diff --git a/vendor/github.com/jcmturner/gokrb5/v8/crypto/rfc3961/encryption.go b/vendor/github.com/jcmturner/gokrb5/v8/crypto/rfc3961/encryption.go
new file mode 100644
index 0000000..1383258
--- /dev/null
+++ b/vendor/github.com/jcmturner/gokrb5/v8/crypto/rfc3961/encryption.go
@@ -0,0 +1,119 @@
+// Package rfc3961 provides encryption and checksum methods as specified in RFC 3961
+package rfc3961
+
+import (
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/hmac"
+	"crypto/rand"
+	"errors"
+	"fmt"
+
+	"github.com/jcmturner/gokrb5/v8/crypto/common"
+	"github.com/jcmturner/gokrb5/v8/crypto/etype"
+)
+
+// DES3EncryptData encrypts the data provided using DES3 and methods specific to the etype provided.
+func DES3EncryptData(key, data []byte, e etype.EType) ([]byte, []byte, error) {
+	if len(key) != e.GetKeyByteSize() {
+		return nil, nil, fmt.Errorf("incorrect keysize: expected: %v actual: %v", e.GetKeyByteSize(), len(key))
+	}
+	data, _ = common.ZeroPad(data, e.GetMessageBlockByteSize())
+
+	block, err := des.NewTripleDESCipher(key)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error creating cipher: %v", err)
+	}
+
+	//RFC 3961: initial cipher state      All bits zero
+	ivz := make([]byte, des.BlockSize)
+
+	ct := make([]byte, len(data))
+	mode := cipher.NewCBCEncrypter(block, ivz)
+	mode.CryptBlocks(ct, data)
+	return ct[len(ct)-e.GetMessageBlockByteSize():], ct, nil
+}
+
+// DES3EncryptMessage encrypts the message provided using DES3 and methods specific to the etype provided.
+// The encrypted data is concatenated with its integrity hash to create an encrypted message.
+func DES3EncryptMessage(key, message []byte, usage uint32, e etype.EType) ([]byte, []byte, error) {
+	//confounder
+	c := make([]byte, e.GetConfounderByteSize())
+	_, err := rand.Read(c)
+	if err != nil {
+		return []byte{}, []byte{}, fmt.Errorf("could not generate random confounder: %v", err)
+	}
+	plainBytes := append(c, message...)
+	plainBytes, _ = common.ZeroPad(plainBytes, e.GetMessageBlockByteSize())
+
+	// Derive key for encryption from usage
+	var k []byte
+	if usage != 0 {
+		k, err = e.DeriveKey(key, common.GetUsageKe(usage))
+		if err != nil {
+			return []byte{}, []byte{}, fmt.Errorf("error deriving key for encryption: %v", err)
+		}
+	}
+
+	iv, b, err := e.EncryptData(k, plainBytes)
+	if err != nil {
+		return iv, b, fmt.Errorf("error encrypting data: %v", err)
+	}
+
+	// Generate and append integrity hash
+	ih, err := common.GetIntegrityHash(plainBytes, key, usage, e)
+	if err != nil {
+		return iv, b, fmt.Errorf("error encrypting data: %v", err)
+	}
+	b = append(b, ih...)
+	return iv, b, nil
+}
+
+// DES3DecryptData decrypts the data provided using DES3 and methods specific to the etype provided.
+func DES3DecryptData(key, data []byte, e etype.EType) ([]byte, error) {
+	if len(key) != e.GetKeyByteSize() {
+		return []byte{}, fmt.Errorf("incorrect keysize: expected: %v actual: %v", e.GetKeyByteSize(), len(key))
+	}
+
+	if len(data) < des.BlockSize || len(data)%des.BlockSize != 0 {
+		return []byte{}, errors.New("ciphertext is not a multiple of the block size")
+	}
+	block, err := des.NewTripleDESCipher(key)
+	if err != nil {
+		return []byte{}, fmt.Errorf("error creating cipher: %v", err)
+	}
+	pt := make([]byte, len(data))
+	ivz := make([]byte, des.BlockSize)
+	mode := cipher.NewCBCDecrypter(block, ivz)
+	mode.CryptBlocks(pt, data)
+	return pt, nil
+}
+
+// DES3DecryptMessage decrypts the message provided using DES3 and methods specific to the etype provided.
+// The integrity of the message is also verified.
+func DES3DecryptMessage(key, ciphertext []byte, usage uint32, e etype.EType) ([]byte, error) {
+	//Derive the key
+	k, err := e.DeriveKey(key, common.GetUsageKe(usage))
+	if err != nil {
+		return nil, fmt.Errorf("error deriving key: %v", err)
+	}
+	// Strip off the checksum from the end
+	b, err := e.DecryptData(k, ciphertext[:len(ciphertext)-e.GetHMACBitLength()/8])
+	if err != nil {
+		return nil, fmt.Errorf("error decrypting: %v", err)
+	}
+	//Verify checksum
+	if !e.VerifyIntegrity(key, ciphertext, b, usage) {
+		return nil, errors.New("error decrypting: integrity verification failed")
+	}
+	//Remove the confounder bytes
+	return b[e.GetConfounderByteSize():], nil
+}
+
+// VerifyIntegrity verifies the integrity of cipertext bytes ct.
+func VerifyIntegrity(key, ct, pt []byte, usage uint32, etype etype.EType) bool {
+	h := make([]byte, etype.GetHMACBitLength()/8)
+	copy(h, ct[len(ct)-etype.GetHMACBitLength()/8:])
+	expectedMAC, _ := common.GetIntegrityHash(pt, key, usage, etype)
+	return hmac.Equal(h, expectedMAC)
+}