change to a lengt/contents fill-in rather than a return value

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@1311 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 40 insertions, 8 deletions

diff --git a/src/lib/crypto/os/rnd_confoun.c b/src/lib/crypto/os/rnd_confoun.c
index 35a8b83e4..aca997395 100644
--- a/src/lib/crypto/os/rnd_confoun.c
+++ b/src/lib/crypto/os/rnd_confoun.c
@@ -22,19 +22,51 @@ static char rcsid_rnd_counfoun_c[] =
 /*
  * Generate a random confounder
  */
-krb5_confounder
-krb5_random_confounder PROTOTYPE((void))
+krb5_error_code
+krb5_random_confounder(size, fillin)
+int size;
+krb5_pointer fillin;
 {
     static int seeded = 0;
-    long retval;
+    register krb5_octet *real_fill; 
 
-    /* XXX this needs an alternative for an X3J11 C environment,
-       to use srand() and rand() */
+#ifdef __STDC__
+    /* Use the srand/rand calls, see X3.159-1989, section 4.10.2 */
+    if (!seeded) {
+	/* time() defined in 4.12.2.4, but returns a time_t, which is an
+	   "arithmetic type" (4.12.1) */
+	srandom((unsigned int) time(0));
+	seeded = 1;
+    }
+#else
+    /* assume Berkeley srandom...after all, this is libos! */
     if (!seeded) {
 	srandom(time(0));
 	seeded = 1;
     }
-    /* this only gives us 31 random buts, but so what ? */
-    retval = random();
-    return (krb5_confounder) retval;
+#endif
+    real_fill = (krb5_octet *)fillin;
+    while (size > 0) {
+
+#ifdef __STDC__
+	int rval;
+	rval = rand();
+	/* RAND_MAX is at least 32767, so we assume we can use the lower 16 bits
+	   of the value of rand(). */
+#else
+	long rval;
+	rval = random();
+	/* BSD random number generator generates "in the range from
+	   0 to (2**31)-1" (random(3)).  So we can use the bottom 16 bits. */
+#endif
+	*real_fill = rval & 0xff;
+	real_fill++;
+	size--;
+	if (size) {
+	    *real_fill = (rval >> 8) & 0xff;
+	    real_fill++;
+	    size--;
+	}
+    }
+    return 0;
 }