Merge pull request #29 from Bit-Nation/feature/aes_ctr

AES CTR

cli/main.go

@@ -289,10 +289,15 @@ func main() {
 				return
 			}
 
+			rawStore, err := exportedAccount.Marshal()
+			if err != nil {
+				panic(err)
+			}
+
 			err = db.Write("account", id.String(), &Account{
 				ID:           id.String(),
 				Name:         accountName,
-				AccountStore: exportedAccount,
+				AccountStore: string(rawStore),
 				Profile:      string(rawProfile),
 			})
 

client/client_key_store.go

@@ -30,6 +30,7 @@ func (s *DoubleRatchetKeyStore) Get(k dr.Key, msgNum uint) (mk dr.Key, ok bool)
 	}
 
 	resp := <-respCha
+
 	if resp.Error != nil {
 		resp.Close(nil)
 		return dr.Key{}, false

client/client_key_store_test.go

@@ -76,7 +76,7 @@ func TestDoubleRatchetKeyStore_GetSuccess(t *testing.T) {
 
 				mustBeEqual(`{"key":"0000000000000000000100010000000000010001000000000000000100000001","msg_num":7}`, rpcCall.Data)
 
-				requireNil(api.Receive(rpcCall.Id, `{"error":"","payload":"{\"key\":\"{\\\"iv\\\":\\\"f+ZgKGwhkz82bokcs7HI8A==\\\",\\\"cipher_text\\\":\\\"Qu0SeXs/ahOjqcwPRIrK0sR9ngirapvt33x3SNLayFs=\\\",\\\"mac\\\":\\\"vJhCluH/bWdkcaA3vtTzDDsYFVO0A7UcL7wbPbvYdG0=\\\",\\\"v\\\":1}\"}"}`))
+				requireNil(api.Receive(rpcCall.Id, `{"error":"","payload":"{\"key\":\"{\\\"iv\\\":\\\"3Zd2O1KxUz2OZnWQPrTgCg==\\\",\\\"cipher_text\\\":\\\"q4FO26h5TICATqwwp9RXXXes1jX8asn+0TkL5Khx8Oc=\\\",\\\"mac\\\":\\\"XwX884HeXuodY3vgoKvmZcGkW0oPu2fBvRafxAsMu/I=\\\",\\\"v\\\":2}\"}"}`))
 
 			}
 		}

crypto/aes/cfb.go

@@ -0,0 +1,77 @@
+package aes
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"io"
+)
+
+var cfbRandReader io.Reader = rand.Reader
+
+// encrypt a plain text with given secret
+// Deprecated: use CTREncrypt instead
+func CFBEncrypt(plainText PlainText, key Secret) (CipherText, error) {
+
+	// create block
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return CipherText{}, err
+	}
+
+	// create IV
+	iv := make([]byte, aes.BlockSize)
+	if _, err := io.ReadFull(cfbRandReader, iv); err != nil {
+		return CipherText{}, err
+	}
+
+	// create cfb encrypter
+	stream := cipher.NewCFBEncrypter(block, iv)
+	cipherText := make([]byte, len(plainText))
+	stream.XORKeyStream(cipherText, plainText)
+
+	// cipher text
+	ct := CipherText{
+		IV:         iv,
+		CipherText: cipherText,
+		Version:    1,
+	}
+
+	// create mac
+	mac, err := vOneMac(ct, key)
+	if err != nil {
+		return CipherText{}, err
+	}
+	ct.Mac = mac
+
+	return ct, nil
+
+}
+
+// decrypt a cipher text with given secret
+// Deprecated: use CFBDecrypt instead
+func CFBDecrypt(cipherText CipherText, key Secret) (PlainText, error) {
+
+	// create block
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return PlainText{}, err
+	}
+
+	valid, err := cipherText.ValidMAC(key)
+	if err != nil {
+		return PlainText{}, err
+	}
+	if !valid {
+		return PlainText{}, MacError
+	}
+
+	stream := cipher.NewCFBDecrypter(block, cipherText.IV)
+
+	cc := cipherText.CipherText
+
+	// XORKeyStream can work in-place if the two arguments are the same.
+	stream.XORKeyStream(cc, cc)
+
+	return cc, nil
+}

