/*******************************************************************************
* FUNCTION NAME : HelperRC4(Char* sIn, UInt32 iInLen, Char* sKey, UInt32
iKeyLen)
* DESCRIPTION : Encrypts (in place) the data pointed to by sIn using the
* encryption key pointed to by sKey
* RETURNS : none
* PARAMETERS : sIn - pointer to the data to encrypt
* iInLen - Number of bytes to encrypt
* sKey - pointer to the encryption key
* iKeyLen - Number of bytes in the encryption key
* PRECONDITION : none
* POSTCONDITION : none
* COMMENTS : RC4 encryption is reversible. ie: use the same function
again
* to decrypt the string.
*******************************************************************************/
void HelperRC4(Char * sIn, UInt32 iInLen, Char * sKey, UInt32 iKeyLen)
{
UInt8 *inp = (UInt8 *) sIn;
UInt8 *key = (UInt8 *) sKey;
UInt8 s[256];
UInt8 k[256];
UInt32 i;
UInt32 j;
UInt8 temp;
UInt32 t;
UInt32 x;
for (i = 0; i < 256; i++)
{
s[i] = (UInt8) i;
}
j = 0;
for (i = 0; i < 256; i++)
{
k[i] = key[j++];
j %= iKeyLen;
}
j = 0;
for (i = 0; i < 256; i++)
{
j = (j + s[i] + k[i]) % 256;
temp = s[i];
s[i] = s[j];
s[j] = temp;
}
i = 0;
j = 0;
for (x = 0; x < iInLen; x++)
{
i = (i + 1) % 256;
j = (j + s[i]) % 256;
temp = s[i];
s[i] = s[j];
s[j] = temp;
t = (s[i] + s[j]) % 256;
inp[x] ^= s[t];
}
}
2008/4/25 Lionscribe <[EMAIL PROTECTED]>:
> AESLib
> http://www.copera.com/AESLib/index.html
>
> --
> For information on using the ACCESS Developer Forums, or to unsubscribe,
> please see http://www.access-company.com/developers/forums/
>
--
Alan Ingleby
--
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see http://www.access-company.com/developers/forums/
