From patchwork Sun Nov 21 16:40:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Mueller X-Patchwork-Id: 12630945 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 845DBC433FE for ; Sun, 21 Nov 2021 16:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238349AbhKUQxc (ORCPT ); Sun, 21 Nov 2021 11:53:32 -0500 Received: from mo4-p04-ob.smtp.rzone.de ([85.215.255.122]:10841 "EHLO mo4-p04-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238345AbhKUQxC (ORCPT ); Sun, 21 Nov 2021 11:53:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1637513321; s=strato-dkim-0002; d=chronox.de; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Cc:Date: From:Subject:Sender; bh=Kb/fhfUUNBmMQAjq+fwP/FS7bj/uNZObBjcQ2yLpfKM=; b=QXp9Ng6d5LLjnAyjUpsHd8Plp5itRx2X0iCZm76MLgW5Wnccyi9uP1HIeqi6higdm0 J0HfLhr+UA/ghSgmCN9g/WnsK2N7ZgCYL307p3xVEcVm206M+EOpIygf/29UgIBW3vcL rS1SRTw8cke6m84EqyL4x7ijC707VI4pa7bkvy8HY4C/2sN2A35SQ/4KKtWlipFf39gG 7cGfcHcDOjPPVsqVeZJ6xCZa/jlXkf6AkaJDOLnodfN2NxdZEKgRzhiWk/9F3dyOZpz/ s4hWUPg3fhya3DCHcT09vbpkyLRb0EpW8bIa7yejxMq6yvlZTmZiRS110FTdwmbldORF jvbQ== Authentication-Results: strato.com; dkim=none X-RZG-AUTH: ":P2ERcEykfu11Y98lp/T7+hdri+uKZK8TKWEqNyiHySGSa9k9xmwdNnzGHXPbJvSfE+K2" X-RZG-CLASS-ID: mo00 Received: from positron.chronox.de by smtp.strato.de (RZmta 47.34.5 DYNA|AUTH) with ESMTPSA id U02dfbxALGme3Wm (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Sun, 21 Nov 2021 17:48:40 +0100 (CET) From: Stephan =?iso-8859-1?q?M=FCller?= To: Tso Ted , linux-crypto@vger.kernel.org Cc: Willy Tarreau , Nicolai Stange , LKML , Arnd Bergmann , Greg Kroah-Hartman , "Eric W. Biederman" , "Alexander E. Patrakov" , "Ahmed S. Darwish" , Matthew Garrett , Vito Caputo , Andreas Dilger , Jan Kara , Ray Strode , William Jon McCann , zhangjs , Andy Lutomirski , Florian Weimer , Lennart Poettering , Peter Matthias , Marcelo Henrique Cerri , Neil Horman , Randy Dunlap , Julia Lawall , Dan Carpenter , Andy Lavr , Eric Biggers , "Jason A. Donenfeld" , Petr Tesarik , John Haxby , Alexander Lobakin , Jirka Hladky Subject: [PATCH v43 03/15] LRNG - sysctls and /proc interface Date: Sun, 21 Nov 2021 17:40:57 +0100 Message-ID: <2386316.XAFRqVoOGU@positron.chronox.de> In-Reply-To: <2036923.9o76ZdvQCi@positron.chronox.de> References: <2036923.9o76ZdvQCi@positron.chronox.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The LRNG sysctl interface provides the same controls as the existing /dev/random implementation. These sysctls behave identically and are implemented identically. The goal is to allow a possible merge of the existing /dev/random implementation with this implementation which implies that this patch tries have a very close similarity. Yet, all sysctls are documented at [1]. In addition, it provides the file lrng_type which provides details about the LRNG: - the name of the DRNG that produces the random numbers for /dev/random, /dev/urandom, getrandom(2) - the hash used to produce random numbers from the entropy pool - the number of secondary DRNG instances - indicator whether the LRNG operates SP800-90B compliant - indicator whether a high-resolution timer is identified - only with a high-resolution timer the interrupt noise source will deliver sufficient entropy - indicator whether the LRNG has been minimally seeded (i.e. is the secondary DRNG seeded with at least 128 bits of entropy) - indicator