我正在嘗試使用和生成此站點正在執行的操作https://codebeautify.org/encrypt-decryptBlowfishCBC我不確定實際術語是什么，但我想實現的加密方法會產生不一致的加密字符串，盡管使用相同的內容和密鑰，例如，如果我Hello用 key加密key123兩次，第一個結果可能會顯示abcde，第二個結果應該顯示其他內容，例如fghij. 但是同時解密abcde和fghijwithkey123將返回相同的Hello.我也可以知道他們用來產生最終結果的編碼類型是什么？比如 hex/base64，因為我都試過了，但似乎沒有產生類似的結果。
2 回答
瀟湘沐
TA貢獻1816條經驗 獲得超6個贊
更新時間 2019 年 4 月 21 日晚上 9:49 UTC
在@MaartenBodewes 和@MarkJeronimus 指出了一些需要考慮的事情之后，我正在更新答案以使其更正確。但是因為這個問題是關于實現的，而不是關于使它更安全的，所以這個和舊版本應該足以至少提供一些洞察力。同樣，通過修改以下代碼可以實現更安全的解決方案。
變更日志
密鑰派生
處理異常及其詳細信息
對每個數據使用單個 SecureRandom 實例（iv[8 字節] 和 salt[32 字節]）
檢查要加密的明文和要解密的加密文本的空值和空值
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.util.Base64;
import javax.xml.bind.DatatypeConverter;
import java.security.SecureRandom;
import java.security.spec.KeySpec;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
public class Crypto {
private static final char[] tempKey = new char[] {'T', 'E', 'M', 'P', '_', 'G', 'E', 'N', '_', 'K', 'E', 'Y'};
private static final SecureRandom secureRandomForSalt = new SecureRandom();
private static final SecureRandom secureRandomForIV = new SecureRandom();
private static byte[] generateSalt() throws RuntimeException {
try{
byte[] saltBytes = new byte[32];
secureRandomForSalt.nextBytes(saltBytes);
return saltBytes;
}
catch(Exception ex){
ex.printStackTrace();
throw new RuntimeException("An error occurred in salt generation part. Reason: " + ex.getMessage());
}
}
public static String enc(String content) throws RuntimeException {
String encClassMethodNameForLogging = Crypto.class.getName() + ".enc" + " || ";
byte[] salt;
byte[] encodedTmpSecretKey;
SecretKeySpec keySpec;
Cipher cipher;
byte[] iv;
IvParameterSpec ivParameterSpec;
String finalEncResult;
if(content == null || content.trim().length() == 0) {
throw new RuntimeException("To be encrypted text is null or empty");
}
System.out.println("-- Encrypting -----------");
try {
salt = generateSalt();
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in salt generation part. Reason: " + ex.getMessage());
}
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(Crypto.tempKey, salt, 65536, 256);
SecretKey tmpSecretKey = factory.generateSecret(spec);
encodedTmpSecretKey = tmpSecretKey.getEncoded();
System.out.println("-- Secret Key Derivation in Encryption: " + Base64.getEncoder().encodeToString(encodedTmpSecretKey));
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (InvalidKeySpecException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: Key length may not be correct");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage());
}
try {
keySpec = new SecretKeySpec(encodedTmpSecretKey, "Blowfish");
cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (NoSuchPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular padding mechanism is requested but is not available in the environment");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage());
}
try {
iv = new byte[cipher.getBlockSize()];
secureRandomForIV.nextBytes(iv);
ivParameterSpec = new IvParameterSpec(iv);
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in iv creation part. Reason: " + ex.getMessage());
}
try {
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
byte[] encoding = cipher.doFinal(content.getBytes("UTF-8"));
String encCon = DatatypeConverter.printBase64Binary(encoding);
String ivStr = DatatypeConverter.printBase64Binary(iv);
String saltStr = DatatypeConverter.printBase64Binary(salt);
System.out.println("-- encCon : " + encCon);
System.out.println("-- iv : " + ivStr);
System.out.println("-- salt : " + saltStr);
finalEncResult = encCon + ":" + ivStr + ":" + saltStr;
System.out.println("-- finalEncRes : " + finalEncResult + "\n");
}
catch (InvalidKeyException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: Most probably you didn't download and copy 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files'");
}
catch (InvalidAlgorithmParameterException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: IV length may not be correct");
}
catch (IllegalBlockSizeException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: The length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher");
}
catch (BadPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: A particular padding mechanism is expected for the input data but the data is not padded properly (Most probably wrong/corrupt key caused this)");
}
catch (UnsupportedEncodingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: The Character Encoding is not supported");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage());
}
return finalEncResult;
}
public static String dec(String encContent) throws RuntimeException {
String decClassMethodNameForLogging = Crypto.class.getName() + ".dec" + " || ";
String decCon;
byte[] salt;
byte[] encodedTmpSecretKey;
SecretKeySpec keySpec;
Cipher cipher;
byte[] iv;
if(encContent == null || encContent.trim().length() == 0) {
throw new RuntimeException("To be decrypted text is null or empty");
