replaced rand() with more "secure" random() // CID 301767

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

4 files changed, 18 insertions, 3 deletions

diff --git a/src/challenge.c b/src/challenge.c
index 24a13f7..4f69298 100644
--- a/src/challenge.c
+++ b/src/challenge.c
@@ -50,6 +50,7 @@
 #include "challenge.h"
 #include "options.h"
 #include "md5.h"
+#include "utils.h"
 
 /* generate_challenge: Generates a random challenge, incorporating the current
  * local timestamp to avoid replay attacks.
@@ -62,9 +63,9 @@ challenge_t* generate_challenge(void) {
 	c = (challenge_t *) calloc(1, sizeof(challenge_t));
 	gettimeofday(&tt, 0);
 	c->sec      = tt.tv_sec;
-	c->usec_rnd = tt.tv_usec + rand();
+	c->usec_rnd = tt.tv_usec + pt_random();
 	for (i=0;i<6;i++)
-		c->random[i] = rand();
+		c->random[i] = pt_random();
 
 	return c;
 }
diff --git a/src/ptunnel.c b/src/ptunnel.c
index 9f435f9..1944041 100644
--- a/src/ptunnel.c
+++ b/src/ptunnel.c
@@ -323,7 +323,7 @@ void pt_forwarder(void) {
 				}
 			}
 			addr	= dest_addr;
-			rand_id	= (uint16_t)rand();
+			rand_id	= (uint16_t) pt_random();
 			create_and_insert_proxy_desc(rand_id, rand_id, new_sock, &addr, opts.given_dst_ip, opts.given_dst_port, kProxy_start, kUser_flag);
 			pthread_mutex_unlock(&num_threads_lock);
 		}
diff --git a/src/utils.c b/src/utils.c
index 66ed4c0..12e7992 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -43,8 +43,12 @@
  * Note that the source code is best viewed with tabs set to 4 spaces.
  */
 
+#include <stdio.h>
+#include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
+#include <time.h>
+#include <assert.h>
 
 #ifndef WIN32
 #include <syslog.h>
@@ -142,3 +146,11 @@ void print_hexstr(unsigned char *buf, size_t siz) {
 	free(out);
 }
 #endif
+
+int pt_random(void) {
+	struct timespec ts;
+
+	assert(timespec_get(&ts, TIME_UTC));
+	srandom(ts.tv_nsec ^ ts.tv_sec);
+	return random();
+}
diff --git a/src/utils.h b/src/utils.h
index 8afa45c..1ad2416 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -60,4 +60,6 @@ int host_to_addr(const char *hostname, uint32_t *result);
 void print_hexstr(unsigned char *buf, size_t siz);
 #endif
 
+int pt_random(void);
+
 #endif