Initial QSfera import

Server/vendor/github.com/trustelem/zxcvbn/time_estimate.go

@@ -0,0 +1,104 @@
+package zxcvbn
+
+import (
+	"fmt"
+	"math"
+)
+
+type EstimatedTimes struct {
+	CrackTimesSeconds map[string]float64 `json:"crack_times_seconds"`
+	CrashTimesDisplay map[string]string  `json:"crack_times_display"`
+	Score             int
+}
+
+func estimateAttackTimes(guesses float64) (t EstimatedTimes) {
+	// crack_times_seconds
+	t.CrackTimesSeconds = make(map[string]float64)
+	t.CrackTimesSeconds["online_throttling_100_per_hour"] = guesses / (100 / 3600)
+	t.CrackTimesSeconds["online_no_throttling_10_per_second"] = guesses / 10
+	t.CrackTimesSeconds["offline_slow_hashing_1e4_per_second"] = guesses / 1e4
+	t.CrackTimesSeconds["offline_fast_hashing_1e10_per_second"] = guesses / 1e10
+
+	t.CrashTimesDisplay = make(map[string]string)
+
+	for scenario, seconds := range t.CrackTimesSeconds {
+		t.CrashTimesDisplay[scenario] = displayTime(seconds)
+	}
+
+	t.Score = guessesToScore(guesses)
+	return
+}
+
+func guessesToScore(guesses float64) int {
+	const DELTA = 5
+	if guesses < 1e3+DELTA {
+		// risky password: "too guessable"
+		return 0
+	}
+	if guesses < 1e6+DELTA {
+		// modest protection from throttled online attacks: "very guessable"
+		return 1
+	}
+	if guesses < 1e8+DELTA {
+		// modest protection from unthrottled online attacks: "somewhat guessable"
+		return 2
+	}
+	if guesses < 1e10+DELTA {
+		// modest protection from offline attacks: "safely unguessable"
+		// assuming a salted, slow hash function like bcrypt, scrypt, PBKDF2, argon, etc
+		return 3
+	}
+	// strong protection from offline attacks under same scenario: "very unguessable"
+	return 4
+}
+
+func displayTime(seconds float64) string {
+	minute := float64(60)
+	hour := minute * 60
+	day := hour * 24
+	month := day * 31
+	year := month * 12
+	century := year * 100
+
+	if seconds < 1 {
+		return "less than a second"
+	}
+	if seconds < minute {
+		return strCount(seconds, "second")
+	} else if seconds < hour {
+		return strCount(seconds/minute, "minute")
+	} else if seconds < day {
+		return strCount(seconds/hour, "hour")
+	} else if seconds < month {
+		return strCount(seconds/day, "day")
+	} else if seconds < year {
+		return strCount(seconds/month, "month")
+	} else if seconds < century {
+		return strCount(seconds/year, "year")
+	} else {
+		return "centuries"
+	}
+}
+
+func strCount(count float64, base string) string {
+	c := int(round(count, 0.5, 0))
+	str := fmt.Sprintf("%d %s", c, base)
+	if c > 1 {
+		str += "s"
+	}
+	return str
+}
+
+func round(val float64, roundOn float64, places int) (newVal float64) {
+	var round float64
+	pow := math.Pow(10, float64(places))
+	digit := pow * val
+	_, div := math.Modf(digit)
+	if div >= roundOn {
+		round = math.Ceil(digit)
+	} else {
+		round = math.Floor(digit)
+	}
+	newVal = round / pow
+	return
+}