Added ability to pass custom salt to everyencrypt call

- created new function for encryption string which takes salt as an argument and original encrypt string is just passing generated salt as argument

openssl.go

@@ -70,14 +70,21 @@ func (o *OpenSSL) decrypt(key, iv, data []byte) ([]byte, error) {
 }
 
 // EncryptString encrypts a string in a manner compatible to OpenSSL encryption
-// functions using AES-256-CBC as encryption algorithm
-func (o *OpenSSL) EncryptString(passphrase, plaintextString string) ([]byte, error) {
+// functions using AES-256-CBC as encryption algorithm. Generating salt.
+func (o *OpenSSL) EncryptString(passphrase string, plaintextString string) ([]byte, error) {
 	salt := make([]byte, 8) // Generate an 8 byte salt
 	_, err := io.ReadFull(rand.Reader, salt)
 	if err != nil {
 		return nil, err
 	}
 
+	return o.EncryptStringWithSalt(passphrase, salt, plaintextString)
+}
+
+// EncryptString encrypts a string in a manner compatible to OpenSSL encryption
+// functions using AES-256-CBC as encryption algorithm. Ability to pass custom
+// salt.
+func (o *OpenSSL) EncryptStringWithSalt(passphrase string, salt []byte, plaintextString string) ([]byte, error) {
 	data := make([]byte, len(plaintextString)+aes.BlockSize)
 	copy(data[0:], o.openSSLSaltHeader)
 	copy(data[8:], salt)

openssl_test.go

@@ -48,6 +48,50 @@ func TestEncryptToDecrypt(t *testing.T) {
 	}
 }
 
+func TestEncryptToDecryptWithCustomSalt(t *testing.T) {
+	plaintext := "hallowelt"
+	passphrase := "z4yH36a6zerhfE5427ZV"
+	salt := []byte("saltsalt")
+
+	o := New()
+
+	enc, err := o.EncryptStringWithSalt(passphrase, salt, plaintext)
+	if err != nil {
+		t.Fatalf("Test errored at encrypt: %s", err)
+	}
+
+	dec, err := o.DecryptString(passphrase, string(enc))
+	if err != nil {
+		t.Fatalf("Test errored at decrypt: %s", err)
+	}
+
+	if string(dec) != plaintext {
+		t.Errorf("Decrypted text did not match input.")
+	}
+}
+
+func TestEncryptWithSaltShouldHaveSameOutput(t *testing.T) {
+	plaintext := "outputshouldbesame"
+	passphrase := "passphrasesupersecure"
+	salt := []byte("saltsalt")
+
+	o := New()
+
+	enc1, err := o.EncryptStringWithSalt(passphrase, salt, plaintext)
+	if err != nil {
+		t.Fatalf("Test errored at encrypt: %s", err)
+	}
+
+	enc2, err := o.EncryptStringWithSalt(passphrase, salt, plaintext)
+	if err != nil {
+		t.Fatalf("Test errored at encrypt: %s", err)
+	}
+
+	if string(enc1) != string(enc2) {
+		t.Errorf("Encrypted outputs are not same.")
+	}
+}
+
 func TestEncryptToOpenSSL(t *testing.T) {
 	plaintext := "hallowelt"
 	passphrase := "z4yH36a6zerhfE5427ZV"