android中AES加解密的使用方法
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2024-03-02 12:01:04
今天在android项目中使用aes对数据进行加解密,遇到了很多问题,网上也找了很多资料,也不行。不过最后还是让我给搞出来了,这里把这个记录下来,不要让别人走我的弯路,因为...
今天在android项目中使用aes对数据进行加解密,遇到了很多问题,网上也找了很多资料,也不行。不过最后还是让我给搞出来了,这里把这个记录下来,不要让别人走我的弯路,因为网上绝大多数的例子都是行不通的。好了,接下来开始讲解
1、aes工具类
package com.example.cheng.aesencrypt; import android.text.textutils; import java.security.nosuchalgorithmexception; import java.security.securerandom; import javax.crypto.cipher; import javax.crypto.keygenerator; import javax.crypto.secretkey; import javax.crypto.spec.ivparameterspec; import javax.crypto.spec.secretkeyspec; /** * class description here * * @author cheng * @version 1.0.0 * @since 2016-11-02 */ public class aes { private static final string sha1prng = "sha1prng"; // sha1prng 强随机种子算法, 要区别4.2以上版本的调用方法 private static final string iv = "qws871bz73msl9x8"; private static final string aes = "aes"; //aes 加密 private static final string ciphermode = "aes/cbc/pkcs5padding"; //algorithm/mode/padding /** * 加密 */ public static string encrypt(string key, string cleartext) { if (textutils.isempty(cleartext)) { return cleartext; } try { byte[] result = encrypt(key, cleartext.getbytes()); return parsebyte2hexstr(result); } catch (exception e) { e.printstacktrace(); } return null; } /** * 加密 */ public static byte[] encrypt(string key, byte[] clear) throws exception { byte[] raw = getrawkey(key.getbytes()); secretkeyspec skeyspec = new secretkeyspec(raw, aes); cipher cipher = cipher.getinstance(ciphermode); cipher.init(cipher.encrypt_mode, skeyspec, new ivparameterspec(new byte[cipher.getblocksize()])); byte[] encrypted = cipher.dofinal(clear); return encrypted; } /** * 解密 */ public static string decrypt(string key, string encrypted) { if (textutils.isempty(encrypted)) { return encrypted; } try { byte[] enc = parsehexstr2byte(encrypted); byte[] result = decrypt(key, enc); return new string(result); } catch (exception e) { e.printstacktrace(); } return null; } /** * 解密 */ public static byte[] decrypt(string key, byte[] encrypted) throws exception { byte[] raw = getrawkey(key.getbytes()); secretkeyspec skeyspec = new secretkeyspec(raw, aes); cipher cipher = cipher.getinstance(ciphermode); cipher.init(cipher.decrypt_mode, skeyspec, new ivparameterspec(new byte[cipher.getblocksize()])); byte[] decrypted = cipher.dofinal(encrypted); return decrypted; } /** * 生成随机数,可以当做动态的密钥 * 加密和解密的密钥必须一致,不然将不能解密 */ public static string generatekey() { try { securerandom securerandom = securerandom.getinstance(sha1prng); byte[] key = new byte[20]; securerandom.nextbytes(key); return tohex(key); } catch (nosuchalgorithmexception e) { e.printstacktrace(); } return null; } /** * 对密钥进行处理 */ public static byte[] getrawkey(byte[] seed) throws exception { keygenerator kgen = keygenerator.getinstance(aes); //for android securerandom sr = null; // 在4.2以上版本中,securerandom获取方式发生了改变 if (android.os.build.version.sdk_int >= 17) { sr = securerandom.getinstance(sha1prng, "crypto"); } else { sr = securerandom.getinstance(sha1prng); } // for java // securerandom = securerandom.getinstance(sha1prng); sr.setseed(seed); kgen.init(128, sr); //256 bits or 128 bits,192bits //aes中128位密钥版本有10个加密循环,192比特密钥版本有12个加密循环,256比特密钥版本则有14个加密循环。 