out

out

关注
发信
关注(28)粉丝(399)

不能从文本文件解密cyphertext，对称键实现。在java中

本文介绍了不能从文本文件解密cyphertext，对称键实现。在java中的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 所以基本上我的程序加密/解密字符串从用户选择的文本文件。 他可以选择五种算法之一。问题是当我用eg创建密文。 AES 然后将此密文保存到文本文件，并要解密，以获取原始字符串不起作用。有人可以指出问题在哪里？ 例如：如果我使用AES加密String：Hello World !!我得到这个密文：1za7slAXv2KZvDlVZlzu / A ==然后我保存到.txt并使用第二种方式进行解密，以获得Hello World !!背部。但结果不好。 我的做法好吗？有没有一些更好的方法？ 忘记添加导入：对于以前的格式化感到抱歉。 import java.io. *; import java.util.Scanner; import javax.crypto.Cipher; import javax.crypto.SecretKey; import javax.crypto.KeyGenerator; import java.security.spec.KeySpec; import java.security.spec.AlgorithmParameterSpec; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.PBEParameterSpec; import javax.crypto.spec.PBEKeySpec; import javax.crypto.BadPaddingException; import java.io.IOException; import java.security.InvalidAlgorithmParameterException; import java.security.NoSuchAlgorithmException; import java.security.InvalidKeyException; import java.security.spec.InvalidKeySpecException; import javax.crypto.NoSuchPaddingException; import javax.crypto.IllegalBlockSizeException; import java.io.UnsupportedEncodingException; public class sifrovaniRaw { 密码sifr，desifr; sifrovaniRaw（SecretKey klic，String algorithmsitmus） { try { sifr = Cipher.getInstance（algorithmsitmus）; desifr = Cipher.getInstance（algorithmsitmus）; sifr.init（Cipher.ENCRYPT_MODE，klic）; desifr.init（Cipher.DECRYPT_MODE，klic）; } catch（NoSuchPaddingException e）{ System.out.println（NoSuchPaddingException）; } catch（NoSuchAlgorithmException e）{ System.out.println（NoSuchAlgorithmException）; } catch（InvalidKeyException e）{ System.out.println（InvalidKeyException）; } } sifrovaniRaw（String passph）{ byte [] sul = { （字节）0xc7，（字节）0x73，（字节）0x21，（字节）0x8c，（字节）0x7e，（字节）0xc8，（字节）0xee，（字节）0x99 }; int iterace = 20; try { KeySpec klicSpecifikace = new PBEKeySpec（passph.toCharArray（），sul，iterace）; SecretKey klic = SecretKeyFactory.getInstance（PBEWithMD5AndTripleDES）。generateSecret（klicSpecifikace）; sifr = Cipher.getInstance（klic.getAlgorithm（））; desifr = Cipher.getInstance（klic.getAlgorithm（））; AlgorithmParameterSpec parametry = new PBEParameterSpec（sul，iterace）; sifr.init（Cipher.ENCRYPT_MODE，klic，parametry）; desifr.init（Cipher.DECRYPT_MODE，klic，parametry）; } catch（InvalidAlgorithmParameterException e）{ System.out.println（InvalidAlgorithmParameterException）; } catch（InvalidKeySpecException e）{ System.out.println（InvalidKeySpecException）; } catch（NoSuchPaddingException e）{ System.out.println（NoSuchPaddingException）; } catch（NoSuchAlgorithmException e）{ System.out.println（NoSuchAlgorithmException）; } catch（InvalidKeyException e）{ System.out.println（InvalidKeyException）; } } public String encryption（String str）{ try { byte [] utf8 = str .getBytes（ UTF8）; byte [] travers = sifr.doFinal（utf8）; 返回新的sun.misc.BASE64Encoder（）。 } catch（BadPaddingException e）{} catch（IllegalBlockSizeException e）{} catch（UnsupportedEncodingException e）{} catch（IOException e）{} 返回null; } public String decrypt（String str）{ try { byte [] dec = new sun.misc.BASE64Decoder（）。