46 lines
916 B
C++
46 lines
916 B
C++
#include "xxtea.h"
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namespace esphome {
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namespace xxtea {
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static const uint32_t DELTA = 0x9e3779b9;
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#define MX ((((z >> 5) ^ (y << 2)) + ((y >> 3) ^ (z << 4))) ^ ((sum ^ y) + (k[(p ^ e) & 7] ^ z)))
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void encrypt(uint32_t *v, size_t n, const uint32_t *k) {
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uint32_t z, y, sum, e;
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size_t p;
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size_t q = 6 + 52 / n;
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sum = 0;
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z = v[n - 1];
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while (q-- != 0) {
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sum += DELTA;
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e = (sum >> 2);
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for (p = 0; p != n - 1; p++) {
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y = v[p + 1];
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z = v[p] += MX;
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}
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y = v[0];
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z = v[n - 1] += MX;
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}
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}
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void decrypt(uint32_t *v, size_t n, const uint32_t *k) {
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uint32_t z, y, sum, e;
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size_t p;
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size_t q = 6 + 52 / n;
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sum = q * DELTA;
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y = v[0];
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while (q-- != 0) {
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e = (sum >> 2);
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for (p = n - 1; p != 0; p--) {
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z = v[p - 1];
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y = v[p] -= MX;
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}
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z = v[n - 1];
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y = v[0] -= MX;
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sum -= DELTA;
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}
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}
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} // namespace xxtea
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} // namespace esphome
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