}
System.out.println("-- Decrypting -----------");
try {
salt = DatatypeConverter.parseBase64Binary(encContent.substring(encContent.lastIndexOf(":") + 1));
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in salt retrieving part. Reason: " + ex.getMessage());
}
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(Crypto.tempKey, salt, 65536, 256);
SecretKey tmpSecretKey = factory.generateSecret(spec);
encodedTmpSecretKey = tmpSecretKey.getEncoded();
System.out.println("-- Secret Key Gathering in Decryption: " + Base64.getEncoder().encodeToString(encodedTmpSecretKey));
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (InvalidKeySpecException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: Key length may not be correct");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage());
}
try {
keySpec = new SecretKeySpec(encodedTmpSecretKey, "Blowfish");
cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (NoSuchPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation : The particular padding mechanism requested is not available in the environment");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage());
}
try {
iv = DatatypeConverter.parseBase64Binary(encContent.substring(encContent.indexOf(":") + 1, encContent.lastIndexOf(":")));
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in iv creation part. Reason: " + ex.getMessage());
}
try {
cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv));
byte[] decoding = cipher.doFinal(Base64.getDecoder().decode(encContent.substring(0, encContent.indexOf(":"))));
decCon = new String(decoding, "UTF-8");
System.out.println("-- decCon : " + decCon + "\n");
}
catch (InvalidKeyException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: Most probably you didn't download and copy 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files'");
}
catch (InvalidAlgorithmParameterException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: IV length may not be correct");
}
catch (IllegalBlockSizeException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: The length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher");
}
catch (BadPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: A particular padding mechanism is expected for the input data but the data is not padded properly (Most probably wrong/corrupt key caused this)");
}
catch (UnsupportedEncodingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: The Character Encoding is not supported");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage());
}
return decCon;
}
public static void main(String args[]) {
System.out.println("-- Original -------------");
String plainText = "hello world";
System.out.println("-- origWord : " + plainText + "\n");
String e = Crypto.enc(plainText);
String d = Crypto.dec(e);
System.out.println("-- Results --------------");
System.out.println("-- PlainText: " + plainText);
System.out.println("-- EncryptedText: " + e);
System.out.println("-- DecryptedText: " + d);
}
}
此外，可執行版本在下面；
https://www.jdoodle.com/a/19HT
絕地無雙
TA貢獻1946條經驗 獲得超4個贊
將不同的輸出映射回同一輸入的唯一方法是向輸入添加額外的數據，并將其從解密的輸出中剝離。使用 PKCS5Padding 是不夠的，因為這不是隨機的，在最壞的情況下，只添加 1 個字節。使用 IV 沒有用，因為它需要在解密時知道。
最簡單的方法是在加密時添加一定數量的字節（例如等于塊大小）的隨機數據，而在解密時忽略這些字節。此隨機數據的名稱是 Number Used Once 中的“nonce”。（不要與密切相關的“鹽”混淆，后者是您保留以備后用的數字）。
順便說一句，我沒有讓這個與網站相匹配。我不知道網站是如何加密的，因為它將所有輸入值發送到服務器并顯示響應。談安全...
private static final SecureRandom SECURE_RANDOM = new SecureRandom();
public static String enc(String content, String key) {
String encCon = "";
try {
String IV = "12345678";
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
byte[] nonce = new byte[cipher.getBlockSize()];
SECURE_RANDOM.nextBytes(nonce);
// Construct plaintext = nonce + secret
byte[] secret = content.getBytes(StandardCharsets.UTF_8);
byte[] plaintext = new byte[nonce.length + secret.length];
System.arraycopy(nonce, 0, plaintext, 0, nonce.length);
System.arraycopy(secret, 0, plaintext, nonce.length, secret.length);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(IV.getBytes(StandardCharsets.UTF_8)));
byte[] encoding = cipher.doFinal(plaintext);
encCon = DatatypeConverter.printBase64Binary(encoding);
} catch (Exception ex) {
ex.printStackTrace();
}
return encCon;
}
public static String dec(String content, String key) {
String decCon = "";
try {
String IV = "12345678";
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
// Decode Base64
byte[] ciphertext = DatatypeConverter.parseBase64Binary(content);
// Decrypt
cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(IV.getBytes(StandardCharsets.UTF_8)));
byte[] message = cipher.doFinal(ciphertext);
decCon = new String(message,
cipher.getBlockSize(),
message.length - cipher.getBlockSize(),
StandardCharsets.UTF_8);
} catch (Exception ex) {
ex.printStackTrace();
}
return decCon;
}
附言。您知道將秘密存儲在字符串中是個壞主意嗎？字符串是最終的，因此內容不能被刪除。字節數組可以被擦除（為簡潔起見，本例中沒有這樣做）。您是否還知道您可以制作任何可以查看任何其他 Windows 程序的完整內存占用的 Windows 程序？
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