[openwrt/openwrt] dropbear: cherry-pick upstream patches
LEDE Commits
lede-commits at lists.infradead.org
Fri Mar 15 15:54:39 PDT 2024
hauke pushed a commit to openwrt/openwrt.git, branch openwrt-23.05:
https://git.openwrt.org/6549a711be6cb9788aaaec6d31e3396b21893163
commit 6549a711be6cb9788aaaec6d31e3396b21893163
Author: Konstantin Demin <rockdrilla at gmail.com>
AuthorDate: Tue Jan 9 03:40:01 2024 +0300
dropbear: cherry-pick upstream patches
critical fixes:
- libtommath: possible integer overflow (CVE-2023-36328)
- implement Strict KEX mode (CVE-2023-48795)
various fixes:
- fix DROPBEAR_DSS and DROPBEAR_RSA config options
- y2038 issues
- remove SO_LINGER socket option
- make banner reading failure non-fatal
- fix "noremotetcp" behavior
- don't try to shutdown a pty
- fix test for multiuser kernels
adds new features:
- option to bind to interface
- allow inetd with non-syslog
- ignore unsupported command line options with dropbearkey
Signed-off-by: Konstantin Demin <rockdrilla at gmail.com>
(cherry picked from commit b5cde260487eae86db1661a53e5e5e0823936aab)
[Only add the patches fixing security problems]
Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
Tested-by: Stijn Segers <foss at volatilesystems.org>
---
package/network/services/dropbear/Makefile | 2 +-
...-libtommath-fix-possible-integer-overflow.patch | 121 ++++++++++++
.../patches/021-Implement-Strict-KEX-mode.patch | 216 +++++++++++++++++++++
3 files changed, 338 insertions(+), 1 deletion(-)
diff --git a/package/network/services/dropbear/Makefile b/package/network/services/dropbear/Makefile
index e98e995ba7..eec02bccc4 100644
--- a/package/network/services/dropbear/Makefile
+++ b/package/network/services/dropbear/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=dropbear
PKG_VERSION:=2022.82
-PKG_RELEASE:=5
+PKG_RELEASE:=6
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
PKG_SOURCE_URL:= \
diff --git a/package/network/services/dropbear/patches/015-libtommath-fix-possible-integer-overflow.patch b/package/network/services/dropbear/patches/015-libtommath-fix-possible-integer-overflow.patch
new file mode 100644
index 0000000000..f39417adb7
--- /dev/null
+++ b/package/network/services/dropbear/patches/015-libtommath-fix-possible-integer-overflow.patch
@@ -0,0 +1,121 @@
+From 3b576d95dcf791d7b945e75f639da8f89c1685a2 Mon Sep 17 00:00:00 2001
+From: czurnieden <czurnieden at gmx.de>
+Date: Tue, 9 May 2023 17:17:12 +0200
+Subject: Fix possible integer overflow
+
+---
+ libtommath/bn_mp_2expt.c | 4 ++++
+ libtommath/bn_mp_grow.c | 4 ++++
+ libtommath/bn_mp_init_size.c | 5 +++++
+ libtommath/bn_mp_mul_2d.c | 4 ++++
+ libtommath/bn_s_mp_mul_digs.c | 4 ++++
+ libtommath/bn_s_mp_mul_digs_fast.c | 4 ++++
+ libtommath/bn_s_mp_mul_high_digs.c | 4 ++++
+ libtommath/bn_s_mp_mul_high_digs_fast.c | 4 ++++
+ 8 files changed, 33 insertions(+)
+
+--- a/libtommath/bn_mp_2expt.c
++++ b/libtommath/bn_mp_2expt.c
+@@ -12,6 +12,10 @@ mp_err mp_2expt(mp_int *a, int b)
