#include <string.h>
#include "aes.h"
#include "commonage.h"
#define byte unsigned char
#define BPOLY 0x1b //!<Lower 8 bits of (x^8+x^4+x^3+x+1), ie. (x^4+x^3+x+1).
#define BLOCKSIZE 16 //!<Block size in number of bytes.
#define KEYBITS 128 //!<Use AES128.
#define ROUNDS 10 //!<Number of rounds.
#define KEYLENGTH 16 //!<Key length in number of bytes.
byte xdata block1[ 256 ]//!<Workspace 1.
byte xdata block2[ 256 ]//!<Worksapce 2.
byte xdata * powTbl//!<Final location of exponentiation lookup table.
byte xdata * logTbl//!<Final location of logarithm lookup table.
byte xdata * sBox//!<Final location of s-box.
byte xdata * sBoxInv//!<Final location of inverse s-box.
byte xdata * expandedKey//!<Final location of expanded key.
void CalcPowLog( byte * powTbl, byte * logTbl )
{
byte xdata i = 0
byte xdata t = 1
do {
// Use 0x03 as root for exponentiation and logarithms.
powTbl[i] = t
logTbl[t] = i
i++
// Muliply t by 3 in GF(2^8).
t ^= (t <<1) ^ (t &0x80 ? BPOLY : 0)
} while( t != 1 )// Cyclic properties ensure that i <255.
powTbl[255] = powTbl[0]// 255 = '-0', 254 = -1, etc.
}
void CalcSBox( byte * sBox )
{
byte xdata i, rot
byte xdata temp
byte xdata result
// Fill all entries of sBox[].
i = 0
do {
// Inverse in GF(2^8).
if( i >0 ) {
temp = powTbl[ 255 - logTbl[i] ]
} else {
temp = 0
}
// Affine transformation in GF(2).
result = temp ^ 0x63// Start with adding a vector in GF(2).
for( rot = 0rot <4rot++ ) {
// Rotate left.
temp = (temp<<1) | (temp>>7)
// Add rotated byte in GF(2).
result ^= temp
}
// Put result in table.
sBox[i] = result
} while( ++i != 0 )
}
void CalcSBoxInv( byte * sBox, byte * sBoxInv )
{
byte xdata i = 0
byte xdata j = 0
// Iterate through all elements in sBoxInv using i.
do {
// Search through sBox using j.
cleardog()
do {
// Check if current j is the inverse of current i.
if( sBox[ j ] == i ) {
// If so, set sBoxInc and indicate search finished.
sBoxInv[ i ] = j
j = 255
}
} while( ++j != 0 )
} while( ++i != 0 )
}
void CycleLeft( byte * row )
{
// Cycle 4 bytes in an array left once.
byte xdata temp = row[0]
row[0] = row[1]
row[1] = row[2]
row[2] = row[3]
row[3] = temp
}
void InvMixColumn( byte * column )
{
byte xdata r0, r1, r2, r3
r0 = column[1] ^ column[2] ^ column[3]
r1 = column[0] ^ column[2] ^ column[3]
r2 = column[0] ^ column[1] ^ column[3]
r3 = column[0] ^ column[1] ^ column[2]
column[0] = (column[0] <<1) ^ (column[0] &0x80 ? BPOLY : 0)
column[1] = (column[1] <<1) ^ (column[1] &0x80 ? BPOLY : 0)
column[2] = (column[2] <<1) ^ (column[2] &0x80 ? BPOLY : 0)
column[3] = (column[3] <<1) ^ (column[3] &0x80 ? BPOLY : 0)
r0 ^= column[0] ^ column[1]
r1 ^= column[1] ^ column[2]
r2 ^= column[2] ^ column[3]
r3 ^= column[0] ^ column[3]
column[0] = (column[0] <<1) ^ (column[0] &0x80 ? BPOLY : 0)
column[1] = (column[1] <<1) ^ (column[1] &0x80 ? BPOLY : 0)
column[2] = (column[2] <<1) ^ (column[2] &0x80 ? BPOLY : 0)
column[3] = (column[3] <<1) ^ (column[3] &0x80 ? BPOLY : 0)
r0 ^= column[0] ^ column[2]
r1 ^= column[1] ^ column[3]
r2 ^= column[0] ^ column[2]
r3 ^= column[1] ^ column[3]
column[0] = (column[0] <<1) ^ (column[0] &0x80 ? BPOLY : 0)
column[1] = (column[1] <<1) ^ (column[1] &0x80 ? BPOLY : 0)
column[2] = (column[2] <<1) ^ (column[2] &0x80 ? BPOLY : 0)
column[3] = (column[3] <<1) ^ (column[3] &0x80 ? BPOLY : 0)
column[0] ^= column[1] ^ column[2] ^ column[3]
r0 ^= column[0]
r1 ^= column[0]
r2 ^= column[0]
r3 ^= column[0]
column[0] = r0
column[1] = r1
column[2] = r2
column[3] = r3
}
byte Multiply( unsigned char num, unsigned char factor )
{
byte mask = 1
byte result = 0
while( mask != 0 ) {
// Check bit of factor given by mask.
