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Merge pull request #1061 from matrix-org/rav/megolm_key_encryption_errors

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Improve error logging/reporting in megolm import/export
This commit is contained in:
Richard van der Hoff 2017-06-12 10:09:52 +01:00 committed by GitHub
commit 57b4c422b1
5 changed files with 176 additions and 96 deletions
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4
src/async-components/views/dialogs/ExportE2eKeysDialog.js
View file

@ -81,11 +81,13 @@ export default React.createClass({
FileSaver.saveAs(blob, 'riot-keys.txt');
this.props.onFinished(true);
}).catch((e) => {
console.error("Error exporting e2e keys:", e);
if (this._unmounted) {
return;
}
const msg = e.friendlyText || _t('Unknown error');
this.setState({
errStr: e.message,
errStr: msg,
phase: PHASE_EDIT,
});
});

4
src/async-components/views/dialogs/ImportE2eKeysDialog.js
View file

@ -89,11 +89,13 @@ export default React.createClass({
// TODO: it would probably be nice to give some feedback about what we've imported here.
this.props.onFinished(true);
}).catch((e) => {
console.error("Error importing e2e keys:", e);
if (this._unmounted) {
return;
}
const msg = e.friendlyText || _t('Unknown error');
this.setState({
errStr: e.message,
errStr: msg,
phase: PHASE_EDIT,
});
});

5
src/i18n/strings/en_EN.json
View file

@ -908,5 +908,8 @@
"Username not available": "Username not available",
"Something went wrong!": "Something went wrong!",
"This will be your account name on the <span></span> homeserver, or you can pick a <a>different server</a>.": "This will be your account name on the <span></span> homeserver, or you can pick a <a>different server</a>.",
"If you already have a Matrix account you can <a>log in</a> instead.": "If you already have a Matrix account you can <a>log in</a> instead."
"If you already have a Matrix account you can <a>log in</a> instead.": "If you already have a Matrix account you can <a>log in</a> instead.",
"Your browser does not support the required cryptography extensions": "Your browser does not support the required cryptography extensions",
"Not a valid Riot keyfile": "Not a valid Riot keyfile",
"Authentication check failed: incorrect password?": "Authentication check failed: incorrect password?"
}