decodeBuffer（str）; byte [] utf8 = desifr.doFinal（dec）; return new String（utf8，UTF8）; } catch（BadPaddingException e）{} catch（IllegalBlockSizeException e）{} catch（UnsupportedEncodingException e）{} catch（IOException e）{} 返回null; } public static void testsecklic（） { System.out.println（使用秘密密钥的测试方法）; System.out.println（）; try { System.out.println（Give a path：）; System.out.println（-----）; System.out.println（for UNIX eg：\/home/user/text_to_encrypt/decrypt.txt\）; System.out.println（for NT Windows eg：\C：//FileIO//text.txt\）; System.out.println（------）; 扫描仪扫描=新扫描仪（System.in）; String filepath = scan.next（）; 文件文件=新建文件（filepath）; BufferedInputStream bin = null; FileInputStream fin = new FileInputStream（file）; bin = new BufferedInputStream（fin）; byte [] contents = new byte [1024]; int bytesRead = 0; String StringCont; while（（bytesRead = bin.read（contents））！= -1） { StringCont = new String（contents，0，bytesRead）; System.out.print（StringCont）; SecretKey aesKlic = KeyGenerator.getInstance（AES）。generateKey（）; SecretKey desKlic = KeyGenerator.getInstance（DES）。generateKey（）; SecretKey desedeKlic = KeyGenerator.getInstance（DESede）。generateKey（）; SecretKey rc2Klic = KeyGenerator.getInstance（RC2）。generateKey（）; SecretKey blowfishKlic = KeyGenerator.getInstance（Blowfish）。generateKey（）; StringEncrypter aesEncrypt = new StringEncrypter（aesKlic，aesKlic.getAlgorithm（））; StringEncrypter desEncrypt = new StringEncrypter（desKlic，desKlic.getAlgorithm（））; StringEncrypter desedeEncrypt = new StringEncrypter（desedeKlic，desedeKlic.getAlgorithm（））; StringEncrypter rc2Encrypt = new StringEncrypter（rc2Klic，rc2Klic.getAlgorithm（））; StringEncrypter blowfishEncrypt = new StringEncrypter（blowfishKlic，blowfishKlic.getAlgorithm（））; String aesEncrypted = aesEncrypt.encrypt（StringCont）; String desEncrypted = desEncrypt.encrypt（StringCont）; String rc2Encrypted = desedeEncrypt.encrypt（StringCont）; String desedeEncrypted = rc2Encrypt.encrypt（StringCont）; String blowfishEncrypted = blowfishEncrypt.encrypt（StringCont）; String aesDecrypt = aesEncrypt.decrypt（aesEncrypted）; String desDecrypt = desEncrypt.decrypt（desEncrypted）; String rc2Decrypt = rc2Encrypt.decrypt（desedeEncrypted）; String desedeDecrypt = desedeEncrypt.decrypt（rc2Encrypted）; String blowfishDecrypt = blowfishEncrypt.decrypt（blowfishEncrypted）; //第一个非工作的解密方式。 System.out.println（你要加密[1]还是解密[2]文本？）; int sifDesif = scan.nextInt（）; if（sifDesif == 1） { System.out.println（你想选择什么cypher？）; System.out.println（AES [1]，DES [2]，rc2 [3]，河豚[4]，desede [5]）; int vyber = scan.nextInt（）; 开关（vyber） {案例1：System.out.println（encrypted：+ aesEncrypted）;打破; case 2：System.out.println（encrypted：+ desEncrypted）;打破; case 3：System.out.println（encrypted：+ rc2Encrypted）;打破; case 4：System.out.println（encrypted：+ blowfishEncrypted）;打破; case 5：System.out.println（encrypted：+ desedeEncrypted）;打破; } } else if（sifDesif == 2） { System.out.println（你想要选择什么cypher？ ）; System.out.println（AES [1]，DES [2]，rc2 [3]，河豚[4]，desede [5]）; int vyber = scan.nextInt（）; 开关（vyber） {案例1：System.out.println（decryptpted：+ aesDecrypt）;打破; case 2：System.out.println（decryptpted：+ desDecrypt）;打破; case 3：System.out.println（decryptpted：+ rc2Decrypt）;打破; case 4：System.out.println（decryptpted：+ blowfishDecrypt）;打破; case 5：System.out.println（decryptpted：+ desedeDecrypt）;打破; } } //第二个工作的解密方式。 System.out.println（Algorith used：+ aesKlic.getAlgorithm（））; System.out.println（text：+ StringCont）; System.out.println（encryption：+ aesEncrypted）; System.out.println（decrypt text：+ aesDecrypt）; System.out.println（）; } } catch（NoSuchAlgorithmException e） { System.out.println（No such Algo ）; } catch（FileNotFoundException e） { System.out.println（File not found+ e）; } catch（IOException ioe） { System.out.println（在读取文件时异常+ ioe）; } } public static void main（String [] args） { testsecklic（）; } } 解决方案由于每次生成加密密钥，程序将无法解密使用不同加密密钥创建的密文。如果要在程序运行之间重用加密密钥，则需要找到一种方法来保存加密密钥。 以下程序是原始的较小版本示例，除了它使用每个密码加密和解密明文。我没有访问 StringEncrypter 类，所以我写了一个简单的版本： import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; public class EncTest { public static void main（String [] args）throws Exception { System.out.println（Testing method using secret key ）; String plaintext =hello world; SecretKey aesKlic = KeyGenerator.getInstance（AES）。generateKey（）; SecretKey desKlic = KeyGenerator.getInstance（DES）。generateKey（）; SecretKey desedeKlic = KeyGenerator.getInstance（DESede）。generateKey（）; SecretKey rc2Klic = KeyGenerator.getInstance（RC2）。generateKey（）; SecretKey blowfishKlic = KeyGenerator.getInstance（Blowfish）。generateKey（）; StringEncrypter [] ciphers = new StringEncrypter [] { new StringEncrypter（aesKlic，aesKlic.getAlgorithm（））， new StringEncrypter（desKlic，desKlic.getAlgorithm（））， new StringEncrypter（desedeKlic，desedeKlic.getAlgorithm（））， new StringEncrypter（rc2Klic，rc2Klic.getAlgorithm（））， new StringEncrypter（blowfishKlic，blowfishKlic.getAlgorithm（））}; byte [] [] ciphertexts = new byte [ciphers.length] []; int i = 0; for（StringEncrypter cipher：ciphers）{ ciphertextts [i] = cipher.encrypt（plaintext）; System.out.println（cipher.getAlgorithm（）+encrypted：+ hexEncode（ciphertextts [i]））; i ++; } System.out.println（）; i = 0; （StringEncrypter cipher：ciphers）{ System.out.println（cipher.getAlgorithm（）+decryptpted：+ cipher.decrypt（ciphertexts [i]））; i ++; } } //从commons-codec解压缩的十六进制编码 private static String hexEncode（byte [] input）{ return new String（encodeHex（input））; } private static char [] encodeHex（byte [] data）{ int l = data.length; char [] out = new char [l //两个字符形成十六进制值。 （int i = 0，j = 0; i< l; i ++）{ out [j ++] = DIGITS [（0xF0& data [i]）>> 4]; out [j ++] = DIGITS [0x0F& data [i]]; } 退出; } private static final char [] DIGITS = {'0'，'1'，'2'，'3'，'4'，'5' '6'，'7'，'8'，'9'，'a'，'b'，'c'，'d'，'e'，'f'} private static class StringEncrypter { private final SecretKey key; 私有final String算法; public StringEncrypter（SecretKey key，String algorithm）{ this.key = key; this.algorithm =算法; } public String getAlgorithm（）{ return algorithm; } public byte [] encrypt（String input）throws异常{加密密码= Cipher.getInstance（algorithm）; cipher.init（Cipher.ENCRYPT_MODE，key）; return cipher.doFinal（input.getBytes（UTF-8））; } public String decrypt（byte [] input）throws异常{加密密码= Cipher.getInstance（algorithm）; cipher.init（Cipher.DECRYPT_MODE，key）; return new String（cipher.doFinal（input））; } } } So basically my program encrypt/decrypt string from text file which user choose.He can select one of five algorithms. The problem is when I create ciphertext with eg. AESand then save this ciphertext to text file and want to decrypt it to get the original string it does not work. Can someone point out where is the problem please ?For example: If I encrypt String using AES: "Hello World !!" I get this ciphertext: "1za7slAXv2KZvDlVZlzu/A==" then I save it to .txt and use the second way for Decryption in order to get "Hello World !!" back. But the result is bad.Is my approach good? Is there some better way?Forget to add imports:And sorry for previous formatting.import java.io.