Remove an incomplete (or corrupted) output file by default.

README.md

@@ -32,7 +32,7 @@ The SlunkCypt command-line program is invoked as follows:
 Commands
 --------
 
-One of the following commands must be chosen:
+One of the following commands **must** be chosen:
 
 - **`--encrypt` (`-e`):**  
   Run application in ***encrypt*** mode. Reads the given *plaintext* and generates *ciphertext*.
@@ -46,7 +46,7 @@ One of the following commands must be chosen:
 Options
 -------
 
-The following options are available:
+The following command-line options are available:
 
 - **`pass:<pass>`**:  
   * Specifies the "secret" passphrase directly on the command-line. This is considered *insecure*.
@@ -62,20 +62,30 @@ The following options are available:
 - **`<length>`**:  
   * Specifies the length of the passphrase to be generated. If *not* specified, defaults to 24.
 
-### Remarks
-
-- If the passphrase is **not** specified on the command-line, it will be read from the `SLUNK_PASSPHRASE` environment variable.
+### Remarks {.unlisted}
 
 - The same passphrase must be used for both, ***encrypt*** and ***decrypt*** mode. The decryption of the ciphertext will only be possible, if the "correct" passphrase is known. It is recommended to choose a "random" password that is at least 12 characters in length and consists of a mix of upper-case characters, lower-case characters, digits as well as special characters.
 
-- Passing the passphrase directly on the command-line is insecure, because the command-line may be visible to other users.
+- Passing the passphrase directly on the command-line is insecure, because the full command-line may be visible to other users!
+
+Environment
+-----------
+
+The following environment variables may be used:
+
+- **`SLUNK_PASSPHRASE`**:  
+  Specifies the "secret" passphrase. This environment variables is only evaluated, if the passphrase was **not** specified on the command-line.  
+  Passing the passphrase via environment variable is considered more secure, because environment variables are not normally visible to other (unprivileged) users.
+
+- **`SLUNK_KEEP_INCOMPLETE`**:  
+  If set to a *non-zero* value, incomplete or corrupted output files will **not** be deleted automatically. Default is `0`.
 
 Examples
 --------
 
 Here are some examples on how to use the SlunkCrypt command-line application:
 
-### Example #1
+### Example #1 {.unlisted}
 
 1. Let's generate a new random (secure) password first:
 
@@ -101,7 +111,7 @@ Here are some examples on how to use the SlunkCrypt command-line application:
 
        sha256sum -b plaintext.txt plaintext.out
 
-### Example #2
+### Example #2 {.unlisted}
 
 1. Generate a new password and store it to a text file:
 
@@ -115,7 +125,7 @@ Here are some examples on how to use the SlunkCrypt command-line application:
 
        slunkcrypt --encrypt file:passwd.txt plaintext.txt ciphertext.enc
 
-### Example #3
+### Example #3 {.unlisted}
 
 1. Generate a new password directly to an environment variable:
 
@@ -158,7 +168,7 @@ Getting started
 
 In order to use the SlunkCypt library in your C++ code, include **`<slunkcrypt.hpp>`** header and instantiate the appropriate SlunkCypt classes:
 
-### Example #1
+### Example #1 {.unlisted}
 
 Here is a simple example on how to use the SlunkCrypt [**`Encryptor`**](#encryptor) class:
 
@@ -186,7 +196,7 @@ Here is a simple example on how to use the SlunkCrypt [**`Encryptor`**](#encrypt
         std::cout << std::hex << slunk_encrypt.get_nonce() << std::endl;
     }
 
-### Example #2
+### Example #2 {.unlisted}
 
 Here is a simple example on how to use the SlunkCrypt [**`Decryptor`**](#decryptor) class:
 

frontend/src/main.c

@@ -40,7 +40,9 @@
 
 #define PW_FROM_ENV (!(argc > 4))
 
-static const CHR* const ENV_PASSWRD = T("SLUNK_PASSPHRASE");
+static const CHR* const ENV_PASSWORD = T("SLUNK_PASSPHRASE");
+static const CHR* const ENV_KEEPFILE = T("SLUNK_KEEP_INCOMPLETE");
+
 static const CHR* const PREFIX_PASS = T("pass:");
 static const CHR* const PREFIX_FILE = T("file:");
 
