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-rw-r--r--Userland/Libraries/LibCrypto/Curves/Curve25519.cpp360
-rw-r--r--Userland/Libraries/LibCrypto/Curves/Curve25519.h73
-rw-r--r--Userland/Libraries/LibCrypto/Curves/X25519.cpp299
3 files changed, 465 insertions, 267 deletions
diff --git a/Userland/Libraries/LibCrypto/Curves/Curve25519.cpp b/Userland/Libraries/LibCrypto/Curves/Curve25519.cpp
new file mode 100644
index 0000000000..5651598ae1
--- /dev/null
+++ b/Userland/Libraries/LibCrypto/Curves/Curve25519.cpp
@@ -0,0 +1,360 @@
+/*
+ * Copyright (c) 2022, stelar7 <dudedbz@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Endian.h>
+#include <AK/Types.h>
+#include <LibCrypto/Curves/Curve25519.h>
+
+namespace Crypto::Curves {
+
+void Curve25519::set(u32* state, u32 value)
+{
+ state[0] = value;
+
+ for (auto i = 1; i < WORDS; i++) {
+ state[i] = 0;
+ }
+}
+
+void Curve25519::modular_square(u32* state, u32 const* value)
+{
+ // Compute R = (A ^ 2) mod p
+ modular_multiply(state, value, value);
+}
+
+void Curve25519::modular_subtract(u32* state, u32 const* first, u32 const* second)
+{
+ // R = (A - B) mod p
+ i64 temp = -19;
+ for (auto i = 0; i < WORDS; i++) {
+ temp += first[i];
+ temp -= second[i];
+ state[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ // Compute R = A + (2^255 - 19) - B
+ state[7] += 0x80000000;
+
+ modular_reduce(state, state);
+}
+
+void Curve25519::modular_add(u32* state, u32 const* first, u32 const* second)
+{
+ // R = (A + B) mod p
+ u64 temp = 0;
+ for (auto i = 0; i < WORDS; i++) {
+ temp += first[i];
+ temp += second[i];
+ state[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ modular_reduce(state, state);
+}
+
+void Curve25519::modular_multiply(u32* state, u32 const* first, u32 const* second)
+{
+ // Compute R = (A * B) mod p
+ u64 temp = 0;
+ u64 carry = 0;
+ u32 output[WORDS * 2];
+
+ // Comba's method
+ for (auto i = 0; i < 16; i++) {
+ if (i < WORDS) {
+ for (auto j = 0; j <= i; j++) {
+ temp += (u64)first[j] * second[i - j];
+ carry += temp >> 32;
+ temp &= 0xFFFFFFFF;
+ }
+ } else {
+ for (auto j = i - 7; j < WORDS; j++) {
+ temp += (u64)first[j] * second[i - j];
+ carry += temp >> 32;
+ temp &= 0xFFFFFFFF;
+ }
+ }
+
+ output[i] = temp & 0xFFFFFFFF;
+ temp = carry & 0xFFFFFFFF;
+ carry >>= 32;
+ }
+
+ // Reduce bit 255 (2^255 = 19 mod p)
+ temp = (output[7] >> 31) * 19;
+ // Mask the most significant bit
+ output[7] &= 0x7FFFFFFF;
+
+ // Fast modular reduction 1st pass
+ for (auto i = 0; i < WORDS; i++) {
+ temp += output[i];
+ temp += (u64)output[i + 8] * 38;
+ output[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ // Reduce bit 256 (2^256 = 38 mod p)
+ temp *= 38;
+ // Reduce bit 255 (2^255 = 19 mod p)
+ temp += (output[7] >> 31) * 19;
+ // Mask the most significant bit
+ output[7] &= 0x7FFFFFFF;
+
+ // Fast modular reduction 2nd pass
+ for (auto i = 0; i < WORDS; i++) {
+ temp += output[i];
+ output[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ modular_reduce(state, output);
+}
+
+void Curve25519::export_state(u32* state, u8* output)
+{
+ for (u32 i = 0; i < WORDS; i++) {
+ state[i] = AK::convert_between_host_and_little_endian(state[i]);
+ }
+
+ memcpy(output, state, BYTES);
+}
+
+void Curve25519::import_state(u32* state, u8 const* data)
+{
+ memcpy(state, data, BYTES);
+ for (u32 i = 0; i < WORDS; i++) {
+ state[i] = AK::convert_between_host_and_little_endian(state[i]);
+ }
+}
+
+void Curve25519::modular_subtract_single(u32* r, u32 const* a, u32 b)
+{
+ i64 temp = -19;
+ temp -= b;
+
+ // Compute R = A - 19 - B
+ for (u32 i = 0; i < 8; i++) {
+ temp += a[i];
