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| | | package com.ruoyi.account.util.weChat; |
| | | |
| | | import java.nio.charset.Charset; |
| | | import java.util.Arrays; |
| | | |
| | | /** |
| | | * 微信小程序加解密 |
| | | * @author pzb |
| | | * @Date 2021/12/3 15:43 |
| | | */ |
| | | public class WxPKCS7Encoder { |
| | | private static final Charset CHARSET = Charset.forName("utf-8"); |
| | | private static final int BLOCK_SIZE = 32; |
| | | |
| | | /** |
| | | * 获得对明文进行补位填充的字节. |
| | | * |
| | | * @param count |
| | | * 需要进行填充补位操作的明文字节个数 |
| | | * @return 补齐用的字节数组 |
| | | */ |
| | | public static byte[] encode(int count) { |
| | | // 计算需要填充的位数 |
| | | int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE); |
| | | if (amountToPad == 0) { |
| | | amountToPad = BLOCK_SIZE; |
| | | } |
| | | // 获得补位所用的字符 |
| | | char padChr = chr(amountToPad); |
| | | String tmp = new String(); |
| | | for (int index = 0; index < amountToPad; index++) { |
| | | tmp += padChr; |
| | | } |
| | | return tmp.getBytes(CHARSET); |
| | | } |
| | | |
| | | /** |
| | | * 删除解密后明文的补位字符 |
| | | * |
| | | * @param decrypted |
| | | * 解密后的明文 |
| | | * @return 删除补位字符后的明文 |
| | | */ |
| | | public static byte[] decode(byte[] decrypted) { |
| | | int pad = decrypted[decrypted.length - 1]; |
| | | if (pad < 1 || pad > 32) { |
| | | pad = 0; |
| | | } |
| | | return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad); |
| | | } |
| | | |
| | | /** |
| | | * 将数字转化成ASCII码对应的字符,用于对明文进行补码 |
| | | * |
| | | * @param a |
| | | * 需要转化的数字 |
| | | * @return 转化得到的字符 |
| | | */ |
| | | public static char chr(int a) { |
| | | byte target = (byte) (a & 0xFF); |
| | | return (char) target; |
| | | } |
| | | } |