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Java加密技术（6）

2012-12-19 
Java加密技术（六）接下来我们介绍DSA数字签名，非对称加密的另一种实现。通过java代码实现如下：Coder类见Java

Java加密技术（六）

接下来我们介绍DSA数字签名，非对称加密的另一种实现。

  1. Java加密技术（6）
  2. Java加密技术（6）

通过java代码实现如下：Coder类见Java代码
  1. import?java.security.Key;??
  2. import?java.security.KeyFactory;??
  3. import?java.security.KeyPair;??
  4. import?java.security.KeyPairGenerator;??
  5. import?java.security.PrivateKey;??
  6. import?java.security.PublicKey;??
  7. import?java.security.SecureRandom;??
  8. import?java.security.Signature;??
  9. import?java.security.interfaces.DSAPrivateKey;??
  10. import?java.security.interfaces.DSAPublicKey;??
  11. import?java.security.spec.PKCS8EncodedKeySpec;??
  12. import?java.security.spec.X509EncodedKeySpec;??
  13. import?java.util.HashMap;??
  14. import?java.util.Map;??
  15. ??
  16. /**?
  17. ?*?DSA安全编码组件?
  18. ?*??
  19. ?*?@author?梁栋?
  20. ?*?@version?1.0?
  21. ?*?@since?1.0?
  22. ?*/??
  23. public?abstract?class?DSACoder?extends?Coder?{??
  24. ??
  25. ????public?static?final?String?ALGORITHM?=?"DSA";??
  26. ??
  27. ????/**?
  28. ?????*?默认密钥字节数?
  29. ?????*??
  30. ?????*?<pre>?
  31. ?????*?DSA??
  32. ?????*?Default?Keysize?1024???
  33. ?????*?Keysize?must?be?a?multiple?of?64,?ranging?from?512?to?1024?(inclusive).?
  34. ?????*?</pre>?
  35. ?????*/??
  36. ????private?static?final?int?KEY_SIZE?=?1024;??
  37. ??
  38. ????/**?
  39. ?????*?默认种子?
  40. ?????*/??
  41. ????private?static?final?String?DEFAULT_SEED?=?"0f22507a10bbddd07d8a3082122966e3";??
  42. ??
  43. ????private?static?final?String?PUBLIC_KEY?=?"DSAPublicKey";??
  44. ????private?static?final?String?PRIVATE_KEY?=?"DSAPrivateKey";??
  45. ??
  46. ????/**?
  47. ?????*?用私钥对信息生成数字签名?
  48. ?????*??
  49. ?????*?@param?data?
  50. ?????*????????????加密数据?
  51. ?????*?@param?privateKey?
  52. ?????*????????????私钥?
  53. ?????*??
  54. ?????*?@return?
  55. ?????*?@throws?Exception?
  56. ?????*/??
  57. ????public?static?String?sign(byte[]?data,?String?privateKey)?throws?Exception?{??
  58. ????????//?解密由base64编码的私钥??
  59. ????????byte[]?keyBytes?=?decryptBASE64(privateKey);??
  60. ??
  61. ????????//?构造PKCS8EncodedKeySpec对象??
  62. ????????PKCS8EncodedKeySpec?pkcs8KeySpec?=?new?PKCS8EncodedKeySpec(keyBytes);??
  63. ??
  64. ????????//?KEY_ALGORITHM?指定的加密算法??
  65. ????????KeyFactory?keyFactory?=?KeyFactory.getInstance(ALGORITHM);??
  66. ??
  67. ????????//?取私钥匙对象??
  68. ????????PrivateKey?priKey?=?keyFactory.generatePrivate(pkcs8KeySpec);??
  69. ??
  70. ????????//?用私钥对信息生成数字签名??
  71. ????????Signature?signature?=?Signature.getInstance(keyFactory.getAlgorithm());??
  72. ????????signature.initSign(priKey);??
  73. ????????signature.update(data);??
  74. ??
  75. ????????return?encryptBASE64(signature.sign());??
  76. ????}??
  77. ??
  78. ????/**?
  79. ?????*?校验数字签名?
  80. ?????*??
  81. ?????*?@param?data?
  82. ?????*????????????加密数据?
  83. ?????*?@param?publicKey?
  84. ?????*????????????公钥?
  85. ?????*?@param?sign?
  86. ?????*????????????数字签名?
