use actual random data with KEX_INIT cookie and packet padding

README

@@ -4,6 +4,8 @@ libssh2 - SSH2 library
 Version 0.5
 -----------
 
+  Fixed KEX_INIT cookie and packet padding to use actual random data
+
   Added DESTDIR support to makefiles (Adam Go<47><6F>biowski -- I hope that character set translates right)
 
 Version 0.4

src/kex.c

@@ -39,6 +39,7 @@
 #include <openssl/bn.h>
 #include <openssl/sha.h>
 #include <openssl/evp.h>
+#include <openssl/rand.h>
 
 /* TODO: Switch this to an inline and handle alloc() failures */
 /* Helper macro called from libssh2_kex_method_diffie_hellman_group1_sha1_key_exchange */
@@ -720,8 +721,7 @@ static int libssh2_kexinit(LIBSSH2_SESSION *session)
 
 	*(s++) = SSH_MSG_KEXINIT;
 
-	/* TODO: Build a better cookie (and the mice will beat a path to my door...) */
-	memcpy(s, "mysecretMYSECRET", 16);
+	RAND_bytes(s, 16);
 	s += 16;
 
 	/* Ennumerating through these lists twice is probably (certainly?) inefficient from a CPU standpoint, but it saves multiple malloc/realloc calls */

src/packet.c

@@ -40,6 +40,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <openssl/evp.h>
+#include <openssl/rand.h>
 
 /* {{{ libssh2_packet_new
  * Create a new packet and attach it to the brigade
@@ -627,7 +628,7 @@ int libssh2_packet_write(LIBSSH2_SESSION *session, unsigned char *data, unsigned
 		/* Copy packet to encoding buffer */
 		memcpy(encbuf, buf, 5);
 		memcpy(encbuf + 5, data, data_len);
-		memcpy(encbuf + 5 + data_len, buf + 5, padding_length);
+		RAND_bytes(encbuf + 5 + data_len, padding_length);
 		if (free_data) {
 			LIBSSH2_FREE(session, data);
 		}