1 files changed, 157 insertions, 0 deletions
diff --git a/vendor/github.com/go-asn1-ber/asn1-ber/real.go b/vendor/github.com/go-asn1-ber/asn1-ber/real.go
new file mode 100644
index 00000000..610a003a
--- /dev/null
+++ b/vendor/github.com/go-asn1-ber/asn1-ber/real.go
@@ -0,0 +1,157 @@
+package ber
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+)
+
+func encodeFloat(v float64) []byte {
+	switch {
+	case math.IsInf(v, 1):
+		return []byte{0x40}
+	case math.IsInf(v, -1):
+		return []byte{0x41}
+	case math.IsNaN(v):
+		return []byte{0x42}
+	case v == 0.0:
+		if math.Signbit(v) {
+			return []byte{0x43}
+		}
+		return []byte{}
+	default:
+		// we take the easy part ;-)
+		value := []byte(strconv.FormatFloat(v, 'G', -1, 64))
+		var ret []byte
+		if bytes.Contains(value, []byte{'E'}) {
+			ret = []byte{0x03}
+		} else {
+			ret = []byte{0x02}
+		}
+		ret = append(ret, value...)
+		return ret
+	}
+}
+
+func ParseReal(v []byte) (val float64, err error) {
+	if len(v) == 0 {
+		return 0.0, nil
+	}
+	switch {
+	case v[0]&0x80 == 0x80:
+		val, err = parseBinaryFloat(v)
+	case v[0]&0xC0 == 0x40:
+		val, err = parseSpecialFloat(v)
+	case v[0]&0xC0 == 0x0:
+		val, err = parseDecimalFloat(v)
+	default:
+		return 0.0, fmt.Errorf("invalid info block")
+	}
+	if err != nil {
+		return 0.0, err
+	}
+
+	if val == 0.0 && !math.Signbit(val) {
+		return 0.0, errors.New("REAL value +0 must be encoded with zero-length value block")
+	}
+	return val, nil
+}
+
+func parseBinaryFloat(v []byte) (float64, error) {
+	var info byte
+	var buf []byte
+
+	info, v = v[0], v[1:]
+
+	var base int
+	switch info & 0x30 {
+	case 0x00:
+		base = 2
+	case 0x10:
+		base = 8
+	case 0x20:
+		base = 16
+	case 0x30:
+		return 0.0, errors.New("bits 6 and 5 of information octet for REAL are equal to 11")
+	}
+
+	scale := uint((info & 0x0c) >> 2)
+
+	var expLen int
+	switch info & 0x03 {
+	case 0x00:
+		expLen = 1
+	case 0x01:
+		expLen = 2
+	case 0x02:
+		expLen = 3
+	case 0x03:
+		expLen = int(v[0])
+		if expLen > 8 {
+			return 0.0, errors.New("too big value of exponent")
+		}
+		v = v[1:]
+	}
+	buf, v = v[:expLen], v[expLen:]
+	exponent, err := ParseInt64(buf)
+	if err != nil {
+		return 0.0, err
+	}
+
+	if len(v) > 8 {
+		return 0.0, errors.New("too big value of mantissa")
+	}
+
+	mant, err := ParseInt64(v)
+	if err != nil {
+		return 0.0, err
+	}
+	mantissa := mant << scale
+
+	if info&0x40 == 0x40 {
+		mantissa = -mantissa
+	}
+
+	return float64(mantissa) * math.Pow(float64(base), float64(exponent)), nil
+}
+
+func parseDecimalFloat(v []byte) (val float64, err error) {
+	switch v[0] & 0x3F {
+	case 0x01: // NR form 1
+		var iVal int64
+		iVal, err = strconv.ParseInt(strings.TrimLeft(string(v[1:]), " "), 10, 64)
+		val = float64(iVal)
+	case 0x02, 0x03: // NR form 2, 3
+		val, err = strconv.ParseFloat(strings.Replace(strings.TrimLeft(string(v[1:]), " "), ",", ".", -1), 64)
+	default:
+		err = errors.New("incorrect NR form")
+	}
+	if err != nil {
+		return 0.0, err
+	}
+
+	if val == 0.0 && math.Signbit(val) {
+		return 0.0, errors.New("REAL value -0 must be encoded as a special value")
+	}
+	return val, nil
+}
+
+func parseSpecialFloat(v []byte) (float64, error) {
+	if len(v) != 1 {
+		return 0.0, errors.New(`encoding of "special value" must not contain exponent and mantissa`)
+	}
+	switch v[0] {
+	case 0x40:
+		return math.Inf(1), nil
+	case 0x41:
+		return math.Inf(-1), nil
+	case 0x42:
+		return math.NaN(), nil
+	case 0x43:
+		return math.Copysign(0, -1), nil
+	}
+	return 0.0, errors.New(`encoding of "special value" not from ASN.1 standard`)
+}