+ r[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ // Compute R = A + (2^255 - 19) - B
+ r[7] += 0x80000000;
+ modular_reduce(r, r);
+}
+
+void Curve25519::modular_add_single(u32* state, u32 const* first, u32 second)
+{
+ u64 temp = second;
+
+ // Compute R = A + B
+ for (u32 i = 0; i < 8; i++) {
+ temp += first[i];
+ state[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ modular_reduce(state, state);
+}
+
+u32 Curve25519::modular_square_root(u32* r, u32 const* a, u32 const* b)
+{
+ u32 c[8];
+ u32 u[8];
+ u32 v[8];
+
+ // To compute the square root of (A / B), the first step is to compute the candidate root x = (A / B)^((p+3)/8)
+ modular_square(v, b);
+ modular_multiply(v, v, b);
+ modular_square(v, v);
+ modular_multiply(v, v, b);
+ modular_multiply(c, a, v);
+ modular_square(u, c);
+ modular_multiply(u, u, c);
+ modular_square(u, u);
+ modular_multiply(v, u, c);
+ to_power_of_2n(u, v, 3);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, c);
+ to_power_of_2n(u, v, 7);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, c);
+ to_power_of_2n(u, v, 15);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, c);
+ to_power_of_2n(u, v, 31);
+ modular_multiply(v, u, v);
+ to_power_of_2n(u, v, 62);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, c);
+ to_power_of_2n(u, v, 125);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_square(u, u);
+ modular_multiply(u, u, c);
+
+ // The first candidate root is U = A * B^3 * (A * B^7)^((p - 5) / 8)
+ modular_multiply(u, u, a);
+ modular_square(v, b);
+ modular_multiply(v, v, b);
+ modular_multiply(u, u, v);
+
+ // The second candidate root is V = U * sqrt(-1)
+ modular_multiply(v, u, SQRT_MINUS_1);
+
+ modular_square(c, u);
+ modular_multiply(c, c, b);
+
+ // Check whether B * U^2 = A
+ u32 first_comparison = compare(c, a);
+
+ modular_square(c, v);
+ modular_multiply(c, c, b);
+
+ // Check whether B * V^2 = A
+ u32 second_comparison = compare(c, a);
+
+ // Select the first or the second candidate root
+ select(r, u, v, first_comparison);
+
+ // Return 0 if the square root exists
+ return first_comparison & second_comparison;
+}
+
+u32 Curve25519::compare(u32 const* a, u32 const* b)
+{
+ u32 mask = 0;
+ for (u32 i = 0; i < 8; i++) {
+ mask |= a[i] ^ b[i];
+ }
+
+ // Return 0 if A = B, else 1
+ return ((u32)(mask | (~mask + 1))) >> 31;
+}
+
+void Curve25519::modular_reduce(u32* state, u32 const* data)
+{
+ // R = A mod p
+ u64 temp = 19;
+ u32 other[WORDS];
+
+ for (auto i = 0; i < WORDS; i++) {
+ temp += data[i];
+ other[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ // Compute B = A - (2^255 - 19)
+ other[7] -= 0x80000000;
+
+ u32 mask = (other[7] & 0x80000000) >> 31;
+ select(state, other, data, mask);
+}
+
+void Curve25519::to_power_of_2n(u32* state, u32 const* value, u8 n)
+{
+ // Pre-compute (A ^ 2) mod p
+ modular_square(state, value);
+
+ // Compute R = (A ^ (2^n)) mod p
+ for (u32 i = 1; i < n; i++) {
+ modular_square(state, state);
+ }
+}
+
+void Curve25519::select(u32* state, u32 const* a, u32 const* b, u32 condition)
+{
+ // If B < (2^255 - 19) then R = B, else R = A
+ u32 mask = condition - 1;
+
+ for (auto i = 0; i < WORDS; i++) {
+ state[i] = (a[i] & mask) | (b[i] & ~mask);
+ }
+}
+
+void Curve25519::copy(u32* state, u32 const* value)
+{
+ for (auto i = 0; i < WORDS; i++) {
+ state[i] = value[i];
+ }
+}
+
+void Curve25519::modular_multiply_inverse(u32* state, u32 const* value)
+{
+ // Compute R = A^-1 mod p
+ u32 u[WORDS];
+ u32 v[WORDS];
+
+ // Fermat's little theorem
+ modular_square(u, value);
+ modular_multiply(u, u, value);
+ modular_square(u, u);
+ modular_multiply(v, u, value);
