libreboot-utils: remove 1989 rand

added as an academic exercise, but pointless
in the year 2026.

or even the year 1989.

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

3 files changed, 1 insertions, 94 deletions

diff --git a/util/libreboot-utils/include/common.h b/util/libreboot-utils/include/common.h
index 97bbdf0c..0bab30de 100644
--- a/util/libreboot-utils/include/common.h
+++ b/util/libreboot-utils/include/common.h
@@ -26,7 +26,7 @@
 #endif
 #if !defined(HAVE_GETRANDOM)
 #include <sys/syscall.h>
-#if defined(SYS_getrandom)
+#if !defined(SYS_getrandom)
 #define HAVE_GETRANDOM_SYSCALL 1
 #endif
 #endif
@@ -396,18 +396,12 @@ int dcat(const char *s, size_t n,
 
 unsigned short hextonum(char ch_s);
 size_t rlong(void);
-#if !(defined(FALLBACK_RAND_1989) && \
-    ((FALLBACK_RAND_1989) > 0))
 #if defined(__linux__)
 #if defined(HAVE_GETRANDOM) || \
     defined(HAVE_GETRANDOM_SYSCALL)
 int fallback_rand_getrandom(void *buf, size_t len);
 #endif
 #endif
-#else
-size_t fallback_rand_1989(void);
-size_t entropy_jitter(void);
-#endif
 
 /* Helper functions for command: dump
  */
diff --git a/util/libreboot-utils/lib/num.c b/util/libreboot-utils/lib/num.c
index c02b6722..41a08f0b 100644
--- a/util/libreboot-utils/lib/num.c
+++ b/util/libreboot-utils/lib/num.c
@@ -13,10 +13,6 @@ TODO: properly handle errno in this file
 #include <sys/param.h>
 #endif
 #include <sys/types.h>
-#if defined(FALLBACK_RAND_1989) && \
-    (FALLBACK_RAND_1989) > 0
-#include <sys/time.h>
-#endif
 
 #include <errno.h>
 #if !((defined(__OpenBSD__) && (OpenBSD) >= 201) || \
@@ -27,10 +23,6 @@ TODO: properly handle errno in this file
 #include <limits.h>
 #include <stddef.h>
 #include <string.h>
-#if defined(FALLBACK_RAND_1989) && \
-    (FALLBACK_RAND_1989) > 0
-#include <time.h>
-#endif
 #include <unistd.h>
 
 #include "../include/common.h"
diff --git a/util/libreboot-utils/lib/rand.c b/util/libreboot-utils/lib/rand.c
index c84664fa..900c3ed3 100644
--- a/util/libreboot-utils/lib/rand.c
+++ b/util/libreboot-utils/lib/rand.c
@@ -11,10 +11,6 @@
 #include <sys/param.h>
 #endif
 #include <sys/types.h>
-#if defined(FALLBACK_RAND_1989) && \
-    (FALLBACK_RAND_1989) > 0
-#include <sys/time.h>
-#endif
 
 #include <errno.h>
 #if !((defined(__OpenBSD__) && (OpenBSD) >= 201) || \
@@ -25,10 +21,6 @@
 #include <limits.h>
 #include <stddef.h>
 #include <string.h>
-#if defined(FALLBACK_RAND_1989) && \
-    (FALLBACK_RAND_1989) > 0
-#include <time.h>
-#endif
 #include <unistd.h>
 
 #include "../include/common.h"
@@ -54,8 +46,6 @@
 size_t
 rlong(void)
 {
-#if !(defined(FALLBACK_RAND_1989) && \
-    ((FALLBACK_RAND_1989) > 0))
 #if (defined(__OpenBSD__) && (OpenBSD) >= 201) || \
     defined(__FreeBSD__) || \
     defined(__NetBSD__) || defined(__APPLE__)
@@ -278,74 +268,5 @@ fallback_rand_getrandom(void *buf, size_t len)
 }
 #endif
 #endif
-#else
-size_t
-fallback_rand_1989(void)
-{
-	static size_t mix = 0;
-	static size_t counter = 0;
-
-	struct timeval tv;
-
-	/* nobody should use this
-	 * (not crypto-safe)
-	 */
-
-	gettimeofday(&tv, NULL);
-
-	mix ^= (size_t)tv.tv_sec
-	    ^ (size_t)tv.tv_usec
-	    ^ (size_t)getpid()
-	    ^ (size_t)&mix
-	    ^ counter++
-	    ^ entropy_jitter();
-
-	/*
-	 * Stack addresses can vary between
-	 * calls, thus increasing entropy.
-	 */
-	mix ^= (size_t)&mix;
-	mix ^= (size_t)&tv;
-	mix ^= (size_t)&counter;
-
-	return mix;
-}
-
-size_t
-entropy_jitter(void)
-{
-	size_t mix;
-
-	struct timeval a, b;
-	ssize_t mix_diff;
-
-	int c;
-
-	mix = 0;
-
-	gettimeofday(&a, NULL);
-
-	for (c = 0; c < 32; c++) {
-
-		getpid();
-		gettimeofday(&b, NULL);
-
-		/*
-		 * prevent negative numbers to prevent overflow,
-		 * which would bias rand to large numbers
-		 */
-		mix_diff = (ssize_t)(b.tv_usec - a.tv_usec);
-		if (mix_diff < 0)
-			mix_diff = -mix_diff;
-
-		mix ^= (size_t)(mix_diff);
-
-		mix ^= (size_t)&mix;
-
-	}
-
-	return mix;
-}
-#endif
 
 #endif