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opti: remove many memcpy

This commit is contained in:
gbrochar 2024-02-18 18:06:18 +01:00
parent 1d9e2936ac
commit badc3fd399
1 changed files with 35 additions and 34 deletions
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69
rsa/bigint.c
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@ -1,5 +1,9 @@
#include "rsa.h" #include "rsa.h"
void my_memcpy(void *dst, void *src, size_t n) {
memcpy(dst, src, n);
}
void bigint_set_random_bytes(bigint_t n, size_t len) { void bigint_set_random_bytes(bigint_t n, size_t len) {
int fd = open("/dev/urandom", O_RDONLY); int fd = open("/dev/urandom", O_RDONLY);
read(fd, n.data, len * sizeof(uint32_t)); read(fd, n.data, len * sizeof(uint32_t));
@ -12,37 +16,33 @@ void bigint_set_msb_and_lsb_to_one(bigint_t n, size_t len) {
} }
void bigint_bitwise_right_shift(bigint_t n) { void bigint_bitwise_right_shift(bigint_t n) {
size_t size = sizeof(uint32_t) * 8 - 1;
for (size_t i = 0; i < n.len - 1; i++) { for (size_t i = 0; i < n.len - 1; i++) {
n.data[i] = n.data[i] >> 1 | (n.data[i + 1] & 1) << size; n.data[i] = n.data[i] >> 1 | (n.data[i + 1] & 1) << 31;
} }
n.data[n.len - 1] >>= 1; n.data[n.len - 1] >>= 1;
} }
void bigint_bitwise_left_shift(bigint_t n) { void bigint_bitwise_left_shift(bigint_t n) {
size_t size = sizeof(uint32_t) * 8 - 1;
for (int i = n.len - 1; i > 0; i--) { for (int i = n.len - 1; i > 0; i--) {
n.data[i] = n.data[i] << 1 | ((n.data[i - 1] & (1 << size)) >> size); n.data[i] = n.data[i] << 1 | ((n.data[i - 1] & (1 << 31)) >> 31);
} }
n.data[0] <<= 1; n.data[0] <<= 1;
} }
void move_bigint_bitwise_left_shift(bigint_t n, bigint_t result) { void move_bigint_bitwise_left_shift(bigint_t n, bigint_t result) {
memcpy(result.data, n.data, n.len * sizeof(uint32_t)); // my_memcpy(result.data, n.data, n.len * sizeof(uint32_t));
size_t size = sizeof(uint32_t) * 8 - 1;
for (int i = result.len - 1; i > 0; i--) { for (int i = result.len - 1; i > 0; i--) {
result.data[i] = result.data[i] << 1 | ((result.data[i - 1] & (1 << size)) >> size); result.data[i] = n.data[i] << 1 | ((n.data[i - 1] & (1 << 31)) >> 31);
} }
result.data[0] <<= 1; result.data[0] = n.data[0] << 1;
} }
// Will underflow // Will underflow
void bigint_decrement(bigint_t n) { void bigint_decrement(bigint_t n) {
size_t cursor = 0; size_t cursor = 0;
size_t size = sizeof(uint32_t) * 8; while (cursor < n.len << 5) {
while (cursor < size * n.len) { n.data[cursor >> 32] = n.data[cursor >> 5] ^ (1 << (cursor % 32));
n.data[cursor / size] = n.data[cursor / size] ^ (1 << (cursor % size)); if (((n.data[cursor >> 5] >> (cursor % 32)) & 1) == 0) {
if (((n.data[cursor / size] >> (cursor % size)) & 1) == 0) {
return; return;
} }
cursor += 1; cursor += 1;
@ -88,8 +88,8 @@ int is_not_zero(bigint_t n) {
// TODO check opti // TODO check opti
void bigint_substraction(bigint_t a, bigint_t b, bigint_t borrow, bigint_t y) { void bigint_substraction(bigint_t a, bigint_t b, bigint_t borrow, bigint_t y) {
