基于C语言实现的aes256加密算法示例
本文实例讲述了基于C语言实现的aes256加密算法。分享给大家供大家参考，具体如下：
aes256.h：
#ifndefuint8_t
#defineuint8_tunsignedchar
#endif
#ifdef__cplusplus
extern"C"{
#endif
typedefstruct{
uint8_tkey[32];
uint8_tenckey[32];
uint8_tdeckey[32];
}aes256_context;
voidaes256_init(aes256_context*,uint8_t*);
voidaes256_done(aes256_context*);
voidaes256_encrypt_ecb(aes256_context*,uint8_t*);
voidaes256_decrypt_ecb(aes256_context*,uint8_t*);
#ifdef__cplusplus
}
#endif
aes256.c：
#include"aes256.h"
#defineF(x)(((x)<<1)^((((x)>>7)&1)*0x1b))
#defineFD(x)(((x)>>1)^(((x)&1)?0x8d:0))
//#defineBACK_TO_TABLES
#ifdefBACK_TO_TABLES
constuint8_tsbox[256]={
0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,
0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76,
0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,
0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0,
0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,
0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15,
0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,
0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75,
0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,
0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84,
0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,
0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf,
0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,
0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8,
0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,
0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2,
0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,
0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73,
0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,
0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb,
0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,
0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79,
0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,
0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08,
0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,
0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a,
0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,
0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e,
0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,
0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf,
0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,
0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16
};
constuint8_tsboxinv[256]={
0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,
0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb,
0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,
0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb,
0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,
0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e,
0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,
0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25,
0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,
0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92,
0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,
0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84,
0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,
0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06,
0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,
0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b,
0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,
0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73,
0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,
0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e,
0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,
0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b,
0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,
0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4,
0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,
0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f,
0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,
0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef,
0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,
0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61,
0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,
0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d
};
#definerj_sbox(x)sbox[(x)]
#definerj_sbox_inv(x)sboxinv[(x)]
#else
uint8_tgf_alog(uint8_tx)//calculateanti-logarithmgen3
{
uint8_tatb=1,z;
while(x--){z=atb;atb<<=1;if(z&0x80)atb^=0x1b;atb^=z;}
returnatb;
}
uint8_tgf_log(uint8_tx)//calculatelogarithmgen3
{
uint8_tatb=1,i=0,z;
do{
if(atb==x)break;
z=atb;atb<<=1;if(z&0x80)atb^=0x1b;atb^=z;
}while(++i>0);
returni;
}
uint8_tgf_mulinv(uint8_tx)//calculatemultiplicativeinverse
