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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def key_str(self, match):
        '''
        Return the specified public key or keys based on a glob
        '''
        ret = {}
        for status, keys in six.iteritems(self.name_match(match)):
            ret[status] = {}
            for key in salt.utils.data.sorted_ignorecase(keys):
                path = os.path.join(self.opts['pki_dir'], status, key)
                with salt.utils.files.fopen(path, 'r') as fp_:
                    ret[status][key] = \
                        salt.utils.stringutils.to_unicode(fp_.read())
        return ret