fix parsing vulnerability

Closes #17

Makefile

@@ -15,15 +15,15 @@ debug: rdo.c
 	${CC} ${CFLAGS_DEBUG} rdo.c -o rdo ${LIBS}
 
 install: rdo
-	cp rdo ${DESTDIR}/usr/bin/rdo
+	cp rdo ${DESTDIR}/usr/local/bin/rdo
-	chown root:root ${DESTDIR}/usr/bin/rdo
+	chown 0:0 ${DESTDIR}/usr/local/bin/rdo
-	chmod 755 ${DESTDIR}/usr/bin/rdo
+	chmod 755 ${DESTDIR}/usr/local/bin/rdo
-	chmod u+s ${DESTDIR}/usr/bin/rdo
+	chmod u+s ${DESTDIR}/usr/local/bin/rdo
 	cp rdo_sample.conf ${DESTDIR}/etc/rdo.conf
 	chmod 600 ${DESTDIR}/etc/rdo.conf
 
 uninstall:
-	rm /usr/bin/rdo
+	rm /usr/local/bin/rdo
 	rm /etc/rdo.conf
 
 clean:

rdo.c

@@ -1,7 +1,6 @@
 #include <pwd.h>
 #include <grp.h>
 #include <err.h>
-#include <crypt.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -14,7 +13,7 @@
 #include "readpassphrase.h"
 #include "sessions.h"
 
-#define VERSION "1.4.2"
+#define VERSION "1.4.3"
 
 char* getpwhash(struct passwd* pw) {
     if (pw->pw_passwd[0] != 'x')
@@ -34,22 +33,23 @@ char* getpwhash(struct passwd* pw) {
 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(entry, line, strlen(entry)) == 0) {
+        if (strncmp(line, entry, entry_len) == 0 &&
-            strtok(line, "=");
+            (line[entry_len] == '=')) {
-            char* token = strtok(NULL, "=");
+            char* value = line + entry_len + 1;
-            if (token) {
+            value[strcspn(value, "\n")] = 0;
-                strncpy(result, token, len_result);
+            strncpy(result, value, len_result);
-                result[strcspn(result, "\n")] = 0;
+            result[len_result - 1] = '\0';
-                free(line);
+            free(line);
-                return;
+            return;
-            }
         }
     }
 
+    free(line);
     errx(1, "Could not get '%s' entry in config", entry);
 }
 
@@ -69,7 +69,7 @@ void runprog(char** program_argv) {
 
 int main(int argc, char** argv) {
     char groupname[64], wrong_pw_sleep[64], session_ttl[64], password[128];
-    unsigned int sleep_us, tries, ts_ttl;
+    int sleep_us, tries, ts_ttl;
 
     int read_pw_from_stdin = 0;
     if (argc > 1)
@@ -101,7 +101,7 @@ int main(int argc, char** argv) {
 
     fclose(fp);
 
-    if (getsession(getppid(), ts_ttl, ruid) == 0 && !read_pw_from_stdin)
+    if (getsession(ts_ttl) == 0 && !read_pw_from_stdin)
         runprog(&argv[1]);
 
     struct passwd* pw = getpwuid(ruid);
@@ -147,7 +147,7 @@ int main(int argc, char** argv) {
 
         if (strcmp(given_hashed_pw, user_hashed_pw) == 0) {
             if (!read_pw_from_stdin)
-                setsession(getppid(), ts_ttl, ruid);
+                setsession(ts_ttl);
             runprog(&argv[read_pw_from_stdin+1]);
         }
 

sessions.h

@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <fcntl.h>
 #include <time.h>
 
@@ -49,24 +50,24 @@ int getpstartts(int pid, unsigned long long* startts) {
 
 int ensuredir() {
     struct stat st;
-    int fd = open("/run/rdo", O_RDONLY, O_DIRECTORY | O_NOFOLLOW);
+    int fd = open("/var/run/rdo", O_RDONLY, O_DIRECTORY | O_NOFOLLOW);
 
     if (fd < 0) {
         if (errno == ENOENT) {
-            if (mkdir("/run/rdo", 0700) < 0)
+            if (mkdir("/var/run/rdo", 0700) < 0)
-                err(1, "Could not create /run/rdo");
+                err(1, "Could not create /var/run/rdo");
 
