improve keys checks for jsthemis in SecureMessage

[vixentael]

In new SecureMessage API we made a mistake when checking keys for SecureMessage. For sign mode we should check private key, for verify mode we should check public key.

This affects only error messages for user, Themis uses correct keys while actual signing/verifying.

After this merge, we should update jsthemis and push to npm again as 0.11.2.

[Lagovas]

would be great to add some regression tests for these cases when we create secure message with empty keys and catch exceptions

[ilammy]

We have some tests here:

themis/tests/jsthemis/test.js

Lines 33 to 40 in bccb755

	it("empty keys", function(){
	encrypted_message = encrypter.encrypt(message);
	signed_message = encrypter.sign(message);
	assert.throws(function(){empty_secure_message.encrypt(message);}, expect_code(addon.INVALID_PARAMETER));
	assert.throws(function(){empty_secure_message.decrypt(encrypted_message);}, expect_code(addon.INVALID_PARAMETER));
	assert.throws(function(){empty_secure_message.sign(message);}, expect_code(addon.INVALID_PARAMETER));
	assert.throws(function(){empty_secure_message.verify(signed_message);}, expect_code(addon.INVALID_PARAMETER));
	})

But unfortunately they don't cover the case when only one of the keys is empty.

They also do not check the specific error message, only the error code. The assert.throws() function can accept a regex for the message (or, probably, it would be better to check both code and message properties).

[vixentael]

@Lagovas @ilammy i've extended test suite

[Lagovas]

nice

[ilammy]

LGTM 👍

I wonder whether we should invest more into code coverage analysis over wrappers to catch mistakes like this...