From 604f5e7fdd98d11cd7fde9f082ccc20f26c86659 Mon Sep 17 00:00:00 2001
From: sw1tchbl4d3 <sw1tchbl4d3@sw1tchbl4d3.com>
Date: Tue, 13 Jul 2021 22:39:28 +0200
Subject: [PATCH] Improve error messages

This commit makes rdo make use of the err.h header
for more pleasant and convenient error logging.
---
 rdo.c | 43 +++++++++++++++++--------------------------
 1 file changed, 17 insertions(+), 26 deletions(-)

diff --git a/rdo.c b/rdo.c
index 42467d4..b752146 100644
--- a/rdo.c
+++ b/rdo.c
@@ -1,4 +1,5 @@
 #include <pwd.h>
+#include <err.h>
 #include <shadow.h>
 #include <crypt.h>
 #include <unistd.h>
@@ -11,21 +12,18 @@ void runprog(int argc, char** argv) {
 		argv[i] = argv[i + 1];
 	setuid(0);
 	setgid(0);
-	if (execvp(argv[0], argv) != 0) perror(argv[0]);
+	if (execvp(argv[0], argv) != 0) 
+		perror(argv[0]);
 }
 
 int main(int argc, char** argv) {
-	if (argc < 2) {
-		fprintf(stderr, "Please specify a program to run.\n");
-		return -1;
-	}
+	if (argc < 2)
+		errx(1, "Please specify a program to run");
 
 	FILE* fp = fopen("/etc/rdo/username", "r");
 	
-	if (fp == NULL) {
-		fprintf(stderr, "The file /etc/rdo/username could not be read.\n");
-		return -2;
-	}
+	if (!fp)
+		err(1, "Could not open /etc/rdo/username");
 
 	int ruid = getuid();
 	if (ruid == 0) {
@@ -40,31 +38,23 @@ int main(int argc, char** argv) {
 	username[strcspn(username, "\n")] = 0;
 
 	struct passwd* p = getpwnam(username);
-	if (!p) {
-		fprintf(stderr, "The user in the username file does not exist.\n");
-		return -3;
-	}
+	if (!p)
+		err(1, "Could not get user info");
 
 	int uid = p->pw_uid;
-	if (uid != ruid && ruid != 0) {
-		fprintf(stderr, "You are not in the username file.\n");
-		return -4;
-	}
+	if (uid != ruid && ruid != 0)
+		errx(1, "You are not in the username file");
 
 	struct spwd* shadowEntry = getspnam(username);
 
-	if (!shadowEntry) {
-		fprintf(stderr, "Could not get shadow entry, suid bit not set or username invalid?\n");
-		return -5;
-	}
+	if (!shadowEntry)
+		err(1, "Could not get shadow entry");
 
 	int tries = 0;
 	char password[128];
 	while (tries < 3) {
-		if (!readpassphrase("(rdo) Password: ", password, sizeof(password), RPP_REQUIRE_TTY)) {
-			fprintf(stderr, "Could not get passphrase, not in a TTY?\n");
-			return -7;
-		}
+		if (!readpassphrase("(rdo) Password: ", password, sizeof(password), RPP_REQUIRE_TTY))
+			err(1, "Could not get passphrase");
 
 		if (strcmp(shadowEntry->sp_pwdp, crypt(password, shadowEntry->sp_pwdp)) == 0) {
 			runprog(argc, argv);
@@ -73,5 +63,6 @@ int main(int argc, char** argv) {
 		fprintf(stderr, "Wrong password.\n");
 		tries++;
 	}
-    return -6;
+	errx(1, "Too many wrong password attempts.");
+	return 1;
 }