[dpdk-dev] [PATCH v1 1/1] examples/l2fwd-crypto: improve random key generator

[Piotr Azarewicz <piotrx.t.azarewicz@intel.com>]

This patch improve generate_random_key() function by replacing rand()
function with reading from /dev/urandom.

CID 120136 : Calling risky function (DC.WEAK_CRYPTO)
dont_call: rand should not be used for security related applications, as
linear congruential algorithms are too easy to break

Coverity issue: 120136

Signed-off-by: Piotr Azarewicz <piotrx.t.azarewicz@intel.com>
---
 examples/l2fwd-crypto/main.c |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/examples/l2fwd-crypto/main.c b/examples/l2fwd-crypto/main.c
index d18c813..e1f0a1e 100644
--- a/examples/l2fwd-crypto/main.c
+++ b/examples/l2fwd-crypto/main.c
@@ -45,6 +45,8 @@
 #include <ctype.h>
 #include <errno.h>
 #include <getopt.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 #include <rte_atomic.h>
 #include <rte_branch_prediction.h>
@@ -581,10 +583,18 @@ l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
 static void
 generate_random_key(uint8_t *key, unsigned length)
 {
-	unsigned i;
+	int fd;
+	int ret;
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		rte_exit(EXIT_FAILURE, "Failed to generate random key\n");
 
-	for (i = 0; i < length; i++)
-		key[i] = rand() % 0xff;
+	ret = read(fd, key, length);
+	close(fd);
+
+	if (ret != (signed)length)
+		rte_exit(EXIT_FAILURE, "Failed to generate random key\n");
 }
 
 static struct rte_cryptodev_sym_session *
@@ -1180,8 +1190,6 @@ l2fwd_crypto_parse_timer_period(struct l2fwd_crypto_options *options,
 static void
 l2fwd_crypto_default_options(struct l2fwd_crypto_options *options)
 {
-	srand(time(NULL));
-
 	options->portmask = 0xffffffff;
 	options->nb_ports_per_lcore = 1;
 	options->refresh_period = 10000;
-- 
1.7.9.5