MSSQLDecryptor

small and simple decryptor for encrypted objects in Microsoft SQL Server

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Usage instructions:

• Find the DAC port in your server (usually 1434).
• If connecting from a remote machine enable remote DAC connections with: sp_configure 'remote admin connections', 1
• Download the latest release or build it yourself.
• Run the program and give it the object name as an argument

you can run the program with -help flag to get more information about the flags

Usage examples:

# to decrypt dbo.EncryptionTest from 172.20.0.2:1434 and login with dbadmin
./MSSQLDecryptor -host 172.20.0.2 -username dbadmin -dacport 1434 -database Playground dbo.EncryptionTest
# for SQL Server 2008
./MSSQLDecryptor -host 172.20.0.2 -username dbadmin -dacport 1434 -database Playground -disable-encryption dbo.EncryptionTest

How it works:

First it tries to get the encrypted object data from sys.sysobjvalues (we need a DAC connection to access this). The objects are encrypted using the RC4 algorithm and the encryption key is derived from SHA1 hash of database family guid + object id + sub object id and the decrypted source code is stored as UTF16LE.

Build instructions:

Prerequisites:

• Golang

Build commands:

git clone https://github.com/er-azh/MSSQLDecryptor
cd MSSQLDecryptor
go mod tidy
go build .

you can also install it from source code with go install github.com/er-azh/MSSQLDecryptor@latest.