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Is DPAPI secure?
DPAPI security relies upon the Windows operating system’s ability to protect the Master Key and RSA private keys from compromise, which in most attack scenarios is most highly reliant on the security of the end user’s credentials. A main encryption/decryption key is derived from user’s password by PBKDF2 function.
What is DPAPI Master key?
Master Keys The DPAPI keys used for encrypting the user’s RSA keys are stored under %APPDATA%\Microsoft\Protect\{SID} directory, where {SID} is the Security Identifier of that user. The DPAPI key is stored in the same file as the master key that protects the users private keys. It usually is 64 bytes of random data.
What is Dpapi Backupkey?
Creation or Modification of Domain Backup DPAPI private keyedit. Identifies the creation or modification of Domain Backup private keys. Adversaries may extract the Data Protection API (DPAPI) domain backup key from a Domain Controller (DC) to be able to decrypt any domain user master key file.
Can a DPAPI be used without a password?
Yes, but it’s not quite as secure. DPAPI encrypts data with a master key, which is independent of the user password. When the user has a password, the master key is encrypted with the user’s password. Without a password, an attacker with local access (via another user account) might extract the master key.
When do I need to create a DPAPI master key?
When a user logs on to a computer for the first time and tries to encrypt data for the first time, the operating system must create a preferred DPAPI MasterKey, which is based on the user’s current password. During the creation of the DPAPI MasterKey, An attempt is made to back up this master key by contacting an RWDC.
What are the keys to the DPAPI blob?
This DPAPI blob is encrypted with the Master Key of the current windows user. There are two types of Master Keys: the ones unique for your device called the System Master Key and the ones unique to every user called the User Master Keys. In the PowerShell example above, replace CurrentUser with LocalMachine to use System Master Keys.
How does DPAPI work with a domain controller?
When a computer is a member of a domain, DPAPI has a backup mechanism to allow unprotection of the data. When a MasterKey is generated, DPAPI talks to a Domain Controller. Domain Controllers have a domain-wide public/private key pair, associated solely with DPAPI.