whether the LRNG has been fully seeded (i.e. is the secondary DRNG seeded with at least 256 bits of entropy) [1] https://www.chronox.de/lrng.html CC: Torsten Duwe CC: "Eric W. Biederman" CC: "Alexander E. Patrakov" CC: "Ahmed S. Darwish" CC: "Theodore Y. Ts'o" CC: Willy Tarreau CC: Matthew Garrett CC: Vito Caputo CC: Andreas Dilger CC: Jan Kara CC: Ray Strode CC: William Jon McCann CC: zhangjs CC: Andy Lutomirski CC: Florian Weimer CC: Lennart Poettering CC: Nicolai Stange Reviewed-by: Alexander Lobakin Tested-by: Alexander Lobakin Reviewed-by: Marcelo Henrique Cerri Reviewed-by: Roman Drahtmueller Tested-by: Marcelo Henrique Cerri Tested-by: Neil Horman Tested-by: Jirka Hladky Reviewed-by: Jirka Hladky Signed-off-by: Stephan Mueller --- drivers/char/lrng/Makefile | 1 + drivers/char/lrng/lrng_interfaces.c | 2 - drivers/char/lrng/lrng_proc.c | 199 ++++++++++++++++++++++++++++ 3 files changed, 200 insertions(+), 2 deletions(-) create mode 100644 drivers/char/lrng/lrng_proc.c diff --git a/drivers/char/lrng/Makefile b/drivers/char/lrng/Makefile index d321d6d21a44..d7df72a702e4 100644 --- a/drivers/char/lrng/Makefile +++ b/drivers/char/lrng/Makefile @@ -8,3 +8,4 @@ obj-y += lrng_es_mgr.o lrng_aux.o \ lrng_interfaces.o lrng_es_aux.o obj-$(CONFIG_LRNG_IRQ) += lrng_es_irq.o +obj-$(CONFIG_SYSCTL) += lrng_proc.o diff --git a/drivers/char/lrng/lrng_interfaces.c b/drivers/char/lrng/lrng_interfaces.c index 6316a534bb54..b656aaf0c6cb 100644 --- a/drivers/char/lrng/lrng_interfaces.c +++ b/drivers/char/lrng/lrng_interfaces.c @@ -38,8 +38,6 @@ static DECLARE_WAIT_QUEUE_HEAD(lrng_write_wait); static DECLARE_WAIT_QUEUE_HEAD(lrng_init_wait); static struct fasync_struct *fasync; -struct ctl_table random_table[]; - /********************************** Helper ***********************************/ /* Is the DRNG seed level too low? */ diff --git a/drivers/char/lrng/lrng_proc.c b/drivers/char/lrng/lrng_proc.c new file mode 100644 index 000000000000..b48094c32b95 --- /dev/null +++ b/drivers/char/lrng/lrng_proc.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +/* + * LRNG proc and sysctl interfaces + * + * Copyright (C) 2016 - 2021, Stephan Mueller + */ + +#include +#include +#include +#include +#include + +#include "lrng_internal.h" + +/* + * This function is used to return both the bootid UUID, and random + * UUID. The difference is in whether table->data is NULL; if it is, + * then a new UUID is generated and returned to the user. + * + * If the user accesses this via the proc interface, the UUID will be + * returned as an ASCII string in the standard UUID format; if via the + * sysctl system call, as 16 bytes of binary data. + */ +static int lrng_proc_do_uuid(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + unsigned char buf[64], tmp_uuid[16], *uuid; + + uuid = table->data; + if (!uuid) { + uuid = tmp_uuid; + generate_random_uuid(uuid); + } else { + static DEFINE_SPINLOCK(bootid_spinlock); + + spin_lock(&bootid_spinlock); + if (!uuid[8]) + generate_random_uuid(uuid); + spin_unlock(&bootid_spinlock); + } + + sprintf(buf, "%pU", uuid); + + fake_table.data = buf; + fake_table.maxlen = sizeof(buf); + + return proc_dostring(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_proc_do_entropy(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + int entropy_count; + + entropy_count = lrng_avail_entropy(); + + fake_table.data = &entropy_count; + fake_table.maxlen = sizeof(entropy_count); + + return proc_dointvec(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_proc_do_poolsize(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + int entropy_count; + + /* LRNG can at most retain entropy in per-CPU pools and aux pool */ + entropy_count = lrng_get_digestsize() + lrng_pcpu_avail_pool_size(); + + fake_table.data = &entropy_count; + fake_table.maxlen = sizeof(entropy_count); + + return proc_dointvec(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_min_write_thresh; +static int lrng_max_write_thresh = (LRNG_WRITE_WAKEUP_ENTROPY << 3); +static char lrng_sysctl_bootid[16]; +static int lrng_drng_reseed_max_min; + +void lrng_proc_update_max_write_thresh(u32 new_digestsize) +{ + lrng_max_write_thresh = (int)new_digestsize; + mb(); +} + +struct ctl_table random_table[] = { + { + .procname = "poolsize", + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = lrng_proc_do_poolsize, + }, + { + .procname = "entropy_avail", + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = lrng_proc_do_entropy, + }, + { + .procname = "write_wakeup_threshold", + .data = &lrng_write_wakeup_bits, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &lrng_min_write_thresh, + .extra2 = &lrng_max_write_thresh, + }, + { + .procname = "boot_id", + .data = &lrng_sysctl_bootid, + .maxlen = 16, + .mode = 0444, + .proc_handler = lrng_proc_do_uuid, + }, + { + .procname = "uuid", + .maxlen = 16, + .mode = 0444, + .proc_handler = lrng_proc_do_uuid, + }, + { + .procname = "urandom_min_reseed_secs", + .data = &lrng_drng_reseed_max_time, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &lrng_drng_reseed_max_min, + }, + { } +}; + +/* Number of online DRNGs */ +static u32 numa_drngs = 1; + +void lrng_pool_inc_numa_node(void) +{ + numa_drngs++; +} + +static int lrng_proc_type_show(struct seq_file *m, void *v) +{ + struct lrng_drng *lrng_drng_init = lrng_drng_init_instance(); + unsigned long flags = 0; + unsigned char buf[250], irq[200], aux[100], cpu[90], jent[45]; + + lrng_drng_lock(lrng_drng_init, &flags); + snprintf(buf, sizeof(buf), + "DRNG name: %s\n" + "LRNG security strength in bits: %d\n" + "number of DRNG instances: %u\n" + "Standards compliance: %s\n" + "Entropy Sources: %s%s%sAuxiliary\n" + "LRNG minimally seeded: %s\n" + "LRNG fully seeded: %s\n", + lrng_drng_init->crypto_cb->lrng_drng_name(), + lrng_security_strength(), + numa_drngs, + lrng_sp80090c_compliant() ? "SP800-90C " : "", + IS_ENABLED(CONFIG_LRNG_IRQ) ? "IRQ " : "", + IS_ENABLED(CONFIG_LRNG_JENT) ? "JitterRNG " : "", + IS_ENABLED(CONFIG_LRNG_CPU) ? "CPU " : "", + lrng_state_min_seeded() ? "true" : "false", + lrng_state_fully_seeded() ? "true" : "false"); + + lrng_aux_es_state(aux, sizeof(aux)); + + irq[0] = '\0'; + lrng_irq_es_state(irq, sizeof(irq)); + + jent[0] = '\0'; + lrng_jent_es_state(jent, sizeof(jent)); + + cpu[0] = '\0'; + lrng_arch_es_state(cpu, sizeof(cpu)); + + lrng_drng_unlock(lrng_drng_init, &flags); + + seq_write(m, buf, strlen(buf)); + seq_write(m, aux, strlen(aux)); + seq_write(m, irq, strlen(irq)); + seq_write(m, jent, strlen(jent)); + seq_write(m, cpu, strlen(cpu)); + + return 0; +} + +static int __init lrng_proc_type_init(void) +{ + proc_create_single("lrng_type", 0444, NULL, &lrng_proc_type_show); + return 0; +} + +module_init(lrng_proc_type_init);