AES加解密算法的C语言实现(VC版)(8100字)

来源:m.fanwen118.com时间:2021.5.2

#include <stdio.h>

#include <windows.h>

#define BYTE unsigned char

#define WORD unsigned long

/* 8 bits

*/

/* 32 bits */

/* rotates x one bit to the left */

#define ROTL(x) (((x)>>7)|((x)<<1))

/* Rotates 32-bit word left by 1, 2 or 3 byte

*/

#define ROTL8(x) (((x)<<8)|((x)>>24))

#define ROTL16(x) (((x)<<16)|((x)>>16))

#define ROTL24(x) (((x)<<24)|((x)>>8))

/* Fixed Data */

static BYTE InCo[4]={0xB,0xD,0x9,0xE};

/* Inverse Coefficients */

static BYTE fbsub[256];

static BYTE rbsub[256];

static BYTE ptab[256],ltab[256];

static WORD ftable[256];

static WORD rtable[256];

static WORD rco[30];

/* Parameter-dependent data */

int Nk,Nb,Nr;

BYTE fi[24],ri[24];

WORD fkey[120];

WORD rkey[120];

static WORD pack(BYTE *b)

{ /* pack bytes into a 32-bit Word */

return ((WORD)b[3]<<24)|((WORD)b[2]<<16)|((WORD)b[1]<<8)|(WORD)b[0]; }

static void unpack(WORD a,BYTE *b)

{ /* unpack bytes from a word */

b[0]=(BYTE)a; b[1]=(BYTE)(a>>8);

b[2]=(BYTE)(a>>16);

b[3]=(BYTE)(a>>24);

}

//???????à???? 0x011b ???? 10b ????

static BYTE xtime(BYTE a)

{

BYTE b;

if (a&0x80)

b=0x1B;

else

a<<=1;

a^=b;

b=0;

return a;

}

static BYTE bmul(BYTE x,BYTE y)

{ /* x.y= AntiLog(Log(x) + Log(y)) */

if (x && y)

return ptab[(ltab[x]+ltab[y])%255];

else

return 0;

}

static WORD SubByte(WORD a)

{

BYTE b[4];

unpack(a,b);

b[0]=fbsub[b[0]];

b[1]=fbsub[b[1]];

b[2]=fbsub[b[2]];

b[3]=fbsub[b[3]];

return pack(b);

}

static BYTE product(WORD x,WORD y)

{ /* dot product of two 4-byte arrays */

BYTE xb[4],yb[4];

unpack(x,xb);

unpack(y,yb);

return bmul(xb[0],yb[0])^bmul(xb[1],yb[1])^bmul(xb[2],yb[2])^bmul(xb[3],yb[3]); }

static WORD InvMixCol(WORD x)

{ /* matrix Multiplication */

WORD y,m;

BYTE b[4];

m=pack(InCo);

b[3]=product(m,x);

m=ROTL24(m);

b[2]=product(m,x);

m=ROTL24(m);

b[1]=product(m,x);

m=ROTL24(m);

b[0]=product(m,x);

y=pack(b);

return y;

}

BYTE ByteSub(BYTE x)

{

BYTE y=ptab[255-ltab[x]];

x=y;

x=ROTL(x); /* multiplicative inverse */

y^=x;

x=ROTL(x);

y^=x;

x=ROTL(x);

y^=x;

x=ROTL(x);

y^=x;

y^=0x63;

return y;

}

void gentables(void)

{ /* generate tables */

int i;

BYTE y,b[4];

/* use 3 as primitive root to generate power and log tables */

ltab[0]=0;

ptab[0]=1;

ptab[1]=3;

ltab[1]=0;

ltab[3]=1;

for (i=2;i<256;i++)

{

ptab[i]=ptab[i-1]^xtime(ptab[i-1]);

ltab[ptab[i]]=i;

}

/* affine transformation:- each bit is xored with itself shifted one bit ·???±??? */ fbsub[0]=0x63;

rbsub[0x63]=0;

for (i=1;i<256;i++)

{

y=ByteSub((BYTE)i);

fbsub[i]=y;

rbsub[y]=i;

