CODEWITHSUNDEEP
javascriptnode.jssecurityencryptioncryptography
Arlen Beiler
Arlen Beiler

Reputation: 15906

Does AES-128-GCM authenticate the IV on Node V6?

Given this code:

const bufIV = Buffer.alloc(16);
const cipher = crypto.createCipheriv(CIPHER, mykey, crypto.randomFillSync(bufIV));
let encrypted = cipher.update(doc, 'utf8', ENCODING);
encrypted += cipher.final(ENCODING);

Will the IV also be authenticated? The end of this article seems to indicate that it needs to be, but I don't really understand how this works.

Using a good IV doesn’t automatically mean your crypto is secure. You have to authenticate your ciphertexts, too. When you do, don’t forget to authenticate the IV.

Upvotes: 1

Views: 157

Answers (1)

Maarten Bodewes
Maarten Bodewes

Reputation: 94058

Yes, AES-GCM will automatically verify the IV, verification of the IV is included within the calculation of the authentication tag.

Now for the bad news: as you need to explicitly set the received authentication tag in NodeJS using the setAuthTag nothing will be verified in the code you've shown us.

Upvotes: 1

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