Attachment 186932 Details for Bug 222807 – patche that enable "pure" entropy sources such as RDRND to actually be mixed

patche that enable "pure" entropy sources such as RDRND to actually be mixed

pure-source.patch (text/plain), 7.78 KB, created by W. Dean Freeman on 2017-10-06 00:45:03 UTC

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Creator: W. Dean Freeman

Created: 2017-10-06 00:45:03 UTC

Size: 7.78 KB

patch

obsolete

>From 0054e3e170e083811acc9f3b637f8be8a86c03e7 Mon Sep 17 00:00:00 2001
>From: Oliver Pinter <oliver.pinter@hardenedbsd.org>
>Date: Sun, 24 Sep 2017 03:32:05 +0200
>Subject: [PATCH] HBSD: rework entropy source registration
>
>Before this patch the pure entropy sources are ignored from mixins.
>This was an implementation bug in random_harvest_direct()'s enabled
>sources check, where the pure sources are always ignore, because they
>are never registered into harvest_context.hc_source_mask bitfield.
>
>This patch implements a registration framework for pure entropy sources,
>which registers them at attach time to harvest_context.hc_source_mask.
>
>From other side, we prevent to disable them from user-space by setting
>only environmental entropy source masks.
>
>This work mostly based on the idea from wfd@. The original idea was to
>igonre the harvest mask in random_harvest_direct(), but I think this is
>the proper implementation, where a newly added pure entropy source
>register itself into harvest mask, and then we prevent to disable
>them from sysctls.
>
>Original-PR: #281
>Details: https://www.funkthat.com/~jmg/vbsdcon_2017_ddfreebsdrng_slides.pdf
>Tested-by: W. Dean Freeman <badfilemagic@gmail.com> <wdfreeman@ieee.org>
>CC: W. Dean Freeman <badfilemagic@gmail.com> <wdfreeman@ieee.org>
>CC: John-Mark Gurney <jmg@funkthat.com>
>CC: Ed Maste <emaste@FreeBSD.org>
>Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
>Reviewed-by: lattera dstolfa wdfreeman jmg
>(cherry picked from commit 137db59df58773d5771025f9fd157827db9d2f8b)
>Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
>---
> sys/dev/random/random_harvestq.c | 61 ++++++++++++++++++++++++++++++++++------
> sys/dev/random/randomdev.c       |  6 ++++
> sys/sys/random.h                 |  8 +++++-
> 3 files changed, 66 insertions(+), 9 deletions(-)
>
>diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
>index 69cbd278d484b..f5dcdb36a15ae 100644
>--- a/sys/dev/random/random_harvestq.c
>+++ b/sys/dev/random/random_harvestq.c
>@@ -1,4 +1,6 @@
>-/*-
>+ /*2
>+ * Copyright (c) 2017 Oliver Pinter
>+ * Copyright (c) 2017 W. Dean Freeman
>  * Copyright (c) 2000-2015 Mark R V Murray
>  * Copyright (c) 2013 Arthur Mesh
>  * Copyright (c) 2004 Robert N. M. Watson
>@@ -240,7 +242,29 @@ read_rate_increment(u_int chunk)
> }
> 
> /* ARGSUSED */
>-RANDOM_CHECK_UINT(harvestmask, 0, RANDOM_HARVEST_EVERYTHING_MASK);
>+static int
>+random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS)
>+{
>+	int error;
>+	u_int value, orig_value;
>+
>+	orig_value = value = harvest_context.hc_source_mask;
>+	error = sysctl_handle_int(oidp, &value, 0, req);
>+	if (error || !req->newptr)
>+		return (error);
>+
>+	if (flsl(value) >= ENTROPYSOURCE)
>+		return (EINVAL);
>+
>+	/*
>+	 * Set the new environmental harvest mask, regardless 
>+	 * from the pure entropy sources.
>+	 * We won't allow to modify the pure entropy source.
>+	 */
>+	harvest_context.hc_source_mask = value | (orig_value & RANDOM_HARVEST_PURE_MASK);
>+
>+	return (0);
>+}
> 
> /* ARGSUSED */
> static int
>@@ -252,7 +276,7 @@ random_print_harvestmask(SYSCTL_HANDLER_ARGS)
> 	error = sysctl_wire_old_buffer(req, 0);
> 	if (error == 0) {
> 		sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
>-		for (i = RANDOM_ENVIRONMENTAL_END; i >= 0; i--)
>+		for (i = ENTROPYSOURCE - 1; i >= 0; i--)
> 			sbuf_cat(&sbuf, (harvest_context.hc_source_mask & (1 << i)) ? "1" : "0");
> 		error = sbuf_finish(&sbuf);
> 		sbuf_delete(&sbuf);
>@@ -272,7 +296,7 @@ static const char *(random_source_descr[]) = {
> 	"SWI",
> 	"FS_ATIME",
> 	"UMA", /* ENVIRONMENTAL_END */
>-	"PURE_OCTEON",
>+	"PURE_OCTEON", /* PURE_START */
> 	"PURE_SAFE",
> 	"PURE_GLXSB",
> 	"PURE_UBSEC",
>@@ -289,15 +313,23 @@ random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS)
> {
> 	struct sbuf sbuf;
> 	int error, i;
>+	bool first;
>+
>+	first = true;
> 
> 	error = sysctl_wire_old_buffer(req, 0);
> 	if (error == 0) {