+ to_power_of_2n(u, v, 3);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, value);
+ to_power_of_2n(u, v, 7);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, value);
+ to_power_of_2n(u, v, 15);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, value);
+ to_power_of_2n(u, v, 31);
+ modular_multiply(v, u, v);
+ to_power_of_2n(u, v, 62);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_multiply(v, u, value);
+ to_power_of_2n(u, v, 125);
+ modular_multiply(u, u, v);
+ modular_square(u, u);
+ modular_square(u, u);
+ modular_multiply(u, u, value);
+ modular_square(u, u);
+ modular_square(u, u);
+ modular_multiply(u, u, value);
+ modular_square(u, u);
+ modular_multiply(state, u, value);
+}
+
+void Curve25519::modular_multiply_single(u32* state, u32 const* first, u32 second)
+{
+ // Compute R = (A * B) mod p
+ u64 temp = 0;
+ u32 output[WORDS];
+
+ for (auto i = 0; i < WORDS; i++) {
+ temp += (u64)first[i] * second;
+ output[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ // Reduce bit 256 (2^256 = 38 mod p)
+ temp *= 38;
+ // Reduce bit 255 (2^255 = 19 mod p)
+ temp += (output[7] >> 31) * 19;
+ // Mask the most significant bit
+ output[7] &= 0x7FFFFFFF;
+
+ // Fast modular reduction
+ for (auto i = 0; i < WORDS; i++) {
+ temp += output[i];
+ output[i] = temp & 0xFFFFFFFF;
+ temp >>= 32;
+ }
+
+ modular_reduce(state, output);
+}
+}
diff --git a/Userland/Libraries/LibCrypto/Curves/Curve25519.h b/Userland/Libraries/LibCrypto/Curves/Curve25519.h
new file mode 100644
index 0000000000..eb4d32e0de
--- /dev/null
+++ b/Userland/Libraries/LibCrypto/Curves/Curve25519.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2022, stelar7 <dudedbz@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Random.h>
+
+namespace Crypto::Curves {
+
+class Curve25519 {
+public:
+ static constexpr u8 BASE_POINT_L_ORDER[33] {
+ 0xED, 0xD3, 0xF5, 0x5C, 0x1A, 0x63, 0x12, 0x58,
+ 0xD6, 0x9C, 0xF7, 0xA2, 0xDE, 0xF9, 0xDE, 0x14,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,
+ 0x00
+ };
+
+ static constexpr u32 CURVE_D[8] {
+ 0x135978A3, 0x75EB4DCA, 0x4141D8AB, 0x00700A4D,
+ 0x7779E898, 0x8CC74079, 0x2B6FFE73, 0x52036CEE
+ };
+
+ static constexpr u32 CURVE_D_2[8] {
+ 0x26B2F159, 0xEBD69B94, 0x8283B156, 0x00E0149A,
+ 0xEEF3D130, 0x198E80F2, 0x56DFFCE7, 0x2406D9DC
+ };
+
+ static constexpr u32 ZERO[8] {
+ 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000
+ };
+
+ static constexpr u32 SQRT_MINUS_1[8] {
+ 0x4A0EA0B0, 0xC4EE1B27, 0xAD2FE478, 0x2F431806,
+ 0x3DFBD7A7, 0x2B4D0099, 0x4FC1DF0B, 0x2B832480
+ };
+
+ static constexpr u8 BARRETT_REDUCTION_QUOTIENT[33] {
+ 0x1B, 0x13, 0x2C, 0x0A, 0xA3, 0xE5, 0x9C, 0xED,
+ 0xA7, 0x29, 0x63, 0x08, 0x5D, 0x21, 0x06, 0x21,
+ 0xEB, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+ 0x0F
+ };
+
+ static constexpr u8 BITS = 255;
+ static constexpr u8 BYTES = 32;
+ static constexpr u8 WORDS = 8;
+ static constexpr u32 A24 = 121666;
+
+ static void set(u32* a, u32 b);
+ static void select(u32* r, u32 const* a, u32 const* b, u32 c);
+ static void copy(u32* a, u32 const* b);
+ static void modular_square(u32* r, u32 const* a);
+ static void modular_subtract(u32* r, u32 const* a, u32 const* b);
+ static void modular_reduce(u32* r, u32 const* a);
+ static void modular_add(u32* r, u32 const* a, u32 const* b);
+ static void modular_multiply(u32* r, u32 const* a, u32 const* b);
+ static void modular_multiply_inverse(u32* r, u32 const* a);
+ static void to_power_of_2n(u32* r, u32 const* a, u8 n);
+ static void export_state(u32* a, u8* data);
+ static void import_state(u32* a, u8 const* data);
+ static void modular_subtract_single(u32* r, u32 const* a, u32 b);
