Steam Guard

Steam Guard is the Two-Factor authentication system you can enable to protect your Steam account. It works exactly as any 2FA protection, except that the One-Time Passwords are generated by the Steam Guard Mobile Authenticator only (or received by e-mail).

As Steam does not provide a standard way to use an alternative OTP app like 2FAuth, the workaround is to get the OTP secret thanks to a third-party app. Once recovered, you will be able to use 2FAuth in place of the Steam Mobile Authenticator.

Getting the Steam secret

Steam Desktop Authenticator (SDA)

If your SDA data are encrypted, you need to (temporarily) disable encryption in order to read the secret:

Get the secret:

• Open your SDA installation directory
• In the ./maFiles subdirectory, open the file *.maFile
• The secret is the string surrounded by secret= and &issuer=Steam in the uri field value

Example

In the following fake .maFile, the secret is D5RTFGT8Z7SW4DYU6I9UH5F4RRE1DF4G

{
    "shared_secret": "KDHC3rsY8+CmiswnXJcE5e5dRfd=",
    "serial_number": "15286247589885632548",
    "revocation_code": "R52287",
    "uri": "otpauth://totp/Steam:johndoe?secret=D5RTFGT8Z7SW4DYU6I9UH5F4RRE1DF4G&issuer=Steam",
    "server_time": 1656059488,
    "account_name": "johndoe",
    "token_gid": "2d5ff8e7zs448e9f",
    "identity_secret": "W~,7%&cXs<8tY&nG=If81zEdrtc=",
    "secret_1": "$=}5NSF@c8o,tjh1zz2=",
    "status": 1,
    "device_id": "android:3dfe0914-d41f-426c-9ba4-b344e563a394",
    "fully_enrolled": true,
    "Session":{...}
}

steamguard-cli

• Open your steamguard-cli config directory, usually ~/.config/steamguard-cli/
• In the ./maFiles subdirectory, open the file *.maFile
• The secret is the string surrounded by secret= and &issuer=Steam in the uri field value

{
    ...
    "uri": "otpauth://totp/Steam:johndoe?secret=D5RTFGT8Z7SW4DYU6I9UH5F4RRE1DF4G&issuer=Steam",
    ...
}

Adding to 2FAuth

The manual way

Now that you got your steam secret, simply create a new account in 2FAuth using the advanced form:

• Click the New button
• Click the Use the advanced form button
• Fill the form:
  • Fill in the Account field
  • Click the STEAM button
  • Fill in the Secret field with your Steam secret
• Click the Create button to save the account

QR code also works

If you feel more confortable with QR codes, you can generate a QR code from the entire uri field of the *.maFile :

otpauth://totp/Steam:johndoe?secret={YourSecretHere}&issuer=Steam

Then flash (or upload) the QR code to add the account to 2FAuth, just like any other QR code.