-            fd = open("/run/rdo", O_RDONLY, O_DIRECTORY | O_NOFOLLOW);
+            fd = open("/var/run/rdo", O_RDONLY, O_DIRECTORY | O_NOFOLLOW);
             if (fd < 0)
-                err(1, "Could not open /run/rdo");
+                err(1, "Could not open /var/run/rdo");
         }
         else
-            err(1, "Could not open /run/rdo");
+            err(1, "Could not open /var/run/rdo");
     }
 
     if (fstat(fd, &st) < 0) {
         close(fd);
-        err(1, "Could not fstat /run/rdo");
+        err(1, "Could not fstat /var/run/rdo");
     }
 
     close(fd);
@@ -77,17 +78,46 @@ int ensuredir() {
     return 0;
 }
 
-void setsession(int pid, unsigned int ts_ttl, int ruid) {
+#ifdef __OpenBSD__
+
+void setsession(int ts_ttl) {
+    if (ts_ttl <= 0)
+        return;
+
+    int ttyfd = open("/dev/tty", O_RDWR);
+    ioctl(ttyfd, TIOCSETVERAUTH, &ts_ttl);
+    close(ttyfd);
+
+    return;
+}
+
+int getsession(int ts_ttl) {
+    if (ts_ttl <= 0)
+        return -1;
+
+    int ttyfd = open("/dev/tty", O_RDWR);
+    int ret = ioctl(ttyfd, TIOCCHKVERAUTH);
+    close(ttyfd);
+
+    return ret;
+}
+
+#else
+
+void setsession(int ts_ttl) {
+    if (ts_ttl <= 0)
+        return;
+
     unsigned long long startts;
     char path[1024], ts_str[32];
 
-    if (ts_ttl == 0)
+    int ppid = getppid();
-        return;
+    int ruid = getuid();
 
-    if (ensuredir() < 0 || getpstartts(pid, &startts) < 0)
+    if (ensuredir() < 0 || getpstartts(ppid, &startts) < 0)
         return;
 
-    snprintf(path, sizeof(path), "/run/rdo/%d-%d-%llu", ruid, pid, startts);
+    snprintf(path, sizeof(path), "/var/run/rdo/%d-%d-%llu", ruid, ppid, startts);
 
     int fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0700);
     if (fd < 0) {
@@ -104,21 +134,23 @@ void setsession(int pid, unsigned int ts_ttl, int ruid) {
     }
 
     close(fd);
-
     return;
 }
 
-int getsession(int pid, unsigned int ts_ttl, int ruid) {
+int getsession(int ts_ttl) {
+    if (ts_ttl <= 0)
+        return -1;
+
     unsigned long long startts, current;
     char path[1024], ts_str[32];
 
-    if (ts_ttl == 0)
+    int ppid = getppid();
-        return -1;
+    int ruid = getuid();
 
-    if (ensuredir() < 0 || getpstartts(pid, &startts) < 0)
+    if (ensuredir() < 0 || getpstartts(ppid, &startts) < 0)
         return -1;
 
-    snprintf(path, sizeof(path), "/run/rdo/%d-%d-%llu", ruid, pid, startts);
+    snprintf(path, sizeof(path), "/var/run/rdo/%d-%d-%llu", ruid, ppid, startts);
 
     int fd = open(path, O_RDONLY);
     if (fd < 0) {
@@ -138,10 +170,12 @@ int getsession(int pid, unsigned int ts_ttl, int ruid) {
     startts = strtoull(ts_str, NULL, 10);
     current = time(NULL);
 
-    if (current - startts > ts_ttl) {
+    if (current - startts > (unsigned int)ts_ttl) {
         unlink(path);
         return -1;
     }
 
     return 0;
 }
+
+#endif