+ {
+ mp_err err;
+
++ if (b < 0) {
++ return MP_VAL;
++ }
++
+ /* zero a as per default */
+ mp_zero(a);
+
+--- a/libtommath/bn_mp_grow.c
++++ b/libtommath/bn_mp_grow.c
+@@ -9,6 +9,10 @@ mp_err mp_grow(mp_int *a, int size)
+ int i;
+ mp_digit *tmp;
+
++ if (size < 0) {
++ return MP_VAL;
++ }
++
+ /* if the alloc size is smaller alloc more ram */
+ if (a->alloc < size) {
+ /* reallocate the array a->dp
+--- a/libtommath/bn_mp_init_size.c
++++ b/libtommath/bn_mp_init_size.c
+@@ -6,6 +6,11 @@
+ /* init an mp_init for a given size */
+ mp_err mp_init_size(mp_int *a, int size)
+ {
++
++ if (size < 0) {
++ return MP_VAL;
++ }
++
+ size = MP_MAX(MP_MIN_PREC, size);
+
+ /* alloc mem */
+--- a/libtommath/bn_mp_mul_2d.c
++++ b/libtommath/bn_mp_mul_2d.c
+@@ -9,6 +9,10 @@ mp_err mp_mul_2d(const mp_int *a, int b,
+ mp_digit d;
+ mp_err err;
+
++ if (b < 0) {
++ return MP_VAL;
++ }
++
+ /* copy */
+ if (a != c) {
+ if ((err = mp_copy(a, c)) != MP_OKAY) {
+--- a/libtommath/bn_s_mp_mul_digs.c
++++ b/libtommath/bn_s_mp_mul_digs.c
+@@ -16,6 +16,10 @@ mp_err s_mp_mul_digs(const mp_int *a, co
+ mp_word r;
+ mp_digit tmpx, *tmpt, *tmpy;
+
++ if (digs < 0) {
++ return MP_VAL;
++ }
++
+ /* can we use the fast multiplier? */
+ if ((digs < MP_WARRAY) &&
+ (MP_MIN(a->used, b->used) < MP_MAXFAST)) {
+--- a/libtommath/bn_s_mp_mul_digs_fast.c
++++ b/libtommath/bn_s_mp_mul_digs_fast.c
+@@ -26,6 +26,10 @@ mp_err s_mp_mul_digs_fast(const mp_int *
+ mp_digit W[MP_WARRAY];
+ mp_word _W;
+
++ if (digs < 0) {
++ return MP_VAL;
++ }
++
+ /* grow the destination as required */
+ if (c->alloc < digs) {
+ if ((err = mp_grow(c, digs)) != MP_OKAY) {
+--- a/libtommath/bn_s_mp_mul_high_digs.c
++++ b/libtommath/bn_s_mp_mul_high_digs.c
+@@ -15,6 +15,10 @@ mp_err s_mp_mul_high_digs(const mp_int *
+ mp_word r;
+ mp_digit tmpx, *tmpt, *tmpy;
+
++ if (digs < 0) {
++ return MP_VAL;
++ }
++
+ /* can we use the fast multiplier? */
+ if (MP_HAS(S_MP_MUL_HIGH_DIGS_FAST)
+ && ((a->used + b->used + 1) < MP_WARRAY)
+--- a/libtommath/bn_s_mp_mul_high_digs_fast.c
++++ b/libtommath/bn_s_mp_mul_high_digs_fast.c
+@@ -19,6 +19,10 @@ mp_err s_mp_mul_high_digs_fast(const mp_
+ mp_digit W[MP_WARRAY];
+ mp_word _W;
+
++ if (digs < 0) {
++ return MP_VAL;
++ }
++
+ /* grow the destination as required */
+ pa = a->used + b->used;
+ if (c->alloc < pa) {
diff --git a/package/network/services/dropbear/patches/021-Implement-Strict-KEX-mode.patch b/package/network/services/dropbear/patches/021-Implement-Strict-KEX-mode.patch
new file mode 100644
index 0000000000..e4a279b9ab
--- /dev/null
+++ b/package/network/services/dropbear/patches/021-Implement-Strict-KEX-mode.patch
@@ -0,0 +1,216 @@
+From 6e43be5c7b99dbee49dc72b6f989f29fdd7e9356 Mon Sep 17 00:00:00 2001
+From: Matt Johnston <matt at ucc.asn.au>
+Date: Mon, 20 Nov 2023 14:02:47 +0800
+Subject: Implement Strict KEX mode
+
+As specified by OpenSSH with kex-strict-c-v00 at openssh.com and
+kex-strict-s-v00 at openssh.com.
