diff options
Diffstat (limited to 'src/curve25519-donna-64bit.h')
| -rw-r--r-- | src/curve25519-donna-64bit.h | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/src/curve25519-donna-64bit.h b/src/curve25519-donna-64bit.h new file mode 100644 index 0000000..ec4df52 --- /dev/null +++ b/src/curve25519-donna-64bit.h @@ -0,0 +1,345 @@ +typedef uint64_t bignum25519[5]; + +static const uint64_t reduce_mask_51 = ((uint64_t)1 << 51) - 1; +static const uint64_t reduce_mask_52 = ((uint64_t)1 << 52) - 1; + +/* out = in */ +DONNA_INLINE static void +curve25519_copy(bignum25519 out, const bignum25519 in) { + out[0] = in[0]; + out[1] = in[1]; + out[2] = in[2]; + out[3] = in[3]; + out[4] = in[4]; +} + +/* out = a + b */ +DONNA_INLINE static void +curve25519_add(bignum25519 out, const bignum25519 a, const bignum25519 b) { + out[0] = a[0] + b[0]; + out[1] = a[1] + b[1]; + out[2] = a[2] + b[2]; + out[3] = a[3] + b[3]; + out[4] = a[4] + b[4]; +} + +static const uint64_t two54m152 = (((uint64_t)1) << 54) - 152; +static const uint64_t two54m8 = (((uint64_t)1) << 54) - 8; + +/* out = a - b */ +DONNA_INLINE static void +curve25519_sub(bignum25519 out, const bignum25519 a, const bignum25519 b) { + out[0] = a[0] + two54m152 - b[0]; + out[1] = a[1] + two54m8 - b[1]; + out[2] = a[2] + two54m8 - b[2]; + out[3] = a[3] + two54m8 - b[3]; + out[4] = a[4] + two54m8 - b[4]; +} + + +/* out = (in * scalar) */ +DONNA_INLINE static void +curve25519_scalar_product(bignum25519 out, const bignum25519 in, const uint64_t scalar) { + uint128_t a; + uint64_t c; + +#if defined(HAVE_NATIVE_UINT128) + a = ((uint128_t) in[0]) * scalar; out[0] = (uint64_t)a & reduce_mask_51; c = (uint64_t)(a >> 51); + a = ((uint128_t) in[1]) * scalar + c; out[1] = (uint64_t)a & reduce_mask_51; c = (uint64_t)(a >> 51); + a = ((uint128_t) in[2]) * scalar + c; out[2] = (uint64_t)a & reduce_mask_51; c = (uint64_t)(a >> 51); + a = ((uint128_t) in[3]) * scalar + c; out[3] = (uint64_t)a & reduce_mask_51; c = (uint64_t)(a >> 51); + a = ((uint128_t) in[4]) * scalar + c; out[4] = (uint64_t)a & reduce_mask_51; c = (uint64_t)(a >> 51); + out[0] += c * 19; +#else + mul64x64_128(a, in[0], scalar) out[0] = lo128(a) & reduce_mask_51; shr128(c, a, 51); + mul64x64_128(a, in[1], scalar) add128_64(a, c) out[1] = lo128(a) & reduce_mask_51; shr128(c, a, 51); + mul64x64_128(a, in[2], scalar) add128_64(a, c) out[2] = lo128(a) & reduce_mask_51; shr128(c, a, 51); + mul64x64_128(a, in[3], scalar) add128_64(a, c) out[3] = lo128(a) & reduce_mask_51; shr128(c, a, 51); + mul64x64_128(a, in[4], scalar) add128_64(a, c) out[4] = lo128(a) & reduce_mask_51; shr128(c, a, 51); + out[0] += c * 19; +#endif +} + +/* out = a * b */ +DONNA_INLINE static void +curve25519_mul(bignum25519 out, const bignum25519 a, const bignum25519 b) { +#if !defined(HAVE_NATIVE_UINT128) + uint128_t mul; +#endif + uint128_t t[5]; + uint64_t r0,r1,r2,r3,r4,s0,s1,s2,s3,s4,c; + + r0 = b[0]; + r1 = b[1]; + r2 = b[2]; + r3 = b[3]; + r4 = b[4]; + + s0 = a[0]; + s1 = a[1]; + s2 = a[2]; + s3 = a[3]; + s4 = a[4]; + +#if defined(HAVE_NATIVE_UINT128) + t[0] = ((uint128_t) r0) * s0; + t[1] = ((uint128_t) r0) * s1 + ((uint128_t) r1) * s0; + t[2] = ((uint128_t) r0) * s2 + ((uint128_t) r2) * s0 + ((uint128_t) r1) * s1; + t[3] = ((uint128_t) r0) * s3 + ((uint128_t) r3) * s0 + ((uint128_t) r1) * s2 + ((uint128_t) r2) * s1; + t[4] = ((uint128_t) r0) * s4 + ((uint128_t) r4) * s0 + ((uint128_t) r3) * s1 + ((uint128_t) r1) * s3 + ((uint128_t) r2) * s2; +#else + mul64x64_128(t[0], r0, s0) + mul64x64_128(t[1], r0, s1) mul64x64_128(mul, r1, s0) add128(t[1], mul) + mul64x64_128(t[2], r0, s2) mul64x64_128(mul, r2, s0) add128(t[2], mul) mul64x64_128(mul, r1, s1) add128(t[2], mul) + mul64x64_128(t[3], r0, s3) mul64x64_128(mul, r3, s0) add128(t[3], mul) mul64x64_128(mul, r1, s2) add128(t[3], mul) mul64x64_128(mul, r2, s1) add128(t[3], mul) + mul64x64_128(t[4], r0, s4) mul64x64_128(mul, r4, s0) add128(t[4], mul) mul64x64_128(mul, r3, s1) add128(t[4], mul) mul64x64_128(mul, r1, s3) add128(t[4], mul) mul64x64_128(mul, r2, s2) add128(t[4], mul) +#endif + + r1 *= 19; + r2 *= 19; + r3 *= 19; + r4 *= 19; + +#if defined(HAVE_NATIVE_UINT128) + t[0] += ((uint128_t) r4) * s1 + ((uint128_t) r1) * s4 + ((uint128_t) r2) * s3 + ((uint128_t) r3) * s2; + t[1] += ((uint128_t) r4) * s2 + ((uint128_t) r2) * s4 + ((uint128_t) r3) * s3; + t[2] += ((uint128_t) r4) * s3 + ((uint128_t) r3) * s4; + t[3] += ((uint128_t) r4) * s4; +#else + mul64x64_128(mul, r4, s1) add128(t[0], mul) mul64x64_128(mul, r1, s4) add128(t[0], mul) mul64x64_128(mul, r2, s3) add128(t[0], mul) mul64x64_128(mul, r3, s2) add128(t[0], mul) + mul64x64_128(mul, r4, s2) add128(t[1], mul) mul64x64_128(mul, r2, s4) add128(t[1], mul) mul64x64_128(mul, r3, s3) add128(t[1], mul) + mul64x64_128(mul, r4, s3) add128(t[2], mul) mul64x64_128(mul, r3, s4) add128(t[2], mul) + mul64x64_128(mul, r4, s4) add128(t[3], mul) +#endif + + r0 = lo128(t[0]) & reduce_mask_51; shr128(c, t[0], 51); + add128_64(t[1], c) r1 = lo128(t[1]) & reduce_mask_51; shr128(c, t[1], 51); + add128_64(t[2], c) r2 = lo128(t[2]) & reduce_mask_51; shr128(c, t[2], 51); + add128_64(t[3], c) r3 = lo128(t[3]) & reduce_mask_51; shr128(c, t[3], 51); + add128_64(t[4], c) r4 = lo128(t[4]) & reduce_mask_51; shr128(c, t[4], 51); + r0 += c * 19; c = r0 >> 51; r0 = r0 & reduce_mask_51; + r1 += c; + + out[0] = r0; + out[1] = r1; + out[2] = r2; + out[3] = r3; + out[4] = r4; +} + +/* out = in^(2 * count) */ +DONNA_INLINE static void +curve25519_square_times(bignum25519 out, const bignum25519 in, uint64_t count) { +#if !defined(HAVE_NATIVE_UINT128) + uint128_t mul; +#endif + uint128_t t[5]; + uint64_t r0,r1,r2,r3,r4,c; + uint64_t d0,d1,d2,d4,d419; + + r0 = in[0]; + r1 = in[1]; + r2 = in[2]; + r3 = in[3]; + r4 = in[4]; + + do { + d0 = r0 * 2; + d1 = r1 * 2; + d2 = r2 * 2 * 19; + d419 = r4 * 19; + d4 = d419 * 2; + +#if defined(HAVE_NATIVE_UINT128) + t[0] = ((uint128_t) r0) * r0 + ((uint128_t) d4) * r1 + (((uint128_t) d2) * (r3 )); + t[1] = ((uint128_t) d0) * r1 + ((uint128_t) d4) * r2 + (((uint128_t) r3) * (r3 * 19)); + t[2] = ((uint128_t) d0) * r2 + ((uint128_t) r1) * r1 + (((uint128_t) d4) * (r3 )); + t[3] = ((uint128_t) d0) * r3 + ((uint128_t) d1) * r2 + (((uint128_t) r4) * (d419 )); + t[4] = ((uint128_t) d0) * r4 + ((uint128_t) d1) * r3 + (((uint128_t) r2) * (r2 )); +#else + mul64x64_128(t[0], r0, r0) mul64x64_128(mul, d4, r1) add128(t[0], mul) mul64x64_128(mul, d2, r3) add128(t[0], mul) + mul64x64_128(t[1], d0, r1) mul64x64_128(mul, d4, r2) add128(t[1], mul) mul64x64_128(mul, r3, r3 * 19) add128(t[1], mul) + mul64x64_128(t[2], d0, r2) mul64x64_128(mul, r1, r1) add128(t[2], mul) mul64x64_128(mul, d4, r3) add128(t[2], mul) + mul64x64_128(t[3], d0, r3) mul64x64_128(mul, d1, r2) add128(t[3], mul) mul64x64_128(mul, r4, d419) add128(t[3], mul) + mul64x64_128(t[4], d0, r4) mul64x64_128(mul, d1, r3) add128(t[4], mul) mul64x64_128(mul, r2, r2) add128(t[4], mul) +#endif + + r0 = lo128(t[0]) & reduce_mask_51; shr128(c, t[0], 51); + add128_64(t[1], c) r1 = lo128(t[1]) & reduce_mask_51; shr128(c, t[1], 51); + add128_64(t[2], c) r2 = lo128(t[2]) & reduce_mask_51; shr128(c, t[2], 51); + add128_64(t[3], c) r3 = lo128(t[3]) & reduce_mask_51; shr128(c, t[3], 51); + add128_64(t[4], c) r4 = lo128(t[4]) & reduce_mask_51; shr128(c, t[4], 51); + r0 += c * 19; c = r0 >> 51; r0 = r0 & reduce_mask_51; + r1 += c; + } while(--count); + + out[0] = r0; + out[1] = r1; + out[2] = r2; + out[3] = r3; + out[4] = r4; +} + +DONNA_INLINE static void +curve25519_square(bignum25519 out, const bignum25519 in) { +#if !defined(HAVE_NATIVE_UINT128) + uint128_t mul; +#endif + uint128_t t[5]; + uint64_t r0,r1,r2,r3,r4,c; + uint64_t d0,d1,d2,d4,d419; + + r0 = in[0]; + r1 = in[1]; + r2 = in[2]; + r3 = in[3]; + r4 = in[4]; + + d0 = r0 * 2; + d1 = r1 * 2; + d2 = r2 * 2 * 19; + d419 = r4 * 19; + d4 = d419 * 2; + +#if defined(HAVE_NATIVE_UINT128) + t[0] = ((uint128_t) r0) * r0 + ((uint128_t) d4) * r1 + (((uint128_t) d2) * (r3 )); + t[1] = ((uint128_t) d0) * r1 + ((uint128_t) d4) * r2 + (((uint128_t) r3) * (r3 * 19)); + t[2] = ((uint128_t) d0) * r2 + ((uint128_t) r1) * r1 + (((uint128_t) d4) * (r3 )); + t[3] = ((uint128_t) d0) * r3 + ((uint128_t) d1) * r2 + (((uint128_t) r4) * (d419 )); + t[4] = ((uint128_t) d0) * r4 + ((uint128_t) d1) * r3 + (((uint128_t) r2) * (r2 )); +#else + mul64x64_128(t[0], r0, r0) mul64x64_128(mul, d4, r1) add128(t[0], mul) mul64x64_128(mul, d2, r3) add128(t[0], mul) + mul64x64_128(t[1], d0, r1) mul64x64_128(mul, d4, r2) add128(t[1], mul) mul64x64_128(mul, r3, r3 * 19) add128(t[1], mul) + mul64x64_128(t[2], d0, r2) mul64x64_128(mul, r1, r1) add128(t[2], mul) mul64x64_128(mul, d4, r3) add128(t[2], mul) + mul64x64_128(t[3], d0, r3) mul64x64_128(mul, d1, r2) add128(t[3], mul) mul64x64_128(mul, r4, d419) add128(t[3], mul) + mul64x64_128(t[4], d0, r4) mul64x64_128(mul, d1, r3) add128(t[4], mul) mul64x64_128(mul, r2, r2) add128(t[4], mul) +#endif + + r0 = lo128(t[0]) & reduce_mask_51; shr128(c, t[0], 51); + add128_64(t[1], c) r1 = lo128(t[1]) & reduce_mask_51; shr128(c, t[1], 51); + add128_64(t[2], c) r2 = lo128(t[2]) & reduce_mask_51; shr128(c, t[2], 51); + add128_64(t[3], c) r3 = lo128(t[3]) & reduce_mask_51; shr128(c, t[3], 51); + add128_64(t[4], c) r4 = lo128(t[4]) & reduce_mask_51; shr128(c, t[4], 51); + r0 += c * 19; c = r0 >> 51; r0 = r0 & reduce_mask_51; + r1 += c; + + out[0] = r0; + out[1] = r1; + out[2] = r2; + out[3] = r3; + out[4] = r4; +} + + +/* Take a little-endian, 32-byte number and expand it into polynomial form */ +DONNA_INLINE static void +curve25519_expand(bignum25519 out, const unsigned char *in) { + static const union { uint8_t b[2]; uint16_t