From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hg2it-0004iE-F3 for barebox@lists.infradead.org; Wed, 26 Jun 2019 07:52:08 +0000 Date: Wed, 26 Jun 2019 09:52:05 +0200 From: Sascha Hauer Message-ID: <20190626075205.k5kkwumyougusmaz@pengutronix.de> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 10/13] arm: uncompress: verify sha256 if enabled To: Rouven Czerwinski Cc: barebox@lists.infradead.org On Wed, Jun 26, 2019 at 06:58:51AM +0200, Rouven Czerwinski wrote: > Add piggydata verification before the ARM uncompress function. > This calculates the sha256sum of the compressed barebox binary and only > continues if the builtin sha256sum matches the calculated sha256sum. > > Signed-off-by: Rouven Czerwinski > --- > arch/arm/cpu/uncompress.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/cpu/uncompress.c b/arch/arm/cpu/uncompress.c > index e527165..ce5f2c1 100644 > --- a/arch/arm/cpu/uncompress.c > +++ b/arch/arm/cpu/uncompress.c > @@ -42,14 +42,18 @@ unsigned long free_mem_end_ptr; > extern unsigned char input_data[]; > extern unsigned char input_data_end[]; > > +extern unsigned char sha_sum[]; > +extern unsigned char sha_sum_end[]; > + > void __noreturn barebox_multi_pbl_start(unsigned long membase, > unsigned long memsize, void *boarddata) > { > - uint32_t pg_len, uncompressed_len; > + uint32_t pg_len, uncompressed_len, pbl_hash_len; > void __noreturn (*barebox)(unsigned long, unsigned long, void *); > unsigned long endmem = membase + memsize; > unsigned long barebox_base; > void *pg_start, *pg_end; > + void *pbl_hash_start, *pbl_hash_end; > unsigned long pc = get_pc(); > > pg_start = input_data + global_variable_offset(); > @@ -92,6 +96,18 @@ void __noreturn barebox_multi_pbl_start(unsigned long membase, > pr_debug("uncompressing barebox binary at 0x%p (size 0x%08x) to 0x%08lx (uncompressed size: 0x%08x)\n", > pg_start, pg_len, barebox_base, uncompressed_len); > > + if (IS_ENABLED(CONFIG_PBL_VERIFY_PIGGY)) { > + pbl_hash_start = sha_sum + global_variable_offset(); > + pbl_hash_end = sha_sum_end + global_variable_offset(); > + pbl_hash_len = pbl_hash_end - pbl_hash_start; > + if (pbl_barebox_verify(pg_start, pg_len, pbl_hash_start, > + pbl_hash_len) != 0) { > + putc_ll('!'); > + pr_err("hash mismatch, refusing to decompress"); > + panic("hash mismatch, refusing to decompress"); Isn't printing the string in panic() enough? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox