我想要最小的努力,最好只是将文件放入我的项目和构建.
理想情况下,您应该已经使用代码在Delphi和C中对文件进行解/隐藏(我想在Atmel UC3微处理器(C编码)和Windows PC(Delphi编码)之间交换文件-de-crypt在两个方向)
我非常喜欢单个.PAS单元和一个.C / .H文件.我不想使用一个支持数十种加密算法的DLL或一个库,只需一个(我肯定不想要任何安装程序).
我希望我在这里听起来不太挑剔,但我一直在搜索和搜索尝试代码一个多星期,仍然找不到两个匹配的实现.我怀疑只有一个已经做到这一点的人可以帮助我…
提前致谢.
随着my previous post的发展,我仍然在寻找一些非常简单的代码,为什么我可以用最少的努力,将一个文件隐藏起来,并在PC上的Delphi和Atmel UC3 u处理器的C之间进行交换.
在理论上听起来很简单,但实际上这是一场噩梦.有很多可能的候选人,我花了几天的时间,并尝试出去 – 无济于事.
有些是可变图书馆,支持许多加密算法,我想要一些轻量级(特别是在C / u处理器端).
一些看起来不错,但是一组源仅提供块操作,其他字符串(我更喜欢整个文件en / de-crypt).
大多数似乎是非常糟糕的文档,没有意义的参数名称和没有示例代码来调用这些功能.
在过去的一个周末(再加上几天),我已经烧了一大堆XTEA,XXTEA和BlowFish的实现,但是在加密的时候,我无法扭转这个过程.
现在我正在看AES-256. Dos任何人都知道C中的一个实现是一个单一的AES.C文件？ (加上AES.H,当然)
坦白说,我会采取任何在Delphi和C之间执行整个文件en / de-crypt的东西,但是除非有人自己做了这些,否则我只希望听到“任何符合标准的实现都应该” – 这是一个很好的但是对我而言却是没有办法:-(
任何简单的AES-256在C那里？我有一些合理的Delphi代码,但一直在尝试之前不会确定.
提前致谢 …
解决方法
C已经在生产系统中使用了五年.
我添加了轻微测试的Delphi代码. Pascal是一个逐行端口,带有unsigned char到Byte.我只运行Pascal在Free Pascal与Delphi选项打开,而不是Delphi本身. C和Pascal都有简单的文件处理器.
加密密文给出了原来的明文.
rc4.h
#ifndef RC4_H
#define RC4_H
/*
* rc4.h -- Declarations for a simple rc4 encryption/decryption implementation.
* The code was inspired by libtomcrypt. See www.libtomcrypt.org.
*/
typedef struct TRC4State_s {
int x,y;
unsigned char buf[256];
} TRC4State;
/* rc4.c */
void init_rc4(TRC4State *state);
void setup_rc4(TRC4State *state,char *key,int keylen);
unsigned endecrypt_rc4(unsigned char *buf,unsigned len,TRC4State *state);
#endif
rc4.c
void init_rc4(TRC4State *state)
{
int x;
state->x = state->y = 0;
for (x = 0; x < 256; x++)
state->buf[x] = x;
}
void setup_rc4(TRC4State *state,int keylen)
{
unsigned tmp;
int x,y;
// use only first 256 characters of key
if (keylen > 256)
keylen = 256;
for (x = y = 0; x < 256; x++) {
y = (y + state->buf[x] + key[x % keylen]) & 255;
tmp = state->buf[x];
state->buf[x] = state->buf[y];
state->buf[y] = tmp;
}
state->x = 255;
state->y = y;
}
unsigned endecrypt_rc4(unsigned char *buf,TRC4State *state)
{
int x,y;
unsigned char *s,tmp;
unsigned n;
x = state->x;
y = state->y;
s = state->buf;
n = len;
while (n--) {
x = (x + 1) & 255;
y = (y + s[x]) & 255;
tmp = s[x]; s[x] = s[y]; s[y] = tmp;
tmp = (s[x] + s[y]) & 255;
*buf++ ^= s[tmp];
}
state->x = x;
state->y = y;
return len;
}
int endecrypt_file(FILE *f_in,FILE *f_out,char *key)
{
TRC4State state[1];
unsigned char buf[4096];
size_t n_read,n_written;
init_rc4(state);
setup_rc4(state,key,strlen(key));
do {
n_read = fread(buf,1,sizeof buf,f_in);
endecrypt_rc4(buf,n_read,state);
n_written = fwrite(buf,f_out);
} while (n_read == sizeof buf && n_written == n_read);
return (n_written == n_read) ? 0 : 1;
}
int endecrypt_file_at(char *f_in_name,char *f_out_name,char *key)
{
int rtn;
FILE *f_in = fopen(f_in_name,"rb");
if (!f_in) {
return 1;
}
FILE *f_out = fopen(f_out_name,"wb");
if (!f_out) {
close(f_in);
return 2;
}
rtn = endecrypt_file(f_in,f_out,key);
fclose(f_in);
fclose(f_out);
return rtn;
}
#ifdef TEST
// Simple test.
int main(void)
{
char *key = "This is the key!";
endecrypt_file_at("rc4.pas","rc4-scrambled.c",key);
endecrypt_file_at("rc4-scrambled.c","rc4-unscrambled.c",key);
return 0;
}
#endif
这里是轻微测试的帕斯卡.我可以在C中加扰源代码,并用Pascal实现解密它.
type
RC4State = record
x,y : Integer;
buf : array[0..255] of Byte;
end;
KeyString = String[255];
procedure initRC4(var state : RC4State);
var
x : Integer;
begin
state.x := 0;
state.y := 0;
for x := 0 to 255 do
state.buf[x] := Byte(x);
end;
procedure setupRC4(var state : RC4State; var key : KeyString);
var
tmp : Byte;
x,y : Integer;
begin
y := 0;
for x := 0 to 255 do begin
y := (y + state.buf[x] + Integer(key[1 + x mod Length(key)])) and 255;
tmp := state.buf[x];
state.buf[x] := state.buf[y];
state.buf[y] := tmp;
end;
state.x := 255;
state.y := y;
end;
procedure endecryptRC4(var buf : array of Byte; len : Integer; var state : RC4State);
var
x,y,i : Integer;
tmp : Byte;
begin
x := state.x;
y := state.y;
for i := 0 to len - 1 do begin
x := (x + 1) and 255;
y := (y + state.buf[x]) and 255;
tmp := state.buf[x];
state.buf[x] := state.buf[y];
state.buf[y] := tmp;
tmp := (state.buf[x] + state.buf[y]) and 255;
buf[i] := buf[i] xor state.buf[tmp]
end;
state.x := x;
state.y := y;
end;
procedure endecryptFile(var fIn,fOut : File; key : KeyString);
var
nRead,nWritten : Longword;
buf : array[0..4095] of Byte;
state : RC4State;
begin
initRC4(state);
setupRC4(state,key);
repeat
BlockRead(fIN,buf,sizeof(buf),nRead);
endecryptRC4(buf,nRead,state);
BlockWrite(fOut,nWritten);
until (nRead <> sizeof(buf)) or (nRead <> nWritten);
end;
procedure endecryptFileAt(fInName,fOutName,key : String);
var
fIn,fOut : File;
begin
Assign(fIn,fInName);
Assign(fOut,fOutName);
Reset(fIn,1);
Rewrite(fOut,1);
endecryptFile(fIn,fOut,key);
Close(fIn);
Close(fOut);
end;
{$IFDEF TEST}
// Very small test.
const
key = 'This is the key!';
begin
endecryptFileAt('rc4.pas','rc4-scrambled.pas',key);
endecryptFileAt('rc4-scrambled.pas','rc4-unscrambled.pas',key);
end.
{$ENDIF}