crypto/aes/cfb_test.go

@@ -0,0 +1,183 @@
+package aes
+
+import (
+	"bytes"
+	"encoding/hex"
+	"testing"
+
+	require "github.com/stretchr/testify/require"
+)
+
+// Test the encrypt and decrypt function in one batch
+func CFBTestSuccessEncryptDecrypt(t *testing.T) {
+
+	secret := Secret{
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}
+	value := []byte("I am the value")
+
+	//Encrypt
+	cipherText, e := CFBEncrypt(value, secret)
+	require.Nil(t, e)
+
+	//Decrypt
+	res, err := CFBDecrypt(cipherText, secret)
+	require.Nil(t, err)
+
+	//Decrypted value must match the given value
+	require.Equal(t, string(value), string(res))
+
+}
+
+func CFBTestFailedDecryption(t *testing.T) {
+
+	secret := Secret{
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}
+	value := []byte("I am the plain text")
+
+	// encrypt
+	cipherText, e := CFBEncrypt(value, secret)
+	require.Nil(t, e)
+
+	// change last byte to fail on decryption
+	secret[31] = 0x01
+
+	// decrypt
+	plainText, err := CFBDecrypt(cipherText, secret)
+	require.Equal(t, PlainText{}, plainText)
+	require.EqualError(t, err, "invalid key - message authentication failed")
+
+}
+
+func TestCFBEncrypt(t *testing.T) {
+
+	// encryption key
+	encryptionKey, err := hex.DecodeString("603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4")
+	require.Nil(t, err)
+
+	// aes cfb test vectors
+	testVectors := []testVector{
+		testVector{
+			iv:         "000102030405060708090a0b0c0d0e0f",
+			plainText:  "6bc1bee22e409f96e93d7e117393172a",
+			cipherText: "dc7e84bfda79164b7ecd8486985d3860",
+		},
+		testVector{
+			iv:         "dc7e84bfda79164b7ecd8486985d3860",
+			plainText:  "ae2d8a571e03ac9c9eb76fac45af8e51",
+			cipherText: "39ffed143b28b1c832113c6331e5407b",
+		},
+		testVector{
+			iv:         "39ffed143b28b1c832113c6331e5407b",
+			plainText:  "30c81c46a35ce411e5fbc1191a0a52ef",
+			cipherText: "df10132415e54b92a13ed0a8267ae2f9",
+		},
+		testVector{
+			iv:         "df10132415e54b92a13ed0a8267ae2f9",
+			plainText:  "f69f2445df4f9b17ad2b417be66c3710",
+			cipherText: "75a385741ab9cef82031623d55b1e471",
+		},
+	}
+
+	for _, v := range testVectors {
+
+		// initialisation vector
+		iv, err := hex.DecodeString(v.iv)
+		require.Nil(t, err)
+		cfbRandReader = bytes.NewReader(iv)
+
+		// plain text
+		plainText, err := hex.DecodeString(v.plainText)
+		require.Nil(t, err)
+
+		// cipher text
+		cipherText, err := hex.DecodeString(v.cipherText)
+		require.Nil(t, err)
+		// create secret key
+		secKey := Secret{}
+		copy(secKey[:], encryptionKey)
+
+		// encrypt
+		ct, err := CFBEncrypt(plainText, secKey)
+		require.Nil(t, err)
+
+		require.Equal(t, hex.EncodeToString(cipherText), hex.EncodeToString(ct.CipherText))
+
+	}
+
+}
+
+func TestCFBDecrypt(t *testing.T) {
+
+	// encryption key
+	encryptionKey, err := hex.DecodeString("603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4")
+	require.Nil(t, err)
+
+	// aes cfb test vectors
+	testVectors := []testVector{
+		testVector{
+			iv:         "000102030405060708090a0b0c0d0e0f",
+			plainText:  "6bc1bee22e409f96e93d7e117393172a",
+			cipherText: "dc7e84bfda79164b7ecd8486985d3860",
+			mac:        "43517b9531fdb8565ce2a6af1cbb24930cb7ec2b3685701cfac6731bb861cb60",
+		},
+		testVector{
+			iv:         "dc7e84bfda79164b7ecd8486985d3860",
+			plainText:  "ae2d8a571e03ac9c9eb76fac45af8e51",
+			cipherText: "39ffed143b28b1c832113c6331e5407b",
+			mac:        "de571950b74a72055810fad70421676aeadd651d6bd3ba6ad0348a7c7c9ebc8e",
+		},
+		testVector{
+			iv:         "39ffed143b28b1c832113c6331e5407b",
+			plainText:  "30c81c46a35ce411e5fbc1191a0a52ef",
+			cipherText: "df10132415e54b92a13ed0a8267ae2f9",
+			mac:        "6ce26e57380b71dec45177dda9d1d322e1dceba40b462b6c15990a43bb1b2ec2",
+		},
+		testVector{
+			iv:         "df10132415e54b92a13ed0a8267ae2f9",
+			plainText:  "f69f2445df4f9b17ad2b417be66c3710",
+			cipherText: "75a385741ab9cef82031623d55b1e471",
+			mac:        "73fb351bba3a8299d2271ff489dc4ed2412e69653b9877bc19a6b408c51e83da",
+		},
+	}
+
+	for _, v := range testVectors {
+
+		// initialisation vector
+		iv, err := hex.DecodeString(v.iv)
+		require.Nil(t, err)
+		cfbRandReader = bytes.NewReader(iv)
+
+		// mac
+		mac, err := hex.DecodeString(v.mac)
+		require.Nil(t, err)
+
+		// cipher text
+		cipherText, err := hex.DecodeString(v.cipherText)
+		require.Nil(t, err)
+
+		// create secret key
+		secKey := Secret{}
+		copy(secKey[:], encryptionKey)
+
+		// encrypt
+		plain, err := CFBDecrypt(CipherText{
+			IV:         iv,
+			Mac:        mac,
+			CipherText: cipherText,
+			Version:    uint8(1),
+		}, secKey)
+		require.Nil(t, err)
+
+		require.Equal(t, v.plainText, hex.EncodeToString(plain))
+
+	}
+
+}

