Skip to content

Fix incorrect padding for messages smaller DEFAULT_PADDING_LENGTH #414

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Fix incorrect padding for messages smaller DEFAULT_PADDING_LENGTH #414

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 16 additions & 0 deletions src/encryption.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,22 @@ describe('encryption', function () {
expect(result.version).toBe('x25519-xsalsa20-poly1305');
});

it('encryption of message which is [1..NACL_EXTRA_BYTES) smaller than DEFAULT_PADDING_LENGTH in JSON', async function () {
const jsonOverhead = '{"data":"","padding":""}'.length;
const message = '0'.repeat(2 ** 11 - jsonOverhead - 10); // DEFAULT_PADDING_LENGTH - jsonOverhead - 10; 10 < NACL_EXTRA_BYTES
const version = 'x25519-xsalsa20-poly1305';
const result = encryptSafely({
publicKey: bob.encryptionPublicKey,
data: message,
version,
});

expect(result.ciphertext).toHaveLength(5464);
expect(result.ephemPublicKey).toHaveLength(44);
expect(result.nonce).toHaveLength(32);
expect(result.version).toBe('x25519-xsalsa20-poly1305');
});

// safe decryption test
it('bob decryptSafely message that Alice encryptSafely for him', async function () {
const version = 'x25519-xsalsa20-poly1305';
Expand Down
4 changes: 2 additions & 2 deletions src/encryption.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -130,11 +130,11 @@ export function encryptSafely({
JSON.stringify(dataWithPadding),
'utf-8',
);
const modVal = dataLength % DEFAULT_PADDING_LENGTH;
const modVal = (dataLength + NACL_EXTRA_BYTES) % DEFAULT_PADDING_LENGTH;
let padLength = 0;
// Only pad if necessary
if (modVal > 0) {
padLength = DEFAULT_PADDING_LENGTH - modVal - NACL_EXTRA_BYTES; // nacl extra bytes
padLength = DEFAULT_PADDING_LENGTH - modVal;
}
dataWithPadding.padding = '0'.repeat(padLength);

Expand Down