if( mask &factor ) {
// Add current multiple of num in GF(2).
result ^= num
}
// Shift mask to indicate next bit.
mask <<= 1
// Double num.
num = (num <<1) ^ (num &0x80 ? BPOLY : 0)
}
return result
}
byte DotProduct( unsigned char * vector1, unsigned char * vector2 )
{
byte result = 0
result ^= Multiply( *vector1++, *vector2++ )
result ^= Multiply( *vector1++, *vector2++ )
result ^= Multiply( *vector1++, *vector2++ )
result ^= Multiply( *vector1 , *vector2 )
return result
}
void MixColumn( byte * column )
{
byte xdata row[8] = {
0x02, 0x03, 0x01, 0x01,
0x02, 0x03, 0x01, 0x01
}// Prepare first row of matrix twice, to eliminate need for cycling.
byte xdata result[4]
// Take dot products of each matrix row and the column vector.
result[0] = DotProduct( row+0, column )
result[1] = DotProduct( row+3, column )
result[2] = DotProduct( row+2, column )
result[3] = DotProduct( row+1, column )
// Copy temporary result to original column.
column[0] = result[0]
column[1] = result[1]
column[2] = result[2]
column[3] = result[3]
}
void SubBytes( byte * bytes, byte count )
{
do {
*bytes = sBox[ *bytes ]// Substitute every byte in state.
bytes++
} while( --count )
}
void InvSubBytesAndXOR( byte * bytes, byte * key, byte count )
{
do {
// *bytes = sBoxInv[ *bytes ] ^ *key// Inverse substitute every byte in state and add key.
*bytes = block2[ *bytes ] ^ *key// Use block2 directly. Increases speed.
bytes++
key++
} while( --count )
}
void InvShiftRows( byte * state )
{
byte temp
// Note: State is arranged column by column.
// Cycle second row right one time.
temp = state[ 1 + 3*4 ]
state[ 1 + 3*4 ] = state[ 1 + 2*4 ]
state[ 1 + 2*4 ] = state[ 1 + 1*4 ]
state[ 1 + 1*4 ] = state[ 1 + 0*4 ]
state[ 1 + 0*4 ] = temp
// Cycle third row right two times.
temp = state[ 2 + 0*4 ]
state[ 2 + 0*4 ] = state[ 2 + 2*4 ]
state[ 2 + 2*4 ] = temp
temp = state[ 2 + 1*4 ]
state[ 2 + 1*4 ] = state[ 2 + 3*4 ]
state[ 2 + 3*4 ] = temp
// Cycle fourth row right three times, ie. left once.
temp = state[ 3 + 0*4 ]
state[ 3 + 0*4 ] = state[ 3 + 1*4 ]
state[ 3 + 1*4 ] = state[ 3 + 2*4 ]
state[ 3 + 2*4 ] = state[ 3 + 3*4 ]
state[ 3 + 3*4 ] = temp
}
void ShiftRows( byte * state )
{
byte temp
// Note: State is arranged column by column.