+ static void modular_multiply_single(u32* r, u32 const* a, u32 b);
+ static void modular_add_single(u32* r, u32 const* a, u32 b);
+ static u32 modular_square_root(u32* r, u32 const* a, u32 const* b);
+ static u32 compare(u32 const* a, u32 const* b);
+};
+}
diff --git a/Userland/Libraries/LibCrypto/Curves/X25519.cpp b/Userland/Libraries/LibCrypto/Curves/X25519.cpp
index faa98f4e8b..07c2ffd300 100644
--- a/Userland/Libraries/LibCrypto/Curves/X25519.cpp
+++ b/Userland/Libraries/LibCrypto/Curves/X25519.cpp
@@ -7,6 +7,7 @@
#include <AK/ByteReader.h>
#include <AK/Endian.h>
#include <AK/Random.h>
+#include <LibCrypto/Curves/Curve25519.h>
#include <LibCrypto/Curves/X25519.h>
namespace Crypto::Curves {
@@ -16,52 +17,6 @@ static constexpr u8 BYTES = 32;
static constexpr u8 WORDS = 8;
static constexpr u32 A24 = 121666;
-static void import_state(u32* state, ReadonlyBytes data)
-{
- for (auto i = 0; i < WORDS; i++) {
- u32 value = ByteReader::load32(data.offset_pointer(sizeof(u32) * i));
- state[i] = AK::convert_between_host_and_little_endian(value);
- }
-}
-
-static ErrorOr<ByteBuffer> export_state(u32* data)
-{
- auto buffer = TRY(ByteBuffer::create_uninitialized(BYTES));
-
- for (auto i = 0; i < WORDS; i++) {
- u32 value = AK::convert_between_host_and_little_endian(data[i]);
- ByteReader::store(buffer.offset_pointer(sizeof(u32) * i), value);
- }
-
- return buffer;
-}
-
-static void select(u32* state, u32* a, u32* b, u32 condition)
-{
- // If B < (2^255 - 19) then R = B, else R = A
- u32 mask = condition - 1;
-
- for (auto i = 0; i < WORDS; i++) {
- state[i] = (a[i] & mask) | (b[i] & ~mask);
- }
-}
-
-static void set(u32* state, u32 value)
-{
- state[0] = value;
-
- for (auto i = 1; i < WORDS; i++) {
- state[i] = 0;
- }
-}
-
-static void copy(u32* state, u32* value)
-{
- for (auto i = 0; i < WORDS; i++) {
- state[i] = value[i];
- }
-}
-
static void conditional_swap(u32* first, u32* second, u32 condition)
{
u32 mask = ~condition + 1;
@@ -72,199 +27,6 @@ static void conditional_swap(u32* first, u32* second, u32 condition)
}
}
-static void modular_reduce(u32* state, u32* data)
-{
- // R = A mod p
- u64 temp = 19;
- u32 other[WORDS];
-
- for (auto i = 0; i < WORDS; i++) {
- temp += data[i];
- other[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- // Compute B = A - (2^255 - 19)
- other[7] -= 0x80000000;
-
- u32 mask = (other[7] & 0x80000000) >> 31;
- select(state, other, data, mask);
-}
-
-static void modular_multiply_single(u32* state, u32* first, u32 second)
-{
- // Compute R = (A * B) mod p
- u64 temp = 0;
- u32 output[WORDS];
-
- for (auto i = 0; i < WORDS; i++) {
- temp += (u64)first[i] * second;
- output[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- // Reduce bit 256 (2^256 = 38 mod p)
- temp *= 38;
- // Reduce bit 255 (2^255 = 19 mod p)
- temp += (output[7] >> 31) * 19;
- // Mask the most significant bit
- output[7] &= 0x7FFFFFFF;
-
- // Fast modular reduction
- for (auto i = 0; i < WORDS; i++) {
- temp += output[i];
- output[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- modular_reduce(state, output);
-}
-
-static void modular_multiply(u32* state, u32* first, u32* second)
-{
- // Compute R = (A * B) mod p
- u64 temp = 0;
- u64 carry = 0;
- u32 output[WORDS * 2];
-
- // Comba's method
- for (auto i = 0; i < 16; i++) {
- if (i < WORDS) {
- for (auto j = 0; j <= i; j++) {
- temp += (u64)first[j] * second[i - j];
- carry += temp >> 32;
- temp &= 0xFFFFFFFF;
- }
- } else {
- for (auto j = i - 7; j < WORDS; j++) {
- temp += (u64)first[j] * second[i - j];
- carry += temp >> 32;
- temp &= 0xFFFFFFFF;
- }
- }
-
