#include?

/*?Prototype?the?encryption/decryption?function?????*/
char?*EnDeCrypt（const?char?*pszText?int?iTextLen?const?char?*pszKey）;
void?swapints（int?*array?int?ndx1?int?ndx2）;

/*?Test?harness?for?the?EnDeCrypt?function?below.???*/
int?main（）
{
????char?buf[256]?passwd[16]?*pEncrypted?*pDecrypted?*pch;
????int?ix?iLen;

????for?（;;）
????{
????????printf（“\nString?to?encrypt?（just?Enter?to?exit）:?“）;
????????fgets（buf?sizeof（buf）?stdin）;
		for?（ix?=?strlen（buf）?-?1;?（ix?>=?0）?&&?（buf[ix]?==?10）;?ix--）
			buf[ix]?=?0;
????????if?（!buf[0]）
????????????break;
????????printf（“\nKey:?“）;
????????fgets（passwd?sizeof（passwd）?stdin）;
		for?（ix?=?strlen（passwd）?-?1;?（ix?>=?0）?&&?（passwd[ix]?==?10）;?ix--）
			passwd[ix]?=?0;
????????if?（!passwd[0]）
????????????break;
		iLen?=?strlen（buf）;
????????pEncrypted?=?EnDeCrypt（buf?iLen?passwd）;
????????printf（“\nEncrypted?output:\n“）;
????????for?（pch?=?pEncrypted?ix=0;?ix?????????{
????????????if?（!（ix?%?20））
????????????????printf（“\n“）;
????????????printf（“%1X?“?（unsigned?char）*pch）;
????????}
????????pDecrypted?=?EnDeCrypt（pEncrypted?iLen?passwd）;
		pDecrypted[iLen]?=?0;	/*?Null-terminate?*/
????????printf（“\nDecrypted?text:?%s“?pDecrypted）;
????????free（pEncrypted）;
????????free（pDecrypted）;
????}
????return?0;
}

/*?:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
???;:::?????????????????????????????????????????????????????????????:::
???;:::??This?function?performs?‘RC4‘?Stream?Encryption?????????????:::
???;:::??（based?on?what?is?widely?thought?to?be?RSA‘s?RC4???????????:::
???;:::??algorithm.?It?produces?output?streams?that?are?identical???:::
???;:::??to?the?commercial?products）????????????????????????????????:::
???;:::?????????????????????????????????????????????????????????????:::
???;:::??Adapted?by?permission?from?a?VB?script?by?Mike?Shaffer?????:::
???;:::??http://www.4guysfromrolla.com/webtech/010100-1.shtml???????:::
???;:::?????????????????????????????????????????????????????????????:::
???;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::?*/

char?*EnDeCrypt（const?char?*pszText?int?iTextLen?const?char?*pszKey）
/*?;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
???;:::??This?routine?does?all?the?work.?Call?it?both?to?ENcrypt????:::
???;:::??and?to?DEcrypt?your?data.??????????????????????????????????:::
???;:::??You?MUST?free?the?returned?pointer?when?no?longer?needed???:::
???;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::?*/
{
????char?*cipher;???????????????????????/*?Output?buffer????????????????*/
????int?a?b?i=0?j=0?k;??????????????/*?Ambiguously?named?counters???*/
????int?ilen;???????????????????????????/*?Length?of?a?string???????????*/
????int?sbox[256];??????????????????????/*?Encryption?array?????????????*/
????int?key[256];???????????????????????/*?Numeric?key?values???????????*/

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????3690??2008-02-01?10:28??c_rc4\rc4.c

?????目錄??????????0??2008-09-09?18:17??c_rc4

-----------?---------??----------?-----??----

?????????????????3690????????????????????2