Delphi与Java的AES加密实现有何差异？-杰瑞科技汇

Of course. This is a very common and important task for developers working with mixed-language systems. The core challenge is ensuring that both the Delphi and Java implementations use the exact same parameters for the AES algorithm.

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Here is a complete, step-by-step guide with code for both Delphi and Java to perform AES encryption and decryption that are fully compatible.

The Golden Rule: Consistency is Key

For Delphi and Java AES to work together, they must agree on every single parameter. The most common cause of failure is a mismatch in one of these areas:

Key Size: 128-bit, 192-bit, or 256-bit (e.g., 16, 24, or 32 bytes).
Initialization Vector (IV) Size: Typically 16 bytes for AES in CBC or GCM mode.
Cipher Mode: AES has several modes like CBC, CTR, GCM, etc. We will use CBC for this example as it's widely used.
Padding Scheme: Data must be padded to a multiple of the block size (16 bytes). PKCS#7 is the standard.
Key and IV Generation: The secret key and IV must be generated or derived in the exact same way on both sides.
Encoding: The resulting encrypted byte array must be converted to a string format that is safe for transport (e.g., Base64). Both sides must use the same encoding (e.g., UTF-8) for this conversion.

Step 1: Choose a Key and IV

For this example, we will use a hardcoded key and IV. In a real application, you should never hardcode secrets. Instead, generate them securely and store them safely (e.g., in a secure configuration store, a key management service, or derived from a user password using a strong Key Derivation Function like PBKDF2).

// Delphi
const
  // Key: 256-bit (32 bytes)
  SECRET_KEY = 'ThisIsASecretKeyForAES256'; // 32 characters
  // IV: 128-bit (16 bytes)
  INIT_VECTOR = 'RandomInitVector123';      // 16 characters

// Java
public static final String SECRET_KEY = "ThisIsASecretKeyForAES256"; // 32 chars = 256 bits
public static final String INIT_VECTOR = "RandomInitVector123";      // 16 chars = 128 bits

Step 2: Delphi Implementation (using `System.Generics.Collections`, `System.SysUtils`, `System.Classes`)

Modern Delphi (XE and later) has built-in support for AES in the System.Hash unit. We will use the TEncryption class.

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Delphi Unit (`uAes.pas`)

unit uAes;
interface
uses
  System.SysUtils, System.Classes, System.Hash, System.Generics.Collections;
type
  TAES = class
  public
    class function Encrypt(const AData, AKey, AIV: string): string;
    class function Decrypt(const AData, AKey, AIV: string): string;
  end;
implementation
{ TAES }
class function TAES.Encrypt(const AData, AKey, AIV: string): string;
var
  LKey, LIV: TBytes;
  LInput: TBytes;
  LOutput: TBytes;
begin
  // Convert strings to byte arrays using UTF-8 encoding
  LKey := TEncoding.UTF8.GetBytes(AKey);
  LIV := TEncoding.UTF8.GetBytes(AIV);
  LInput := TEncoding.UTF8.GetBytes(AData);
  // Use the TEncryption class for AES encryption
  // It automatically handles PKCS#7 padding
  LOutput := TEncryption.Encrypt(LInput, LKey, LIV, TAlgorithm.AES256);
  // Convert the encrypted bytes to a Base64 string for safe transport
  Result := TEncoding.Base64String.Encode(LOutput);
end;
class function TAES.Decrypt(const AData, AKey, AIV: string): string;
var
  LKey, LIV: TBytes;
  LInput: TBytes;
  LOutput: TBytes;
begin
  // Convert Base64 string back to byte array
  LInput := TEncoding.Base64String.Decode(AData);
  // Convert key and IV strings to byte arrays
  LKey := TEncoding.UTF8.GetBytes(AKey);
  LIV := TEncoding.UTF8.GetBytes(AIV);
  // Use the TEncryption class for AES decryption
  // It automatically removes PKCS#7 padding
  LOutput := TEncryption.Decrypt(LInput, LKey, LIV, TAlgorithm.AES256);
  // Convert the decrypted bytes back to a string
  Result := TEncoding.UTF8.GetString(LOutput);
end;
end.

Step 3: Java Implementation (using Java Cryptography Architecture - JCA)

Java's standard library has robust support for cryptography. We will use Cipher, SecretKeySpec, and IvParameterSpec.

Java Class (`Aes.java`)

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
public class Aes {
    // The key and IV must be exactly the same as in Delphi
    private static final String SECRET_KEY = "ThisIsASecretKeyForAES256";
    private static final String INIT_VECTOR = "RandomInitVector123";
    public static String encrypt(String value) {
        try {
            // 1. Create Key and IV from the strings
            IvParameterSpec iv = new IvParameterSpec(INIT_VECTOR.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(SECRET_KEY.getBytes("UTF-8"), "AES");
            // 2. Initialize Cipher for encryption
            // "AES/CBC/PKCS5Padding" is the standard transformation string
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
            // 3. Encrypt the data
            byte[] encrypted = cipher.doFinal(value.getBytes());
            // 4. Encode the bytes to Base64
            return Base64.getEncoder().encodeToString(encrypted);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }
    public static String decrypt(String encrypted) {
        try {
            // 1. Create Key and IV
            IvParameterSpec iv = new IvParameterSpec(INIT_VECTOR.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(SECRET_KEY.getBytes("UTF-8"), "AES");
            // 2. Initialize Cipher for decryption
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
            // 3. Decode the Base64 string to bytes
            byte[] original = cipher.doFinal(Base64.getDecoder().decode(encrypted));
            // 4. Convert bytes back to string
            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }
    public static void main(String[] args) {
        String originalString = "This is a secret message from Delphi/Java!";
        // --- Test from Java perspective ---
        System.out.println("Original: " + originalString);
        String encrypted = encrypt(originalString);
        System.out.println("Encrypted: " + encrypted);
        String decrypted = decrypt(encrypted);
        System.out.println("Decrypted: " + decrypted);
        System.out.println("---------------------------------");
        // --- Test the string that Delphi would produce ---
        // Use the Delphi code to get this string, then paste it here to test
        String delphiEncryptedString = "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