加密代碼
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/**解密
* @param content 待解密內容
* @param password 解密密鑰
* @return
*/
public
static
byte
[] decrypt(
byte
[] content, String password) {
try
{
KeyGenerator kgen = KeyGenerator.getInstance(
"AES"
);
kgen.init(
128
,
new
SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte
[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key =
new
SecretKeySpec(enCodeFormat,
"AES"
);
Cipher cipher = Cipher.getInstance(
"AES"
);
// 建立密碼器
cipher.init(Cipher.DECRYPT_MODE, key);
// 初始化
byte
[] result = cipher.doFinal(content);
return
result;
// 加密
}
catch
(NoSuchAlgorithmException e) {
e.printStackTrace();
}
catch
(NoSuchPaddingException e) {
e.printStackTrace();
}
catch
(InvalidKeyException e) {
e.printStackTrace();
}
catch
(IllegalBlockSizeException e) {
e.printStackTrace();
}
catch
(BadPaddingException e) {
e.printStackTrace();
}
return
null
;
}
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解密代碼
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/**解密
* @param content 待解密內容
* @param password 解密密鑰
* @return
*/
public
static
byte
[] decrypt(
byte
[] content, String password) {
try
{
KeyGenerator kgen = KeyGenerator.getInstance(
"AES"
);
kgen.init(
128
,
new
SecureRandom(password.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte
[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key =
new
SecretKeySpec(enCodeFormat,
"AES"
);
Cipher cipher = Cipher.getInstance(
"AES"
);
// 建立密碼器
cipher.init(Cipher.DECRYPT_MODE, key);
// 初始化
byte
[] result = cipher.doFinal(content);
return
result;
// 加密
}
catch
(NoSuchAlgorithmException e) {
e.printStackTrace();
}
catch
(NoSuchPaddingException e) {
e.printStackTrace();
}
catch
(InvalidKeyException e) {
e.printStackTrace();
}
catch
(IllegalBlockSizeException e) {
e.printStackTrace();
}
catch
(BadPaddingException e) {
e.printStackTrace();
}
return
null
;
}
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解密代碼
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String content =
"test"
;
String password =
"12345678"
;
//加密
System.out.println(
"加密前："
+ content);
byte
[] encryptResult = encrypt(content, password);
try
{
String encryptResultStr =
new
String(encryptResult,
"utf-8"
);
//解密
byte
[] decryptResult = decrypt(encryptResultStr.getBytes(
"utf-8"
),password);
System.out.println(
"解密後："
+
new
String(decryptResult));
}
catch
(UnsupportedEncodingException e) {
e.printStackTrace();
}
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偶爾會報錯 拋出異常，java
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
緣由 加密後的byte數組是不能強制轉換成字符串的，換言之：字符串和byte數組在這種狀況下不是互逆的；要避免這種狀況，咱們須要作一些修訂，能夠考慮將二進制數據轉換成十六進制表示
解決方案
二進制轉換成16進制
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/**將16進制轉換爲二進制
* @param hexStr
* @return
*/
public
static
byte
[] parseHexStr2Byte(String hexStr) {
if
(hexStr.length() <
1
)
return
null
;
byte
[] result =
new
byte
[hexStr.length()/
2
];
for
(
int
i =
0
;i< hexStr.length()/
2
; i++) {
int
high = Integer.parseInt(hexStr.substring(i*
2
, i*
2
+
1
),
16
);
int
low = Integer.parseInt(hexStr.substring(i*
2
+
1
, i*
2
+
2
),
16
);
result[i] = (
byte
) (high *
16
+ low);
}
return
result;
}
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16進制轉換爲二進制
測試結果，問題解決數組
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String content =
"test"
;
String password =
"12345678"
;
//加密
System.out.println(
"加密前："
+ content);
byte
[] encryptResult = encrypt(content, password);
String encryptResultStr = parseByte2HexStr(encryptResult);
System.out.println(
"加密後："
+ encryptResultStr);
//解密
byte
[] decryptFrom = parseHexStr2Byte(encryptResultStr);
byte
[] decryptResult = decrypt(decryptFrom,password);
System.out.println(
"解密後："
+
new
String(decryptResult));
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測試結果以下：
加密前：test
加密後：73C58BAFE578C59366D8C995CD0B9D6D
解密後：test
加密後：73C58BAFE578C59366D8C995CD0B9D6D
解密後：test