235
src/utils/MegolmExportEncryption.js
View file

@ -27,31 +27,57 @@ if (!TextDecoder) {
TextDecoder = TextEncodingUtf8.TextDecoder;
}
import { _t } from '../languageHandler';
const subtleCrypto = window.crypto.subtle || window.crypto.webkitSubtle;
/**
* Make an Error object which has a friendlyText property which is already
* translated and suitable for showing to the user.
*
* @param {string} msg message for the exception
* @param {string} friendlyText
* @returns {Error}
*/
function friendlyError(msg, friendlyText) {
const e = new Error(msg);
e.friendlyText = friendlyText;
return e;
}
function cryptoFailMsg() {
return _t('Your browser does not support the required cryptography extensions');
}
/**
* Decrypt a megolm key file
*
* @param {ArrayBuffer} data file to decrypt
* @param {String} password
* @return {Promise<String>} promise for decrypted output
*
*
*/
export function decryptMegolmKeyFile(data, password) {
export async function decryptMegolmKeyFile(data, password) {
const body = unpackMegolmKeyFile(data);
// check we have a version byte
if (body.length < 1) {
throw new Error('Invalid file: too short');
throw friendlyError('Invalid file: too short',
_t('Not a valid Riot keyfile'));
}
const version = body[0];
if (version !== 1) {
throw new Error('Unsupported version');
throw friendlyError('Unsupported version',
_t('Not a valid Riot keyfile'));
}
const ciphertextLength = body.length-(1+16+16+4+32);
if (ciphertextLength < 0) {
throw new Error('Invalid file: too short');
throw friendlyError('Invalid file: too short',
_t('Not a valid Riot keyfile'));
}
const salt = body.subarray(1, 1+16);
@ -60,33 +86,41 @@ export function decryptMegolmKeyFile(data, password) {
const ciphertext = body.subarray(37, 37+ciphertextLength);
const hmac = body.subarray(-32);
return deriveKeys(salt, iterations, password).then((keys) => {
const [aesKey, hmacKey] = keys;
const [aesKey, hmacKey] = await deriveKeys(salt, iterations, password);
const toVerify = body.subarray(0, -32);
const toVerify = body.subarray(0, -32);
return subtleCrypto.verify(
let isValid;
try {
isValid = await subtleCrypto.verify(
{name: 'HMAC'},
hmacKey,
hmac,
toVerify,
).then((isValid) => {
if (!isValid) {
throw new Error('Authentication check failed: incorrect password?');
}
);
} catch (e) {
throw friendlyError('subtleCrypto.verify failed: ' + e, cryptoFailMsg());
}
if (!isValid) {
throw friendlyError('hmac mismatch',
_t('Authentication check failed: incorrect password?'));
}
return subtleCrypto.decrypt(
{
name: "AES-CTR",
counter: iv,
length: 64,
},
aesKey,
ciphertext,
);
});
}).then((plaintext) => {
return new TextDecoder().decode(new Uint8Array(plaintext));
});
let plaintext;
try {
plaintext = await subtleCrypto.decrypt(
{
name: "AES-CTR",
counter: iv,
length: 64,
},
aesKey,
ciphertext,
);
} catch(e) {
throw friendlyError('subtleCrypto.decrypt failed: ' + e, cryptoFailMsg());
}
return new TextDecoder().decode(new Uint8Array(plaintext));
}
@ -100,7 +134,7 @@ export function decryptMegolmKeyFile(data, password) {
* key-derivation function.
* @return {Promise<ArrayBuffer>} promise for encrypted output
*/
export function encryptMegolmKeyFile(data, password, options) {
export async function encryptMegolmKeyFile(data, password, options) {
options = options || {};
const kdfRounds = options.kdf_rounds || 500000;
@ -115,44 +149,54 @@ export function encryptMegolmKeyFile(data, password, options) {
// of a single bit of iv is a price we have to pay.
iv[9] &= 0x7f;
return deriveKeys(salt, kdfRounds, password).then((keys) => {
const [aesKey, hmacKey] = keys;
const [aesKey, hmacKey] = await deriveKeys(salt, kdfRounds, password);
const encodedData = new TextEncoder().encode(data);
return subtleCrypto.encrypt(
let ciphertext;
try {
ciphertext = await subtleCrypto.encrypt(
{
name: "AES-CTR",
counter: iv,
length: 64,
},
aesKey,
new TextEncoder().encode(data),
).then((ciphertext) => {
const cipherArray = new Uint8Array(ciphertext);
const bodyLength = (1+salt.length+iv.length+4+cipherArray.length+32);
const resultBuffer = new Uint8Array(bodyLength);
let idx = 0;
resultBuffer[idx++] = 1; // version
resultBuffer.set(salt, idx); idx += salt.length;
resultBuffer.set(iv, idx); idx += iv.length;
resultBuffer[idx++] = kdfRounds >> 24;
resultBuffer[idx++] = (kdfRounds >> 16) & 0xff;
resultBuffer[idx++] = (kdfRounds >> 8) & 0xff;
resultBuffer[idx++] = kdfRounds & 0xff;
resultBuffer.set(cipherArray, idx); idx += cipherArray.length;
encodedData,
);
} catch (e) {
throw friendlyError('subtleCrypto.encrypt failed: ' + e, cryptoFailMsg());
}
const toSign = resultBuffer.subarray(0, idx);
const cipherArray = new Uint8Array(ciphertext);
const bodyLength = (1+salt.length+iv.length+4+cipherArray.length+32);
const resultBuffer = new Uint8Array(bodyLength);
let idx = 0;
resultBuffer[idx++] = 1; // version
resultBuffer.set(salt, idx); idx += salt.length;
resultBuffer.set(iv, idx); idx += iv.length;
resultBuffer[idx++] = kdfRounds >> 24;
resultBuffer[idx++] = (kdfRounds >> 16) & 0xff;
resultBuffer[idx++] = (kdfRounds >> 8) & 0xff;
resultBuffer[idx++] = kdfRounds & 0xff;
resultBuffer.set(cipherArray, idx); idx += cipherArray.length;
return subtleCrypto.sign(
{name: 'HMAC'},
hmacKey,
toSign,
).then((hmac) => {
hmac = new Uint8Array(hmac);
resultBuffer.set(hmac, idx);
return packMegolmKeyFile(resultBuffer);
});
});
});
const toSign = resultBuffer.subarray(0, idx);
let hmac;
try {
hmac = await subtleCrypto.sign(
{name: 'HMAC'},
hmacKey,
toSign,
);
} catch (e) {
throw friendlyError('subtleCrypto.sign failed: ' + e, cryptoFailMsg());
}
const hmacArray = new Uint8Array(hmac);
resultBuffer.set(hmacArray, idx);
return packMegolmKeyFile(resultBuffer);
}
/**
@ -163,16 +207,25 @@ export function encryptMegolmKeyFile(data, password, options) {
* @param {String} password password
* @return {Promise<[CryptoKey, CryptoKey]>} promise for [aes key, hmac key]
*/
function deriveKeys(salt, iterations, password) {
async function deriveKeys(salt, iterations, password) {
const start = new Date();
return subtleCrypto.importKey(
'raw',
new TextEncoder().encode(password),
{name: 'PBKDF2'},
false,
['deriveBits'],
).then((key) => {
return subtleCrypto.deriveBits(
let key;
try {
key = await subtleCrypto.importKey(
'raw',
new TextEncoder().encode(password),
{name: 'PBKDF2'},
false,
['deriveBits'],
);
} catch (e) {
throw friendlyError('subtleCrypto.importKey failed: ' + e, cryptoFailMsg());
}
let keybits;
try {
keybits = await subtleCrypto.deriveBits(
{
name: 'PBKDF2',
salt: salt,
@ -182,32 +235,40 @@ function deriveKeys(salt, iterations, password) {
key,
512,
);
}).then((keybits) => {
const now = new Date();
console.log("E2e import/export: deriveKeys took " + (now - start) + "ms");
} catch (e) {
throw friendlyError('subtleCrypto.deriveBits failed: ' + e, cryptoFailMsg());
}
const aesKey = keybits.slice(0, 32);
const hmacKey = keybits.slice(32);
const now = new Date();
console.log("E2e import/export: deriveKeys took " + (now - start) + "ms");
const aesProm = subtleCrypto.importKey(
'raw',
aesKey,
{name: 'AES-CTR'},
false,
['encrypt', 'decrypt'],
);
const hmacProm = subtleCrypto.importKey(
'raw',
hmacKey,
{
name: 'HMAC',
hash: {name: 'SHA-256'},
},
false,
['sign', 'verify'],
);
return Promise.all([aesProm, hmacProm]);
const aesKey = keybits.slice(0, 32);
const hmacKey = keybits.slice(32);
const aesProm = subtleCrypto.importKey(
'raw',
aesKey,
{name: 'AES-CTR'},
false,
['encrypt', 'decrypt'],
).catch((e) => {
throw friendlyError('subtleCrypto.importKey failed for AES key: ' + e, cryptoFailMsg());
});
const hmacProm = subtleCrypto.importKey(
'raw',
hmacKey,
{
name: 'HMAC',
hash: {name: 'SHA-256'},
},
false,
['sign', 'verify'],
).catch((e) => {
throw friendlyError('subtleCrypto.importKey failed for HMAC key: ' + e, cryptoFailMsg());
});
return await Promise.all([aesProm, hmacProm]);
}
const HEADER_LINE = '-----BEGIN MEGOLM SESSION DATA-----';

