Added proper password reading.

source/app.d

@@ -3,6 +3,7 @@ import std.path;
 import std.file;
 import std.algorithm : endsWith;
 import std.string : strip;
+import std.getopt;
 
 import botan.block.block_cipher : BlockCipher;
 import botan.block.aes : AES256;
@@ -12,32 +13,21 @@ import botan.hash.sha2_32 : SHA256;
 import cipher_utils;
 
 int main(string[] args) {
-	string action = "encrypt";
-	if (args.length >= 2) {
-		string command = args[1];
-		if (command == "encrypt") {
-			action = "encrypt";
-		} else if (command == "decrypt") {
-			action = "decrypt";
-		} else {
-			stderr.writefln!"Invalid action: %s"(command);
-			return 1;
-		}
+	Params params;
+	int result = parseParams(args, params);
+	if (result != 0) {
+		printUsage();
+		return result;
 	}
 
-	string target = ".";
-	if (args.length >= 3) {
-		target = args[2];
-		if (!exists(target)) {
-			stderr.writefln!"Target \"%s\" doesn't exist."(target);
-			return 1;
-		}
-	}
 
 	BlockCipher cipher = null;
 	// TODO: Use args to determine block cipher.
 	writeln("Enter a password:");
-	string password = readln().strip();
+	string password = readPassphrase();
+	if (password is null) {
+		return 2;
+	}
 
 	HashFunction hash = new SHA256();
 	auto secureKeyVector = hash.process(password);
@@ -45,23 +35,17 @@ int main(string[] args) {
 	cipher.setKey(secureKeyVector);
 
 	ubyte[] buffer = new ubyte[cipher.blockSize];
-	if (isDir(target)) {
-		if (action == "encrypt") {
-			encryptDir(target, cipher, buffer, true);
-		} else if (action == "decrypt") {
-			decryptDir(target, cipher, buffer, true);
+	if (isDir(params.target)) {
+		if (params.action == Action.ENCRYPT) {
+			encryptDir(params.target, cipher, buffer, params.recursive);
 		} else {
-			stderr.writefln!"Unsupported action: %s"(action);
-			return 1;
+			decryptDir(params.target, cipher, buffer, params.recursive);
 		}
-	} else if (isFile(target)) {
-		if (action == "encrypt") {
-			encryptAndRemoveFile(target, cipher, buffer);
-		} else if (action == "decrypt") {
-			decryptAndRemoveFile(target, cipher, buffer);
+	} else if (isFile(params.target)) {
+		if (params.action == Action.ENCRYPT) {
+			encryptAndRemoveFile(params.target, cipher, buffer);
 		} else {
-			stderr.writefln!"Unsupported action: %s"(action);
-			return 1;
+			decryptAndRemoveFile(params.target, cipher, buffer);
 		}
 	} else {
 		stderr.writeln("Target is not a directory or file.");
@@ -70,6 +54,109 @@ int main(string[] args) {
 	return 0;
 }
 
+enum Action {
+	ENCRYPT,
+	DECRYPT
+}
+
+struct Params {
+	Action action = Action.ENCRYPT;
+	string target = ".";
+	bool recursive = false;
+	bool verbose = false;
+}
+
+int parseParams(string[] args, ref Params params) {
+	getopt(
+		args,
+		"recursive|r", &params.recursive,
+		"verbose|v", &params.verbose
+	);
+	if (args.length < 2) {
+		stderr.writeln("Missing required action.");
+		return 1;
+	}
+	string action = args[1].strip();
+	if (action != "encrypt" && action != "decrypt") {
+		stderr.writeln("Invalid action.");
+		return 1;
+	}
+	if (action == "encrypt") {
+		params.action = Action.ENCRYPT;
+	} else if (action == "decrypt") {
+		params.action = Action.DECRYPT;
+	}
+
+	if (args.length >= 3) {
+		params.target = args[2];
+		if (!exists(params.target)) {
+			stderr.writefln!"Target \"%s\" doesn't exist."(params.target);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+string readPassphrase() {
+	version(Posix) {
+		import core.sys.posix.termios : termios, tcgetattr, tcsetattr, ECHO;
+		import core.sys.posix.stdio;
+		termios term;
+		tcgetattr(0, &term);
+		term.c_lflag &= ~ECHO;
+		tcsetattr(0, 0, &term);
+
+		string passphrase = readln().strip();
+
+		term.c_lflag |= ECHO;
+		tcsetattr(0, 0, &term);
+
+		return passphrase;
+	} else version(Windows) {
+		import core.sys.windows.windows;
+		DWORD con_mode;
+		DWORD dwRead;
+		HANDLE hIn = GetStdHandle(STD_INPUT_HANDLE);
+		GetConsoleMode(hIn, &con_mode);
+		SetConsoleMode(hIn, con_mode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT));
+
+		string password = "";
+		char BACKSPACE = 8;
+		char RETURN = 13;
+		char ch = 0;
+		while (ReadConsoleA(hIn, &ch, 1, &dwRead, NULL) && ch != RETURN) {
+			if (ch == BACKSPACE) {
+				if (password.length > 0) {
+					password = password[0 .. $ - 1];
+				}
+			} else {
+				password ~= ch;
+			}
+		}
+		return password;
+	} else {
+		stderr.writeln("Unsupported password reading.");
+		return null;
+	}
+}
+
+void printUsage() {
+	writeln(q"HELP
+Usage: scrambler <encrypt|decrypt> [target] [options]
+Scramber is a command-line tool for "scrambling", or encrypting files with a
+passphrase so they can only be read after they're decrypted using the same
+passphrase.
+
+Provide either the "encrypt" or "decrypt" command, followed by a target that's
+either a directory, or an individual file. By default, the target is the
+directory that Scrambler was invoked from.
+
+The following options are available:
+  -r | --recursive       Recursively encrypt/decrypt nested directories.
+  -v | --verbose         Show verbose output during runtime.
+HELP");
+}
+
 void encryptAndRemoveFile(string filename, BlockCipher cipher, ref ubyte[] buffer) {
 	string encryptedFilename = filename ~ ".enc";
 	encryptFile(filename, encryptedFilename, cipher, buffer);