*;import java.util.Scanner;import javax.crypto.Cipher;import javax.crypto.SecretKey;import javax.crypto.KeyGenerator;import java.security.spec.KeySpec;import java.security.spec.AlgorithmParameterSpec;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.PBEParameterSpec;import javax.crypto.spec.PBEKeySpec;import javax.crypto.BadPaddingException;import java.io.IOException;import java.security.InvalidAlgorithmParameterException;import java.security.NoSuchAlgorithmException;import java.security.InvalidKeyException;import java.security.spec.InvalidKeySpecException;import javax.crypto.NoSuchPaddingException;import javax.crypto.IllegalBlockSizeException;import java.io.UnsupportedEncodingException;public class sifrovaniRaw {Cipher sifr, desifr;sifrovaniRaw(SecretKey klic, String algoritmus){ try { sifr = Cipher.getInstance(algoritmus); desifr = Cipher.getInstance(algoritmus); sifr.init(Cipher.ENCRYPT_MODE, klic); desifr.init(Cipher.DECRYPT_MODE, klic); } catch (NoSuchPaddingException e) { System.out.println(" NoSuchPaddingException"); } catch (NoSuchAlgorithmException e) { System.out.println(" NoSuchAlgorithmException"); } catch (InvalidKeyException e) { System.out.println(" InvalidKeyException"); }}sifrovaniRaw(String passph) { byte[] sul = { (byte)0xc7, (byte)0x73, (byte)0x21, (byte)0x8c, (byte)0x7e, (byte)0xc8, (byte)0xee, (byte)0x99 }; int iterace = 20; try { KeySpec klicSpecifikace = new PBEKeySpec(passph.toCharArray(), sul, iterace); SecretKey klic = SecretKeyFactory.getInstance("PBEWithMD5AndTripleDES").generateSecret(klicSpecifikace); sifr = Cipher.getInstance(klic.getAlgorithm()); desifr = Cipher.getInstance(klic.getAlgorithm()); AlgorithmParameterSpec parametry = new PBEParameterSpec(sul, iterace); sifr.init(Cipher.ENCRYPT_MODE, klic, parametry); desifr.init(Cipher.DECRYPT_MODE, klic, parametry); } catch (InvalidAlgorithmParameterException e) { System.out.println(" InvalidAlgorithmParameterException"); } catch (InvalidKeySpecException e) { System.out.println(" InvalidKeySpecException"); } catch (NoSuchPaddingException e) { System.out.println(" NoSuchPaddingException"); } catch (NoSuchAlgorithmException e) { System.out.println(" NoSuchAlgorithmException"); } catch (InvalidKeyException e) { System.out.println(" InvalidKeyException"); }}public String encryption(String str) { try { byte[] utf8 = str.getBytes("UTF8"); byte[] enco = sifr.doFinal(utf8); return new sun.misc.BASE64Encoder().encode(enco); } catch (BadPaddingException e) { } catch (IllegalBlockSizeException e) { } catch (UnsupportedEncodingException e) { } catch (IOException e) { } return null;}public String decryption(String str) { try { byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str); byte[] utf8 = desifr.doFinal(dec); return new String(utf8, "UTF8"); } catch (BadPaddingException e) { } catch (IllegalBlockSizeException e) { } catch (UnsupportedEncodingException e) { } catch (IOException e) { } return null;}public static void testsecklic(){ System.out.println("Testing method using secret key"); System.out.println(""); try { System.out.println("Give a path:"); System.out.println("-----"); System.out.println("for UNIX eg: \"/home/user/text_to_encrypt/decrypt.txt\""); System.out.println("for NT Windows eg: \"C://FileIO//text.txt\""); System.out.println("------"); Scanner