24
test/utils/MegolmExportEncryption-test.js
View file

@ -81,15 +81,23 @@ describe('MegolmExportEncryption', function() {
describe('decrypt', function() {
it('should handle missing header', function() {
const input=stringToArray(`-----`);
expect(()=>MegolmExportEncryption.decryptMegolmKeyFile(input, ''))
.toThrow('Header line not found');
return MegolmExportEncryption.decryptMegolmKeyFile(input, '')
.then((res) => {
throw new Error('expected to throw');
}, (error) => {
expect(error.message).toEqual('Header line not found');
});
});
it('should handle missing trailer', function() {
const input=stringToArray(`-----BEGIN MEGOLM SESSION DATA-----
-----`);
expect(()=>MegolmExportEncryption.decryptMegolmKeyFile(input, ''))
.toThrow('Trailer line not found');
return MegolmExportEncryption.decryptMegolmKeyFile(input, '')
.then((res) => {
throw new Error('expected to throw');
}, (error) => {
expect(error.message).toEqual('Trailer line not found');
});
});
it('should handle a too-short body', function() {
@ -98,8 +106,12 @@ AXNhbHRzYWx0c2FsdHNhbHSIiIiIiIiIiIiIiIiIiIiIAAAACmIRUW2OjZ3L2l6j9h0lHlV3M2dx
cissyYBxjsfsAn
-----END MEGOLM SESSION DATA-----
`);
expect(()=>MegolmExportEncryption.decryptMegolmKeyFile(input, ''))
.toThrow('Invalid file: too short');
return MegolmExportEncryption.decryptMegolmKeyFile(input, '')
.then((res) => {
throw new Error('expected to throw');
}, (error) => {
expect(error.message).toEqual('Invalid file: too short');
});
});
it('should decrypt a range of inputs', function(done) {