added option to delete used key bytes

1 files changed, 51 insertions, 21 deletions

diff --git a/onetimebluh.c b/onetimebluh.c
index 10cbca4..8c46524 100644
--- a/onetimebluh.c
+++ b/onetimebluh.c
@@ -15,6 +15,7 @@ int main(int argc, char* argv[]) {
 	int opt = 1;
 	int command = 0;
 	int comm = 0;
+	int tear = 0;
 	char* message = NULL;
 	char* keyfile = NULL;
 	char* output = NULL;
@@ -33,10 +34,11 @@ int main(int argc, char* argv[]) {
 			{"help",	no_argument,		0,	'h'},
 			{"nbytes",	required_argument,	0,	'b'},
 			{"output",	required_argument,	0,	'o'},
+			{"tear-page",	no_argument,		0,	't'},
 			{0,		0,			0,	0},
 		};
 
-		if ((opt = getopt_long(argc, argv, "b:d:e:ghk:o:", options, &option_index)) == -1)
+		if ((opt = getopt_long(argc, argv, "b:d:e:ghk:o:t", options, &option_index)) == -1)
 			break;
 
 		switch (opt) {
@@ -46,7 +48,7 @@ int main(int argc, char* argv[]) {
 		case 'd':
 			message = argv[optind-1];
 			command++;
-			comm = 'd';
+			comm = 'u';
 			break;
 		case 'e':
 			message = argv[optind-1];
@@ -73,6 +75,9 @@ int main(int argc, char* argv[]) {
 		case 'o':
 			output = argv[optind-1];
 			break;
+		case 't':
+			tear = 1;
+			break;
 		case '?':
 			break;
 		default:
@@ -98,11 +103,14 @@ int main(int argc, char* argv[]) {
 
 	/* Next section detects the functions to call */
 
-	if (comm == 'e' || comm == 'd') {
+	if (comm == 'e' || comm == 'u') {
 		if (keyfile == NULL) {
 			printf("No key specified: exit! \n");
 			exit(EXIT_FAILURE);
 		}
+		if (tear == 1) {
+			comm++;
+		}
 		xor(comm, message, keyfile, output);
 	} else if (comm == 'g') {
 		keyrand(nbytes, output);
@@ -119,22 +127,35 @@ void xor(int ed, char* mess, char* keyf, char* outp) {
 	/* In absence of input by users nex block sets the default values */
 
 	if (outp == NULL) {
-		if (ed == 'e') {
+		if (ed == 'e' || ed == 'f') {
 			printf("WARNING no output name specified using default value 'critt' \n");
 			outp = defenoutp;
-		} else if (ed == 'd') {
+		} else if (ed == 'u' || ed == 'v') {
 			printf("WARNING no output name specified usign default value 'decritt' \n");
 			outp = defdeoutp;
 		}
 	}
 
 	FILE* mex = fopen(mess, "r");
-	FILE* keyx = fopen(keyf, "r");
+	FILE* keyx = fopen(keyf, "r+");
 	FILE* critt = fopen(outp, "w");
+
+	long mess_size;
+	long pad_size;
+
+	if (ed == 'f' || ed == 'v') {
+		fseek(mex, 0L, SEEK_END);
+		mess_size = ftell(mex);
+		rewind(mex);
+		fseek(keyx, 0L, SEEK_END);
+		pad_size = ftell(keyx);
+		fseek(keyx, (pad_size - mess_size), SEEK_SET);
+	}
+
 	int i = 1;
 	char a, b;
 
-	while(i != EOF) {
+	while (i != EOF) {
 		i = fscanf(mex, "%c", &a);
 		fscanf(keyx, "%c", &b);
 		if(i != EOF) {
@@ -142,13 +163,21 @@ void xor(int ed, char* mess, char* keyf, char* outp) {
 		}
 	}
 
+	if (ed == 'f' || ed == 'v') {
+		ftruncate(fileno(keyx), (pad_size - mess_size));
+		fseek(keyx, 0L, SEEK_END);
+		long new_pad_size = ftell(keyx);
+		printf("Your pad is now %li bytes shorter \n", mess_size);
+		printf("You now have %li bytes left \n", new_pad_size);
+	}
+
 	fclose(mex);
 	fclose(keyx);
 	fclose(critt);
 
-	if (ed == 'e') {
+	if (ed == 'e' || ed == 'f') {
 		printf("Message successfully encrypted \n");
-	} else if (ed == 'd') {
+	} else if (ed == 'u' || ed == 'v') {
 		printf("Message successfully decrypted \n");
 	}
 
@@ -197,18 +226,19 @@ void keyrand(int nb, char* outp) {
 }
 
 void help(char* av[]) {
-	printf("ONETIMEBLUH USAGE: \n");
-	printf("%s [COMMAND] [OPTIONS] \n \n", av[0]);
-	printf("COMMANDS: \n");
-	printf("-d, --decrypt=FILE	decrypt message (input) same ad --encrypt, just for the feeling \n");
-	printf("-e, --encrypt=FILE	encrypt message (input) \n");
-	printf("-h, --help		print this help \n");
-	printf("-g, --key-gen		create key file \n \n");
-	printf("OPTIONS \n");
-	printf("-k, --key-file=KEY_FILE	use key (input) \n");
-	printf("-b, --nbytes=NUM	number of bytes \n");
-	printf("-o, --output=FILE	output name \n \n");
-	printf("Onetimebluh project repository at https://git.eigenlab.org/Seppia/onetimebluh \n");
+	fprintf(stdout,"ONETIMEBLUH USAGE: \n"
+	"%s [COMMAND] [OPTIONS] \n \n"
+	"COMMANDS: \n"
+	"-d, --decrypt=FILE	decrypt message (input) same ad --encrypt, just for the feeling \n"
+	"-e, --encrypt=FILE	encrypt message (input) \n"
+	"-h, --help		print this help \n"
+	"-g, --key-gen		create key file \n \n"
+	"OPTIONS \n"
+	"-k, --key-file=KEY_FILE	use key (input) \n"
+	"-b, --nbytes=NUM	number of bytes \n"
+	"-o, --output=FILE	output name \n"
+	"-t, --tear-page		deletes from the pad file the bytes used to encrypt/decrypt \n \n"
+	"Onetimebluh project repository at https://git.eigenlab.org/Seppia/onetimebluh \n", av[0]);
 
 	return;
 }