new: parsing BLE flags and company identifiers from advertisements

vendor/github.com/nbutton23/zxcvbn-go/matching/sequenceMatch.go

@@ -0,0 +1,75 @@
+package matching
+
+import (
+	"strings"
+
+	"github.com/nbutton23/zxcvbn-go/entropy"
+	"github.com/nbutton23/zxcvbn-go/match"
+)
+
+const SEQUENCE_MATCHER_NAME = "SEQ"
+
+func FilterSequenceMatcher(m match.Matcher) bool {
+	return m.ID == SEQUENCE_MATCHER_NAME
+}
+
+func sequenceMatch(password string) []match.Match {
+	var matches []match.Match
+	for i := 0; i < len(password); {
+		j := i + 1
+		var seq string
+		var seqName string
+		seqDirection := 0
+		for seqCandidateName, seqCandidate := range SEQUENCES {
+			iN := strings.Index(seqCandidate, string(password[i]))
+			var jN int
+			if j < len(password) {
+				jN = strings.Index(seqCandidate, string(password[j]))
+			} else {
+				jN = -1
+			}
+
+			if iN > -1 && jN > -1 {
+				direction := jN - iN
+				if direction == 1 || direction == -1 {
+					seq = seqCandidate
+					seqName = seqCandidateName
+					seqDirection = direction
+					break
+				}
+			}
+
+		}
+
+		if seq != "" {
+			for {
+				var prevN, curN int
+				if j < len(password) {
+					prevChar, curChar := password[j-1], password[j]
+					prevN, curN = strings.Index(seq, string(prevChar)), strings.Index(seq, string(curChar))
+				}
+
+				if j == len(password) || curN-prevN != seqDirection {
+					if j-i > 2 {
+						matchSequence := match.Match{
+							Pattern:        "sequence",
+							I:              i,
+							J:              j - 1,
+							Token:          password[i:j],
+							DictionaryName: seqName,
+						}
+
+						matchSequence.Entropy = entropy.SequenceEntropy(matchSequence, len(seq), (seqDirection == 1))
+						matches = append(matches, matchSequence)
+					}
+					break
+				} else {
+					j += 1
+				}
+
+			}
+		}
+		i = j
+	}
+	return matches
+}