changed compiler to cc, shortened rdo.c

Makefile

@@ -3,7 +3,7 @@ CFLAGS_RELEASE = ${CFLAGS} -O2 -s -D_FORTIFY_SOURCE=2
 CFLAGS_DEBUG = ${CFLAGS} -O0 -g -fsanitize=undefined
 CFLAGS_STATIC = ${CFLAGS_RELEASE} -static-pie
 LIBS = -lcrypt
-CC = gcc
+CC = cc
 
 all: rdo.c
 	${CC} ${CFLAGS_RELEASE} rdo.c -o rdo ${LIBS}

rdo.c

@@ -5,41 +5,31 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-
+#include <errno.h>
 #ifdef __linux__
 #include <shadow.h>
 #endif
-
 #include "readpassphrase.h"
 #include "sessions.h"
-
 #define VERSION "1.4.3"
-
 char* getpwhash(struct passwd* pw) {
     if (pw->pw_passwd[0] != 'x')
         return pw->pw_passwd;
-
 #ifdef __linux__
     struct spwd* pw_entry = getspnam(pw->pw_name);
-
     if (!pw_entry || !pw_entry->sp_pwdp)
         err(1, "Could not get shadow entry");
     return pw_entry->sp_pwdp;
 #endif
-
     errx(1, "Could not get hashed password entry");
 }
-
 void getconf(FILE* fp, const char* entry, char* result, size_t len_result) {
     char* line = NULL;
     size_t len = 0;
     size_t entry_len = strlen(entry);
-
     fseek(fp, 0, SEEK_SET);
-
     while (getline(&line, &len, fp) != -1) {
-        if (strncmp(line, entry, entry_len) == 0 &&
+        if (strncmp(line, entry, entry_len) == 0 && (line[entry_len] == '=')) {
-            (line[entry_len] == '=')) {
             char* value = line + entry_len + 1;
             value[strcspn(value, "\n")] = 0;
             strncpy(result, value, len_result);
@@ -48,62 +38,45 @@ void getconf(FILE* fp, const char* entry, char* result, size_t len_result) {
             return;
         }
     }
-
     free(line);
     errx(1, "Could not get '%s' entry in config", entry);
 }
-
 void runprog(char** program_argv) {
     if (setuid(0) < 0)
         err(1, "Could not setuid");
     if (setgid(0) < 0)
         err(1, "Could not setgid");
-
     putenv("HOME=/root");
-
-    // NOTE: this does not return when no error occurred.
     execvp(program_argv[0], program_argv);
-
     err(1, "%s", program_argv[0]);
 }
-
 int main(int argc, char** argv) {
     char groupname[64], wrong_pw_sleep[64], session_ttl[64], password[128];
     int sleep_us, tries, ts_ttl;
-
     int read_pw_from_stdin = 0;
     if (argc > 1)
         read_pw_from_stdin = strcmp(argv[1], "-") == 0;
-
     if (argc == 1 || (read_pw_from_stdin && argc == 2)) {
         printf("RootDO version: %s\n\n", VERSION);
         printf("Usage: %s [command]\n", argv[0]);
         return 0;
     }
-
     if (geteuid() != 0)
         errx(1, "The rdo binary needs to be installed as SUID.");
-
     int ruid = getuid();
     if (ruid == 0)
         runprog(&argv[read_pw_from_stdin+1]);
-
     FILE* fp = fopen("/etc/rdo.conf", "r");
-
     if (!fp)
         err(1, "Could not open /etc/rdo.conf");
-
     getconf(fp, "group", groupname, sizeof(groupname));
     getconf(fp, "wrong_pw_sleep", wrong_pw_sleep, sizeof(wrong_pw_sleep));
     getconf(fp, "session_ttl", session_ttl, sizeof(session_ttl));
     sleep_us = atoi(wrong_pw_sleep) * 1000;
     ts_ttl = atoi(session_ttl) * 60;
-
     fclose(fp);
-
     if (getsession(ts_ttl) == 0 && !read_pw_from_stdin)
         runprog(&argv[1]);
-
     struct passwd* pw = getpwuid(ruid);
     if (!pw) {
         if (errno == 0)
@@ -111,46 +84,40 @@ int main(int argc, char** argv) {
         else
             err(1, "Could not get user info");
     }
-
     struct group* current_group_entry = getgrent();
     while (current_group_entry) {
         if (strcmp(current_group_entry->gr_name, groupname) == 0)
             break;
         current_group_entry = getgrent();
     }
-
     if (!current_group_entry)
         errx(1, "The group '%s' does not exist.", groupname);
-
     char* current_member = current_group_entry->gr_mem[0];
     for (int i = 1; current_member; i++) {
         if (strcmp(current_member, pw->pw_name) == 0)
             break;
         current_member = current_group_entry->gr_mem[i];
     }
-
     if (!current_member)
         errx(1, "You are not allowed to execute rdo.");
-
     char* user_hashed_pw = getpwhash(pw);
-
     tries = 0;
     while (tries < 3) {
-        if (!readpassphrase("(rdo) Password: ", password, sizeof(password), read_pw_from_stdin))
+        char hostname[64];
+        gethostname(hostname, sizeof(hostname));
+        char prompt[256];
+        snprintf(prompt, sizeof(prompt), "[rdo: (%s@%s) Password]: ", pw->pw_name, hostname);
+        if (!readpassphrase(prompt, password, sizeof(password), read_pw_from_stdin))
             err(1, "Could not get passphrase");
-
         char* given_hashed_pw = crypt(password, user_hashed_pw);
         memset(password, 0, sizeof(password));
-
         if (!given_hashed_pw)
             errx(1, "Could not hash password, does your user have a password?");
-
         if (strcmp(given_hashed_pw, user_hashed_pw) == 0) {
             if (!read_pw_from_stdin)
                 setsession(ts_ttl);
             runprog(&argv[read_pw_from_stdin+1]);
         }
-
         usleep(sleep_us);
         fprintf(stderr, "Wrong password.\n");
         tries++;
@@ -158,3 +125,4 @@ int main(int argc, char** argv) {
     errx(1, "Too many wrong password attempts.");
     return 1;
 }
+