des算法详述.htm

这个是数据加密标准的VC算法

    kwork[53] = key[19];<br>
    kwork[54] = key[11];<br>
    kwork[55] = key[ 3];<br>
    <br>
    /* 16 Iterations */<br>
    for (iter = 1; iter &lt; 17; iter++) {<br>
    for (i = 0; i &lt; 32; i++)<br>
    buffer[i] = bufout[32+i];<br>
    <br>
    /* Calculation of F(R, K) */<br>
    /* Permute - E */<br>
    worka[ 0] = buffer[31];<br>
    worka[ 1] = buffer[ 0];<br>
    worka[ 2] = buffer[ 1];<br>
    worka[ 3] = buffer[ 2];<br>
    worka[ 4] = buffer[ 3];<br>
    worka[ 5] = buffer[ 4];<br>
    worka[ 6] = buffer[ 3];<br>
    worka[ 7] = buffer[ 4];<br>
    worka[ 8] = buffer[ 5];<br>
    worka[ 9] = buffer[ 6];<br>
    worka[10] = buffer[ 7];<br>
    worka[11] = buffer[ 8];<br>
    worka[12] = buffer[ 7];<br>
    worka[13] = buffer[ 8];<br>
    worka[14] = buffer[ 9];<br>
    worka[15] = buffer[10];<br>
    worka[16] = buffer[11];<br>
    worka[17] = buffer[12];<br>
    worka[18] = buffer[11];<br>
    worka[19] = buffer[12];<br>
    worka[20] = buffer[13];<br>
    worka[21] = buffer[14];<br>
    worka[22] = buffer[15];<br>
    worka[23] = buffer[16];<br>
    worka[24] = buffer[15];<br>
    worka[25] = buffer[16];<br>
    worka[26] = buffer[17];<br>
    worka[27] = buffer[18];<br>
    worka[28] = buffer[19];<br>
    worka[29] = buffer[20];<br>
    worka[30] = buffer[19];<br>
    worka[31] = buffer[20];<br>
    worka[32] = buffer[21];<br>
    worka[33] = buffer[22];<br>
    worka[34] = buffer[23];<br>
    worka[35] = buffer[24];<br>
    worka[36] = buffer[23];<br>
    worka[37] = buffer[24];<br>
    worka[38] = buffer[25];<br>
    worka[39] = buffer[26];<br>
    worka[40] = buffer[27];<br>
    worka[41] = buffer[28];<br>
    worka[42] = buffer[27];<br>
    worka[43] = buffer[28];<br>
    worka[44] = buffer[29];<br>
    worka[45] = buffer[30];<br>
    worka[46] = buffer[31];<br>
    worka[47] = buffer[ 0];<br>
    <br>
    /* KS Function Begin */<br>
    if (flg) {<br>
    nbrofshift = shift[iter-1];<br>
    for (i = 0; i &lt; (int) nbrofshift; i++) {<br>
    temp1 = kwork[0];<br>
    temp2 = kwork[28];<br>
    for (j = 0; j &lt; 27; j++) {<br>
    kwork[j] = kwork[j+1];<br>
    kwork[j+28] = kwork[j+29];<br>
    }<br>
    kwork[27] = temp1;<br>
    kwork[55] = temp2;<br>
    }<br>
    } else if (iter &gt; 1) {<br>
    nbrofshift = shift[17-iter];<br>
    for (i = 0; i &lt; (int) nbrofshift; i++) {<br>
    temp1 = kwork[27];<br>
    temp2 = kwork[55];<br>
    for (j = 27; j &gt; 0; j--) {<br>
    kwork[j] = kwork[j-1];<br>
    kwork[j+28] = kwork[j+27];<br>
    }<br>
    kwork[0] = temp1;<br>
    kwork[28] = temp2;<br>
    }<br>
    }<br>
    <br>
    /* Permute kwork - PC2 */<br>
    kn[ 0] = kwork[13];<br>
    kn[ 1] = kwork[16];<br>
    kn[ 2] = kwork[10];<br>
    kn[ 3] = kwork[23];<br>
    kn[ 4] = kwork[ 0];<br>
    kn[ 5] = kwork[ 4];<br>
    kn[ 6] = kwork[ 2];<br>
    kn[ 7] = kwork[27];<br>
    kn[ 8] = kwork[14];<br>
    kn[ 9] = kwork[ 5];<br>
    kn[10] = kwork[20];<br>
    kn[11] = kwork[ 9];<br>
    kn[12] = kwork[22];<br>
    kn[13] = kwork[18];<br>
    kn[14] = kwork[11];<br>
    kn[15] = kwork[ 3];<br>
    kn[16] = kwork[25];<br>
    kn[17] = kwork[ 7];<br>
    kn[18] = kwork[15];<br>
    kn[19] = kwork[ 6];<br>
    kn[20] = kwork[26];<br>
    kn[21] = kwork[19];<br>
    kn[22] = kwork[12];<br>
    kn[23] = kwork[ 1];<br>
    kn[24] = kwork[40];<br>
    kn[25] = kwork[51];<br>
    kn[26] = kwork[30];<br>
    kn[27] = kwork[36];<br>
    kn[28] = kwork[46];<br>
    kn[29] = kwork[54];<br>
    kn[30] = kwork[29];<br>
