我在java代码中有一个使用tripleDes和MD5的算法。有我的java代码：
private String _encrypt(String message, String secretKey) throws Exception {
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] digestOfPassword = md.digest(secretKey.getBytes("utf-8"));
byte[] keyBytes = Arrays.copyOf(digestOfPassword, 16);
SecretKey key = new SecretKeySpec(keyBytes, "DESede/ECB/PKCS7Padding");
Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS7Padding");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] plainTextBytes = message.getBytes("utf-8");
byte[] buf = cipher.doFinal(plainTextBytes);
byte [] base64Bytes = Base64.encodeBase64(buf);
String base64EncryptedString = new String(base64Bytes);
return base64EncryptedString;
}
我想在swift中使用tripleDes和MD5，我将这个java代码转换为swift但是swift中存在一个问题因为在java中使用16字节而swift使用24字节。如何解决java和swift编码之间的这种差异？ 有我的快捷代码：
func myEncrypt(encryptData:String) -> String?{
let myKeyData : NSData = ("Fanava@Wrapper!1395" as NSString).data(using: String.Encoding.utf8.rawValue)! as NSData
let myRawData : NSData = encryptData.data(using: String.Encoding.utf8)! as NSData
let mykeydatamd5 = Data(bytes: myKeyData.bytes, count: 24) // this key convert to 24 bytes but does not hash to md5
let mykeydatamd5 = Data(bytes: myKeyData.md5().bytes, count: 24) // this line converted key to md5(), 24byte, but it
let buffer_size : size_t = myRawData.length + kCCBlockSize3DES
let buffer = UnsafeMutablePointer<NSData>.allocate(capacity: buffer_size)
var num_bytes_encrypted : size_t = 0
let operation: CCOperation = UInt32(kCCEncrypt)
let algoritm: CCAlgorithm = UInt32(kCCAlgorithm3DES)
let options: CCOptions = UInt32(kCCOptionECBMode | kCCOptionPKCS7Padding)
let keyLength = size_t(kCCKeySize3DES)
let Crypto_status: CCCryptorStatus = CCCrypt(operation, algoritm, options, mykeydatamd5.bytes , keyLength, nil, myRawData.bytes, myRawData.count, buffer, buffer_size, &num_bytes_encrypted)
if UInt32(Crypto_status) == UInt32(kCCSuccess){
let myResult: NSData = NSData(bytes: buffer, length: num_bytes_encrypted)
free(buffer)
return myResult.base64EncodedString(options: [])
}else{
free(buffer)
return nil
}
}
答案 0 :(得分：0)
以下是可以轻松修改TrippleDES的示例代码：
来自子集化的SO文档部分
对于CBC模式下的AES加密，使用随机IV（Swift 3 +）
iv以加密数据为前缀
aesCBC128Encrypt将创建一个随机IV，并以加密代码为前缀
aesCBC128Decrypt将在解密期间使用带前缀的IV。
输入是数据，键是数据对象。如果需要的编码形式（如Base64）在调用方法中转换为和/或来自
密钥长度应为128位（16字节），192位（24字节）或256位（32字节）。如果使用其他密钥大小，则会抛出错误。
PKCS#7 padding默认设置。
此示例需要Common Crypto
项目必须有一个桥接标题：
#import <CommonCrypto/CommonCrypto.h>
将Security.framework添加到项目中。
这是示例，而非生产代码。
enum AESError: Error {
case KeyError((String, Int))
case IVError((String, Int))
case CryptorError((String, Int))
}
// The iv is prefixed to the encrypted data
func aesCBCEncrypt(data:Data, keyData:Data) throws -> Data {
let keyLength = keyData.count
let validKeyLengths = [kCCKeySizeAES128, kCCKeySizeAES192, kCCKeySizeAES256]
if (validKeyLengths.contains(keyLength) == false) {
throw AESError.KeyError(("Invalid key length", keyLength))
}
let ivSize = kCCBlockSizeAES128;
let cryptLength = size_t(ivSize + data.count + kCCBlockSizeAES128)
var cryptData = Data(count:cryptLength)
let status = cryptData.withUnsafeMutableBytes {ivBytes in
SecRandomCopyBytes(kSecRandomDefault, kCCBlockSizeAES128, ivBytes)
}
if (status != 0) {
throw AESError.IVError(("IV generation failed", Int(status)))
}
var numBytesEncrypted :size_t = 0
let options = CCOptions(kCCOptionPKCS7Padding)
let cryptStatus = cryptData.withUnsafeMutableBytes {cryptBytes in
data.withUnsafeBytes {dataBytes in
keyData.withUnsafeBytes {keyBytes in
CCCrypt(CCOperation(kCCEncrypt),
CCAlgorithm(kCCAlgorithmAES),
options,
keyBytes, keyLength,
cryptBytes,
dataBytes, data.count,
cryptBytes+kCCBlockSizeAES128, cryptLength,
&numBytesEncrypted)
}
}
}
if UInt32(cryptStatus) == UInt32(kCCSuccess) {
cryptData.count = numBytesEncrypted + ivSize
}
else {
throw AESError.CryptorError(("Encryption failed", Int(cryptStatus)))
}
return cryptData;
}
// The iv is prefixed to the encrypted data
func aesCBCDecrypt(data:Data, keyData:Data) throws -> Data? {
let keyLength = keyData.count
let validKeyLengths = [kCCKeySizeAES128, kCCKeySizeAES192, kCCKeySizeAES256]
if (validKeyLengths.contains(keyLength) == false) {
throw AESError.KeyError(("Invalid key length", keyLength))
}
let ivSize = kCCBlockSizeAES128;
let clearLength = size_t(data.count - ivSize)
var clearData = Data(count:clearLength)
var numBytesDecrypted :size_t = 0
let options = CCOptions(kCCOptionPKCS7Padding)
let cryptStatus = clearData.withUnsafeMutableBytes {cryptBytes in
data.withUnsafeBytes {dataBytes in
keyData.withUnsafeBytes {keyBytes in
CCCrypt(CCOperation(kCCDecrypt),
CCAlgorithm(kCCAlgorithmAES128),
options,
keyBytes, keyLength,
dataBytes,
dataBytes+kCCBlockSizeAES128, clearLength,
cryptBytes, clearLength,
&numBytesDecrypted)
}
}
}
if UInt32(cryptStatus) == UInt32(kCCSuccess) {
clearData.count = numBytesDecrypted
}
else {
throw AESError.CryptorError(("Decryption failed", Int(cryptStatus)))
}
return clearData;
}
使用示例：
let clearData = "clearData0123456".data(using:String.Encoding.utf8)!
