/* 2^20 - 2^10 */ fsquare_times(t0, b, 10);
|
||||
/* 2^20 - 2^0 */ fmul(c, t0, b);
|
||||
/* 2^40 - 2^20 */ fsquare_times(t0, c, 20);
|
||||
/* 2^40 - 2^0 */ fmul(t0, t0, c);
|
||||
/* 2^50 - 2^10 */ fsquare_times(t0, t0, 10);
|
||||
/* 2^50 - 2^0 */ fmul(b, t0, b);
|
||||
/* 2^100 - 2^50 */ fsquare_times(t0, b, 50);
|
||||
/* 2^100 - 2^0 */ fmul(c, t0, b);
|
||||
/* 2^200 - 2^100 */ fsquare_times(t0, c, 100);
|
||||
/* 2^200 - 2^0 */ fmul(t0, t0, c);
|
||||
/* 2^250 - 2^50 */ fsquare_times(t0, t0, 50);
|
||||
/* 2^250 - 2^0 */ fmul(t0, t0, b);
|
||||
/* 2^255 - 2^5 */ fsquare_times(t0, t0, 5);
|
||||
/* 2^255 - 21 */ fmul(out, t0, a);
|
||||
/* 2 */ fe_square_times(a, z, 1); /* a = 2 */
|
||||
/* 8 */ fe_square_times(t0, a, 2);
|
||||
/* 9 */ fe_mul_restrict(b, t0, z); /* b = 9 */
|
||||
/* 11 */ fe_mul_restrict(a, b, a); /* a = 11 */
|
||||
/* 22 */ fe_square_times(t0, a, 1);
|
||||
/* 2^5 - 2^0 = 31 */ fe_mul_restrict(b, t0, b);
|
||||
/* 2^10 - 2^5 */ fe_square_times(t0, b, 5);
|
||||
/* 2^10 - 2^0 */ fe_mul_restrict(b, t0, b);
|
||||
/* 2^20 - 2^10 */ fe_square_times(t0, b, 10);
|
||||
/* 2^20 - 2^0 */ fe_mul_restrict(c, t0, b);
|
||||
/* 2^40 - 2^20 */ fe_square_times(t0, c, 20);
|
||||
/* 2^40 - 2^0 */ fe_mul_restrict(t0, t0, c);
|
||||
/* 2^50 - 2^10 */ fe_square_times(t0, t0, 10);
|
||||
/* 2^50 - 2^0 */ fe_mul_restrict(b, t0, b);
|
||||
/* 2^100 - 2^50 */ fe_square_times(t0, b, 50);
|
||||
/* 2^100 - 2^0 */ fe_mul_restrict(c, t0, b);
|
||||
/* 2^200 - 2^100 */ fe_square_times(t0, c, 100);
|
||||
/* 2^200 - 2^0 */ fe_mul_restrict(t0, t0, c);
|
||||
/* 2^250 - 2^50 */ fe_square_times(t0, t0, 50);
|
||||
/* 2^250 - 2^0 */ fe_mul_restrict(t0, t0, b);
|
||||
/* 2^255 - 2^5 */ fe_square_times(t0, t0, 5);
|
||||
/* 2^255 - 21 */ fe_mul_restrict(out, t0, a);
|
||||
}
|
||||
|
||||
static int
|
||||
@@ -506,7 +374,7 @@ crypto_scalarmult_curve25519_donna_c64(unsigned char *q,
|
||||
const unsigned char *n,
|
||||
const unsigned char *p)
|
||||
{
|
||||
limb bp[5], x[5], z[5], zmone[5];
|
||||
fe bp, x, z, zmone;
|
||||
unsigned char *t = q;
|
||||
int i;
|
||||
|
||||
@@ -517,11 +385,11 @@ crypto_scalarmult_curve25519_donna_c64(unsigned char *q,
|
||||
t[31] &= 127;
|
||||
t[31] |= 64;
|
||||
|
||||
fexpand(bp, p);
|
||||
fe_frombytes(bp, p);
|
||||
cmult(x, z, t, bp);
|
||||
crecip(zmone, z);
|
||||
fmul(z, x, zmone);
|
||||
fcontract(q, z);
|
||||
fe_mul_restrict(z, x, zmone);
|
||||
fe_tobytes(q, z);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user