前端使用jsencrypt库实现RSA公钥解密——uniapp同样适用_uniapp jsencrypt

一、安装jsencrypt库

npm i jsencrypt
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方法一、更改库的原生方法

在node_modules目录下，根据如下路径找到rsa.js文件：jsencrypt/lib/lib/jsbn/rsa.js

1. 修改 RSAKey.prototype.decrypt 方法（将doPrivate改为doPublic）

RSAKey.prototype.decrypt = function (ctext) {
    var c = parseBigInt(ctext, 16);
    // var m = this.doPrivate(c);
    var m = this.doPublic(c);
    if (m == null) {
        return null;
    }
    return pkcs1unpad2(m, (this.n.bitLength() + 7) >> 3);
};
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2. 修改 rsa.js文件下的pkcs1unpad2方法

function pkcs1unpad2(d, n) {
    var b = d.toByteArray();
    var i = 0;
    while (i < b.length && b[i] == 0) {
        ++i;
    }
    // 将这三行代码注释
    // if (b.length - i != n - 1 || b[i] != 2) {
    //     return null;
    // }
    ++i;
    while (b[i] != 0) {
        if (++i >= b.length) {
            return null;
        }
    }
    var ret = "";
    while (++i < b.length) {
        var c = b[i] & 255;
        if (c < 128) { // utf-8 decode
            ret += String.fromCharCode(c);
        }
        else if ((c > 191) && (c < 224)) {
            ret += String.fromCharCode(((c & 31) << 6) | (b[i + 1] & 63));
            ++i;
        }
        else {
            ret += String.fromCharCode(((c & 15) << 12) | ((b[i + 1] & 63) << 6) | (b[i + 2] & 63));
            i += 2;
        }
    }
    return ret;
}
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3. 保存文件

方法二、重写库的原生方法

1. 封装decrypt.js文件，在文件中引入jsencrypt，并对解密方法重写

import JSEncrypt from 'jsencrypt'
import { parseBigInt } from 'jsencrypt/lib/lib/jsbn/jsbn'

function pkcs1unpad2(d, n) {
  var b = d.toByteArray()
  var i = 0
  while (i < b.length && b[i] === 0) {
    ++i
  }
  // if (b.length - i !== n - 1 || b[i] !== 2) {
  //   return null
  // }
  ++i
  while (b[i] !== 0) {
    if (++i >= b.length) {
      return null
    }
  }
  var ret = ''
  while (++i < b.length) {
    var c = b[i] & 255
    if (c < 128) { // utf-8 decode
      ret += String.fromCharCode(c)
    } else if ((c > 191) && (c < 224)) {
      ret += String.fromCharCode(((c & 31) << 6) | (b[i + 1] & 63))
      ++i
    } else {
      ret += String.fromCharCode(((c & 15) << 12) | ((b[i + 1] & 63) << 6) | (b[i + 2] & 63))
      i += 2
    }
  }
  return ret
}

export function decrypt(data, publicKey) {
    const encrypt = new JSEncrypt()
    encrypt.setPublicKey(publicKey)
    // 不支持公钥解密
    // 自定义解析方法支持公钥解析
    const rsaKey = encrypt.getKey()
    rsaKey.decrypt = function(ctext) {
      var c = parseBigInt(ctext, 16)
      var m = this.doPublic(c)
      if (m == null) {
        return null
      }
      return pkcs1unpad2(m, (this.n.bitLength() + 7) >> 3)
    }
    return encrypt.decrypt(data)
  }
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2. 引用decrypt.js文件，调用方法解密

	import {
		decrypt
	} from './decrypt.js'
	let decrypted = decrypt(encryptedData, publicKey);
	console.log(decrypted); // 解密后的明文
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