From 550c93085aac67e88486355121e71678c41c38e1 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Fri, 24 Sep 2021 23:06:57 +0200
Subject: [PATCH] tools: kwboot: Don't patch image header if signed
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
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It is not possible to modify image with secure header due to
cryptographic signature.
Signed-off-by: Pali Rohár <pali@kernel.org>
[ refactored ]
Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
tools/kwboot.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/tools/kwboot.c b/tools/kwboot.c
index 9394a51380..2446d0a7b5 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -756,6 +756,18 @@ kwboot_img_csum8(void *_data, size_t size)
return csum;
}
+static int
+kwboot_img_is_secure(void *img)
+{
+ struct opt_hdr_v1 *ohdr;
+
+ for_each_opt_hdr_v1 (ohdr, img)
+ if (ohdr->headertype == OPT_HDR_V1_SECURE_TYPE)
+ return 1;
+
+ return 0;
+}
+
static int
kwboot_img_patch_hdr(void *img, size_t size)
{
@@ -764,6 +776,7 @@ kwboot_img_patch_hdr(void *img, size_t size)
uint8_t csum;
size_t hdrsz = sizeof(*hdr);
int image_ver;
+ int is_secure;
rc = -1;
hdr = img;
@@ -796,12 +809,19 @@ kwboot_img_patch_hdr(void *img, size_t size)
goto out;
}
- if (hdr->blockid == IBR_HDR_UART_ID) {
- rc = 0;
- goto out;
- }
+ is_secure = kwboot_img_is_secure(img);
- hdr->blockid = IBR_HDR_UART_ID;
+ if (hdr->blockid != IBR_HDR_UART_ID) {
+ if (is_secure) {
+ fprintf(stderr,
+ "Image has secure header with signature for non-UART booting\n");
+ errno = EINVAL;
+ goto out;
+ }
+
+ kwboot_printv("Patching image boot signature to UART\n");
+ hdr->blockid = IBR_HDR_UART_ID;
+ }
if (image_ver == 0) {
struct main_hdr_v0 *hdr_v0 = img;
--
2.39.5