(Visual FoxPro) Determine if a Zip is Encrypted or Password-Protected

Determins whether or not a zip archive is AES encrypted or password-protected.

Download Chilkat 32-bit Zip ActiveX (.msi) (includes objects for .zip, .gz, .bz2, and .Z)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

LOCAL loZip
LOCAL lnSuccess
LOCAL lnBPwdProt
LOCAL lnEncValue

loZip = CreateObject('Chilkat.Zip2')

*  Any string unlocks the component for the 1st 30-days.
lnSuccess = loZip.UnlockComponent("Anything for 30-day trial")
IF (lnSuccess <> 1) THEN
    ? loZip.LastErrorText
    QUIT
ENDIF

*  An encrypted or password-protected zip can be opened
*  without specifying the password.  However, the contents
*  of the files cannot be unzipped without providing the correct
*  password.

lnSuccess = loZip.OpenZip("something.zip")
IF (lnSuccess <> 1) THEN
    ? loZip.LastErrorText
    QUIT
ENDIF

*  If the zip is password-protected, meaning that it uses
*  the old (insecure) Zip 2.0 encryption, then the
*  PasswordProtect property will be 1

lnBPwdProt = loZip.PasswordProtect
IF (lnBPwdProt) THEN
    ? "This zip is password-protected."
ENDIF

*  If the zip is AES encrypted (WinZip compatible) then
*  the Encryption property will be equal to 4.

lnEncValue = loZip.Encryption
IF (lnEncValue = 4) THEN
    ? "This zip is AES encrypted."
ENDIF

*  If the Encryption property = 0, then the zip is NOT
*  strong encrypted, and is either password-protected or
*  entirely unencrypted, depending on the value of the
*  PasswordProtect property.

*  If the Encryption property = 1, 2, or 3, then the zip was
*  encrypted using AES, Blowfish, or Twofish using a
*  Chilkat-specific encryption format that was implemented
*  prior to the publication of the Zip AES standard.

loZip.CloseZip()