diff --git a/vendor/gopkg.in/jcmturner/gokrb5.v7/asn1tools/tools.go b/vendor/gopkg.in/jcmturner/gokrb5.v7/asn1tools/tools.go
new file mode 100644
index 0000000..f27740b
--- /dev/null
+++ b/vendor/gopkg.in/jcmturner/gokrb5.v7/asn1tools/tools.go
@@ -0,0 +1,86 @@
+// Package asn1tools provides tools for managing ASN1 marshaled data.
+package asn1tools
+
+import (
+	"github.com/jcmturner/gofork/encoding/asn1"
+)
+
+// MarshalLengthBytes returns the ASN1 encoded bytes for the length 'l'
+//
+// There are two forms: short (for lengths between 0 and 127), and long definite (for lengths between 0 and 2^1008 -1).
+//
+// Short form: One octet. Bit 8 has value "0" and bits 7-1 give the length.
+//
+// Long form: Two to 127 octets. Bit 8 of first octet has value "1" and bits 7-1 give the number of additional length octets. Second and following octets give the length, base 256, most significant digit first.
+func MarshalLengthBytes(l int) []byte {
+	if l <= 127 {
+		return []byte{byte(l)}
+	}
+	var b []byte
+	p := 1
+	for i := 1; i < 127; {
+		b = append([]byte{byte((l % (p * 256)) / p)}, b...)
+		p = p * 256
+		l = l - l%p
+		if l <= 0 {
+			break
+		}
+	}
+	return append([]byte{byte(128 + len(b))}, b...)
+}
+
+// GetLengthFromASN returns the length of a slice of ASN1 encoded bytes from the ASN1 length header it contains.
+func GetLengthFromASN(b []byte) int {
+	if int(b[1]) <= 127 {
+		return int(b[1])
+	}
+	// The bytes that indicate the length
+	lb := b[2 : 2+int(b[1])-128]
+	base := 1
+	l := 0
+	for i := len(lb) - 1; i >= 0; i-- {
+		l += int(lb[i]) * base
+		base = base * 256
+	}
+	return l
+}
+
+// GetNumberBytesInLengthHeader returns the number of bytes in the ASn1 header that indicate the length.
+func GetNumberBytesInLengthHeader(b []byte) int {
+	if int(b[1]) <= 127 {
+		return 1
+	}
+	// The bytes that indicate the length
+	return 1 + int(b[1]) - 128
+}
+
+// AddASNAppTag adds an ASN1 encoding application tag value to the raw bytes provided.
+func AddASNAppTag(b []byte, tag int) []byte {
+	r := asn1.RawValue{
+		Class:      asn1.ClassApplication,
+		IsCompound: true,
+		Tag:        tag,
+		Bytes:      b,
+	}
+	ab, _ := asn1.Marshal(r)
+	return ab
+}
+
+/*
+// The Marshal method of golang's asn1 package does not enable you to define wrapping the output in an application tag.
+// This method adds that wrapping tag.
+func AddASNAppTag(b []byte, tag int) []byte {
+	// The ASN1 wrapping consists of 2 bytes:
+	// 1st byte -> Identifier Octet - Application Tag
+	// 2nd byte -> The length (this will be the size indicated in the input bytes + 2 for the additional bytes we add here.
+	// Application Tag:
+	//| Bit:        | 8                            | 7                          | 6                                         | 5 | 4 | 3 | 2 | 1             |
+	//| Value:      | 0                            | 1                          | 1                                         | From the RFC spec 4120        |
+	//| Explanation | Defined by the ASN1 encoding rules for an application tag | A value of 1 indicates a constructed type | The ASN Application tag value |
+	// Therefore the value of the byte is an integer = ( Application tag value + 96 )
+	//b = append(MarshalLengthBytes(int(b[1])+2), b...)
+	b = append(MarshalLengthBytes(len(b)), b...)
+	b = append([]byte{byte(96 + tag)}, b...)
+	return b
+}
+*/