+---
+ cli-session.c | 11 +++++++++++
+ common-algo.c | 6 ++++++
+ common-kex.c | 26 +++++++++++++++++++++++++-
+ kex.h | 3 +++
+ process-packet.c | 34 +++++++++++++++++++---------------
+ ssh.h | 4 ++++
+ svr-session.c | 3 +++
+ 7 files changed, 71 insertions(+), 16 deletions(-)
+
+--- a/cli-session.c
++++ b/cli-session.c
+@@ -46,6 +46,7 @@ static void cli_finished(void) ATTRIB_NO
+ static void recv_msg_service_accept(void);
+ static void cli_session_cleanup(void);
+ static void recv_msg_global_request_cli(void);
++static void cli_algos_initialise(void);
+
+ struct clientsession cli_ses; /* GLOBAL */
+
+@@ -117,6 +118,7 @@ void cli_session(int sock_in, int sock_o
+ }
+
+ chaninitialise(cli_chantypes);
++ cli_algos_initialise();
+
+ /* Set up cli_ses vars */
+ cli_session_init(proxy_cmd_pid);
+@@ -487,3 +489,12 @@ void cli_dropbear_log(int priority, cons
+ fflush(stderr);
+ }
+
++static void cli_algos_initialise(void) {
++ algo_type *algo;
++ for (algo = sshkex; algo->name; algo++) {
++ if (strcmp(algo->name, SSH_STRICT_KEX_S) == 0) {
++ algo->usable = 0;
++ }
++ }
++}
++
+--- a/common-algo.c
++++ b/common-algo.c
+@@ -315,6 +315,12 @@ algo_type sshkex[] = {
+ {SSH_EXT_INFO_C, 0, NULL, 1, NULL},
+ #endif
+ #endif
++#if DROPBEAR_CLIENT
++ {SSH_STRICT_KEX_C, 0, NULL, 1, NULL},
++#endif
++#if DROPBEAR_SERVER
++ {SSH_STRICT_KEX_S, 0, NULL, 1, NULL},
++#endif
+ {NULL, 0, NULL, 0, NULL}
+ };
+
+--- a/common-kex.c
++++ b/common-kex.c
+@@ -183,6 +183,10 @@ void send_msg_newkeys() {
+ gen_new_keys();
+ switch_keys();
+
++ if (ses.kexstate.strict_kex) {
++ ses.transseq = 0;
++ }
++
+ TRACE(("leave send_msg_newkeys"))
+ }
+
+@@ -193,7 +197,11 @@ void recv_msg_newkeys() {
+
+ ses.kexstate.recvnewkeys = 1;
+ switch_keys();
+-
++
++ if (ses.kexstate.strict_kex) {
++ ses.recvseq = 0;
++ }
++
+ TRACE(("leave recv_msg_newkeys"))
+ }
+
+@@ -550,6 +558,10 @@ void recv_msg_kexinit() {
+
+ ses.kexstate.recvkexinit = 1;
+
++ if (ses.kexstate.strict_kex && !ses.kexstate.donefirstkex && ses.recvseq != 1) {
++ dropbear_exit("First packet wasn't kexinit");
++ }
++
+ TRACE(("leave recv_msg_kexinit"))
+ }
+
+@@ -859,6 +871,18 @@ static void read_kex_algos() {
+ }
+ #endif
+
++ if (!ses.kexstate.donefirstkex) {
++ const char* strict_name;
++ if (IS_DROPBEAR_CLIENT) {
++ strict_name = SSH_STRICT_KEX_S;
++ } else {
++ strict_name = SSH_STRICT_KEX_C;
++ }
++ if (buf_has_algo(ses.payload, strict_name) == DROPBEAR_SUCCESS) {
++ ses.kexstate.strict_kex = 1;
++ }
++ }
++
+ algo = buf_match_algo(ses.payload, sshkex, kexguess2, &goodguess);
+ allgood &= goodguess;
+ if (algo == NULL || algo->data == NULL) {
