请问,如何对长度大于255的字符串加密?高手能否帮忙写个函数出来? (200分)

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长度大于255的字符串如何加密截密?能否请各位高手写个函数出来?
谢谢

最好对此函数修改让她能处理大于255的字符串

unit Cl_crypt32;

interface

uses
SysUtils;

const
StartKey = 978; {Start default key}
MultKey = 58395; {Mult default key}
AddKey = 22368; {Add default key}

function cl_encrypt(s:string):string;
function cl_decrypt(s:string):string;

//function Encrypt(const InString:string; StartKey,MultKey,AddKey:Integer): string;
//function Decrypt(const InString:string; StartKey,MultKey,AddKey:Integer): string;

implementation

{$R-}
{$Q-}
{*******************************************************
* Standard Encryption algorithm - Copied from Borland *
*******************************************************}
function Encrypt(const InString:string; StartKey,MultKey,AddKey:Integer): string;
var
I : Byte;
begin
Result := '';
for I := 1 to Length(InString) do
begin
Result := Result + CHAR(Byte(InString) xor (StartKey shr 8));
StartKey := (Byte(Result) + StartKey) * MultKey + AddKey;
end;
end;
{*******************************************************
* Standard Decryption algorithm - Copied from Borland *
*******************************************************}
function Decrypt(const InString:string; StartKey,MultKey,AddKey:Integer): string;
var
I : Byte;
begin
Result := '';
for I := 1 to Length(InString) do
begin
Result := Result + CHAR(Byte(InString) xor (StartKey shr 8));
StartKey := (Byte(InString) + StartKey) * MultKey + AddKey;
end;
end;
{$R+}
{$Q+}

{Coded by cloudy}
Function cl_intto0str(int1:integer; len:integer):string;
var
i,j:integer;
begin
if length(inttostr(int1))>=len then
result:=inttostr(int1)
else
begin
result:='';
i:=len-length(inttostr(int1));
for j:=1 to i do result:=result+'0';
result:=result+inttostr(int1);
end;
end;

{Coded by cloudy}
function cl_chartobytestr(s:string):string;
var
i:byte;
begin
result:='';
for i:=1 to length(s) do
result:=result+cl_intto0str(byte(s),3);
end;

function cl_bytetocharstr(s:string):string;
var
i:integer;
begin
i:=1;
result:='';
if (length(s) mod 3)=0 then
while i<length(s) do
begin
result:=result+char(strtoint(copy(s,i,3)));
i:=i+3;
end;
end;

{Coded by cloudy}
function cl_encrypt(s:string):string;
var
years, months, days, hours, mins, secs, msec:word;
cl_StartKey, cl_MultKey, cl_AddKey: longint;

begin
decodedate(now, years, months, days);
decodetime(now, hours, mins, secs, msec);
cl_StartKey:=msec;
if cl_StartKey<256 then cl_StartKey:=cl_StartKey+256;
cl_Multkey:=((years-1900)*12+months)*30+days+cl_StartKey*10+cl_StartKey;
cl_AddKey:=(23*hours+mins)*60+secs+cl_StartKey*10+cl_StartKey;
result:=cl_chartobytestr(Encrypt(cl_intto0str(cl_StartKey,3),StartKey,MultKey,AddKey))+cl_chartobytestr(Encrypt(cl_intto0str(cl_Multkey,5),StartKey,MultKey,AddKey))+cl_chartobytestr(Encrypt(cl_intto0str(cl_Addkey,5),StartKey,MultKey,AddKey))+cl_chartobytestr(Encrypt(s,cl_StartKey,cl_MultKey,cl_AddKey));
end;

{Coded by cloudy}
function cl_decrypt(s:string):string;
var
cl_StartKey, cl_Multkey, cl_AddKey:longint;
begin
cl_StartKey:=strtoint(decrypt(cl_bytetocharstr(copy(s, 1, 9)),StartKey,MultKey,AddKey));
cl_MultKey:=strtoint(decrypt(cl_bytetocharstr(copy(s, 10, 15)),StartKey,MultKey,AddKey));
cl_AddKey:=strtoint(decrypt(cl_bytetocharstr(copy(s, 25, 15)),StartKey,MultKey,AddKey));
result:=decrypt(cl_bytetocharstr(copy(s, 40, length(s)-39)),cl_StartKey,cl_MultKey,cl_AddKey);
end;


end.
 

看你的语气好象有小于255长度加密源码,
对于大于255的,可以用数组
array [0..Length] of char
改一下就行了。

 
这个还不简单?

字符串分段!文件分块!
 
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