// Cycle second row left one time.
temp = state[ 1 + 0*4 ]
state[ 1 + 0*4 ] = state[ 1 + 1*4 ]
state[ 1 + 1*4 ] = state[ 1 + 2*4 ]
state[ 1 + 2*4 ] = state[ 1 + 3*4 ]
state[ 1 + 3*4 ] = temp
// Cycle third row left two times.
temp = state[ 2 + 0*4 ]
state[ 2 + 0*4 ] = state[ 2 + 2*4 ]
state[ 2 + 2*4 ] = temp
temp = state[ 2 + 1*4 ]
state[ 2 + 1*4 ] = state[ 2 + 3*4 ]
state[ 2 + 3*4 ] = temp
// Cycle fourth row left three times, ie. right once.
temp = state[ 3 + 3*4 ]
state[ 3 + 3*4 ] = state[ 3 + 2*4 ]
state[ 3 + 2*4 ] = state[ 3 + 1*4 ]
state[ 3 + 1*4 ] = state[ 3 + 0*4 ]
state[ 3 + 0*4 ] = temp
}
void InvMixColumns( byte * state )
{
InvMixColumn( state + 0*4 )
InvMixColumn( state + 1*4 )
InvMixColumn( state + 2*4 )
InvMixColumn( state + 3*4 )
}
void MixColumns( byte * state )
{
MixColumn( state + 0*4 )
MixColumn( state + 1*4 )
MixColumn( state + 2*4 )
MixColumn( state + 3*4 )
}
void XORBytes( byte * bytes1, byte * bytes2, byte count )
{
do {
*bytes1 ^= *bytes2// Add in GF(2), ie. XOR.
bytes1++
bytes2++
} while( --count )
}
void CopyBytes( byte * to, byte * from, byte count )
{
do {
*to = *from
to++
from++
} while( --count )
}
void KeyExpansion( byte * expandedKey )
{
byte xdata temp[4]
byte i
byte xdata Rcon[4] = { 0x01, 0x00, 0x00, 0x00 }// Round constant.
unsigned char xdata *key
unsigned char xdata a[16]
key=a
//以下为加解密密码，共16字节。可以选择任意值
key[0]=0x30
key[1]=0x30
key[2]=0x30
key[3]=0x30
key[4]=0x30
key[5]=0x30
key[6]=0x30
key[7]=0x30
key[8]=0x30
key[9]=0x30
key[10]=0x30
key[11]=0x30
key[12]=0x30
key[13]=0x30
key[14]=0x30
key[15]=0x30
////////////////////////////////////////////
// Copy key to start of expanded key.
i = KEYLENGTH
do {
*expandedKey = *key
expandedKey++
key++
} while( --i )
// Prepare last 4 bytes of key in temp.
expandedKey -= 4
temp[0] = *(expandedKey++)
temp[1] = *(expandedKey++)
temp[2] = *(expandedKey++)
temp[3] = *(expandedKey++)
// Expand key.
i = KEYLENGTH
while( i <BLOCKSIZE*(ROUNDS+1) ) {
// Are we at the start of a multiple of the key size?
if( (i % KEYLENGTH) == 0 ) {
CycleLeft( temp )// Cycle left once.
SubBytes( temp, 4 )// Substitute each byte.
XORBytes( temp, Rcon, 4 )// Add constant in GF(2).
*Rcon = (*Rcon <<1) ^ (*Rcon &0x80 ? BPOLY : 0)
}
// Keysize larger than 24 bytes, ie. larger that 192 bits?
#if KEYLENGTH >24
// Are we right past a block size?
else if( (i % KEYLENGTH) == BLOCKSIZE ) {
SubBytes( temp, 4 )// Substitute each byte.
}
#endif
// Add bytes in GF(2) one KEYLENGTH away.
XORBytes( temp, expandedKey - KEYLENGTH, 4 )
// Copy result to current 4 bytes.
*(expandedKey++) = temp[ 0 ]
*(expandedKey++) = temp[ 1 ]
*(expandedKey++) = temp[ 2 ]
*(expandedKey++) = temp[ 3 ]
i += 4// Next 4 bytes.
