尝试从Oracle加密功能读取DES3加密值

Question

I am working with legacy system which already has oracle function for encryption and decryption and I am using ODP.net in C# to communicate with Oracle DB.

I have to encrypt value using oracle encrypt function which is using DES3 encryption algorithm in Oracle and use this encrypted value to read data from Oracle database.
I can call the Oracle function and it encrypts but its returning encrypted text with bunch of rectangles which are characters unable to covert so when I use this encrypted value to read data from the Oracle database, its not working meaning returning nothing.

My question is, How do I properly read the encrypted text from the Oracle encrypt function basically how can I use this returned encrypted text to read data from the oracle database? This oracle encrypt function takes one input parameter to be encrypted and spit out the encrypted value. Any ideas would be helpful in any language, C# would be great.

Thank you so much in advance. God Bless You! R

Answer 1

I'm not quite clear.

I presume you have data in Oracle that is encrypted. You want to pull that data from the table, then use the Oracle function to decrypt it.

When you encrypt data you generally want to store is a RAW or BLOB because it is no longer a string and you don't want any string like character set conversion to happen on it (eg removing accents from characters). An alternative to RAW/BLOB storage is converting the bytes to a hexadecimal representation, but that wastes a lot of storage so I wouldn't recommend it.

So the first step is to determine whether the Oracle data is stored as RAW/BLOB, HEX or whether they've used a VARCHAR2 and have used the same characterset throughout to avoid any conversion issues. If the latter, determine the database character set (the DBA should be able to get this from v$nls_parameters, if he doesn't know it off hand).

Basically you need to ensure that exactly the same bytes are pushed into the decryption algorithm as were pulled from the database. Depending on the architecture you may be able to simply do a

SELECT decrypt(encrypted_column,:key_variable) FROM table WHERE id = ....;

Answer 2

Does the Oracle function use string data types? If so, you need to use the same encoding in your C# application (I don't know how though) and convert the string to bytes.