memcpy(borrow.data, b.data, b.len * sizeof(uint32_t)); //my_memcpy(borrow.data, b.data, b.len * sizeof(uint32_t));
memcpy(y.data, b.data, b.len * sizeof(uint32_t)); my_memcpy(y.data, b.data, b.len * sizeof(uint32_t));
while (is_not_zero(y)) { while (is_not_zero(y)) {
for (size_t i = 0; i < a.len; i++) { for (size_t i = 0; i < a.len; i++) {
borrow.data[i] = ~a.data[i] & y.data[i]; borrow.data[i] = ~a.data[i] & y.data[i];
@ -102,7 +102,7 @@ void bigint_substraction(bigint_t a, bigint_t b, bigint_t borrow, bigint_t y) {
// TODO check opti // TODO check opti
void custom_bigint_modulo(bigint_t a, bigint_t b, bigint_t result, bigint_t mod, bigint_t borrow_sub, bigint_t y_sub) { void custom_bigint_modulo(bigint_t a, bigint_t b, bigint_t result, bigint_t mod, bigint_t borrow_sub, bigint_t y_sub) {
bigint_set_zeros(result); bigint_set_zeros(result);
memcpy(result.data, a.data, a.len * sizeof(uint32_t)); my_memcpy(result.data, a.data, a.len * sizeof(uint32_t));
if (bigint_cmp(result, b) < 0) { if (bigint_cmp(result, b) < 0) {
return ; return ;
} }
@ -145,7 +145,7 @@ bigint_t bigint_clone(bigint_t src) {
dst.len = src.len; dst.len = src.len;
dst.data = (uint32_t *)protected_malloc(src.len * sizeof(uint32_t)); dst.data = (uint32_t *)protected_malloc(src.len * sizeof(uint32_t));
memcpy(dst.data, src.data, src.len * sizeof(uint32_t)); my_memcpy(dst.data, src.data, src.len * sizeof(uint32_t));
return dst; return dst;
} }
@ -178,11 +178,11 @@ void custom_bigint_mul(bigint_t a, bigint_t b, bigint_t result, bigint_t *b_tool
int width = a.len * 32; int width = a.len * 32;
bigint_set_zeros(result); bigint_set_zeros(result);
bigint_set_zeros(b_tool[0]); bigint_set_zeros(b_tool[0]);
memcpy(b_tool[0].data, b.data, b.len * sizeof(uint32_t)); my_memcpy(b_tool[0].data, b.data, b.len * sizeof(uint32_t));
for (int i = 1; i < 32; i++) { for (int i = 1; i < 32; i++) {
bigint_set_zeros(b_tool[i]); bigint_set_zeros(b_tool[i]);
memcpy(b_tool[i].data, b_tool[i - 1].data, b.len * sizeof(uint32_t)); my_memcpy(b_tool[i].data, b_tool[i - 1].data, b.len * sizeof(uint32_t));
bigint_bitwise_left_shift(b_tool[i]); bigint_bitwise_left_shift(b_tool[i]);
} }
@ -201,10 +201,9 @@ void custom_bigint_pow_mod(bigint_t a, bigint_t e, bigint_t n, bigint_t result,
bigint_set_zeros(result); bigint_set_zeros(result);
bigint_set_zeros(custom); bigint_set_zeros(custom);
bigint_set_zeros(custom2); bigint_set_zeros(custom2);
memcpy(result.data, a.data, a.len * sizeof(uint32_t)); my_memcpy(result.data, a.data, a.len * sizeof(uint32_t));
size_t size = sizeof(uint32_t) * 8; int cursor = (e.len << 5) - 1;
int cursor = e.len * size - 1; while (!(e.data[cursor >> 5] & 1 << (cursor % 32))) {
while (!(e.data[cursor / 32] & 1 << (cursor % 32))) {
cursor--; cursor--;
} }
cursor--; cursor--;
@ -212,11 +211,11 @@ void custom_bigint_pow_mod(bigint_t a, bigint_t e, bigint_t n, bigint_t result,
custom_bigint_mul(result, result, custom, b_tool); custom_bigint_mul(result, result, custom, b_tool);
