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| #include <stdio.h>
#define KEYLEN 4
#define PLEN 2
#define DELTA 0x9e3779b9
#define LUN 32
void Encrypt(unsigned int * v, unsigned int * k);
void Decrypt(unsigned int * v, unsigned int * k);
int main(void)
{
unsigned int v[PLEN] = { 0x20210000, 0x1205 }, k[KEYLEN] = { 1, 2, 3, 4 };
printf("Encrypt:");
Encrypt(v, k);
printf("0x%x, 0x%x", v[0], v[1]);
puts("\n");
printf("Decrypt:");
Decrypt(v, k);
printf("0x%x, 0x%x", v[0], v[1]);
return 0;
}
void Encrypt(unsigned int * v, unsigned int * k)
{
unsigned int k0 = k[0], k1 = k[1], k2 = k[2], k3 = k[3];
unsigned int v0 = v[0], v1 = v[1];
unsigned int sum = 0 * DELTA;
int i;
for ( i = 0; i < LUN; i++ )
{
sum += DELTA;
v0 += ((v1 << 4) + k0) ^ (v1 + sum) ^ ((v1 >> 5) + k1);
v1 += ((v0 << 4) + k2) ^ (v0 + sum) ^ ((v0 >> 5) + k3);
}
v[0] = v0;
v[1] = v1;
}
void Decrypt(unsigned int * v, unsigned int * k)
{
unsigned int k0 = k[0], k1 = k[1], k2 = k[2], k3 = k[3];
unsigned int v0 = v[0], v1 = v[1];
unsigned int sum = LUN * DELTA;
int i;
for ( i = 0; i < LUN; i++ )
{
v1 -= ((v0 << 4) + k2) ^ (v0 + sum) ^ ((v0 >> 5) + k3);
v0 -= ((v1 << 4) + k0) ^ (v1 + sum) ^ ((v1 >> 5) + k1);
sum -= DELTA;
}
v[0] = v0;
v[1] = v1;
}
|
