C#的DES加密出来结果不对，求解

在oracle中有个DES加密函数，现在需要将它改写到C#，但写完以后测试发现同样的文本和密钥，加密出来的结果不一样，怎么都找不到问题。后来到网上找了一个在线DES加密的工具，加出来又是另外一个结果。到底是哪里出了问题呢？

附Oracle加密代码

create or replace function
encrypt_des(p_text varchar2, p_key varchar2) return varchar2 is
v_text varchar2(4000);
v_enc varchar2(4000);
raw_input RAW(128) ;
key_input RAW(128) ;
decrypted_raw RAW(2048);
decrypted_string varchar2(4000);

begin
v_text := rpad( p_text, (trunc(length(p_text)/8)+1)*8, chr(0));
raw_input := UTL_RAW.CAST_TO_RAW(v_text);
key_input := UTL_RAW.CAST_TO_RAW(p_key);
dbms_obfuscation_toolkit.DESEncrypt(input => raw_input,key => key_input,encrypted_data =>decrypted_raw);
v_enc := rawtohex(decrypted_raw);
dbms_output.put_line(v_enc);
return v_enc;
end;


附C#加密代码

byte[] rgbKey = Encoding.ASCII.GetBytes("aaaaaaaa".Substring(0, 8));
byte[] rgbIV = Encoding.ASCII.GetBytes("aaaaaaaa".Substring(0, 8));
byte[] inputByteArray = Encoding.UTF8.GetBytes("9804ff20-4429-42ed-87a7-d6794d607e4b");
DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
dCSP.Mode = CipherMode.ECB;
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey,
rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
StringBuilder builder = new StringBuilder();
foreach (byte num in mStream.ToArray())
{
builder.AppendFormat("{0:X2}", num);
}
mStream.Close();
var result= builder.ToString();

Oracle加密结果：
select encrypt_des('9804ff20-4429-42ed-87a7-d6794d607e4b','aaaaaaaa') from dual
29B63290034C40DA4108122EE2EA1CF7C07FC2A9FCE4D5A2B1F7613508D813F897FC0503C4518397
C#加密结果：
29B63290034C40DA38FEFE37F13F8B0BAFE2FC3A4A9200931AF43A2593CC7536A04BC9280C24914C