s; } endian_check = {{1,0}}; + uint64_t x0,x1,x2,x3; + + if (endian_check.s == 1) { + x0 = *(uint64_t *)(in + 0); + x1 = *(uint64_t *)(in + 8); + x2 = *(uint64_t *)(in + 16); + x3 = *(uint64_t *)(in + 24); + } else { + #define F(s) \ + ((((uint64_t)in[s + 0]) ) | \ + (((uint64_t)in[s + 1]) << 8) | \ + (((uint64_t)in[s + 2]) << 16) | \ + (((uint64_t)in[s + 3]) << 24) | \ + (((uint64_t)in[s + 4]) << 32) | \ + (((uint64_t)in[s + 5]) << 40) | \ + (((uint64_t)in[s + 6]) << 48) | \ + (((uint64_t)in[s + 7]) << 56)) + + x0 = F(0); + x1 = F(8); + x2 = F(16); + x3 = F(24); + } + + out[0] = x0 & reduce_mask_51; x0 = (x0 >> 51) | (x1 << 13); + out[1] = x0 & reduce_mask_51; x1 = (x1 >> 38) | (x2 << 26); + out[2] = x1 & reduce_mask_51; x2 = (x2 >> 25) | (x3 << 39); + out[3] = x2 & reduce_mask_51; x3 = (x3 >> 12); + out[4] = x3 & reduce_mask_51; /* ignore the top bit */ +} + +/* Take a fully reduced polynomial form number and contract it into a + * little-endian, 32-byte array + */ +DONNA_INLINE static void +curve25519_contract(unsigned char *out, const bignum25519 input) { + uint64_t t[5]; + uint64_t f, i; + + t[0] = input[0]; + t[1] = input[1]; + t[2] = input[2]; + t[3] = input[3]; + t[4] = input[4]; + + #define curve25519_contract_carry() \ + t[1] += t[0] >> 51; t[0] &= reduce_mask_51; \ + t[2] += t[1] >> 51; t[1] &= reduce_mask_51; \ + t[3] += t[2] >> 51; t[2] &= reduce_mask_51; \ + t[4] += t[3] >> 51; t[3] &= reduce_mask_51; + + #define curve25519_contract_carry_full() curve25519_contract_carry() \ + t[0] += 19 * (t[4] >> 51); t[4] &= reduce_mask_51; + + #define curve25519_contract_carry_final() curve25519_contract_carry() \ + t[4] &= reduce_mask_51; + + curve25519_contract_carry_full() + curve25519_contract_carry_full() + + /* now t is between 0 and 2^255-1, properly carried. */ + /* case 1: between 0 and 2^255-20. case 2: between 2^255-19 and 2^255-1. */ + t[0] += 19; + curve25519_contract_carry_full() + + /* now between 19 and 2^255-1 in both cases, and offset by 19. */ + t[0] += 0x8000000000000 - 19; + t[1] += 0x8000000000000 - 1; + t[2] += 0x8000000000000 - 1; + t[3] += 0x8000000000000 - 1; + t[4] += 0x8000000000000 - 1; + + /* now between 2^255 and 2^256-20, and offset by 2^255. */ + curve25519_contract_carry_final() + + #define write51full(n,shift) \ + f = ((t[n] >> shift) | (t[n+1] << (51 - shift))); \ + for (i = 0; i < 8; i++, f >>= 8) *out++ = (unsigned char)f; + #define write51(n) write51full(n,13*n) + + write51(0) + write51(1) + write51(2) + write51(3) + + #undef curve25519_contract_carry + #undef curve25519_contract_carry_full + #undef curve25519_contract_carry_final + #undef write51full + #undef write51 +} + +/* + * Swap the contents of [qx] and [qpx] iff @swap is non-zero + */ +DONNA_INLINE static void +curve25519_swap_conditional(bignum25519 x, bignum25519 qpx, uint64_t iswap) { + const uint64_t swap = (uint64_t)(-(int64_t)iswap); + uint64_t x0,x1,x2,x3,x4; + + x0 = swap & (x[0] ^ qpx[0]); x[0] ^= x0; qpx[0] ^= x0; + x1 = swap & (x[1] ^ qpx[1]); x[1] ^= x1; qpx[1] ^= x1; + x2 = swap & (x[2] ^ qpx[2]); x[2] ^= x2; qpx[2] ^= x2; + x3 = swap & (x[3] ^ qpx[3]); x[3] ^= x3; qpx[3] ^= x3; + x4 = swap & (x[4] ^ qpx[4]); x[4] ^= x4; qpx[4] ^= x4; + +} + |