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(SQL Server) AES 256-bit CBC using PBKDF2 Generated Secret KeySee more Encryption ExamplesFirst generates a 32-byte secret key using PBKDF2 (with HMAC-SHA256), and then uses the secret key to do 256-bit AES CBC mode decryption.(Duplicates the following Java code)
public String decrypt(String strToDecrypt) {
try {
// Read the initialization vector from the first bytes for the data
byte [] rawData = Base64.getDecoder().decode(strToDecrypt);
byte [] iv = new byte[Config.get().encryptionIVLength()];
byte [] encryptedData = new byte[rawData.length - iv.length];
System.arraycopy(rawData, 0, iv, 0, iv.length);
System.arraycopy(rawData, iv.length, encryptedData, 0, encryptedData.length);
IvParameterSpec ivspec = new IvParameterSpec(iv);
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(secretKey.toCharArray(), salt.getBytes(), 65536, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKeySpec secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, secretKey, ivspec);
return new String(cipher.doFinal(encryptedData));
}
catch (Exception e) {
log.error("Could not decrypt the string.", e);
}
return null;
}
-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls. -- CREATE PROCEDURE ChilkatSample AS BEGIN DECLARE @hr int -- This example requires the Chilkat API to have been previously unlocked. -- See Global Unlock Sample for sample code. DECLARE @crypt int -- Use "Chilkat_9_5_0.Crypt2" for versions of Chilkat < 10.0.0 EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT IF @hr <> 0 BEGIN PRINT 'Failed to create ActiveX component' RETURN END DECLARE @password nvarchar(4000) SELECT @password = 'some arbitrary length password' -- We have 8 bytes of salt encoded using hex. -- (The salt can be any number of bytes, in any desired encoding such as base64, hex, etc.) DECLARE @saltHex nvarchar(4000) SELECT @saltHex = '0102030405060708' -- Generate the 256-bit (32-byte) AES secret key we'll use to decrypt. DECLARE @iterationCount int SELECT @iterationCount = 65536 DECLARE @outputKeyBitLen int SELECT @outputKeyBitLen = 256 DECLARE @secretKeyHex nvarchar(4000) EXEC sp_OAMethod @crypt, 'Pbkdf2', @secretKeyHex OUT, @password, 'utf-8', 'sha256', @saltHex, @iterationCount, @outputKeyBitLen, 'hex' -- Setup for 256-bit AES CBC decryption. EXEC sp_OASetProperty @crypt, 'CryptAlgorithm', 'aes' EXEC sp_OASetProperty @crypt, 'KeyLength', 256 EXEC sp_OASetProperty @crypt, 'CipherMode', 'cbc' EXEC sp_OASetProperty @crypt, 'PaddingScheme', 0 -- The IV for AES is 16 bytes. DECLARE @iv nvarchar(4000) SELECT @iv = '000102030405060708090A0B0C0D0E0F' EXEC sp_OAMethod @crypt, 'SetEncodedIV', NULL, @iv, 'hex' -- Set the secret key for 256-bit AES. EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, @secretKeyHex, 'hex' -- AES decrypt -- assume our string to decrypt is base64 DECLARE @strToDecrypt nvarchar(4000) SELECT @strToDecrypt = '....' EXEC sp_OASetProperty @crypt, 'EncodingMode', 'base64' DECLARE @decryptedStr nvarchar(4000) EXEC sp_OAMethod @crypt, 'DecryptStringENC', @decryptedStr OUT, @strToDecrypt PRINT @decryptedStr EXEC @hr = sp_OADestroy @crypt END GO |
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