diff --git a/vendor/gopkg.in/jcmturner/gokrb5.v7/crypto/rc4-hmac.go b/vendor/gopkg.in/jcmturner/gokrb5.v7/crypto/rc4-hmac.go
new file mode 100644
index 0000000..9df55ee
--- /dev/null
+++ b/vendor/gopkg.in/jcmturner/gokrb5.v7/crypto/rc4-hmac.go
@@ -0,0 +1,135 @@
+package crypto
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/md5"
+	"hash"
+	"io"
+
+	"golang.org/x/crypto/md4"
+	"gopkg.in/jcmturner/gokrb5.v7/crypto/rfc3961"
+	"gopkg.in/jcmturner/gokrb5.v7/crypto/rfc4757"
+	"gopkg.in/jcmturner/gokrb5.v7/iana/chksumtype"
+	"gopkg.in/jcmturner/gokrb5.v7/iana/etypeID"
+)
+
+//http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/8u40-b25/sun/security/krb5/internal/crypto/dk/ArcFourCrypto.java#ArcFourCrypto.encrypt%28byte%5B%5D%2Cint%2Cbyte%5B%5D%2Cbyte%5B%5D%2Cbyte%5B%5D%2Cint%2Cint%29
+
+// RC4HMAC implements Kerberos encryption type aes256-cts-hmac-sha1-96
+type RC4HMAC struct {
+}
+
+// GetETypeID returns the EType ID number.
+func (e RC4HMAC) GetETypeID() int32 {
+	return etypeID.RC4_HMAC
+}
+
+// GetHashID returns the checksum type ID number.
+func (e RC4HMAC) GetHashID() int32 {
+	return chksumtype.KERB_CHECKSUM_HMAC_MD5
+}
+
+// GetKeyByteSize returns the number of bytes for key of this etype.
+func (e RC4HMAC) GetKeyByteSize() int {
+	return 16
+}
+
+// GetKeySeedBitLength returns the number of bits for the seed for key generation.
+func (e RC4HMAC) GetKeySeedBitLength() int {
+	return e.GetKeyByteSize() * 8
+}
+
+// GetHashFunc returns the hash function for this etype.
+func (e RC4HMAC) GetHashFunc() func() hash.Hash {
+	return md5.New
+}
+
+// GetMessageBlockByteSize returns the block size for the etype's messages.
+func (e RC4HMAC) GetMessageBlockByteSize() int {
+	return 1
+}
+
+// GetDefaultStringToKeyParams returns the default key derivation parameters in string form.
+func (e RC4HMAC) GetDefaultStringToKeyParams() string {
+	return ""
+}
+
+// GetConfounderByteSize returns the byte count for confounder to be used during cryptographic operations.
+func (e RC4HMAC) GetConfounderByteSize() int {
+	return 8
+}
+
+// GetHMACBitLength returns the bit count size of the integrity hash.
+func (e RC4HMAC) GetHMACBitLength() int {
+	return md5.Size * 8
+}
+
+// GetCypherBlockBitLength returns the bit count size of the cypher block.
+func (e RC4HMAC) GetCypherBlockBitLength() int {
+	return 8 // doesn't really apply
+}
+
+// StringToKey returns a key derived from the string provided.
+func (e RC4HMAC) StringToKey(secret string, salt string, s2kparams string) ([]byte, error) {
+	return rfc4757.StringToKey(secret)
+}
+
+// RandomToKey returns a key from the bytes provided.
+func (e RC4HMAC) RandomToKey(b []byte) []byte {
+	r := bytes.NewReader(b)
+	h := md4.New()
+	io.Copy(h, r)
+	return h.Sum(nil)
+}
+
+// EncryptData encrypts the data provided.
+func (e RC4HMAC) EncryptData(key, data []byte) ([]byte, []byte, error) {
+	b, err := rfc4757.EncryptData(key, data, e)
+	return []byte{}, b, err
+}
+
+// EncryptMessage encrypts the message provided and concatenates it with the integrity hash to create an encrypted message.
+func (e RC4HMAC) EncryptMessage(key, message []byte, usage uint32) ([]byte, []byte, error) {
+	b, err := rfc4757.EncryptMessage(key, message, usage, false, e)
+	return []byte{}, b, err
+}
+
+// DecryptData decrypts the data provided.
+func (e RC4HMAC) DecryptData(key, data []byte) ([]byte, error) {
+	return rfc4757.DecryptData(key, data, e)
+}
+
+// DecryptMessage decrypts the message provided and verifies the integrity of the message.
+func (e RC4HMAC) DecryptMessage(key, ciphertext []byte, usage uint32) ([]byte, error) {
+	return rfc4757.DecryptMessage(key, ciphertext, usage, false, e)
+}
+
+// DeriveKey derives a key from the protocol key based on the usage value.
+func (e RC4HMAC) DeriveKey(protocolKey, usage []byte) ([]byte, error) {
+	return rfc4757.HMAC(protocolKey, usage), nil
+}
+
+// DeriveRandom generates data needed for key generation.
+func (e RC4HMAC) DeriveRandom(protocolKey, usage []byte) ([]byte, error) {
+	return rfc3961.DeriveRandom(protocolKey, usage, e)
+}
+
+// VerifyIntegrity checks the integrity of the plaintext message.
+func (e RC4HMAC) VerifyIntegrity(protocolKey, ct, pt []byte, usage uint32) bool {
+	return rfc4757.VerifyIntegrity(protocolKey, pt, ct, e)
+}
+
+// GetChecksumHash returns a keyed checksum hash of the bytes provided.
+func (e RC4HMAC) GetChecksumHash(protocolKey, data []byte, usage uint32) ([]byte, error) {
+	return rfc4757.Checksum(protocolKey, usage, data)
+}
+
+// VerifyChecksum compares the checksum of the message bytes is the same as the checksum provided.
+func (e RC4HMAC) VerifyChecksum(protocolKey, data, chksum []byte, usage uint32) bool {
+	checksum, err := rfc4757.Checksum(protocolKey, usage, data)
+	if err != nil {
+		return false
+	}
+	return hmac.Equal(checksum, chksum)
+}