pdfencrypt.py 文件源码

def __init__(self, userPassword, ownerPassword=None, canPrint=1, canModify=1, canCopy=1, canAnnotate=1, strength=40):
        '''
        This class defines the encryption properties to be used while creating a pdf document.
        Once initiated, a StandardEncryption object can be applied to a Canvas or a BaseDocTemplate.
        The userPassword parameter sets the user password on the encrypted pdf.
        The ownerPassword parameter sets the owner password on the encrypted pdf.
        The boolean flags canPrint, canModify, canCopy, canAnnotate determine wether a user can
        perform the corresponding actions on the pdf when only a user password has been supplied.
        If the user supplies the owner password while opening the pdf, all actions can be performed regardless
        of the flags.
        Note that the security provided by these encryption settings (and even more so for the flags) is very weak.
        '''
        self.ownerPassword = ownerPassword
        self.userPassword = userPassword
        if strength == 40:
            self.revision = 2
        elif strength == 128:
            self.revision = 3
        self.canPrint = canPrint
        self.canModify = canModify
        self.canCopy = canCopy
        self.canAnnotate = canAnnotate
        self.O = self.U = self.P = self.key = None