基于密码加密.doc

基于密码加密 /wiki/security/1715-password-based-encryption原创作者: snowolf 阅读:689次 评论:0条 更新时间:2009-05-27 除了DES，我们还知道有DESede(TripleDES,就是3DES)、AES、Blowfish、RC2、RC4(ARCFOUR)等多种对称加密方式，其实现方式大同小异，这里介绍对称加密的另一个算法PBE PBE PBEPassword-based encryption（基于密码加密）。其特点在于口令由用户自己掌管，不借助任何物理媒体；采用随机数（这里我们叫做盐）杂凑多重加密等方法保证数据的安全性。是一种简便的加密方式。 通过java代码实现如下：Coder类见 单向加密 Java代码 1. importjava.security.Key; 2. importjava.util.Random; 3. 4. importjavax.crypto.Cipher; 5. importjavax.crypto.SecretKey; 6. importjavax.crypto.SecretKeyFactory; 7. importjavax.crypto.spec.PBEKeySpec; 8. importjavax.crypto.spec.PBEParameterSpec; 9. 10. /* 11. *PBE安全编码组件 12. * 13. *author梁栋 14. *version1.0 15. *since1.0 16. */17. publicabstractclassPBECoderextendsCoder 18. /* 19. *支持以下任意一种算法 20. * 21. * 22. *PBEWithMD5AndDES 23. *PBEWithMD5AndTripleDES 24. *PBEWithSHA1AndDESede 25. *PBEWithSHA1AndRC2_40 26. * 27. */28. publicstaticfinalStringALGORITHM=PBEWITHMD5andDES; 29. 30. /* 31. *盐初始化 32. * 33. *return 34. *throwsException 35. */36. publicstaticbyteinitSalt()throwsException 37. bytesalt=newbyte8; 38. Randomrandom=newRandom(); 39. random.nextBytes(salt); 40. returnsalt; 41. 42. 43. /* 44. *转换密钥 45. * 46. *parampassword 47. *return 48. *throwsException 49. */50. privatestaticKeytoKey(Stringpassword)throwsException 51. PBEKeySpeckeySpec=newPBEKeySpec(password.toCharArray(); 52. SecretKeyFactorykeyFactory=SecretKeyFactory.getInstance(ALGORITHM); 53. SecretKeysecretKey=keyFactory.generateSecret(keySpec); 54. 55. returnsecretKey; 56. 57. 58. /* 59. *加密 60. * 61. *paramdata 62. *数据 63. *parampassword 64. *密码 65. *paramsalt 66. *盐 67. *return 68. *throwsException 69. */70. publicstaticbyteencrypt(bytedata,Stringpassword,bytesalt) 71. throwsException 72. 73. Keykey=toKey(password); 74. 75. PBEParameterSpecparamSpec=newPBEParameterSpec(salt,100); 76. Ciphercipher=Cipher.getInstance(ALGORITHM); 77. cipher.init(Cipher.ENCRYPT_MODE,key,paramSpec); 78. 79. returncipher.doFinal(data); 80. 81. 82. 83. /* 84. *解密 85. * 86. *paramdata 87. *数据 88. *parampassword 89. *密码 90. *paramsalt 91. *盐 92. *return 93. *throwsException 94. */95. publicstaticbytedecrypt(bytedata,Stringpassword,bytesalt) 96. throwsException 97. 98. Keykey=toKey(password); 99. 100. PBEParameterSpecparamSpec=newPBEParameterSpec(salt,100); 101. Ciphercipher=Cipher.getInstance(ALGORITHM); 102. cipher.init(Cipher.DECRYPT_MODE,key,paramSpec); 103. 104. returncipher.doFinal(data); 105. 106. 107. import java.security.Key;import java.util.Random;import javax.crypto.Cipher;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.PBEKeySpec;import javax.crypto.spec.PBEParameterSpec;/* * PBE安全编码组件 * * author 梁栋 * version 1.0 * since 1.0 */public abstract class PBECoder extends Coder /* * 支持以下任意一种算法 * * * PBEWithMD5AndDES * PBEWithMD5AndTripleDES * PBEWithSHA1AndDESede * PBEWithSHA1AndRC2_40 * */public static final String ALGORITHM = PBEWITHMD5andDES;/* * 盐初始化 * * return * throws Exception */public static byte initSalt() throws Exception byte salt = new byte8;Random random = new Random();random.nextBytes(salt);return salt;/* * 转换密钥 * * param password * return * throws Exception */private static Key toKey(String password) throws Exception PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray();SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);SecretKey secretKey = keyFactory.generateSecret(keySpec);return secretKey;/* * 加密 * * param data * 数据 * param password * 密码 * param salt * 盐 * return * throws Exception */public static byte encrypt(byte data, String password, byte salt)throws Exception Key key = toKey(password);PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 100);Cipher cipher = Cipher.getInstance(ALGORITHM);cipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);return cipher.doFinal(data);/* * 解密 * * param data * 数据 * param password * 密码 * param salt * 盐 * return * throws Exception */public static byte decrypt(byte data, String password, byte salt)throws Exception Key key = toKey(password);PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 100);Cipher cipher = Cipher.getInstance(ALGORITHM);cipher.init(Cipher.DECRYPT_MODE, key, paramSpec);return cipher.doFinal(data);再给出一个测试类： Java代码 1. importstaticorg.junit.Assert.*; 2. 3. importorg.junit.Test; 4. 5. /* 6. * 7. *author梁栋 8. *version1.0 9. *since1.0 10. */11. publicclassPBECoderTest 12. 13. Test14. publicvoidtest()throwsException 15. StringinputStr=abc; 16. System.err.println(原文:+inputStr); 17. byteinput=inputStr.getBytes(); 18. 19. Stringpwd=efg; 20. System.err.println(密码:+pwd); 21. 22. bytesalt=PBECoder.initSalt(); 23. 24. bytedata=PBECoder.encrypt(input,pwd,salt); 25. 26. System.err.println(加密后:+PBECoder.encryptBASE64(data); 27. 28. byteoutput=PBECoder.decrypt(data,pwd,salt); 29. StringoutputStr=newString(output); 30. 31. System.err.println(解密后:+outputStr); 32. assertEquals(inputStr,outputStr); 33. 34. 35. import static org.junit.Assert.*;import org.junit.Test;/* * * author 梁栋 * version 1.0 * since 1.0 */public class PBECoderTest Testpublic void test() throws Exception String inputStr = abc;System.err.println(原文: + inputStr);byte input = inputStr.getBytes();String pwd = efg;System.err.println(密码: + pwd);byte salt = PBECoder.initSalt();byte data = PBECoder.encrypt(input, pwd, salt);Sys