我正在尝试使用 AES 解密来解密 Base64Encoded String 消息。
加密消息(Base64Encoded 字符串):
tNC6umcfBS/gelbo2VJF3i4LAhUKMp4oDHWN5KyYUTWeJIQKKYx6oAcQnGncIrPJNC1tUYMKV4kJQj3q9voIorxc1n7FmRFvDXeRgWGNcGYO66dH3VjoEgF0oxZOpfzwSZKSv3Jm7Q==
密码(字符串) = "一些密码字符串"
解密消息的步骤:
a. Specs created with passphrase and IV as salt, 62233 as iteration count
b. Used PBKDF2WithHmacSHA256 to generate a secret factory because it's appropriate for turning passwords into keys.
c. This key is further encoded and converted to another key with AES encryption.
a. Used AES in GCM, GCM specs are prepared using tag size of 128 bits and the IV
b. Cipher object is initialized using AES/GCM/PKCS5Padding.
c. Based on operational mode the cipher is initialized with op mode(encryption), secret key and GCM params.
下面是用于解密输入消息的 JAVA 代码
public class Decryption {
private static final String KEY_GENERATING_ALGO = "PBKDF2WithHmacSHA256";
private static final String ENCRYPTION = "AES";
private static final String TRANSFORMATION_ALGORITHM= "AES/GCM/PKCS5Padding";
private static final int KEY_SIZE_BITS = 256;
private static final int TAG_SIZE_BITS = 128;
private static final int ITERATION_COUNT = 62233;
// Use following sample data to test the decryption-
//tNC6umcfBS/gelbo2VJF3i4LAhUKMp4oDHWN5KyYUTWeJIQKKYx6oAcQnGncIrPJNC1tUYMKV4kJQj3q9voIOrxc1n7FmRFvDXeRgWGNcGYO66dH3VjoEgF0oxZOpfzwSZKSv3Jm7Q==
// This key has is base 64 encoded with IV prepended with encrypted text
public Cipher initCipher(int encryptMode, String password, byte[] iv) throws InvalidKeySpecException {
try {
GCMParameterSpec gcmparams = new GCMParameterSpec(TAG_SIZE_BITS, iv);
PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), iv, ITERATION_COUNT, KEY_SIZE_BITS);
SecretKeyFactory factory = SecretKeyFactory.getInstance(KEY_GENERATING_ALGO);
SecretKey pbeKey = factory.generateSecret(pbeKeySpec);
byte[] keyBytes = pbeKey.getEncoded();
SecretKey key = new SecretKeySpec(keyBytes, ENCRYPTION);
Cipher cipher = Cipher.getInstance(TRANSFORMATION_ALGORITHM);
cipher.init(encryptMode, key, gcmparams);
return cipher;
} catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
| InvalidAlgorithmParameterException | InvalidKeySpecException ex) {
throw new AssertionError(ex);
}
}
//Decryption Algo
public String decrypt(String encrypted){
byte[] decFeeder = Base64.getDecoder().decode(encrypted);
String key = "someKey"; // A new key will be provided by APIF through a secure channel
char[] password = key.toCharArray();
try {
byte[] iv = Arrays.copyOfRange(decFeeder, 0, 32);
byte[] ciphertext = Arrays.copyOfRange(decFeeder, iv.length, decFeeder.length);
Cipher cipher = initCipher(Cipher.DECRYPT_MODE, key, iv);
byte[] message = cipher.doFinal(ciphertext);
String decrypted = new String(message);
return decrypted;
} catch (IllegalBlockSizeException | BadPaddingException | InvalidKeySpecException ex) {
throw new AssertionError(ex);
}
}
}
我在 Swift 中使用下面的代码来生成与上面的 JAVA 代码相同的代码,但是我无法解密消息/密文。 func aesDecrypt(encryptedData: Data, password: String) -> Data? {
let iv = Array([UInt8](encryptedData)[0 ..< 33])
let ivData = Data(iv)
let encryptedCipher = [UInt8](encryptedData)[iv.count ..< encryptedData.count]