crypto/aes/ctr.go

@@ -0,0 +1,74 @@
+package aes
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"io"
+)
+
+var ctrRandReader io.Reader = rand.Reader
+
+// encrypt plain text by given key using AES CTR 256
+func CTREncrypt(plainText PlainText, secret Secret) (CipherText, error) {
+
+	// block
+	block, err := aes.NewCipher(secret[:])
+	if err != nil {
+		return CipherText{}, err
+	}
+
+	// initialisation vector
+	iv := make([]byte, 16)
+	_, err = io.ReadFull(ctrRandReader, iv)
+	if err != nil {
+		return CipherText{}, err
+	}
+
+	// create cipher text
+	cipherText := make([]byte, len(plainText))
+
+	// encrypt
+	stream := cipher.NewCTR(block, iv)
+	stream.XORKeyStream(cipherText, plainText)
+
+	// create cipher text
+	ct := CipherText{
+		IV:         iv,
+		CipherText: cipherText,
+		Version:    2,
+	}
+
+	// create mac
+	mac, err := vTwoMac(ct, secret)
+	ct.Mac = mac
+
+	return ct, err
+}
+
+// decrypt cipher text by given key
+func CTRDecrypt(cipherText CipherText, key Secret) (PlainText, error) {
+
+	// create block
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return PlainText{}, err
+	}
+
+	// validate key
+	valid, err := cipherText.ValidMAC(key)
+	if err != nil {
+		return PlainText{}, err
+	}
+	if !valid {
+		return PlainText{}, MacError
+	}
+
+	// decrypt
+	plainText := make(PlainText, len(cipherText.CipherText))
+	stream := cipher.NewCTR(block, cipherText.IV)
+	stream.XORKeyStream(plainText, cipherText.CipherText)
+
+	return plainText, nil
+
+}