    kn[31] = kwork[39];<br>
    kn[32] = kwork[50];<br>
    kn[33] = kwork[44];<br>
    kn[34] = kwork[32];<br>
    kn[35] = kwork[47];<br>
    kn[36] = kwork[43];<br>
    kn[37] = kwork[48];<br>
    kn[38] = kwork[38];<br>
    kn[39] = kwork[55];<br>
    kn[40] = kwork[33];<br>
    kn[41] = kwork[52];<br>
    kn[42] = kwork[45];<br>
    kn[43] = kwork[41];<br>
    kn[44] = kwork[49];<br>
    kn[45] = kwork[35];<br>
    kn[46] = kwork[28];<br>
    kn[47] = kwork[31];<br>
    /* KS Function End */<br>
    <br>
    /* worka XOR kn */<br>
    for (i = 0; i &lt; 48; i++)<br>
    worka[i] = worka[i] ^ kn[i];<br>
    <br>
    /* 8 s-functions */<br>
    valindex = s1[2*worka[ 0]+worka[ 5]]<br>
    [2*(2*(2*worka[ 1]+worka[ 2])+<br>
    worka[ 3])+worka[ 4]];<br>
    valindex = valindex * 4;<br>
    kn[ 0] = binary[0+valindex];<br>
    kn[ 1] = binary[1+valindex];<br>
    kn[ 2] = binary[2+valindex];<br>
    kn[ 3] = binary[3+valindex];<br>
    valindex = s2[2*worka[ 6]+worka[11]]<br>
    [2*(2*(2*worka[ 7]+worka[ 8])+<br>
    worka[ 9])+worka[10]];<br>
    valindex = valindex * 4;<br>
    kn[ 4] = binary[0+valindex];<br>
    kn[ 5] = binary[1+valindex];<br>
    kn[ 6] = binary[2+valindex];<br>
    kn[ 7] = binary[3+valindex];<br>
    valindex = s3[2*worka[12]+worka[17]]<br>
    [2*(2*(2*worka[13]+worka[14])+<br>
    worka[15])+worka[16]];<br>
    valindex = valindex * 4;<br>
    kn[ 8] = binary[0+valindex];<br>
    kn[ 9] = binary[1+valindex];<br>
    kn[10] = binary[2+valindex];<br>
    kn[11] = binary[3+valindex];<br>
    valindex = s4[2*worka[18]+worka[23]]<br>
    [2*(2*(2*worka[19]+worka[20])+<br>
    worka[21])+worka[22]];<br>
    valindex = valindex * 4;<br>
    kn[12] = binary[0+valindex];<br>
    kn[13] = binary[1+valindex];<br>
    kn[14] = binary[2+valindex];<br>
    kn[15] = binary[3+valindex];<br>
    valindex = s5[2*worka[24]+worka[29]]<br>
    [2*(2*(2*worka[25]+worka[26])+<br>
    worka[27])+worka[28]];<br>
    valindex = valindex * 4;<br>
    kn[16] = binary[0+valindex];<br>
    kn[17] = binary[1+valindex];<br>
    kn[18] = binary[2+valindex];<br>
    kn[19] = binary[3+valindex];<br>
    valindex = s6[2*worka[30]+worka[35]]<br>
    [2*(2*(2*worka[31]+worka[32])+<br>
    worka[33])+worka[34]];<br>
    valindex = valindex * 4;<br>
    kn[20] = binary[0+valindex];<br>
    kn[21] = binary[1+valindex];<br>
    kn[22] = binary[2+valindex];<br>
    kn[23] = binary[3+valindex];<br>
    valindex = s7[2*worka[36]+worka[41]]<br>
    [2*(2*(2*worka[37]+worka[38])+<br>
    worka[39])+worka[40]];<br>
    valindex = valindex * 4;<br>
    kn[24] = binary[0+valindex];<br>
    kn[25] = binary[1+valindex];<br>
    kn[26] = binary[2+valindex];<br>
    kn[27] = binary[3+valindex];<br>
    valindex = s8[2*worka[42]+worka[47]]<br>
    [2*(2*(2*worka[43]+worka[44])+<br>
    worka[45])+worka[46]];<br>
    valindex = valindex * 4;<br>
    kn[28] = binary[0+valindex];<br>
    kn[29] = binary[1+valindex];<br>
    kn[30] = binary[2+valindex];<br>
    kn[31] = binary[3+valindex];<br>
    <br>
    /* Permute - P */<br>
    worka[ 0] = kn[15];<br>
    worka[ 1] = kn[ 6];<br>
    worka[ 2] = kn[19];<br>
    worka[ 3] = kn[20];<br>
    worka[ 4] = kn[28];<br>
    worka[ 5] = kn[11];<br>
    worka[ 6] = kn[27];<br>
    worka[ 7] = kn[16];<br>
    worka[ 8] = kn[ 0];<br>
    worka[ 9] = kn[14];<br>
    worka[10] = kn[22];<br>
    worka[11] = kn[25];<br>
    worka[12] = kn[ 4];<br>
    worka[13] = kn[17];<br>
    worka[14] = kn[30];<br>
    worka[15] = kn[ 9];<br>