let keyData = "keyData890123456".data(using:String.Encoding.utf8)!
print("clearData: \(clearData as NSData)")
print("keyData: \(keyData as NSData)")
var cryptData :Data?
do {
cryptData = try aesCBCEncrypt(data:clearData, keyData:keyData)
print("cryptData: \(cryptData! as NSData)")
}
catch (let status) {
print("Error aesCBCEncrypt: \(status)")
}
let decryptData :Data?
do {
let decryptData = try aesCBCDecrypt(data:cryptData!, keyData:keyData)
print("decryptData: \(decryptData! as NSData)")
}
catch (let status) {
print("Error aesCBCDecrypt: \(status)")
}
示例输出：
clearData: <636c6561 72446174 61303132 33343536>
keyData: <6b657944 61746138 39303132 33343536>
cryptData: <92c57393 f454d959 5a4d158f 6e1cd3e7 77986ee9 b2970f49 2bafcf1a 8ee9d51a bde49c31 d7780256 71837a61 60fa4be0>
decryptData: <636c6561 72446174 61303132 33343536>
注意：
CBC模式示例代码的一个典型问题是它将随机IV的创建和共享留给用户。此示例包括生成IV，加密数据前缀并在解密期间使用前缀IV。这使临时用户免于CBC mode所需的详细信息。
为了安全起见，加密数据也应该具有身份验证，这个示例代码不会提供这样的代码，因为它很小并且可以为其他平台提供更好的互操作性。
同样缺少密钥的密钥派生密钥，建议使用PBKDF2文本密码作为密钥材料使用。
对于强大的生产就绪的多平台加密代码，请参阅RNCryptor。
如果你必须为3DES修改这个功能。
对于PBKDF2加密**基于密码的密钥派生2（Swift 3 +）
基于密码的密钥派生既可用于从密码文本中导出加密密钥，也可用于保存密码以进行身份验证。
可以使用几种哈希算法，包括SHA1，SHA256，SHA512，这些算法由此示例代码提供。
rounds参数用于使计算变慢，以便攻击者必须在每次尝试上花费大量时间。典型的延迟值在100ms到500ms之间，如果有不可接受的性能，可以使用更短的值。
此示例需要Common Crypto
项目必须有一个桥接标题：
#import <CommonCrypto/CommonCrypto.h>
将Security.framework添加到项目中。
参数：
password password String
salt salt Data
keyByteCount number of key bytes to generate
rounds Iteration rounds
returns Derived key
func pbkdf2SHA1(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA1), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}
func pbkdf2SHA256(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA256), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}
func pbkdf2SHA512(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA512), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}
func pbkdf2(hash :CCPBKDFAlgorithm, password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
let passwordData = password.data(using:String.Encoding.utf8)!
var derivedKeyData = Data(repeating:0, count:keyByteCount)
let derivationStatus = derivedKeyData.withUnsafeMutableBytes {derivedKeyBytes in
salt.withUnsafeBytes { saltBytes in
CCKeyDerivationPBKDF(
CCPBKDFAlgorithm(kCCPBKDF2),
password, passwordData.count,
saltBytes, salt.count,
hash,
UInt32(rounds),
derivedKeyBytes, derivedKeyData.count)
}
}
if (derivationStatus != 0) {
print("Error: \(derivationStatus)")
return nil;
}
return derivedKeyData
}
使用示例：
let password = "password"
//let salt = "saltData".data(using: String.Encoding.utf8)!
let salt = Data(bytes: [0x73, 0x61, 0x6c, 0x74, 0x44, 0x61, 0x74, 0x61])
let keyByteCount = 16
let rounds = 100000
let derivedKey = pbkdf2SHA1(password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
print("derivedKey (SHA1): \(derivedKey! as NSData)")
示例输出：
derivedKey (SHA1): <6b9d4fa3 0385d128 f6d196ee 3f1d6dbf>