scan = new Scanner(System.in); String filepath = scan.next(); File file = new File(filepath); BufferedInputStream bin = null; FileInputStream fin = new FileInputStream(file); bin = new BufferedInputStream(fin); byte[] contents = new byte[1024]; int bytesRead=0; String StringCont; while( (bytesRead = bin.read(contents)) != -1) { StringCont = new String(contents, 0, bytesRead); System.out.print(StringCont); SecretKey aesKlic = KeyGenerator.getInstance("AES").generateKey(); SecretKey desKlic = KeyGenerator.getInstance("DES").generateKey(); SecretKey desedeKlic = KeyGenerator.getInstance("DESede").generateKey(); SecretKey rc2Klic = KeyGenerator.getInstance("RC2").generateKey(); SecretKey blowfishKlic = KeyGenerator.getInstance("Blowfish").generateKey(); StringEncrypter aesEncrypt = new StringEncrypter(aesKlic, aesKlic.getAlgorithm()); StringEncrypter desEncrypt = new StringEncrypter(desKlic, desKlic.getAlgorithm()); StringEncrypter desedeEncrypt = new StringEncrypter(desedeKlic, desedeKlic.getAlgorithm()); StringEncrypter rc2Encrypt = new StringEncrypter(rc2Klic, rc2Klic.getAlgorithm()); StringEncrypter blowfishEncrypt = new StringEncrypter(blowfishKlic, blowfishKlic.getAlgorithm()); String aesEncrypted = aesEncrypt.encrypt(StringCont); String desEncrypted = desEncrypt.encrypt(StringCont); String rc2Encrypted = desedeEncrypt.encrypt(StringCont); String desedeEncrypted = rc2Encrypt.encrypt(StringCont); String blowfishEncrypted = blowfishEncrypt.encrypt(StringCont); String aesDecrypt = aesEncrypt.decrypt(aesEncrypted); String desDecrypt = desEncrypt.decrypt(desEncrypted); String rc2Decrypt = rc2Encrypt.decrypt(desedeEncrypted); String desedeDecrypt = desedeEncrypt.decrypt(rc2Encrypted); String blowfishDecrypt = blowfishEncrypt.decrypt(blowfishEncrypted); //FIRST NON-WORKING WAY of decrypting. System.out.println("Do you want to encrypt[1] or decrypt[2] text ?"); int sifDesif = scan.nextInt(); if(sifDesif == 1) { System.out.println("What cypher do you want to choose?"); System.out.println("AES[1], DES[2], rc2[3], blowfish[4], desede[5]"); int vyber = scan.nextInt(); switch(vyber) { case 1: System.out.println("encrypted : " + aesEncrypted); break; case 2: System.out.println("encrypted : " + desEncrypted); break; case 3: System.out.println("encrypted : " + rc2Encrypted); break; case 4: System.out.println("encrypted : " + blowfishEncrypted); break; case 5: System.out.println("encrypted : " + desedeEncrypted); break; } } else if(sifDesif == 2) { System.out.println("What cypher do you want to choose?"); System.out.println("AES[1], DES[2], rc2[3], blowfish[4], desede[5]"); int vyber = scan.nextInt(); switch(vyber) { case 1:System.out.println("decrypted : " + aesDecrypt); break; case 2:System.out.println("decrypted : " + desDecrypt); break; case 3:System.out.println("decrypted : " + rc2Decrypt); break; case 4:System.out.println("decrypted : " + blowfishDecrypt); break; case 5:System.out.println("decrypted : " + desedeDecrypt); break; } } //SECOND WORKING WAY of decrypting. System.out.println("Algorith used:" + aesKlic.getAlgorithm()); System.out.println("text : " + StringCont); System.out.println("encryption : " + aesEncrypted); System.out.println("decryption text : " + aesDecrypt); System.out.println(); } } catch (NoSuchAlgorithmException e) { System.out.println(" No