Cleaned up, added release script.

README.md

@@ -1,5 +1,5 @@
 # scrambler
-Tool for encrypting and decrypting entire directories on-the-fly.
+A tool for encrypting and decrypting entire directories on-the-fly.
 
 scrambler uses a block cipher and passphrase to encrypt and decrypt files in-place, as a means for quickly securing content without having to move things and/or create archives. scrambler appends a `.enc` extension to encrypted files, so it can use context clues to determine whether you want to perform encryption or decryption.
 

build-release.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+dub clean
+rm -f scrambler
+
+dub build --non-interactive --build=release --color=on --compiler=/home/andrew/Downloads/ldc2-1.32.0-linux-x86_64/bin/ldc2

source/app.d

@@ -25,21 +25,9 @@ int main(string[] args) {
 		return result;
 	}
 
-	string passphrase;
-	if (params.passphraseFile !is null && exists(params.passphraseFile) && isFile(params.passphraseFile)) {
-		if (params.verbose) {
-			writefln!"Reading passphrase from \"%s\""(params.passphraseFile);
-		}
-		passphrase = readText(params.passphraseFile).strip();
-	} else {
-		write("Enter passphrase: ");
-		passphrase = readPassphrase();
-		writeln();
-	}
-	if (passphrase is null || passphrase.length == 0) {
-		stderr.writeln("Invalid or missing passphrase.");
-		return 2;
-	}
+	auto nullablePassphrase = getPassphrase(params);
+	if (nullablePassphrase.isNull) return 2;
+	string passphrase = nullablePassphrase.get();
 
 	HashFunction hash = new SHA256();
 	auto secureKeyVector = hash.process(passphrase);
@@ -53,7 +41,7 @@ int main(string[] args) {
 		} else {
 			bool success = decryptDir(params.target, cipher, buffer, params.recursive, params.verbose);
 			if (!success) {
-				stderr.writeln("Decryption failed.");
+				stderr.writeln("Decryption failed. The passphrase is probably incorrect.");
 				return 3;
 			}
 		}
@@ -63,7 +51,7 @@ int main(string[] args) {
 		} else {
 			bool success = decryptAndRemoveFile(params.target, cipher, buffer, params.verbose);
 			if (!success) {
-				stderr.writeln("Decryption failed.");
+				stderr.writeln("Decryption failed. The passphrase is probably incorrect.");
 				return 3;
 			}
 		}

source/cipher_utils.d

@@ -3,6 +3,7 @@ module cipher_utils;
 import botan.block.block_cipher : BlockCipher;
 import std.stdio;
 import std.file;
+import std.datetime.stopwatch;
 
 public const string ENCRYPTED_SUFFIX = ".enc";
 
@@ -16,6 +17,7 @@ public void encryptFile(string filename, string outputFilename, BlockCipher ciph
             cipher.name
         );
     }
+    StopWatch sw = StopWatch(AutoStart.yes);
     File fIn = File(filename, "rb");
     File fOut = File(outputFilename, "wb");
     // First, write one block containing the file's size.
@@ -36,8 +38,9 @@ public void encryptFile(string filename, string outputFilename, BlockCipher ciph
     }
     fIn.close();
     fOut.close();
+    sw.stop();
     if (verbose) {
-        writefln!"  Encrypted file has a size of %d bytes."(getSize(outputFilename));
+        writefln!"  Encrypted file in %d ms, new size %d bytes."(sw.peek().total!"msecs", getSize(outputFilename));
     }
 }
 
