diff --git a/vendor/github.com/jcmturner/aescts/v2/aescts.go b/vendor/github.com/jcmturner/aescts/v2/aescts.go
new file mode 100644
index 0000000..fee3b43
--- /dev/null
+++ b/vendor/github.com/jcmturner/aescts/v2/aescts.go
@@ -0,0 +1,186 @@
+// Package aescts provides AES CBC CipherText Stealing encryption and decryption methods
+package aescts
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"errors"
+	"fmt"
+)
+
+// Encrypt the message with the key and the initial vector.
+// Returns: next iv, ciphertext bytes, error
+func Encrypt(key, iv, plaintext []byte) ([]byte, []byte, error) {
+	l := len(plaintext)
+
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return []byte{}, []byte{}, fmt.Errorf("error creating cipher: %v", err)
+	}
+	mode := cipher.NewCBCEncrypter(block, iv)
+
+	m := make([]byte, len(plaintext))
+	copy(m, plaintext)
+
+	/*For consistency, ciphertext stealing is always used for the last two
+	blocks of the data to be encrypted, as in [RC5].  If the data length
+	is a multiple of the block size, this is equivalent to plain CBC mode
+	with the last two ciphertext blocks swapped.*/
+	/*The initial vector carried out from one encryption for use in a
+	subsequent encryption is the next-to-last block of the encryption
+	output; this is the encrypted form of the last plaintext block.*/
+	if l <= aes.BlockSize {
+		m, _ = zeroPad(m, aes.BlockSize)
+		mode.CryptBlocks(m, m)
+		return m, m, nil
+	}
+	if l%aes.BlockSize == 0 {
+		mode.CryptBlocks(m, m)
+		iv = m[len(m)-aes.BlockSize:]
+		rb, _ := swapLastTwoBlocks(m, aes.BlockSize)
+		return iv, rb, nil
+	}
+	m, _ = zeroPad(m, aes.BlockSize)
+	rb, pb, lb, err := tailBlocks(m, aes.BlockSize)
+	if err != nil {
+		return []byte{}, []byte{}, fmt.Errorf("error tailing blocks: %v", err)
+	}
+	var ct []byte
+	if rb != nil {
+		// Encrpt all but the lats 2 blocks and update the rolling iv
+		mode.CryptBlocks(rb, rb)
+		iv = rb[len(rb)-aes.BlockSize:]
+		mode = cipher.NewCBCEncrypter(block, iv)
+		ct = append(ct, rb...)
+	}
+	mode.CryptBlocks(pb, pb)
+	mode = cipher.NewCBCEncrypter(block, pb)
+	mode.CryptBlocks(lb, lb)
+	// Cipher Text Stealing (CTS) - Ref: https://en.wikipedia.org/wiki/Ciphertext_stealing#CBC_ciphertext_stealing
+	// Swap the last two cipher blocks
+	// Truncate the ciphertext to the length of the original plaintext
+	ct = append(ct, lb...)
+	ct = append(ct, pb...)
+	return lb, ct[:l], nil
+}
+
+// Decrypt the ciphertext with the key and the initial vector.
+func Decrypt(key, iv, ciphertext []byte) ([]byte, error) {
+	// Copy the cipher text as golang slices even when passed by value to this method can result in the backing arrays of the calling code value being updated.