@@ -107,7 +109,7 @@ static void print_manpage(const CHR *const program)
 	FPRINTF(stderr, T("  %") T(PRISTR) T(" --encrypt [pass:<pass>|file:<file>] <input.txt> <output.enc>\n"), program);
 	FPRINTF(stderr, T("  %") T(PRISTR) T(" --decrypt [pass:<pass>|file:<file>] <input.enc> <output.txt>\n"), program);
 	FPRINTF(stderr, T("  %") T(PRISTR) T(" --make-pw [<length>]\n\n"), program);
-	FPRINTF(stderr, T("Optionally, reads passphrase from the %") T(PRISTR) T(" environment variable.\n\n"), ENV_PASSWRD);
+	FPRINTF(stderr, T("Optionally, reads passphrase from the %") T(PRISTR) T(" environment variable.\n\n"), ENV_PASSWORD);
 }
 
 static char *copy_passphrase(const CHR *const passphrase)
@@ -259,6 +261,16 @@ static int open_files(FILE **const file_in, FILE **const file_out, const CHR *co
 	return EXIT_SUCCESS;
 }
 
+static int remove_incomplete_files(void)
+{
+	const CHR* const keep_files = GETENV(ENV_KEEPFILE);
+	if (keep_files)
+	{
+		return (!STRTOUL(keep_files));
+	}
+	return 1;
+}
+
 static void sigint_handler(const int sig)
 {
 	if (sig == SIGINT)
@@ -430,6 +442,13 @@ clean_up:
 	if (file_out)
 	{
 		fclose(file_out);
+		if ((result != EXIT_SUCCESS) && remove_incomplete_files())
+		{
+			if (REMOVE(output_path))
+			{
+				FPUTS(T("Warning: Failed to remove incomplete output file!\n\n"), stderr);
+			}
+		}
 	}
 
 	if (file_in)
@@ -620,6 +639,13 @@ clean_up:
 	if (file_out)
 	{
 		fclose(file_out);
+		if ((result != EXIT_SUCCESS) && remove_incomplete_files())
+		{
+			if (REMOVE(output_path))
+			{
+				FPUTS(T("Warning: Failed to remove incomplete output file!\n\n"), stderr);
+			}
+		}
 	}
 
 	if (file_in)
@@ -816,7 +842,7 @@ int MAIN(const int argc, CHR *const argv[])
 		goto clean_up;
 	}
 
-	const CHR *const passphrase = PW_FROM_ENV ? GETENV(ENV_PASSWRD) : argv[2U];
+	const CHR *const passphrase = PW_FROM_ENV ? GETENV(ENV_PASSWORD) : argv[2U];
 	const CHR *const input_file = argv[PW_FROM_ENV ? 2U : 3U], *const output_file = argv[PW_FROM_ENV ? 3U : 4U];
 
 	if ((!passphrase) || (!passphrase[0U]))

frontend/src/platform.h

@@ -60,6 +60,7 @@
 #	define STRTOUL(X) wcstoul((X), NULL, 0)
 #	define FPUTS(X,Y) fputws((X),(Y))
 #	define FPRINTF(X,Y,...) fwprintf((X),(Y),__VA_ARGS__)
+#	define REMOVE(X) _wremove((X))
 #	define FOPEN(X,Y) _wfsopen((X),(Y),_SH_SECURE)
 #	ifdef __USE_MINGW_ANSI_STDIO
 #		define PRISTR "ls"
@@ -82,6 +83,7 @@
 #	define STRTOUL(X) strtoul((X), NULL, 0)
 #	define FPUTS(X,Y) fputs((X),(Y))
 #	define FPRINTF(X,Y,...) fprintf((X),(Y),__VA_ARGS__)
+#	define REMOVE(X) remove((X))
 #	define FOPEN(X,Y) fopen((X),(Y))
 #	define PRISTR "s"
 #	define PRIstr "s"