mirror of
https://github.com/0intro/conterm
synced 2024-11-22 05:41:28 +03:00
105 lines
1.4 KiB
C
105 lines
1.4 KiB
C
#include "os.h"
|
|
#include <libsec.h>
|
|
|
|
void
|
|
setupRC4state(RC4state *key, uchar *start, int n)
|
|
{
|
|
int t;
|
|
int index2;
|
|
uchar *state;
|
|
uchar *p, *e, *sp, *se;
|
|
|
|
state = key->state;
|
|
se = &state[256];
|
|
for(sp = state; sp < se; sp++)
|
|
*sp = sp - state;
|
|
|
|
key->x = 0;
|
|
key->y = 0;
|
|
index2 = 0;
|
|
e = start + n;
|
|
p = start;
|
|
for(sp = state; sp < se; sp++)
|
|
{
|
|
t = *sp;
|
|
index2 = (*p + t + index2) & 255;
|
|
*sp = state[index2];
|
|
state[index2] = t;
|
|
if(++p >= e)
|
|
p = start;
|
|
}
|
|
}
|
|
|
|
void
|
|
rc4(RC4state *key, uchar *p, int len)
|
|
{
|
|
int tx, ty;
|
|
int x, y;
|
|
uchar *state;
|
|
uchar *e;
|
|
|
|
x = key->x;
|
|
y = key->y;
|
|
state = &key->state[0];
|
|
for(e = p + len; p < e; p++)
|
|
{
|
|
x = (x+1)&255;
|
|
tx = state[x];
|
|
y = (y+tx)&255;
|
|
ty = state[y];
|
|
state[x] = ty;
|
|
state[y] = tx;
|
|
*p ^= state[(tx+ty)&255];
|
|
}
|
|
key->x = x;
|
|
key->y = y;
|
|
}
|
|
|
|
void
|
|
rc4skip(RC4state *key, int len)
|
|
{
|
|
int tx, ty;
|
|
int x, y;
|
|
uchar *state;
|
|
int i;
|
|
|
|
x = key->x;
|
|
y = key->y;
|
|
state = &key->state[0];
|
|
for(i=0; i<len; i++)
|
|
{
|
|
x = (x+1)&255;
|
|
tx = state[x];
|
|
y = (y+tx)&255;
|
|
ty = state[y];
|
|
state[x] = ty;
|
|
state[y] = tx;
|
|
}
|
|
key->x = x;
|
|
key->y = y;
|
|
}
|
|
|
|
void
|
|
rc4back(RC4state *key, int len)
|
|
{
|
|
int tx, ty;
|
|
int x, y;
|
|
uchar *state;
|
|
int i;
|
|
|
|
x = key->x;
|
|
y = key->y;
|
|
state = &key->state[0];
|
|
for(i=0; i<len; i++)
|
|
{
|
|
ty = state[x];
|
|
tx = state[y];
|
|
state[y] = ty;
|
|
state[x] = tx;
|
|
y = (y-tx)&255;
|
|
x = (x-1)&255;
|
|
}
|
|
key->x = x;
|
|
key->y = y;
|
|
}
|