auth: Fix secret length

The former length of 64 bytes (512-bit) is transformed into base64url (a 6-bit code) ~86 characters long. This is too long for bcrypt as it ignores any characters beyond the 72th.
This fix therefore reduces the amount of generated bytes to 54 (as 72*6/8 = 54) characters. This ensures that removing one character from the token the hash won't be the same anymore.

Signed-off-by: Philip Molares <philip.molares@udo.edu>
This commit is contained in:
Philip Molares 2021-01-28 12:18:20 +01:00 committed by David Mehren
parent 8b27f6f393
commit 46b5cdfb47
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GPG key ID: 185982BA4C42B7C3
2 changed files with 25 additions and 1 deletions

View file

@ -13,6 +13,7 @@ import { UsersModule } from '../users/users.module';
import { Identity } from '../users/identity.entity';
import { LoggerModule } from '../logger/logger.module';
import { AuthToken } from './auth-token.entity';
import { TokenNotValidError } from '../errors/errors';
describe('AuthService', () => {
let service: AuthService;
@ -105,6 +106,16 @@ describe('AuthService', () => {
.checkPassword(testPassword, hash)
.then((result) => expect(result).toBeTruthy());
});
it('fails, if secret is too short', async () => {
const secret = service.BufferToBase64Url(await service.randomString(54));
const hash = await service.hashPassword(secret);
service
.checkPassword(secret, hash)
.then((result) => expect(result).toBeTruthy());
service
.checkPassword(secret.substr(0, secret.length - 1), hash)
.then((result) => expect(result).toBeFalsy());
});
});
describe('getTokensByUsername', () => {
@ -148,6 +159,11 @@ describe('AuthService', () => {
authTokens: [authToken],
});
});
it('fails on too long token', () => {
expect(
service.validateToken(`${authToken.keyId}.${'a'.repeat(73)}`),
).rejects.toBeInstanceOf(TokenNotValidError);
});
});
describe('removeToken', () => {

View file

@ -37,6 +37,14 @@ export class AuthService {
async validateToken(token: string): Promise<User> {
try {
const [keyId, secret] = token.split('.');
if (secret.length > 72) {
// Only the first 72 characters of the tokens are considered by bcrypt
// This should prevent strange corner cases
// At the very least it won't hurt us
throw new TokenNotValidError(
`AuthToken '${secret}' is too long the be a proper token`,
);
}
const accessToken = await this.getAuthTokenAndValidate(keyId, secret);
await this.setLastUsedToken(keyId);
return this.usersService.getUserByUsername(accessToken.user.userName);
@ -92,7 +100,7 @@ export class AuthService {
`User '${user.userName}' has already 200 tokens and can't have anymore`,
);
}
const secret = this.BufferToBase64Url(await this.randomString(64));
const secret = this.BufferToBase64Url(await this.randomString(54));
const keyId = this.BufferToBase64Url(await this.randomString(8));
const accessToken = await this.hashPassword(secret);
let token;