}
}
void InvCipher( byte * block, byte * expandedKey )
{
byte round = ROUNDS-1
expandedKey += BLOCKSIZE * ROUNDS
XORBytes( block, expandedKey, 16 )
expandedKey -= BLOCKSIZE
do {
InvShiftRows( block )
InvSubBytesAndXOR( block, expandedKey, 16 )
expandedKey -= BLOCKSIZE
InvMixColumns( block )
} while( --round )
InvShiftRows( block )
InvSubBytesAndXOR( block, expandedKey, 16 )
}
void Cipher( byte * block, byte * expandedKey )//完成一个块(16字节，128bit)的加密
{
byte round = ROUNDS-1
XORBytes( block, expandedKey, 16 )
expandedKey += BLOCKSIZE
do {
SubBytes( block, 16 )
ShiftRows( block )
MixColumns( block )
XORBytes( block, expandedKey, 16 )
expandedKey += BLOCKSIZE
} while( --round )
SubBytes( block, 16 )
ShiftRows( block )
XORBytes( block, expandedKey, 16 )
}
void aesInit( unsigned char * tempbuf )
{
powTbl = block1
logTbl = block2
CalcPowLog( powTbl, logTbl )
sBox = tempbuf
CalcSBox( sBox )
expandedKey = block1 //至此block1用来存贮密码表
KeyExpansion( expandedKey )
sBoxInv = block2// Must be block2. block2至此开始只用来存贮SBOXINV
CalcSBoxInv( sBox, sBoxInv )
}
//对一个16字节块解密,参数buffer是解密密缓存，chainBlock是要解密的块
void aesDecrypt( unsigned char * buffer, unsigned char * chainBlock )
{
//byte xdata temp[ BLOCKSIZE ]
//CopyBytes( temp, buffer, BLOCKSIZE )
CopyBytes(buffer,chainBlock,BLOCKSIZE)
InvCipher( buffer, expandedKey )
//XORBytes( buffer, chainBlock, BLOCKSIZE )
CopyBytes( chainBlock, buffer, BLOCKSIZE )
}
//对一个16字节块完成加密，参数buffer是加密缓存，chainBlock是要加密的块
void aesEncrypt( unsigned char * buffer, unsigned char * chainBlock )
{
CopyBytes( buffer, chainBlock, BLOCKSIZE )
//XORBytes( buffer, chainBlock, BLOCKSIZE )
Cipher( buffer, expandedKey )
CopyBytes( chainBlock, buffer, BLOCKSIZE )
}
//加解密函数，参数为加解密标志，要加解密的数据缓存起始指针，要加解密的数据长度（如果解密运算，必须是16的整数倍。）
unsigned char aesBlockDecrypt(bit Direct,unsigned char *ChiperDataBuf,unsigned char DataLen)
{
unsigned char xdata i
unsigned char xdata Blocks
unsigned char xdata sBoxbuf[256]
unsigned char xdata tempbuf[16]
unsigned long int xdata OrignLen=0//未加密数据的原始长度
if(Direct==0)
{
*((unsigned char *)&OrignLen+3)=ChiperDataBuf[0]
*((unsigned char *)&OrignLen+2)=ChiperDataBuf[1]
*((unsigned char *)&OrignLen+1)=ChiperDataBuf[2]
*((unsigned char *)&OrignLen)=ChiperDataBuf[3]
DataLen=DataLen-4
}
else
{
memmove(ChiperDataBuf+4,ChiperDataBuf,DataLen)
OrignLen=DataLen
ChiperDataBuf[0]=OrignLen
ChiperDataBuf[1]=OrignLen>>8
ChiperDataBuf[2]=OrignLen>>16
ChiperDataBuf[3]=OrignLen>>24
}
cleardog()
aesInit(sBoxbuf) //初始化
if(Direct==0)//解密
{
Blocks=DataLen/16
for(i=0i<Blocksi++)
{
cleardog()
aesDecrypt(tempbuf,ChiperDataBuf+4+16*i)
}
memmove(ChiperDataBuf,ChiperDataBuf+4,OrignLen)
cleardog()
return(OrignLen)
}
else//加密
{
if(DataLen%16!=0)
{
Blocks=DataLen/16+1
//memset(ChiperDataBuf+4+Blocks*16-(DataLen%16),0x00,DataLen%16)//不足16字节的块补零处理
}
else
{
Blocks=DataLen/16
}
for(i=0i<Blocksi++)
{
cleardog()
aesEncrypt(tempbuf,ChiperDataBuf+4+16*i)
}
cleardog()
return(Blocks*16+4)
}
}
//#endif
以上是C文件。以下是头文件
#ifndef AES_H
#define AES_H
extern void aesInit( unsigned char * tempbuf )