- output[i] = temp & 0xFFFFFFFF;
- temp = carry & 0xFFFFFFFF;
- carry >>= 32;
- }
-
- // Reduce bit 255 (2^255 = 19 mod p)
- temp = (output[7] >> 31) * 19;
- // Mask the most significant bit
- output[7] &= 0x7FFFFFFF;
-
- // Fast modular reduction 1st pass
- for (auto i = 0; i < WORDS; i++) {
- temp += output[i];
- temp += (u64)output[i + 8] * 38;
- output[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- // Reduce bit 256 (2^256 = 38 mod p)
- temp *= 38;
- // Reduce bit 255 (2^255 = 19 mod p)
- temp += (output[7] >> 31) * 19;
- // Mask the most significant bit
- output[7] &= 0x7FFFFFFF;
-
- // Fast modular reduction 2nd pass
- for (auto i = 0; i < WORDS; i++) {
- temp += output[i];
- output[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- modular_reduce(state, output);
-}
-
-static void modular_square(u32* state, u32* value)
-{
- // Compute R = (A ^ 2) mod p
- modular_multiply(state, value, value);
-}
-
-static void modular_add(u32* state, u32* first, u32* second)
-{
- // R = (A + B) mod p
- u64 temp = 0;
- for (auto i = 0; i < WORDS; i++) {
- temp += first[i];
- temp += second[i];
- state[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- modular_reduce(state, state);
-}
-
-static void modular_subtract(u32* state, u32* first, u32* second)
-{
- // R = (A - B) mod p
- i64 temp = -19;
- for (auto i = 0; i < WORDS; i++) {
- temp += first[i];
- temp -= second[i];
- state[i] = temp & 0xFFFFFFFF;
- temp >>= 32;
- }
-
- // Compute R = A + (2^255 - 19) - B
- state[7] += 0x80000000;
-
- modular_reduce(state, state);
-}
-
-static void to_power_of_2n(u32* state, u32* value, u8 n)
-{
- // compute R = (A ^ (2^n)) mod p
- modular_square(state, value);
- for (auto i = 1; i < n; i++) {
- modular_square(state, state);
- }
-}
-
-static void modular_multiply_inverse(u32* state, u32* value)
-{
- // Compute R = A^-1 mod p
- u32 u[WORDS];
- u32 v[WORDS];
-
- // Fermat's little theorem
- modular_square(u, value);
- modular_multiply(u, u, value);
- modular_square(u, u);
- modular_multiply(v, u, value);
- to_power_of_2n(u, v, 3);
- modular_multiply(u, u, v);
- modular_square(u, u);
- modular_multiply(v, u, value);
- to_power_of_2n(u, v, 7);
- modular_multiply(u, u, v);
- modular_square(u, u);
- modular_multiply(v, u, value);
- to_power_of_2n(u, v, 15);
- modular_multiply(u, u, v);
- modular_square(u, u);
- modular_multiply(v, u, value);
- to_power_of_2n(u, v, 31);
- modular_multiply(v, u, v);
- to_power_of_2n(u, v, 62);
- modular_multiply(u, u, v);
- modular_square(u, u);
- modular_multiply(v, u, value);
- to_power_of_2n(u, v, 125);
- modular_multiply(u, u, v);
- modular_square(u, u);
- modular_square(u, u);
- modular_multiply(u, u, value);
- modular_square(u, u);
- modular_square(u, u);
- modular_multiply(u, u, value);
- modular_square(u, u);
- modular_multiply(state, u, value);
-}
-
ErrorOr<ByteBuffer> X25519::generate_private_key()
{
auto buffer = TRY(ByteBuffer::create_uninitialized(BYTES));
@@ -291,7 +53,7 @@ ErrorOr<ByteBuffer> X25519::compute_coordinate(ReadonlyBytes input_k, ReadonlyBy
u32 t2[WORDS] {};
// Copy input to internal state
- import_state(k, input_k);
+ Curve25519::import_state(k, input_k.data());
// Set the three least significant bits of the first byte and the most significant bit of the last to zero,
// set the second most significant bit of the last byte to 1
@@ -300,18 +62,18 @@ ErrorOr<ByteBuffer> X25519::compute_coordinate(ReadonlyBytes input_k, ReadonlyBy
k[7] |= 0x40000000;
// Copy coordinate to internal state
- import_state(u, input_u);
+ Curve25519::import_state(u, input_u.data());
// mask the most significant bit in the final byte.
