Update

src/state/utils.go

@@ -0,0 +1,83 @@
+package state
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/hex"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+	"unicode"
+)
+
+func randomHex(bytes int) string {
+	buf := make([]byte, bytes)
+	_, _ = rand.Read(buf)
+	return hex.EncodeToString(buf)
+}
+
+func newUUIDv4() string {
+	buf := make([]byte, 16)
+	_, _ = rand.Read(buf)
+	buf[6] = (buf[6] & 0x0f) | 0x40
+	buf[8] = (buf[8] & 0x3f) | 0x80
+
+	return fmt.Sprintf("%x-%x-%x-%x-%x", buf[0:4], buf[4:6], buf[6:8], buf[8:10], buf[10:16])
+}
+
+func normalizeName(input string, max int) string {
+	trimmed := strings.TrimSpace(input)
+	if trimmed == "" {
+		return ""
+	}
+
+	builder := strings.Builder{}
+	for _, r := range trimmed {
+		if r == '\n' || r == '\r' || r == '\t' {
+			continue
+		}
+		if unicode.IsPrint(r) {
+			builder.WriteRune(r)
+		}
+		if builder.Len() >= max {
+			break
+		}
+	}
+	return strings.TrimSpace(builder.String())
+}
+
+func normalizeCard(input string) string {
+	return normalizeName(input, 8)
+}
+
+func hashPassword(password, salt string) string {
+	h := sha256.Sum256([]byte(salt + ":" + password))
+	return hex.EncodeToString(h[:])
+}
+
+func passwordMatches(password, salt, expectedHash string) bool {
+	computed := hashPassword(password, salt)
+	return subtle.ConstantTimeCompare([]byte(computed), []byte(expectedHash)) == 1
+}
+
+func nowUTC() time.Time {
+	return time.Now().UTC()
+}
+
+func sortParticipants(participants map[string]*Participant) []*Participant {
+	list := make([]*Participant, 0, len(participants))
+	for _, participant := range participants {
+		list = append(list, participant)
+	}
+
+	sort.SliceStable(list, func(i, j int) bool {
+		if list[i].JoinedAt.Equal(list[j].JoinedAt) {
+			return list[i].Username < list[j].Username
+		}
+		return list[i].JoinedAt.Before(list[j].JoinedAt)
+	})
+
+	return list
+}