func Omnimatch(password string, userInputs []string) (matches []match.Match) {
//Can I run into the issue where nil is not equal to nil?
if DICTIONARY_MATCHERS == nil || ADJACENCY_GRAPHS == nil {
loadFrequencyList()
}
if userInputs != nil {
userInputMatcher := buildDictMatcher("user_inputs", buildRankedDict(userInputs))
matches = userInputMatcher(password)
}
for _, matcher := range MATCHERS {
mtemp := matcher(password)
matches = append(matches, mtemp...)
}
sort.Sort(match.Matches(matches))
return matches
}
/*
Returns minimum entropy
Takes a list of overlapping matches, returns the non-overlapping sublist with
minimum entropy. O(nm) dp alg for length-n password with m candidate matches.
*/
func MinimumEntropyMatchSequence(password string, matches []match.Match) MinEntropyMatch {
bruteforceCardinality := float64(entropy.CalcBruteForceCardinality(password))
upToK := make([]float64, len(password))
backPointers := make([]match.Match, len(password))
for k := 0; k < len(password); k++ {
upToK[k] = get(upToK, k-1) + math.Log2(bruteforceCardinality)
for _, match := range matches {
if match.J != k {
continue
}
i, j := match.I, match.J
// see if best entropy up to i-1 + entropy of match is less that current min at j
upTo := get(upToK, i-1)
calculatedEntropy := match.Entropy
match.Entropy = calculatedEntropy
candidateEntropy := upTo + calculatedEntropy
if candidateEntropy < upToK[j] {
upToK[j] = candidateEntropy
match.Entropy = candidateEntropy
backPointers[j] = match
}
}
}
//walk backwards and decode the best sequence
var matchSequence []match.Match
passwordLen := len(password)
passwordLen--
for k := passwordLen; k >= 0; {
match := backPointers[k]
if match.Pattern != "" {
matchSequence = append(matchSequence, match)
k = match.I - 1
} else {
k--
}
}
sort.Sort(match.Matches(matchSequence))
makeBruteForceMatch := func(i, j int) match.Match {
return match.Match{Pattern: "bruteforce",
I: i,
J: j,
Token: password[i : j+1],
Entropy: math.Log2(math.Pow(bruteforceCardinality, float64(j-i)))}
}
k := 0
var matchSequenceCopy []match.Match
for _, match := range matchSequence {
i, j := match.I, match.J
if i-k > 0 {
matchSequenceCopy = append(matchSequenceCopy, makeBruteForceMatch(k, i-1))
}
k = j + 1
matchSequenceCopy = append(matchSequenceCopy, match)
}
if k < len(password) {
matchSequenceCopy = append(matchSequenceCopy, makeBruteForceMatch(k, len(password)-1))
}
var minEntropy float64
if len(password) == 0 {
minEntropy = float64(0)
} else {
minEntropy = upToK[len(password)-1]
}
crackTime := roundToXDigits(entropyToCrackTime(minEntropy), 3)
return MinEntropyMatch{Password: password,
Entropy: roundToXDigits(minEntropy, 3),
MatchSequence: matchSequenceCopy,
CrackTime: crackTime,
CrackTimeDisplay: displayTime(crackTime),
Score: crackTimeToScore(crackTime)}
}