Merge pull request #43 from SecurityCze/salt_position

Add new salt position options:

- As a separate word itself (#36)
- Prefix and suffix a word (#38)

Author: nitz

Diceware.cs

@@ -294,6 +294,25 @@ private static void ApplySalt(string[] words, SaltType salt, IEnumerable<SaltSou
 
 					words[targetIndex] = $"{words[targetIndex]}{separator}{singleSalt}";
 					break;
+				case SaltType.SuffixToRandomWord:
+					int suffixToIndex = random.AtMost(words.Length - 1);
+					words[suffixToIndex] = $"{words[suffixToIndex]}{singleSalt}";
+					break;
+				case SaltType.PrefixToRandomWord:
+					int prefixToIndex = random.AtMost(words.Length - 1);
+					words[prefixToIndex] = $"{singleSalt}{words[prefixToIndex]}";
+					break;
+				case SaltType.AsSeparateWordOnce:
+					int insertBefore = random.AtMost(words.Length);
+					if (insertBefore != words.Length)
+					{
+						words[insertBefore] = $"{singleSalt}{separator}{words[insertBefore]}";
+					}
+					else // There is no word with index insertBefore, we need to append it
+					{
+						words[insertBefore - 1] = $"{words[insertBefore - 1]}{separator}{singleSalt}";
+					}
+					break;
 				default:
 					throw new ArgumentOutOfRangeException(nameof(salt));
 			}

SaltType.cs

@@ -36,5 +36,11 @@ public enum SaltType
 		BetweenOne,
 		[Description("Between each word")]
 		BetweenEach,
+		[Description("Prepend to the beginning of a random word")]
+		PrefixToRandomWord,
+		[Description("Appended to the end of a random word")]
+		SuffixToRandomWord,
+		[Description("Insert as a separate word at a random position, once")]
+		AsSeparateWordOnce,
 	}
 }