+	ct := make([]byte, len(ciphertext))
+	copy(ct, ciphertext)
+	if len(ct) < aes.BlockSize {
+		return []byte{}, fmt.Errorf("ciphertext is not large enough. It is less that one block size. Blocksize:%v; Ciphertext:%v", aes.BlockSize, len(ct))
+	}
+	// Configure the CBC
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, fmt.Errorf("error creating cipher: %v", err)
+	}
+	var mode cipher.BlockMode
+
+	//If ciphertext is multiple of blocksize we just need to swap back the last two blocks and then do CBC
+	//If the ciphertext is just one block we can't swap so we just decrypt
+	if len(ct)%aes.BlockSize == 0 {
+		if len(ct) > aes.BlockSize {
+			ct, _ = swapLastTwoBlocks(ct, aes.BlockSize)
+		}
+		mode = cipher.NewCBCDecrypter(block, iv)
+		message := make([]byte, len(ct))
+		mode.CryptBlocks(message, ct)
+		return message[:len(ct)], nil
+	}
+
+	// Cipher Text Stealing (CTS) using CBC interface. Ref: https://en.wikipedia.org/wiki/Ciphertext_stealing#CBC_ciphertext_stealing
+	// Get ciphertext of the 2nd to last (penultimate) block (cpb), the last block (clb) and the rest (crb)
+	crb, cpb, clb, _ := tailBlocks(ct, aes.BlockSize)
+	v := make([]byte, len(iv), len(iv))
+	copy(v, iv)
+	var message []byte
+	if crb != nil {
+		//If there is more than just the last and the penultimate block we decrypt it and the last bloc of this becomes the iv for later
+		rb := make([]byte, len(crb))
+		mode = cipher.NewCBCDecrypter(block, v)
+		v = crb[len(crb)-aes.BlockSize:]
+		mode.CryptBlocks(rb, crb)
+		message = append(message, rb...)
+	}
+
+	// We need to modify the cipher text
+	// Decryt the 2nd to last (penultimate) block with a the original iv
+	pb := make([]byte, aes.BlockSize)
+	mode = cipher.NewCBCDecrypter(block, iv)
+	mode.CryptBlocks(pb, cpb)
+	// number of byte needed to pad
+	npb := aes.BlockSize - len(ct)%aes.BlockSize
+	//pad last block using the number of bytes needed from the tail of the plaintext 2nd to last (penultimate) block
+	clb = append(clb, pb[len(pb)-npb:]...)
+
+	// Now decrypt the last block in the penultimate position (iv will be from the crb, if the is no crb it's zeros)
+	// iv for the penultimate block decrypted in the last position becomes the modified last block
+	lb := make([]byte, aes.BlockSize)
+	mode = cipher.NewCBCDecrypter(block, v)
+	v = clb
+	mode.CryptBlocks(lb, clb)
+	message = append(message, lb...)
+
+	// Now decrypt the penultimate block in the last position (iv will be from the modified last block)
+	mode = cipher.NewCBCDecrypter(block, v)
+	mode.CryptBlocks(cpb, cpb)
+	message = append(message, cpb...)
+
+	// Truncate to the size of the original cipher text
+	return message[:len(ct)], nil
+}
+
+func tailBlocks(b []byte, c int) ([]byte, []byte, []byte, error) {
+	if len(b) <= c {
+		return []byte{}, []byte{}, []byte{}, errors.New("bytes slice is not larger than one block so cannot tail")
+	}
+	// Get size of last block
+	var lbs int
+	if l := len(b) % aes.BlockSize; l == 0 {
+		lbs = aes.BlockSize
+	} else {
+		lbs = l
+	}
+	// Get last block
+	lb := b[len(b)-lbs:]
+	// Get 2nd to last (penultimate) block
+	pb := b[len(b)-lbs-c : len(b)-lbs]
+	if len(b) > 2*c {
+		rb := b[:len(b)-lbs-c]
+		return rb, pb, lb, nil
+	}
+	return nil, pb, lb, nil
+}
+
+func swapLastTwoBlocks(b []byte, c int) ([]byte, error) {
+	rb, pb, lb, err := tailBlocks(b, c)
+	if err != nil {
+		return nil, err
+	}
+	var out []byte
+	if rb != nil {
+		out = append(out, rb...)
+	}
+	out = append(out, lb...)
+	out = append(out, pb...)
+	return out, nil
+}
+
+// zeroPad pads bytes with zeros to nearest multiple of message size m.
+func zeroPad(b []byte, m int) ([]byte, error) {
+	if m <= 0 {
+		return nil, errors.New("invalid message block size when padding")
+	}
+	if b == nil || len(b) == 0 {
+		return nil, errors.New("data not valid to pad: Zero size")
+	}
+	if l := len(b) % m; l != 0 {
+		n := m - l
+		z := make([]byte, n)
+		b = append(b, z...)
+	}
+	return b, nil
+}