aezeed: fix mnemonic word validation

A user complained about getting a misleading error after a typo in the
mnemonic. The word was `hear` and it passed the check even when it is
not in the list of valid words.

The reason is that we where checking if the word is in the variable
`englishWordList` (which includes all the words) instead of checking if the
variable is in the `defaultWordList` (which is basically `englishWoldList`
split by spaces). That means that `hear` passed the check because `heart`
appears in the list.

Related issue [4733](https://github.com/lightningnetwork/lnd/issues/4733)
This commit is contained in:
positiveblue 2020-10-30 10:10:41 +01:00
parent ce17c3be96
commit 5089cfc1be
2 changed files with 22 additions and 3 deletions

@ -6,7 +6,6 @@ import (
"encoding/binary"
"hash/crc32"
"io"
"strings"
"time"
"github.com/Yawning/aez"
@ -506,8 +505,13 @@ func (m *Mnemonic) Decipher(pass []byte) ([DecipheredCipherSeedSize]byte, error)
// Before we attempt to map the mnemonic back to the original
// ciphertext, we'll ensure that all the word are actually a part of
// the current default word list.
wordDict := make(map[string]struct{}, len(defaultWordList))
for _, word := range defaultWordList {
wordDict[word] = struct{}{}
}
for i, word := range m {
if !strings.Contains(englishWordList, word) {
if _, ok := wordDict[word]; !ok {
emptySeed := [DecipheredCipherSeedSize]byte{}
return emptySeed, ErrUnknownMnenomicWord{
Word: word,

@ -550,6 +550,22 @@ func TestDecipherUnknownMnenomicWord(t *testing.T) {
t.Fatalf("wrong index detected: expected %v, got %v",
randIndex, wordErr.Index)
}
// If the mnemonic includes a word that is not in the englishList
// it fails, even when it is a substring of a valid word
// Example: `heart` is in the list, `hear` is not
mnemonic[randIndex] = "hear"
// If we attempt to map back to the original cipher seed now, then we
// should get ErrUnknownMnenomicWord.
_, err = mnemonic.ToCipherSeed(pass)
if err == nil {
t.Fatalf("expected ErrUnknownMnenomicWord error")
}
_, ok = err.(ErrUnknownMnenomicWord)
if !ok {
t.Fatalf("expected ErrUnknownMnenomicWord instead got %T", err)
}
}
// TestDecipherIncorrectMnemonic tests that if we obtain a cipherseed, but then
@ -582,7 +598,6 @@ func TestDecipherIncorrectMnemonic(t *testing.T) {
if err != ErrIncorrectMnemonic {
t.Fatalf("expected ErrIncorrectMnemonic error")
}
}
// TODO(roasbeef): add test failure checksum fail is modified, new error