@@ -51,28 +54,16 @@ public bool decryptFile(string filename, string outputFilename, BlockCipher ciph
             cipher.name
         );
     }
+    StopWatch sw = StopWatch(AutoStart.yes);
     File fIn = File(filename, "rb");
     // First, read one block containing the file's size.
     fIn.rawRead(buffer);
     cipher.decrypt(buffer);
     // Verify the sequence of values to ensure decryption was successful.
-    if (buffer.length > 8) {
-        ubyte expectedMarker = 1;
-        for (size_t i = 8; i < buffer.length; i++) {
-            if (buffer[i] != expectedMarker) {
-                if (verbose) {
-                    writefln!"  Decryption validation failed. Expected byte at index %d to be %d, but got %d."(
-                        i,
-                        expectedMarker,
-                        buffer[i]
-                    );
-                }
+    if (buffer.length > 8 && !validateBufferDecryptionMarker(buffer[8..$], verbose)) {
         fIn.close();
         return false;
     }
-            expectedMarker++;
-        }
-    }
     ulong size = readSizeBytes(buffer);
     if (verbose) {
         writefln!"  Original file had size of %d bytes."(size);
@@ -91,8 +82,27 @@ public bool decryptFile(string filename, string outputFilename, BlockCipher ciph
     }
     fIn.close();
     fOut.close();
+    sw.stop();
     if (verbose) {
-        writefln!"  Decrypted file has a size of %d bytes."(getSize(outputFilename));
+        writefln!"  Decrypted file in %d ms, new size %d bytes."(sw.peek().total!"msecs", getSize(outputFilename));
+    }
+    return true;
+}
+
+private bool validateBufferDecryptionMarker(ubyte[] bufferSlice, bool verbose) {
+    ubyte expectedMarker = 1;
+    for (size_t i = 0; i < bufferSlice.length; i++) {
+        if (bufferSlice[i] != expectedMarker) {
+            if (verbose) {
+                writefln!"  Decryption validation failed. Expected byte at index %d to be %d, but got %d."(
+                    i,
+                    expectedMarker,
+                    bufferSlice[i]
+                );
+            }
+            return false;
+        }
+        expectedMarker++;
     }
     return true;
 }

source/cli_utils.d

@@ -1,6 +1,7 @@
 module cli_utils;
 
 import cipher_utils : ENCRYPTED_SUFFIX;
+import std.typecons;
 
 enum Action {
 	ENCRYPT,
@@ -12,6 +13,7 @@ struct Params {
 	string target = ".";
 	bool recursive = false;
 	bool verbose = false;
+	bool noSuffix = false;
 	string passphraseFile = null;
 }
 
@@ -28,6 +30,7 @@ int parseParams(string[] args, ref Params params) {
 		"verbose|v", &params.verbose,
 		"encrypt|e", &isEncrypting,
 		"decrypt|d", &isDecrypting,
+		"no-suffix|s", &params.noSuffix,
 		"passphrase-file|p", &params.passphraseFile
 	);
 	if (isEncrypting && isDecrypting) {
@@ -52,7 +55,14 @@ int parseParams(string[] args, ref Params params) {
 	return 0;
 }
 
-Action determineBestAction(string target) {
+/** 
+ * Determines the most appropriate action to perform on a target file or
+ * directory, based on its contents.
+ * Params:
+ *   target = The target to check.
+ * Returns: Whether to encrypt or decrypt.
+ */
+private Action determineBestAction(string target) {
 	import std.file;
 	import std.algorithm : endsWith;
 
@@ -68,7 +78,10 @@ Action determineBestAction(string target) {
 	}
 }
 
-void printUsage() {
+/** 
+ * Prints a standard usage/help message to stdout.
+ */
+public void printUsage() {
     import std.stdio : writeln;
 	writeln(q"HELP
 Usage: scrambler [target] [options]
@@ -94,7 +107,39 @@ Scrambler will try to determine which operation to do based on the presence of
 HELP");
 }
 
-string readPassphrase() {
+public Nullable!string getPassphrase(Params params) {
+	import std.file;
+	import std.stdio;
+	import std.string : strip;
+	if (params.passphraseFile !is null && params.passphraseFile.length > 0) {
+		if (exists(params.passphraseFile) && isFile(params.passphraseFile)) {
+			if (params.verbose) {
+				writefln!"Reading passphrase from \"%s\""(params.passphraseFile);
+			}
+			return nullable(readText(params.passphraseFile).strip());
+		} else {
+			stderr.writefln!"Invalid or missing passphrase file: \"%s\""(params.passphraseFile);
+			return Nullable!string.init;
+		}
+	}
+
+	// No passphrase file specified, so read from stdin.
+	write("Enter passphrase: ");
+	string passphrase = readPassphrase();
+	writeln();
+	if (passphrase is null || passphrase.length == 0) {
+		stderr.writeln("Invalid or missing passphrase.");
+		return Nullable!string.init;
+	}
+	return nullable(passphrase);
+}
+
+/** 
+ * Reads a passphrase from stdin while disabling terminal echoing, so that the
+ * entered password does not appear.
+ * Returns: The passphrase string, or null if we could not securely read it.
+ */
+public string readPassphrase() {
     import std.stdio;
     import std.string : strip;
 	version(Posix) {
@@ -137,7 +182,7 @@ string readPassphrase() {
         SetConsoleMode(hIn, prev_con_mode);
 		return password;
 	} else {
-        stderr.writeln("Cannot securely read password from terminal.");
+        stderr.writeln("Cannot securely read password from terminal. Please supply a passphrase file with -p.");
 		return null;
 	}
 }