    worka[16] = kn[ 1];<br>
    worka[17] = kn[ 7];<br>
    worka[18] = kn[23];<br>
    worka[19] = kn[13];<br>
    worka[20] = kn[31];<br>
    worka[21] = kn[26];<br>
    worka[22] = kn[ 2];<br>
    worka[23] = kn[ 8];<br>
    worka[24] = kn[18];<br>
    worka[25] = kn[12];<br>
    worka[26] = kn[29];<br>
    worka[27] = kn[ 5];<br>
    worka[28] = kn[21];<br>
    worka[29] = kn[10];<br>
    worka[30] = kn[ 3];<br>
    worka[31] = kn[24];<br>
    <br>
    /* bufout XOR worka */<br>
    for (i = 0; i &lt; 32; i++) {<br>
    bufout[i+32] = bufout[i] ^ worka[i];<br>
    bufout[i] = buffer[i];<br>
    }<br>
    } /* End of Iter */<br>
    <br>
    /* Prepare Output */<br>
    for (i = 0; i &lt; 32; i++) {<br>
    j = bufout[i];<br>
    bufout[i] = bufout[32+i];<br>
    bufout[32+i] = j;<br>
    }<br>
    <br>
    /* Inverse Initial Permutation */<br>
    buffer[ 0] = bufout[39];<br>
    buffer[ 1] = bufout[ 7];<br>
    buffer[ 2] = bufout[47];<br>
    buffer[ 3] = bufout[15];<br>
    buffer[ 4] = bufout[55];<br>
    buffer[ 5] = bufout[23];<br>
    buffer[ 6] = bufout[63];<br>
    buffer[ 7] = bufout[31];<br>
    buffer[ 8] = bufout[38];<br>
    buffer[ 9] = bufout[ 6];<br>
    buffer[10] = bufout[46];<br>
    buffer[11] = bufout[14];<br>
    buffer[12] = bufout[54];<br>
    buffer[13] = bufout[22];<br>
    buffer[14] = bufout[62];<br>
    buffer[15] = bufout[30];<br>
    buffer[16] = bufout[37];<br>
    buffer[17] = bufout[ 5];<br>
    buffer[18] = bufout[45];<br>
    buffer[19] = bufout[13];<br>
    buffer[20] = bufout[53];<br>
    buffer[21] = bufout[21];<br>
    buffer[22] = bufout[61];<br>
    buffer[23] = bufout[29];<br>
    buffer[24] = bufout[36];<br>
    buffer[25] = bufout[ 4];<br>
    buffer[26] = bufout[44];<br>
    buffer[27] = bufout[12];<br>
    buffer[28] = bufout[52];<br>
    buffer[29] = bufout[20];<br>
    buffer[30] = bufout[60];<br>
    buffer[31] = bufout[28];<br>
    buffer[32] = bufout[35];<br>
    buffer[33] = bufout[ 3];<br>
    buffer[34] = bufout[43];<br>
    buffer[35] = bufout[11];<br>
    buffer[36] = bufout[51];<br>
    buffer[37] = bufout[19];<br>
    buffer[38] = bufout[59];<br>
    buffer[39] = bufout[27];<br>
    buffer[40] = bufout[34];<br>
    buffer[41] = bufout[ 2];<br>
    buffer[42] = bufout[42];<br>
    buffer[43] = bufout[10];<br>
    buffer[44] = bufout[50];<br>
    buffer[45] = bufout[18];<br>
    buffer[46] = bufout[58];<br>
    buffer[47] = bufout[26];<br>
    buffer[48] = bufout[33];<br>
    buffer[49] = bufout[ 1];<br>
    buffer[50] = bufout[41];<br>
    buffer[51] = bufout[ 9];<br>
    buffer[52] = bufout[49];<br>
    buffer[53] = bufout[17];<br>
    buffer[54] = bufout[57];<br>
    buffer[55] = bufout[25];<br>
    buffer[56] = bufout[32];<br>
    buffer[57] = bufout[ 0];<br>
    buffer[58] = bufout[40];<br>
    buffer[59] = bufout[ 8];<br>
    buffer[60] = bufout[48];<br>
    buffer[61] = bufout[16];<br>
    buffer[62] = bufout[56];<br>
    buffer[63] = bufout[24];<br>
    <br>
    j = 0;<br>
    for (i = 0; i &lt; 8; i++) {<br>
    *(dest + i) = 0x00;<br>
    for (k = 0; k &lt; 7; k++)<br>
    *(dest + i) = ((*(dest + i)) + buffer[j+k]) * 2;<br>
    *(dest + i) = *(dest + i) + buffer[j+7];<br>
    j += 8;<br>
    }<br>
    }</font><br>
　</td>
  </tr>
  <tr>
    <td width="100%">
    <p style="text-align: justify; text-justify: inter-ideograph; line-height: 200%">　</td>
  </tr>
</table></td></tr></table>
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<hr width=95%>
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