}

for (i=0,y=1;i<30;i++)

{

rco[i]=y;

y=xtime(y);

}

/* calculate forward and reverse tables */

for (i=0;i<256;i++)

{

y=fbsub[i];

b[3]=y^xtime(y);

b[2]=y;

b[1]=y;

ftable[i]=pack(b);

b[0]=xtime(y);

y=rbsub[i];

b[3]=bmul(InCo[0],y);

b[2]=bmul(InCo[1],y);

b[1]=bmul(InCo[2],y);

b[0]=bmul(InCo[3],y);

rtable[i]=pack(b);

}

}

void strtoHex(char *str,char *hex)

{

char ch;

int i=0, by = 0;

while(i < 64 && *str)

{

ch = toupper(*str++);

// the maximum key length is 32 bytes(256 bits) and // hence at most 64 hexadecimal digits // process a hexadecimal digit

if(ch >= '0' && ch <= '9')

by = (by << 4) + ch - '0';

else if(ch >= 'A' && ch <= 'F')

by = (by << 4) + ch - 'A' + 10;

else

{

printf("key must be in hexadecimal notation\n");

exit(0);

} // error if not hexadecimal

// store a key byte for each pair of hexadecimal digits

if(i++ & 1)

hex[i / 2 - 1] = by & 0xff;

}

}

void hextoStr(char *hex,char *str)

{

int i=0, by = 0;

while(i < 32 && *hex)

{

by = *hex ;

// the maximum key length is 32 bytes(256 bits) and // hence at most 64 hexadecimal digits

// process a hexadecimal digit(high)

by=by>>4 &0x0f;

if(by >= 0 && by <= 9)

*str++ = by + '0';

else if(by >= 0x0A && by <= 0x0F)

*str++ = by - 10 + 'A';

by = *hex++;

by=by &0x0f;

if(by >= 0 && by <= 9)

*str++ = by + '0';

else if(by >= 0x0A && by <= 0x0F)

*str++ = by -10 + 'A';

i++;

}

}

void gkey(int nb,int nk,char *key)

{

int i,j,k,m,N;

int C1,C2,C3;

WORD CipherKey[8];

Nb=nb;

Nk=nk;

/* Nr is number of rounds */

if (Nb>=Nk)

Nr=6+Nb;

else

Nr=6+Nk;

C1=1;

if (Nb<8)

{

C2=2;

C3=3;

}

else

{

C2=3;

C3=4;

}

for (m=j=0;j<nb;j++,m+=3)

} { fi[m]=(j+C1)%nb; fi[m+1]=(j+C2)%nb; fi[m+2]=(j+C3)%nb; ri[m]=(nb+j-C1)%nb; ri[m+1]=(nb+j-C2)%nb; ri[m+2]=(nb+j-C3)%nb; } N=Nb*(Nr+1); for (i=j=0;i<Nk;i++,j+=4) { CipherKey[i]=pack((BYTE *)&key[j]); } for (i=0;i<Nk;i++) fkey[i]=CipherKey[i]; for (j=Nk,k=0;j<N;j+=Nk,k++) { fkey[j]=fkey[j-Nk]^SubByte(ROTL24(fkey[j-1]))^rco[k]; if (Nk<=6) { for (i=1;i<Nk && (i+j)<N;i++) fkey[i+j]=fkey[i+j-Nk]^fkey[i+j-1]; } else { for (i=1;i<4 &&(i+j)<N;i++) fkey[i+j]=fkey[i+j-Nk]^fkey[i+j-1]; if ((j+4)<N) fkey[j+4]=fkey[j+4-Nk]^SubByte(fkey[j+3]); for (i=5;i<Nk && (i+j)<N;i++) fkey[i+j]=fkey[i+j-Nk]^fkey[i+j-1]; } } for (j=0;j<Nb;j++) rkey[j+N-Nb]=fkey[j]; for (i=Nb;i<N-Nb;i+=Nb) { k=N-Nb-i; for (j=0;j<Nb;j++) rkey[k+j]=InvMixCol(fkey[i+j]); } for (j=N-Nb;j<N;j++) rkey[j-N+Nb]=fkey[j];