> 		sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
>-		for (i = RANDOM_ENVIRONMENTAL_END; i >= 0; i--) {
>-			sbuf_cat(&sbuf, (i == RANDOM_ENVIRONMENTAL_END) ? "" : ",");
>+		for (i = ENTROPYSOURCE - 1; i >= 0; i--) {
>+			if (i >= RANDOM_PURE_START &&
>+			    (harvest_context.hc_source_mask & (1 << i)) == 0)
>+				continue;
>+			if (!first)
>+				sbuf_cat(&sbuf, ",");
> 			sbuf_cat(&sbuf, !(harvest_context.hc_source_mask & (1 << i)) ? "[" : "");
> 			sbuf_cat(&sbuf, random_source_descr[i]);
> 			sbuf_cat(&sbuf, !(harvest_context.hc_source_mask & (1 << i)) ? "]" : "");
>+			first = false;
> 		}
> 		error = sbuf_finish(&sbuf);
> 		sbuf_delete(&sbuf);
>@@ -319,8 +351,7 @@ random_harvestq_init(void *unused __unused)
> 	SYSCTL_ADD_PROC(&random_clist,
> 	    SYSCTL_CHILDREN(random_sys_o),
> 	    OID_AUTO, "mask", CTLTYPE_UINT | CTLFLAG_RW,
>-	    &harvest_context.hc_source_mask, 0,
>-	    random_check_uint_harvestmask, "IU",
>+	    NULL, 0, random_check_uint_harvestmask, "IU",
> 	    "Entropy harvesting mask");
> 	SYSCTL_ADD_PROC(&random_clist,
> 	    SYSCTL_CHILDREN(random_sys_o),
>@@ -493,4 +524,18 @@ random_harvest_direct(const void *entropy, u_int size, u_int bits, enum random_e
> 	explicit_bzero(&event, sizeof(event));
> }
> 
>+void
>+random_harvest_register_source(enum random_entropy_source source)
>+{
>+
>+	harvest_context.hc_source_mask |= (1 << source);
>+}
>+
>+void
>+random_harvest_deregister_source(enum random_entropy_source source)
>+{
>+
>+	harvest_context.hc_source_mask &= ~(1 << source);
>+}
>+
> MODULE_VERSION(random_harvestq, 1);
>diff --git a/sys/dev/random/randomdev.c b/sys/dev/random/randomdev.c
>index 7edfca8ad6075..28a191f8f7b6b 100644
>--- a/sys/dev/random/randomdev.c
>+++ b/sys/dev/random/randomdev.c
>@@ -1,4 +1,5 @@
> /*-
>+ * Copyright (c) 2017 Oliver Pinter
>  * Copyright (c) 2000-2015 Mark R V Murray
>  * All rights reserved.
>  *
>@@ -321,6 +322,8 @@ random_source_register(struct random_source *rsource)
> 	rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK);
> 	rrs->rrs_source = rsource;
> 
>+	random_harvest_register_source(rsource->rs_source);
>+
> 	printf("random: registering fast source %s\n", rsource->rs_ident);
> 	LIST_INSERT_HEAD(&source_list, rrs, rrs_entries);
> }
>@@ -331,6 +334,9 @@ random_source_deregister(struct random_source *rsource)
> 	struct random_sources *rrs = NULL;
> 
> 	KASSERT(rsource != NULL, ("invalid input to %s", __func__));
>+
>+	random_harvest_deregister_source(rsource->rs_source);
>+
> 	LIST_FOREACH(rrs, &source_list, rrs_entries)
> 		if (rrs->rrs_source == rsource) {
> 			LIST_REMOVE(rrs, rrs_entries);
>diff --git a/sys/sys/random.h b/sys/sys/random.h
>index 480621a1e2d33..fed1210acb7f3 100644
>--- a/sys/sys/random.h
>+++ b/sys/sys/random.h
>@@ -81,7 +81,8 @@ enum random_entropy_source {
> 	RANDOM_UMA,	/* Special!! UMA/SLAB Allocator */
> 	RANDOM_ENVIRONMENTAL_END = RANDOM_UMA,
> 	/* Fast hardware random-number sources from here on. */
>-	RANDOM_PURE_OCTEON,
>+	RANDOM_PURE_START,
>+	RANDOM_PURE_OCTEON = RANDOM_PURE_START,
> 	RANDOM_PURE_SAFE,
> 	RANDOM_PURE_GLXSB,
> 	RANDOM_PURE_UBSEC,
>@@ -95,6 +96,7 @@ enum random_entropy_source {
> };
> 
> #define RANDOM_HARVEST_EVERYTHING_MASK ((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1)
>+#define RANDOM_HARVEST_PURE_MASK (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START))
> 
> #define RANDOM_LEGACY_BOOT_ENTROPY_MODULE	"/boot/entropy"
> #define RANDOM_CACHED_BOOT_ENTROPY_MODULE	"boot_entropy_cache"
>@@ -104,10 +106,14 @@ enum random_entropy_source {
> void random_harvest_queue(const void *, u_int, u_int, enum random_entropy_source);
> void random_harvest_fast(const void *, u_int, u_int, enum random_entropy_source);
> void random_harvest_direct(const void *, u_int, u_int, enum random_entropy_source);
>+void random_harvest_register_source(enum random_entropy_source);
>+void random_harvest_deregister_source(enum random_entropy_source);
> #else
> #define random_harvest_queue(a, b, c, d) do {} while (0)
> #define random_harvest_fast(a, b, c, d) do {} while (0)
> #define random_harvest_direct(a, b, c, d) do {} while (0)
>+#define random_harvest_register_source(a) do {} while (0)
>+#define random_harvest_deregister_source(a) do {} while (0)
> #endif
> 
> #if defined(RANDOM_ENABLE_UMA)

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Attachments on bug 222807: 186932 | 186933 | 186937