TEA 加密解密算法

#define BLOCKLEN 8
int hex2bin(char* hexstr,unsigned char* outb)
{
    int len = strlen(hexstr);
    int i=0;
    for(;i<len;i+=2)
    {
        unsigned char v = 0;
        unsigned  char c1 = hexstr[i];
        unsigned  char c2 = hexstr[i+1];

        if( c1>='0' && c1 <='9')
        {
            v = (c1-'0')<<4;
        }else{
            v = ((c1-'a')+10)<<4;
        }

        if( c2>='0' && c2 <='9')
        {
            v += (c2-'0');
        }else{
            v += ((c2-'a')+10);
        }

        outb[0]=v;
        outb++;
    }

    return len/2;
}
void bin2hex(unsigned char* inb,int len,char* hexstr)
{
    int i=0;
    for(;i<len;i++)
    {
        unsigned  char v = inb[i];
        unsigned  char vh = (v&0xf0)>>4;
        unsigned  char vl = v&0x0f;

        if(vh>9)
        {
            hexstr[i*2] = vh-10+'a';
        }else{
            hexstr[i*2] = vh+'0';
        }
        if(vl>9)
        {
            hexstr[i*2+1] = vl-10+'a';
        }else{
            hexstr[i*2+1] = vl+'0';
        }
    }
    hexstr[i*2]=0;
}

void b2ws(unsigned char* bs,unsigned int* ws)
{
    int v = 0;
    v |= bs[0]<<24;
    v |= bs[1]<<16;
    v |= bs[2]<<8;
    v |= bs[3];
    ws[0] = v;
}
void w2bs(unsigned int ws,unsigned char* bs)
{
    bs[0] = (unsigned char)(ws>>24);
    bs[1] = (unsigned char)(ws>>16);
    bs[2] = (unsigned char)(ws>>8);
    bs[3] = (unsigned char)ws;
}
void iXor(unsigned char * deced, unsigned char  const* keyd)
{
    int i=0;
    for(i=0;i<BLOCKLEN;i++)
    {
        deced[i] = deced[i]^keyd[i];
    }
}

void DecryptBlock(unsigned char  * ind, unsigned char * oud,unsigned char * kd)
{
    unsigned int delta=0x9e3779b9;
    unsigned int sum=0xC6EF3720, i=0;

    unsigned int v0 = 0;
    unsigned int v1 = 0;
    unsigned int tv1=0,tv2=0;

    b2ws(ind,&v0);
    b2ws(ind+4,&v1);

    //74726f716b64646d74726f716b63646d

    for(i=0;i<32;i++)
    {
        tv1 = (v0<<4) ^ (v0>>5);
        tv2 = *(int*)(kd+ ((sum>>11)&3)*4);

        v1 = v1 - ( (sum + tv2) ^ ( tv1  + v0) );

        sum -= delta;

        tv1 = (v1<<4) ^ (v1>>5);
        tv2 = *(int*)(kd+ (sum&3)*4);

        v0 = v0 - ( (sum + tv2) ^ ( tv1  + v1) );
    }

    w2bs(v0,oud);
    w2bs(v1,oud+4);
}
void EncryptBlock(unsigned char  * ind, unsigned char * oud,unsigned char * kd)
{
    unsigned int delta=0x9e3779b9;
    unsigned int sum=0, i=0;

    unsigned int v0 = 0;
    unsigned int v1 = 0;
    unsigned int tv1=0,tv2=0;

    b2ws(ind,&v0);
    b2ws(ind+4,&v1);

    for(i=0;i<32;i++)
    {
        tv1 = (v1<<4) ^ (v1>>5);
        tv2 = *(int*)(kd+ (sum&3)*4);

        v0 = v0 + ( (sum + tv2) ^ ( tv1  + v1) );

        sum += delta;

        tv1 = (v0<<4) ^ (v0>>5);
        tv2 = *(int*)(kd+ ((sum>>11)&3)*4);

        v1 = v1 + ( (sum + tv2) ^ ( tv1  + v0) );
    }

    w2bs(v0,oud);
    w2bs(v1,oud+4);
}
//74726f716b64646d74726f716b63646d
void CTEA_Decrypt(char* inputstr, char * outstr, char* keystr)
{
    unsigned char cachedat[64];

    unsigned char inputbytes[24];
    unsigned char outbytes[24];
    unsigned char keybytes[16];

    int iblock=0;
    int inputlen = strlen(inputstr)/2;

    hex2bin(inputstr,inputbytes);
    hex2bin(keystr,keybytes);

    unsigned char* pIn=inputbytes;
    unsigned char* pOu=outbytes;

    memset(cachedat,0x0,64);

    while(iblock *BLOCKLEN < inputlen)
    {
        //decblock
        DecryptBlock(pIn,pOu,keybytes);

        //xor
        iXor(pOu,cachedat);
        pOu[BLOCKLEN]=0;

        memcpy(cachedat,inputbytes,BLOCKLEN);

        pIn += BLOCKLEN;
        pOu += BLOCKLEN;
        iblock++;
    }

    strcpy(outstr,(char*)outbytes);
}

void CTEA_Encrypt(char* plain,char* outstr,char* keystr)
{
    unsigned char cachedat[64];

    //unsigned char inputbytes[24];
    unsigned char outbytes[24];
    unsigned char keybytes[16];

    //hex2bin(inputstr,inputbytes);
    hex2bin(keystr,keybytes);

    int iblock=0;
    int inputlen = strlen(plain);

    unsigned char* pIn=(unsigned char*)plain;
    unsigned char* pOu=outbytes;

    memset(cachedat,0x0,64);

    while(iblock *BLOCKLEN < inputlen)
    {
        iXor(cachedat,pIn);

        EncryptBlock(cachedat,pOu,keybytes);

        memcpy(cachedat,pOu,BLOCKLEN);

        pIn += BLOCKLEN;
        pOu += BLOCKLEN;
        iblock++;
    }

    bin2hex(outbytes,inputlen,outstr);
}