Merge from OPENSSH_3_8_1P1_GSSAPI_20040713 to OPENSSH_3_9P1_GSSAPI_20040818.

[gssapi-openssh.git] / openssh / openbsd-compat / bsd-arc4random.c

diff --git a/openssh/openbsd-compat/bsd-arc4random.c b/openssh/openbsd-compat/bsd-arc4random.c
index 5cbb233afe5151b5c4df6b5d82f1e7da25692f47..625bf7375afdbe3ce31b6ed1fee7d14bfb3bda97 100644 (file)
--- a/openssh/openbsd-compat/bsd-arc4random.c
+++ b/openssh/openbsd-compat/bsd-arc4random.c
@@ -56,13 +56,21 @@ unsigned int arc4random(void)
 void arc4random_stir(void)
 {
        unsigned char rand_buf[SEED_SIZE];
+       int i;
 
        memset(&rc4, 0, sizeof(rc4));
        if (RAND_bytes(rand_buf, sizeof(rand_buf)) <= 0)
                fatal("Couldn't obtain random bytes (error %ld)",
                    ERR_get_error());
        RC4_set_key(&rc4, sizeof(rand_buf), rand_buf);
-       RC4(&rc4, sizeof(rand_buf), rand_buf, rand_buf);
+
+       /*
+        * Discard early keystream, as per recommendations in:
+        * http://www.wisdom.weizmann.ac.il/~itsik/RC4/Papers/Rc4_ksa.ps
+        */
+       for(i = 0; i <= 256; i += sizeof(rand_buf))
+               RC4(&rc4, sizeof(rand_buf), rand_buf, rand_buf);
+
        memset(rand_buf, 0, sizeof(rand_buf));
 
        rc4_ready = REKEY_BYTES;