u[7] &= 0x7FFFFFFF;
// Implementations MUST accept non-canonical values and process them as
// if they had been reduced modulo the field prime.
- modular_reduce(u, u);
+ Curve25519::modular_reduce(u, u);
- set(x1, 1);
- set(z1, 0);
- copy(x2, u);
- set(z2, 1);
+ Curve25519::set(x1, 1);
+ Curve25519::set(z1, 0);
+ Curve25519::copy(x2, u);
+ Curve25519::set(z2, 1);
// Montgomery ladder
u32 swap = 0;
@@ -323,35 +85,38 @@ ErrorOr<ByteBuffer> X25519::compute_coordinate(ReadonlyBytes input_k, ReadonlyBy
swap = b;
- modular_add(t1, x2, z2);
- modular_subtract(x2, x2, z2);
- modular_add(z2, x1, z1);
- modular_subtract(x1, x1, z1);
- modular_multiply(t1, t1, x1);
- modular_multiply(x2, x2, z2);
- modular_square(z2, z2);
- modular_square(x1, x1);
- modular_subtract(t2, z2, x1);
- modular_multiply_single(z1, t2, A24);
- modular_add(z1, z1, x1);
- modular_multiply(z1, z1, t2);
- modular_multiply(x1, x1, z2);
- modular_subtract(z2, t1, x2);
- modular_square(z2, z2);
- modular_multiply(z2, z2, u);
- modular_add(x2, x2, t1);
- modular_square(x2, x2);
+ Curve25519::modular_add(t1, x2, z2);
+ Curve25519::modular_subtract(x2, x2, z2);
+ Curve25519::modular_add(z2, x1, z1);
+ Curve25519::modular_subtract(x1, x1, z1);
+ Curve25519::modular_multiply(t1, t1, x1);
+ Curve25519::modular_multiply(x2, x2, z2);
+ Curve25519::modular_square(z2, z2);
+ Curve25519::modular_square(x1, x1);
+ Curve25519::modular_subtract(t2, z2, x1);
+ Curve25519::modular_multiply_single(z1, t2, A24);
+ Curve25519::modular_add(z1, z1, x1);
+ Curve25519::modular_multiply(z1, z1, t2);
+ Curve25519::modular_multiply(x1, x1, z2);
+ Curve25519::modular_subtract(z2, t1, x2);
+ Curve25519::modular_square(z2, z2);
+ Curve25519::modular_multiply(z2, z2, u);
+ Curve25519::modular_add(x2, x2, t1);
+ Curve25519::modular_square(x2, x2);
}
conditional_swap(x1, x2, swap);
conditional_swap(z1, z2, swap);
// Retrieve affine representation
- modular_multiply_inverse(u, z1);
- modular_multiply(u, u, x1);
+ Curve25519::modular_multiply_inverse(u, z1);
+ Curve25519::modular_multiply(u, u, x1);
// Encode state for export
- return export_state(u);
+ auto buffer = TRY(ByteBuffer::create_uninitialized(BYTES));
+ Curve25519::export_state(u, buffer.data());
+
+ return buffer;
}
ErrorOr<ByteBuffer> X25519::derive_premaster_key(ReadonlyBytes shared_point)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 19:07:58 +0000