[bug?] unable to getData from a password zip with checkPasswordOnly

[lslzl3000]

for a password protected zip, if read with checkPasswordOnly, unable to getData, always return undefined
e.g. a zip with a json file and password test : d.zip

let zipReader = new ZipReader(new BlobReader(file), {
    checkPasswordOnly: true,
    password: 'test'
});
const entries = await zipReader.getEntries();
const content = await entries[0].getData(new TextWriter()); // will return undefined

if not set checkPasswordOnly, the content will be returned, but how to check if the zip was set the target password or not?
zipReader can read anyway for a non-password zip without checkPasswordOnly, unable to check if the right password was set. meanwhile unable to getData with checkPasswordOnly

[gildas-lormeau]

If the password is invalid and checkPasswordOnly is set to false (the default value) then getData throws an error. You can check if this error is related to an invalid password by testing error.message == zip.ERR_INVALID_PASSWORD.

[lslzl3000]

If the password is invalid and checkPasswordOnly is set to false (the default value) then getData throws an error. You can check if this error is related to an invalid password by testing error.message == zip.ERR_INVALID_PASSWORD.

my first problem is getData will return undefined when set checkPasswordOnly=true with correct password, you can try the d.zip with password test
the second problem is getData not fire zip.ERR_INVALID_PASSWORD on zips without password/encrypted, so how to check if a zip set a passwrod or not?

[gildas-lormeau]

The behavior you're describing is normal. If getData (with checkPasswordOnly set to true or false) does not throw a zip.ERR_INVALID_PASSWORD error then it means the password, if provided, is correct. If you want to know if an entry is encrypted before calling getData then you can test its encrypted property. It is set to true when an entry is encrypted. Note that getData also throws the zip.ERR_ENCRYPTED error if you try to read an encrypted entry without providing the expected password.

You can also have a look at the code below which shows how to handle encrypted entries without checking the encrypted property.

zip.js/tests/all/test-crypto.js

Lines 21 to 41 in dfe4c11

	try {
	data = await entries[0].getData(dataBlobWriter);
	data = null;
	} catch (error) {
	if (error.message == zip.ERR_ENCRYPTED) {
	const dataBlobWriter = new zip.BlobWriter(zip.getMimeType(entries[0].filename));
	try {
	data = await entries[0].getData(dataBlobWriter, { password: "notagoodpassword" });
	data = null;
	} catch (error) {
	const dataBlobWriter = new zip.BlobWriter(zip.getMimeType(entries[0].filename));
	if (error.message == zip.ERR_INVALID_PASSWORD) {
	data = await entries[0].getData(dataBlobWriter, { password: "password", checkSignature: true });
	} else {
	throw error;
	}
	}
	} else {
	throw error;
	}
	}