extern void aesDecrypt(unsigned char *buffer, unsigned char *chainBlock)
extern void aesEncrypt( unsigned char * buffer, unsigned char * chainBlock )
extern void aesInit( unsigned char * tempbuf )
extern void aesDecrypt( unsigned char * buffer, unsigned char * chainBlock )
extern void aesEncrypt( unsigned char * buffer, unsigned char * chainBlock )
extern unsigned char aesBlockDecrypt(bit Direct,unsigned char *ChiperDataBuf,unsigned char DataLen)
#endif // AES_H
这是我根据网上程序改写的。只支持128位加解密。没有使用占内存很多的查表法。故运算速度会稍慢。
c语言文件加密和解密方法如下：
1、首先打开VC++6.0；
2、选择文件，新建；
3、选择C++ source file 新建一个空白文档；
4、声明头文件
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
首先写个加密函数，算法就是简介里说的
void EncryptFile(FILE *sfp,FILE *dfp,char pwd){
char ch
if(sfp==0||dfp==0)
{
printf("ERROR!\n")
return
}
while((ch=fgetc(sfp))!=EOF)
{
if((ch>='a')&&(ch<='z'))
{
ch=(ch-'a'+1)%26+'a'
ch=ch^pwd
}
if((ch>='A')&&(ch<='Z'))
{
ch=(ch-'A'+1)%26+'A'
ch=ch^pwd
}
fputc(ch,dfp)
}
}
写解密子函数：与加密的过程相反
void DecryptFile(FILE *sfp,FILE *dfp,char pwd){
char ch
while((ch=fgetc(sfp))!=EOF)
{
if((ch>='a')&&(ch<='z'))
{
ch=ch^pwd
ch=(ch-'a'+25)%26+'a'
}
if((ch>='A')&&(ch<='Z'))
{
ch=ch^pwd
ch=(ch-'A'+25)%26+'A'
}
fputc(ch,dfp)
}
}
输出函数，输出文件内容
void OutputFile(FILE *fp)
{
char ch
while((ch=fgetc(fp))!=EOF)
putchar(ch)
}
主函数，主要调用这几个函数
int main()
{
/*用户输入的要加密的文件名*/
char sfilename[20]
/*用户输入加密后保存的文件名*/
char dfilename[20]
/*用来保存密码字符*/
char pwd
FILE *sfp,*dfp
printf("\nPlease input filename to be encrypted:\n")
/*得到要加密的文件名*/
gets(sfilename)
/*得到加密后你要的文件名*/
printf("input filename to save the encrypted file:\n")
gets(dfilename)
/*得到加密字符*/
printf("Please input your Password:\n")
//scanf("%c",&pwd)
pwd=getch()
/*屏幕以*来表示输入的加密字符*/
printf("*\n")
/*以只读方式打开要加密的文件*/
if((sfp=fopen(sfilename,"r"))==0)
{
printf("Can't open the file :%s\n",sfilename)
exit(0)
}
/*输出要加密的文件*/
printf("\nThe the text of file to be encrypted is:\n")
OutputFile(sfp)
/*建立加密后的文件*/
if((dfp=fopen(dfilename,"w+"))==0)
{
printf("Can't open or create the file :%s\n",dfilename)
//exit(0)
}
/*文件加密*/
fseek(sfp,0L,SEEK_SET)
EncryptFile(sfp,dfp,pwd)
printf("\n\nEncrypted the file successfully!\n")
/*输出加密后的文件*/
printf("\nAfter encrypting the text of file is:\n")
fseek(dfp,0L,SEEK_SET)
OutputFile(dfp)
fclose(sfp)
fclose(dfp)
getch()
return 0
}
C语言设计一个简单的加密解密程序如下：
加密程序代码：
#include<stdio.h>
main()
{
char c,filename[20]
FILE *fp1,*fp2
printf("请输入待加密的文件名:\n")
scanf("%s",filename)
fp1=fopen(filename,"r")
fp2=fopen("miwen.txt","w")
do
{
c=fgetc(fp1)
if(c>=32&&c<=126)
{
c=c-32
c=126-c
}
if(c!=-1)
fprintf(fp2,"%c",c)
}
while(c!=-1)
}
解密程序代码：
#include<stdio.h>
#include<string.h>
main()
{
char c,filename[20]
char yanzhengma[20]
FILE *fp1,*fp2
printf("请输入待解密文件名:\n")
scanf("%s",filename)
printf("请输入验证码:\n")
scanf("%s",yanzhengma)
if(strcmp(yanzhengma,"shan")==0)
{
fp1=fopen(filename,"r")
fp2=fopen("yuanwen.txt","w")
do
{
c=fgetc(fp1)
if(c>=32&&c<=126)
{
c=126-c
c=32+c
}
if(c!=-1)
fprintf(fp2,"%c",c)
}
while(c!=-1)
}
else
{
printf("验证码错误！请重新输入:\n")
scanf("%s",filename)
}
}
