[feature] add TOTP two-factor authentication (2FA) (#3960)

* [feature] add TOTP two-factor authentication (2FA)

* use byteutil.S2B to avoid allocations when comparing + generating password hashes

* don't bother with string conversion  for consts

* use io.ReadFull

* use MustGenerateSecret for backup codes

* rename util functions

1 files changed, 23 insertions, 0 deletions

diff --git a/vendor/github.com/boombuler/barcode/qr/automatic.go b/vendor/github.com/boombuler/barcode/qr/automatic.go
new file mode 100644
index 000000000..e7c56013f
--- /dev/null
+++ b/vendor/github.com/boombuler/barcode/qr/automatic.go
@@ -0,0 +1,23 @@
+package qr
+
+import (
+	"fmt"
+
+	"github.com/boombuler/barcode/utils"
+)
+
+func encodeAuto(content string, ecl ErrorCorrectionLevel) (*utils.BitList, *versionInfo, error) {
+	bits, vi, _ := Numeric.getEncoder()(content, ecl)
+	if bits != nil && vi != nil {
+		return bits, vi, nil
+	}
+	bits, vi, _ = AlphaNumeric.getEncoder()(content, ecl)
+	if bits != nil && vi != nil {
+		return bits, vi, nil
+	}
+	bits, vi, _ = Unicode.getEncoder()(content, ecl)
+	if bits != nil && vi != nil {
+		return bits, vi, nil
+	}
+	return nil, nil, fmt.Errorf("No encoding found to encode \"%s\"", content)
+}