let encryptedCipherData = Data(encryptedCipher)
let passwordKey = createKey(password:Data(password.utf8) , salt: ivData)
var decryptSuccess = false
let size = (encryptedCipher.count) + kCCBlockSizeAES128
var clearTextData = Data.init(count: size)
var numberOfBytesDecrypted : size_t = 0
let cryptStatus = ivData.withUnsafeBytes {ivBytes in
clearTextData.withUnsafeMutableBytes {clearTextBytes in
encryptedCipherData.withUnsafeBytes {encryptedBytes in
passwordKey.withUnsafeBytes {keyBytes in
CCCrypt(CCOperation(kCCDecrypt),
CCAlgorithm(kCCAlgorithmAES128),
CCOptions(kCCOptionPKCS7Padding),
keyBytes,
passwordKey.count,
ivBytes,
encryptedBytes,
(encryptedCipher.count),
clearTextBytes,
size,
&numberOfBytesDecrypted)
}
}
}
}
if cryptStatus == Int32(kCCSuccess)
{
clearTextData.count = numberOfBytesDecrypted
debugPrint(clearTextData)
decryptSuccess = true
}
return decryptSuccess ? clearTextData : Data.init(count: 0)
}
func createKey(password: Data, salt: Data) -> Data? {
let length = kCCKeySizeAES256
var status = Int32(0)
var derivedBytes = [UInt8](repeating: 0, count: length)
password.withUnsafeBytes { (passwordBytes: UnsafePointer<Int8>!) in
salt.withUnsafeBytes { (saltBytes: UnsafePointer<UInt8>!) in
status = CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2), // algorithm
passwordBytes, // password
password.count, // passwordLen
saltBytes, // salt
salt.count, // saltLen
UInt32(kCCPRFHmacAlgSHA256), // prf
UInt32(62233), // rounds
&derivedBytes, // derivedKey
length) // derivedKeyLen
}
}
guard status == 0 else {
return nil
}
return Data(bytes: UnsafePointer<UInt8>(derivedBytes), count: length)
}
用法: guard let encryptedData = Data(base64Encoded: input) else{
return nil
}
let decryptData = aesDecrypt3(encryptedData: encryptedData)
let decryptedMessage = String(data: decryptData, encoding: .utf8) ?? "Unable to Decrypt"
任何线索将不胜感激,我想知道在尝试快速转换时是否缺少一些配置或数据转换。
最佳答案
我能够使用“CryptoSwift”框架解密输入,想知道我们是否可以使用苹果 iOS 来解决这个问题通用加密 框架。
任何使用“CommonCrypto”的线索将不胜感激
class func decryptCode123(_ cipher:String)-> String{
let key = "SOMEKEY"
var keyBytes: [UInt8] = []
var codeBytes: [UInt8] = []
var code = ""
if let keyData = NSData(base64Encoded:key, options: .ignoreUnknownCharacters) {
keyBytes = [UInt8](keyData as Data)
}
if let codeData = NSData(base64Encoded: cipher, options: .ignoreUnknownCharacters) {
codeBytes = [UInt8](codeData as Data)
}
debugPrint(codeBytes)
let codeBytescount = [UInt8](codeBytes).count
let iv = Array([UInt8](codeBytes)[0 ..< 32])
let cipher = Array([UInt8](codeBytes)[iv.count ..< codeBytescount])
do{
let gcm = GCM(iv: iv, mode: .combined)
let derKey = createKey(password:Data(key.utf8), salt: Data(iv))!
keyBytes = [UInt8](derKey)
let aes = try AES(key: keyBytes, blockMode: gcm, padding: .pkcs5)
print("aes created")
let decrypted = try aes.decrypt(cipher)
print("decrypted completed")
if let decryptedString = String(bytes: decrypted, encoding: .utf8) {
code = decryptedString
}
debugPrint(code)
}catch let error as AES.Error {
debugPrint(error.localizedDescription)
return code
} catch {
return code
}
return code
}
关于ios - 解密 AES/GCM/PKCS5Padding iOS Swift,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/62586164/