  87. ?????*??
  88. ?????*?@return?校验成功返回true?失败返回false?
  89. ?????*?@throws?Exception?
  90. ?????*??
  91. ?????*/??
  92. ????public?static?boolean?verify(byte[]?data,?String?publicKey,?String?sign)??
  93. ????????????throws?Exception?{??
  94. ??
  95. ????????//?解密由base64编码的公钥??
  96. ????????byte[]?keyBytes?=?decryptBASE64(publicKey);??
  97. ??
  98. ????????//?构造X509EncodedKeySpec对象??
  99. ????????X509EncodedKeySpec?keySpec?=?new?X509EncodedKeySpec(keyBytes);??
  100. ??
  101. ????????//?ALGORITHM?指定的加密算法??
  102. ????????KeyFactory?keyFactory?=?KeyFactory.getInstance(ALGORITHM);??
  103. ??
  104. ????????//?取公钥匙对象??
  105. ????????PublicKey?pubKey?=?keyFactory.generatePublic(keySpec);??
  106. ??
  107. ????????Signature?signature?=?Signature.getInstance(keyFactory.getAlgorithm());??
  108. ????????signature.initVerify(pubKey);??
  109. ????????signature.update(data);??
  110. ??
  111. ????????//?验证签名是否正常??
  112. ????????return?signature.verify(decryptBASE64(sign));??
  113. ????}??
  114. ??
  115. ????/**?
  116. ?????*?生成密钥?
  117. ?????*??
  118. ?????*?@param?seed?
  119. ?????*????????????种子?
  120. ?????*?@return?密钥对象?
  121. ?????*?@throws?Exception?
  122. ?????*/??
  123. ????public?static?Map<String,?Object>?initKey(String?seed)?throws?Exception?{??
  124. ????????KeyPairGenerator?keygen?=?KeyPairGenerator.getInstance(ALGORITHM);??
  125. ????????//?初始化随机产生器??
  126. ????????SecureRandom?secureRandom?=?new?SecureRandom();??
  127. ????????secureRandom.setSeed(seed.getBytes());??
  128. ????????keygen.initialize(KEY_SIZE,?secureRandom);??
  129. ??
  130. ????????KeyPair?keys?=?keygen.genKeyPair();??
  131. ??
  132. ????????DSAPublicKey?publicKey?=?(DSAPublicKey)?keys.getPublic();??
  133. ????????DSAPrivateKey?privateKey?=?(DSAPrivateKey)?keys.getPrivate();??
  134. ??
  135. ????????Map<String,?Object>?map?=?new?HashMap<String,?Object>(2);??
  136. ????????map.put(PUBLIC_KEY,?publicKey);??
  137. ????????map.put(PRIVATE_KEY,?privateKey);??
  138. ??
  139. ????????return?map;??
  140. ????}??
  141. ??
  142. ????/**?
  143. ?????*?默认生成密钥?
  144. ?????*??
  145. ?????*?@return?密钥对象?
  146. ?????*?@throws?Exception?
  147. ?????*/??
  148. ????public?static?Map<String,?Object>?initKey()?throws?Exception?{??
  149. ????????return?initKey(DEFAULT_SEED);??
  150. ????}??
  151. ??
  152. ????/**?
  153. ?????*?取得私钥?
  154. ?????*??
  155. ?????*?@param?keyMap?
  156. ?????*?@return?
  157. ?????*?@throws?Exception?
  158. ?????*/??
  159. ????public?static?String?getPrivateKey(Map<String,?Object>?keyMap)??
  160. ????????????throws?Exception?{??
  161. ????????Key?key?=?(Key)?keyMap.get(PRIVATE_KEY);??
  162. ??
  163. ????????return?encryptBASE64(key.getEncoded());??
  164. ????}??
  165. ??
  166. ????/**?
  167. ?????*?取得公钥?
  168. ?????*??
  169. ?????*?@param?keyMap?
  170. ?????*?@return?
  171. ?????*?@throws?Exception?
  172. ?????*/??
  173. ????public?static?String?getPublicKey(Map<String,?Object>?keyMap)??</

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