rand.c: fix initialisation bug in mrkbuf

should be null on bad return

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/libreboot-utils/lib/rand.c

@@ -118,7 +118,7 @@ mkrstr(size_t n) /* emulates spkmodem-decode */
 void *
 mkrbuf(size_t n)
 {
-	void *buf = "";
+	void *buf = NULL;
 
 	if (n == 0)
 		err_no_cleanup(0, EPERM, "mkrbuf: zero-byte request");

util/libreboot-utils/lottery.c

@@ -2,20 +2,74 @@
  * Copyright (c) 2026 Leah Rowe <leah@libreboot.org>                    /| |\
    Something something non-determinism                                   / \ */
 
+#include <ctype.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
 #include "include/common.h"
 
+static void
+spew_buf(const void *data, size_t len);
+
 int
 main(int argc, char **argv)
 {
 	int same = 0;
+	char *buf;
+
 	(void) argc, (void) argv;
 	xpledgex("stdio", NULL);
 
-	if (rsize(SIZE_MAX) == rsize(SIZE_MAX))
+	buf = mkrbuf(BUFSIZ + 1);
+	if (!memcmp(buf, buf + (BUFSIZ >> 1), BUFSIZ >> 1))
 		same = 1;
 
-	printf("%s\n", same ? "You win!" : "You lose!");
+	if (argc < 2) /* no spew */
+		spew_buf(buf, BUFSIZ);
+	free(buf);
+
+	fprintf(stderr, "\n%s\n", same ? "You win!" : "You lose!");
 	return same ^ 1;
 }
+
+static void
+spew_buf(const void *data, size_t len)
+{
+	const unsigned char *buf = data;
+	unsigned char c;
+	size_t i, j;
+
+	if (buf == NULL ||
+	    len == 0)
+		return;
+
+	for (i = 0; i < len; i += 16) {
+
+		printf("%08zx  ", i);
+
+		for (j = 0; j < 16; j++) {
+
+			if (i + j < len)
+				printf("%02x ", buf[i + j]);
+			else
+				printf("   ");
+
+			if (j == 7)
+				printf(" ");
+		}
+
+		printf(" |");
+
+		for (j = 0; j < 16 && i + j < len; j++) {
+
+			c = buf[i + j];
+			printf("%c", isprint(c) ? c : '.');
+		}
+
+		printf("|\n");
+	}
+
+	printf("%08zx\n", len);
+}