secretkey skey = kgen.generatekey(); byte[] raw = skey.getencoded(); return raw; } /** * 二进制转字符 */ public static string tohex(byte[] buf) { if (buf == null) return ""; stringbuffer result = new stringbuffer(2 * buf.length); for (int i = 0; i < buf.length; i++) { appendhex(result, buf[i]); } return result.tostring(); } private static void appendhex(stringbuffer sb, byte b) { sb.append(iv.charat((b >> 4) & 0x0f)).append(iv.charat(b & 0x0f)); } /** * 将二进制转换成16进制 * * @param buf * @return */ public static string parsebyte2hexstr(byte buf[]) { stringbuilder sb = new stringbuilder(); for (int i = 0; i < buf.length; i++) { string hex = integer.tohexstring(buf[i] & 0xff); if (hex.length() == 1) { hex = '0' + hex; } sb.append(hex.touppercase()); } return sb.tostring(); } /** * 将16进制转换为二进制 * * @param hexstr * @return */ public static byte[] parsehexstr2byte(string hexstr) { if (hexstr.length() < 1) return null; byte[] result = new byte[hexstr.length() / 2]; for (int i = 0; i < hexstr.length() / 2; i++) { int high = integer.parseint(hexstr.substring(i * 2, i * 2 + 1), 16); int low = integer.parseint(hexstr.substring(i * 2 + 1, i * 2 + 2), 16); result[i] = (byte) (high * 16 + low); } return result; } }
2、mainactivity和layout文件如下:
package com.example.cheng.aesencrypt; import android.os.bundle; import android.support.v7.app.appcompatactivity; import android.view.view; import android.widget.edittext; import android.widget.textview; import android.widget.toast; public class mainactivity extends appcompatactivity { private edittext minputet; private textview mshowencryputtv; private textview mshowinputtv; private static final string password_string = "12345678"; @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); minputet = (edittext) findviewbyid(r.id.ase_input); mshowencryputtv = (textview) findviewbyid(r.id.show_oringe_encrypt); mshowinputtv = (textview) findviewbyid(r.id.show_ase_encrypt); } /** * 加密 * * @param view */ public void encrypt(view view) { string inputstring = minputet.gettext().tostring().trim(); if (inputstring.length() == 0) { toast.maketext(this, "请输入要加密的内容", toast.length_short).show(); return; } string encrystr = aes.encrypt(password_string, inputstring); mshowinputtv.settext(encrystr); } /** * 解密 * * @param view */ public void decrypt(view view) { string encryptstring = mshowinputtv.gettext().tostring().trim(); if (encryptstring.length() == 0) { toast.maketext(this, "解密字符串不能为空", toast.length_short).show(); return; } string decrystr = aes.decrypt(password_string, encryptstring); mshowencryputtv.settext(decrystr); } }
layout文件
<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center_vertical" android:orientation="vertical" android:paddingbottom="@dimen/activity_vertical_margin" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" android:paddingtop="@dimen/activity_vertical_margin" tools:context="com.example.cheng.aesencrypt.mainactivity"> <edittext android:id="@+id/ase_input" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="输入要加密的内容" /> <button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onclick="encrypt" android:text="点击进行ase加密" /> <textview android:id="@+id/show_ase_encrypt" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margintop="10dp" android:text="显示加密后的内容" /> <button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onclick="decrypt" android:text="点击进行ase解密" /> <textview android:id="@+id/show_oringe_encrypt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="10dp" android:text="显示加密后的内容" /> </linearlayout>
3、最后的效果如下:
1)、是一个输入框,输入钥加密的字符串;
2)、点击“aes加密”按钮后生产的加密字符串;
3)、点击“aes解密”按钮后,对加密字符串进行解密,然后在3处看到解密后的字符串,可以看到加密字符串和解密字符串相同,所以aes加解密成功了
4、总结
要用真机测试,模拟器是不行的,具体原因没去研究;
点击获取本例的github地址:
也可以通过android studio直接git下来,git地址为https://github.com/chenguo4930/androidaes.git
其中也还有des、rsa的加解密demo的github地址为https://github.com/chenguo4930/encodedemo
git地址为: https://github.com/chenguo4930/encodedemo.git
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。