30 lines
708 B
C
30 lines
708 B
C
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#include <stdint.h>
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#include <stdlib.h>
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#include "verify.h"
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/* returns 0 for equal strings, 1 for non-equal strings */
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unsigned char PQCLEAN_NTRUHPS4096821_CLEAN_verify(const unsigned char *a, const unsigned char *b, size_t len) {
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uint64_t r;
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size_t i;
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r = 0;
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for (i = 0; i < len; i++) {
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r |= a[i] ^ b[i];
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}
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r = (~r + 1); // Two's complement
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r >>= 63;
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return (unsigned char)r;
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}
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/* b = 1 means mov, b = 0 means don't mov*/
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void PQCLEAN_NTRUHPS4096821_CLEAN_cmov(unsigned char *r, const unsigned char *x, size_t len, unsigned char b) {
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size_t i;
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b = (~b + 1); // Two's complement
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for (i = 0; i < len; i++) {
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r[i] ^= b & (x[i] ^ r[i]);
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}
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}
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