1 files changed, 105 insertions, 0 deletions
diff --git a/vendor/github.com/go-asn1-ber/asn1-ber/generalizedTime.go b/vendor/github.com/go-asn1-ber/asn1-ber/generalizedTime.go
new file mode 100644
index 00000000..51215f06
--- /dev/null
+++ b/vendor/github.com/go-asn1-ber/asn1-ber/generalizedTime.go
@@ -0,0 +1,105 @@
+package ber
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strconv"
+	"time"
+)
+
+// ErrInvalidTimeFormat is returned when the generalizedTime string was not correct.
+var ErrInvalidTimeFormat = errors.New("invalid time format")
+
+var zeroTime = time.Time{}
+
+// ParseGeneralizedTime parses a string value and if it conforms to
+// GeneralizedTime[^0] format, will return a time.Time for that value.
+//
+// [^0]: https://www.itu.int/rec/T-REC-X.690-201508-I/en Section 11.7
+func ParseGeneralizedTime(v []byte) (time.Time, error) {
+	var format string
+	var fract time.Duration
+
+	str := []byte(DecodeString(v))
+	tzIndex := bytes.IndexAny(str, "Z+-")
+	if tzIndex < 0 {
+		return zeroTime, ErrInvalidTimeFormat
+	}
+
+	dot := bytes.IndexAny(str, ".,")
+	switch dot {
+	case -1:
+		switch tzIndex {
+		case 10:
+			format = `2006010215Z`
+		case 12:
+			format = `200601021504Z`
+		case 14:
+			format = `20060102150405Z`
+		default:
+			return zeroTime, ErrInvalidTimeFormat
+		}
+
+	case 10, 12:
+		if tzIndex < dot {
+			return zeroTime, ErrInvalidTimeFormat
+		}
+		// a "," is also allowed, but would not be parsed by time.Parse():
+		str[dot] = '.'
+
+		// If <minute> is omitted, then <fraction> represents a fraction of an
+		// hour; otherwise, if <second> and <leap-second> are omitted, then
+		// <fraction> represents a fraction of a minute; otherwise, <fraction>
+		// represents a fraction of a second.
+
+		// parse as float from dot to timezone
+		f, err := strconv.ParseFloat(string(str[dot:tzIndex]), 64)
+		if err != nil {
+			return zeroTime, fmt.Errorf("failed to parse float: %s", err)
+		}
+		// ...and strip that part
+		str = append(str[:dot], str[tzIndex:]...)
+		tzIndex = dot
+
+		if dot == 10 {
+			fract = time.Duration(int64(f * float64(time.Hour)))
+			format = `2006010215Z`
+		} else {
+			fract = time.Duration(int64(f * float64(time.Minute)))
+			format = `200601021504Z`
+		}
+
+	case 14:
+		if tzIndex < dot {
+			return zeroTime, ErrInvalidTimeFormat
+		}
+		str[dot] = '.'
+		// no need for fractional seconds, time.Parse() handles that
+		format = `20060102150405Z`
+
+	default:
+		return zeroTime, ErrInvalidTimeFormat
+	}
+
+	l := len(str)
+	switch l - tzIndex {
+	case 1:
+		if str[l-1] != 'Z' {
+			return zeroTime, ErrInvalidTimeFormat
+		}
+	case 3:
+		format += `0700`
+		str = append(str, []byte("00")...)
+	case 5:
+		format += `0700`
+	default:
+		return zeroTime, ErrInvalidTimeFormat
+	}
+
+	t, err := time.Parse(format, string(str))
+	if err != nil {
+		return zeroTime, fmt.Errorf("%s: %s", ErrInvalidTimeFormat, err)
+	}
+	return t.Add(fract), nil
+}