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added stupid network byte order shuffel to xxtea

This commit is contained in:
schneider 2011-07-18 10:31:20 +02:00
parent 2d4e1163d0
commit 0343e5f895
1 changed files with 23 additions and 1 deletions
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24
firmware/basic/xxtea.c
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@ -9,16 +9,35 @@
*/
#include <stdint.h>
#include "xxtea.h"
uint32_t htonl(uint32_t v)
{
uint32_t r;
r |= (v>> 0)&0xFF; r<<=8;
r |= (v>> 8)&0xFF; r<<=8;
r |= (v>>16)&0xFF; r<<=8;
r |= (v>>24)&0xFF;
return r;
}
void htonlp(uint32_t *v, uint8_t n)
{
while(n--){
v[n] = htonl(v[n]);
}
}
#define DELTA 0x9e3779b9
#define MX (((z>>5^y<<2) + (y>>3^z<<4)) ^ ((sum^y) + (k[(p&3)^e] ^ z)))
#include "xxtea.h"
void xxtea_encode_words(uint32_t *v, int n, uint32_t const k[4])
{
if(k[0] == 0 && k[1] == 0 && k[2] == 0 && k[3] == 0) return;
uint32_t y, z, sum;
unsigned p, rounds, e;
htonlp(v ,n);
rounds = 6 + 52/n;
sum = 0;
z = v[n-1];
@ -32,6 +51,7 @@ void xxtea_encode_words(uint32_t *v, int n, uint32_t const k[4])
y = v[0];
z = v[n-1] += MX;
} while (--rounds);
htonlp(v ,n);
}
void xxtea_decode_words(uint32_t *v, int n, uint32_t const k[4])
@ -39,6 +59,7 @@ void xxtea_decode_words(uint32_t *v, int n, uint32_t const k[4])
if(k[0] == 0 && k[1] == 0 && k[2] == 0 && k[3] == 0) return;
uint32_t y, z, sum;
unsigned p, rounds, e;
htonlp(v ,n);
rounds = 6 + 52/n;
sum = rounds*DELTA;
@ -52,5 +73,6 @@ void xxtea_decode_words(uint32_t *v, int n, uint32_t const k[4])
z = v[n-1];
y = v[0] -= MX;
} while ((sum -= DELTA) != 0);
htonlp(v ,n);
}