{
return(x)?gf_alog(255-gf_log(x)):0;
}
uint8_trj_sbox(uint8_tx)
{
uint8_ty,sb;
sb=y=gf_mulinv(x);
y=(y<<1)|(y>>7);sb^=y;y=(y<<1)|(y>>7);sb^=y;
y=(y<<1)|(y>>7);sb^=y;y=(y<<1)|(y>>7);sb^=y;
return(sb^0x63);
}
uint8_trj_sbox_inv(uint8_tx)
{
uint8_ty,sb;
y=x^0x63;
sb=y=(y<<1)|(y>>7);
y=(y<<2)|(y>>6);sb^=y;y=(y<<3)|(y>>5);sb^=y;
returngf_mulinv(sb);
}
#endif
uint8_trj_xtime(uint8_tx)
{
return(x&0x80)?((x<<1)^0x1b):(x<<1);
}
voidaes_subBytes(uint8_t*buf)
{
registeruint8_ti=16;
while(i--)buf[i]=rj_sbox(buf[i]);
}
voidaes_subBytes_inv(uint8_t*buf)
{
registeruint8_ti=16;
while(i--)buf[i]=rj_sbox_inv(buf[i]);
}
voidaes_addRoundKey(uint8_t*buf,uint8_t*key)
{
registeruint8_ti=16;
while(i--)buf[i]^=key[i];
}
voidaes_addRoundKey_cpy(uint8_t*buf,uint8_t*key,uint8_t*cpk)
{
registeruint8_ti=16;
while(i--)buf[i]^=(cpk[i]=key[i]),cpk[16+i]=key[16+i];
}
voidaes_shiftRows(uint8_t*buf)
{
registeruint8_ti,j;
i=buf[1];buf[1]=buf[5];buf[5]=buf[9];buf[9]=buf[13];buf[13]=i;
i=buf[10];buf[10]=buf[2];buf[2]=i;
j=buf[3];buf[3]=buf[15];buf[15]=buf[11];buf[11]=buf[7];buf[7]=j;
j=buf[14];buf[14]=buf[6];buf[6]=j;
}
voidaes_shiftRows_inv(uint8_t*buf)
{
registeruint8_ti,j;
i=buf[1];buf[1]=buf[13];buf[13]=buf[9];buf[9]=buf[5];buf[5]=i;
i=buf[2];buf[2]=buf[10];buf[10]=i;
j=buf[3];buf[3]=buf[7];buf[7]=buf[11];buf[11]=buf[15];buf[15]=j;
j=buf[6];buf[6]=buf[14];buf[14]=j;
}
voidaes_mixColumns(uint8_t*buf)
{
registeruint8_ti,a,b,c,d,e;
for(i=0;i<16;i+=4)
{
a=buf[i];b=buf[i+1];c=buf[i+2];d=buf[i+3];
e=a^b^c^d;
buf[i]^=e^rj_xtime(a^b);buf[i+1]^=e^rj_xtime(b^c);
buf[i+2]^=e^rj_xtime(c^d);buf[i+3]^=e^rj_xtime(d^a);
}
}
voidaes_mixColumns_inv(uint8_t*buf)
{
registeruint8_ti,a,b,c,d,e,x,y,z;
for(i=0;i<16;i+=4)
{
a=buf[i];b=buf[i+1];c=buf[i+2];d=buf[i+3];
e=a^b^c^d;
z=rj_xtime(e);
x=e^rj_xtime(rj_xtime(z^a^c));y=e^rj_xtime(rj_xtime(z^b^d));
buf[i]^=x^rj_xtime(a^b);buf[i+1]^=y^rj_xtime(b^c);
buf[i+2]^=x^rj_xtime(c^d);buf[i+3]^=y^rj_xtime(d^a);
}
}
voidaes_expandEncKey(uint8_t*k,uint8_t*rc)
{
registeruint8_ti;
k[0]^=rj_sbox(k[29])^(*rc);
k[1]^=rj_sbox(k[30]);
k[2]^=rj_sbox(k[31]);
k[3]^=rj_sbox(k[28]);
*rc=F(*rc);
for(i=4;i<16;i+=4)k[i]^=k[i-4],k[i+1]^=k[i-3],
k[i+2]^=k[i-2],k[i+3]^=k[i-1];
k[16]^=rj_sbox(k[12]);
k[17]^=rj_sbox(k[13]);
k[18]^=rj_sbox(k[14]);
k[19]^=rj_sbox(k[15]);
for(i=20;i<32;i+=4)k[i]^=k[i-4],k[i+1]^=k[i-3],
k[i+2]^=k[i-2],k[i+3]^=k[i-1];
}
voidaes_expandDecKey(uint8_t*k,uint8_t*rc)
{
uint8_ti;
for(i=28;i>16;i-=4)k[i+0]^=k[i-4],k[i+1]^=k[i-3],
k[i+2]^=k[i-2],k[i+3]^=k[i-1];
k[16]^=rj_sbox(k[12]);
k[17]^=rj_sbox(k[13]);
k[18]^=rj_sbox(k[14]);
k[19]^=rj_sbox(k[15]);
for(i=12;i>0;i-=4)k[i+0]^=k[i-4],k[i+1]^=k[i-3],
k[i+2]^=k[i-2],k[i+3]^=k[i-1];
*rc=FD(*rc);
k[0]^=rj_sbox(k[29])^(*rc);
k[1]^=rj_sbox(k[30]);
k[2]^=rj_sbox(k[31]);
k[3]^=rj_sbox(k[28]);
}
voidaes256_init(aes256_context*ctx,uint8_t*k)
{
uint8_trcon=1;
registeruint8_ti;
for(i=0;i<sizeof(ctx->key);i++)ctx->enckey[i]=ctx->deckey[i]=k[i];
for(i=8;--i;)aes_expandEncKey(ctx->deckey,&rcon);
}
voidaes256_done(aes256_context*ctx)
{
registeruint8_ti;
for(i=0;i<sizeof(ctx->key);i++)
ctx->key[i]=ctx->enckey[i]=ctx->deckey[i]=0;
}
voidaes256_encrypt_ecb(aes256_context*ctx,uint8_t*buf)
{
uint8_ti,rcon;
aes_addRoundKey_cpy(buf,ctx->enckey,ctx->key);
for(i=1,rcon=1;i<14;++i)
{
aes_subBytes(buf);
aes_shiftRows(buf);
aes_mixColumns(buf);
if(i&1)aes_addRoundKey(buf,&ctx->key[16]);
elseaes_expandEncKey(ctx->key,&rcon),aes_addRoundKey(buf,ctx->key);
}
aes_subBytes(buf);
aes_shiftRows(buf);
aes_expandEncKey(ctx->key,&rcon);
aes_addRoundKey(buf,ctx->key);
}
voidaes256_decrypt_ecb(aes256_context*ctx,uint8_t*buf)
{
uint8_ti,rcon;
aes_addRoundKey_cpy(buf,ctx->deckey,ctx->key);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);
for(i=14,rcon=0x80;--i;)
{
if((i&1))
{
aes_expandDecKey(ctx->key,&rcon);
aes_addRoundKey(buf,&ctx->key[16]);
}
elseaes_addRoundKey(buf,ctx->key);
aes_mixColumns_inv(buf);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);
}
aes_addRoundKey(buf,ctx->key);
}
demo.c：
#include
#include
#include"aes256.h"
#defineDUMP(s,i,buf,sz){printf(s);/
for(i=0;i<(sz);i++)/
printf("x",buf[i]);/
printf("/n");}
intmain(intargc,char*argv[])
{
aes256_contextctx;
uint8_tkey[32];
uint8_tbuf[16],i;
for(i=0;i<sizeof(buf);i++)buf[i]=i*16+i;
for(i=0;i<sizeof(key);i++)key[i]=i;
DUMP("txt:",i,buf,sizeof(buf));
DUMP("key:",i,key,sizeof(key));
printf("---/n");
aes256_init(&ctx,key);
aes256_encrypt_ecb(&ctx,buf);
DUMP("enc:",i,buf,sizeof(buf));
printf("tst:8ea2b7ca516745bfeafc49904b496089/n");
aes256_init(&ctx,key);
aes256_decrypt_ecb(&ctx,buf);
DUMP("dec:",i,buf,sizeof(buf));
aes256_done(&ctx);
return0;
}
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希望本文所述对大家C语言程序设计有所帮助。