/* There is an obvious time/space trade-off possible here. * Instead of just one ftable[], I could have 4, the other *

*

* 3 pre-rotated to save the ROTL8, ROTL16 and ROTL24 overhead */

void encrypt(char *buff)

{

int i,j,k,m;

WORD a[8],b[8],*x,*y,*t;

for (i=j=0;i<Nb;i++,j+=4)

{

a[i]=pack((BYTE *)&buff[j]);

a[i]^=fkey[i];

}

k=Nb;

x=a;

y=b;

/* State alternates between a and b */

for (i=1;i<Nr;i++)

{

for (m=j=0;j<Nb;j++,m+=3)

{

y[j]=fkey[k++]^ftable[(BYTE)x[j]]^

ROTL8(ftable[(BYTE)(x[fi[m]]>>8)])^

ROTL16(ftable[(BYTE)(x[fi[m+1]]>>16)])^

ROTL24(ftable[x[fi[m+2]]>>24]);

}

t=x;

x=y;

y=t;

}

for (m=j=0;j<Nb;j++,m+=3)

{

y[j]=fkey[k++]^(WORD)fbsub[(BYTE)x[j]]^

ROTL8((WORD)fbsub[(BYTE)(x[fi[m]]>>8)])^

ROTL16((WORD)fbsub[(BYTE)(x[fi[m+1]]>>16)])^

ROTL24((WORD)fbsub[x[fi[m+2]]>>24]);

}

for (i=j=0;i<Nb;i++,j+=4)

{

unpack(y[i],(BYTE *)&buff[j]);

x[i]=y[i]=0;

}

return;

}

void decrypt(char *buff)

{

int i,j,k,m;

WORD a[8],b[8],*x,*y,*t;

for (i=j=0;i<Nb;i++,j+=4)

{

a[i]=pack((BYTE *)&buff[j]);

a[i]^=rkey[i];

}

k=Nb;

x=a;

y=b;

/* State alternates between a and b */

for (i=1;i<Nr;i++)

{

for (m=j=0;j<Nb;j++,m+=3)

{

y[j]=rkey[k++]^rtable[(BYTE)x[j]]^

ROTL8(rtable[(BYTE)(x[ri[m]]>>8)])^

ROTL16(rtable[(BYTE)(x[ri[m+1]]>>16)])^ ROTL24(rtable[x[ri[m+2]]>>24]); }

t=x; x=y; y=t;

}

for (m=j=0;j<Nb;j++,m+=3)

{

y[j]=rkey[k++]^(WORD)rbsub[(BYTE)x[j]]^

ROTL8((WORD)rbsub[(BYTE)(x[ri[m]]>>8)])^

ROTL16((WORD)rbsub[(BYTE)(x[ri[m+1]]>>16)])^ ROTL24((WORD)rbsub[x[ri[m+2]]>>24]); }

for (i=j=0;i<Nb;i++,j+=4)

{

unpack(y[i],(BYTE *)&buff[j]);

x[i]=y[i]=0;

}

return;

}

int main()

{

int i,nb,nk;

char

str[]="abcd1234567890123456789012345678901212345678901234567890123456789012";

} char key[32]; char block[32]; gentables(); strtoHex(str,key); hextoStr(key,str); printf("Key="); for (i=0;i<64;i++) printf("%c",str[i]); printf("\n"); for (i=0;i<32;i++) block[i]=i; for (nb=4;nb<=8;nb+=2) for (nk=4;nk<=8;nk+=2) { printf("\nBlock Size= %d bits, Key Size= %d bits\n",nb*32,nk*32); gkey(nb,nk,key); printf("Plain= "); for (i=0;i<nb*4;i++) printf("%02x",block[i]); printf("\n"); encrypt(block); printf("Encrypt= "); for (i=0;i<nb*4;i++) printf("%02x",(unsigned char)block[i]); printf("\n"); decrypt(block); printf("Decrypt= "); for (i=0;i<nb*4;i++) printf("%02x",block[i]); printf("\n"); } return 0;

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