custom_bigint_modulo(custom, n, custom2, mod, borrow_sub, y_sub); custom_bigint_modulo(custom, n, custom2, mod, borrow_sub, y_sub);
bigint_set_zeros(result); bigint_set_zeros(result);
memcpy(result.data, custom2.data, custom2.len * sizeof(uint32_t)); my_memcpy(result.data, custom2.data, custom2.len * sizeof(uint32_t));
if (e.data[cursor / 32] & 1 << (cursor % 32)) { if (e.data[cursor >> 5] & 1 << (cursor % 32)) {
custom_bigint_mul(result, a, custom, b_tool); custom_bigint_mul(result, a, custom, b_tool);
custom_bigint_modulo(custom, n, custom2, mod, borrow_sub, y_sub); custom_bigint_modulo(custom, n, custom2, mod, borrow_sub, y_sub);
memcpy(result.data, custom2.data, custom2.len * sizeof(uint32_t)); my_memcpy(result.data, custom2.data, custom2.len * sizeof(uint32_t));
} }
cursor -= 1; cursor -= 1;
} }
@ -241,7 +240,9 @@ void bulk_destroy(bigint_t x, bigint_t y, bigint_t n, bigint_t d, bigint_t two,
} }
bigint_t bigint_prime(size_t len) { bigint_t bigint_prime(size_t len) {
bigint_t n = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); size_t my_size = len * 2;
bigint_t n = bigint_zero(my_size);
bigint_set_random_bytes(n, len); bigint_set_random_bytes(n, len);
bigint_set_msb_and_lsb_to_one(n, len); bigint_set_msb_and_lsb_to_one(n, len);
@ -257,19 +258,19 @@ bigint_t bigint_prime(size_t len) {
s += 1; s += 1;
} }
bigint_t x = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t x = bigint_zero(my_size);
bigint_t y = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t y = bigint_zero(my_size);
bigint_t custom = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t custom = bigint_zero(my_size);
bigint_t custom2 = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t custom2 = bigint_zero(my_size);
bigint_t *b_tool = (bigint_t *)protected_malloc(32 * sizeof(bigint_t)); bigint_t *b_tool = (bigint_t *)protected_malloc(32 * sizeof(bigint_t));
for (int i = 0; i < 32; i++) { for (int i = 0; i < 32; i++) {
b_tool[i] = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 4); b_tool[i] = bigint_zero(my_size * 2);
} }
bigint_t two = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t two = bigint_zero(my_size);
bigint_t one = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t one = bigint_zero(my_size);
two.data[0] = 2; two.data[0] = 2;
one.data[0] = 1; one.data[0] = 1;
bigint_t n_minus_two = bigint_clone(n); bigint_t n_minus_two = bigint_clone(n);
@ -277,7 +278,7 @@ bigint_t bigint_prime(size_t len) {
n_minus_two.data[0] -= 1; n_minus_two.data[0] -= 1;
n_minus_one.data[0] -= 1; n_minus_one.data[0] -= 1;
bigint_decrement(n_minus_two); bigint_decrement(n_minus_two);
bigint_t a = bigint_zero(RSA_BLOCK_SIZE / 8 / sizeof(uint32_t) * 2); bigint_t a = bigint_zero(my_size);
for (uint32_t k = 0; k < 128; k++) { for (uint32_t k = 0; k < 128; k++) {
bigint_set_zeros(a); bigint_set_zeros(a);
while (bigint_cmp(a, two) < 0 || bigint_cmp(a, n_minus_two) > 0) { while (bigint_cmp(a, two) < 0 || bigint_cmp(a, n_minus_two) > 0) {