such Algo"); } catch(FileNotFoundException e) { System.out.println("File not found" + e); } catch(IOException ioe) { System.out.println("Exception while reading the file "+ ioe); }}public static void main(String[] args){ testsecklic();}} 解决方案 Since you're generating the encryption keys every time, the program won't be able to decrypt a ciphertext that was created using a different encryption key. You'll need to find a way to persist the encryption key if you want to reuse it between runs of your program.The following program is a smaller version of your original example except that it encrypts and decrypts the plaintext with each cipher. I didn't have access to the StringEncrypter class so I wrote a simple version:import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;public class EncTest { public static void main(String[] args) throws Exception { System.out.println("Testing method using secret key"); String plaintext = "hello world"; SecretKey aesKlic = KeyGenerator.getInstance("AES").generateKey(); SecretKey desKlic = KeyGenerator.getInstance("DES").generateKey(); SecretKey desedeKlic = KeyGenerator.getInstance("DESede").generateKey(); SecretKey rc2Klic = KeyGenerator.getInstance("RC2").generateKey(); SecretKey blowfishKlic = KeyGenerator.getInstance("Blowfish").generateKey(); StringEncrypter[] ciphers = new StringEncrypter[] { new StringEncrypter(aesKlic, aesKlic.getAlgorithm()), new StringEncrypter(desKlic, desKlic.getAlgorithm()), new StringEncrypter(desedeKlic, desedeKlic.getAlgorithm()), new StringEncrypter(rc2Klic, rc2Klic.getAlgorithm()), new StringEncrypter(blowfishKlic, blowfishKlic.getAlgorithm()) }; byte[][] ciphertexts = new byte[ciphers.length][]; int i = 0; for (StringEncrypter cipher : ciphers) { ciphertexts[i] = cipher.encrypt(plaintext); System.out.println(cipher.getAlgorithm() + " encrypted: " + hexEncode(ciphertexts[i])); i++; } System.out.println(); i = 0; for (StringEncrypter cipher : ciphers) { System.out.println(cipher.getAlgorithm() + " decrypted: " + cipher.decrypt(ciphertexts[i])); i++; } } // Hex encoding lifted from commons-codec private static String hexEncode(byte [] input) { return new String(encodeHex(input)); } private static char[] encodeHex(byte[] data) { int l = data.length; char[] out = new char[l << 1]; // two characters form the hex value. for (int i = 0, j = 0; i < l; i++) { out[j++] = DIGITS[(0xF0 & data[i]) >>> 4 ]; out[j++] = DIGITS[ 0x0F & data[i] ]; } return out; } private static final char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; private static class StringEncrypter { private final SecretKey key; private final String algorithm; public StringEncrypter(SecretKey key, String algorithm) { this.key = key; this.algorithm = algorithm; } public String getAlgorithm() { return algorithm; } public byte[] encrypt(String input) throws Exception { Cipher cipher = Cipher.getInstance(algorithm); cipher.init(Cipher.ENCRYPT_MODE, key); return cipher.doFinal(input.getBytes("UTF-8")); } public String decrypt(byte[] input) throws Exception { Cipher cipher = Cipher.getInstance(algorithm); cipher.init(Cipher.DECRYPT_MODE, key); return new String(cipher.doFinal(input)); } }} 这篇关于不能从文本文件解密cyphertext，对称键实现。在java中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！
10-14 18:40
Powered by LMLPHP ©2024 out 0.009124