+--- a/kex.h
++++ b/kex.h
+@@ -83,6 +83,9 @@ struct KEXState {
+
+ unsigned our_first_follows_matches : 1;
+
++ /* Boolean indicating that strict kex mode is in use */
++ unsigned int strict_kex;
++
+ time_t lastkextime; /* time of the last kex */
+ unsigned int datatrans; /* data transmitted since last kex */
+ unsigned int datarecv; /* data received since last kex */
+--- a/process-packet.c
++++ b/process-packet.c
+@@ -44,6 +44,7 @@ void process_packet() {
+
+ unsigned char type;
+ unsigned int i;
++ unsigned int first_strict_kex = ses.kexstate.strict_kex && !ses.kexstate.donefirstkex;
+ time_t now;
+
+ TRACE2(("enter process_packet"))
+@@ -54,22 +55,24 @@ void process_packet() {
+ now = monotonic_now();
+ ses.last_packet_time_keepalive_recv = now;
+
+- /* These packets we can receive at any time */
+- switch(type) {
+
+- case SSH_MSG_IGNORE:
+- goto out;
+- case SSH_MSG_DEBUG:
+- goto out;
+-
+- case SSH_MSG_UNIMPLEMENTED:
+- /* debugging XXX */
+- TRACE(("SSH_MSG_UNIMPLEMENTED"))
+- goto out;
+-
+- case SSH_MSG_DISCONNECT:
+- /* TODO cleanup? */
+- dropbear_close("Disconnect received");
++ if (type == SSH_MSG_DISCONNECT) {
++ /* Allowed at any time */
++ dropbear_close("Disconnect received");
++ }
++
++ /* These packets may be received at any time,
++ except during first kex with strict kex */
++ if (!first_strict_kex) {
++ switch(type) {
++ case SSH_MSG_IGNORE:
++ goto out;
++ case SSH_MSG_DEBUG:
++ goto out;
++ case SSH_MSG_UNIMPLEMENTED:
++ TRACE(("SSH_MSG_UNIMPLEMENTED"))
++ goto out;
++ }
+ }
+
+ /* Ignore these packet types so that keepalives don't interfere with
+@@ -98,7 +101,8 @@ void process_packet() {
+ if (type >= 1 && type <= 49
+ && type != SSH_MSG_SERVICE_REQUEST
+ && type != SSH_MSG_SERVICE_ACCEPT
+- && type != SSH_MSG_KEXINIT)
++ && type != SSH_MSG_KEXINIT
++ && !first_strict_kex)
+ {
+ TRACE(("unknown allowed packet during kexinit"))
+ recv_unimplemented();
+--- a/ssh.h
++++ b/ssh.h
+@@ -100,6 +100,10 @@
+ #define SSH_EXT_INFO_C "ext-info-c"
+ #define SSH_SERVER_SIG_ALGS "server-sig-algs"
+
++/* OpenSSH strict KEX feature */
++#define SSH_STRICT_KEX_S "kex-strict-s-v00 at openssh.com"
++#define SSH_STRICT_KEX_C "kex-strict-c-v00 at openssh.com"
++
+ /* service types */
+ #define SSH_SERVICE_USERAUTH "ssh-userauth"
+ #define SSH_SERVICE_USERAUTH_LEN 12
+--- a/svr-session.c
++++ b/svr-session.c
+@@ -368,6 +368,9 @@ static void svr_algos_initialise(void) {
+ algo->usable = 0;
+ }
+ #endif
++ if (strcmp(algo->name, SSH_STRICT_KEX_C) == 0) {
++ algo->usable = 0;
++ }
+ }
+ }
+
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