[PATCH 1/2] image-host: add a check of the return value of snprintf.

[Hugo Cornelis]

This patch allows to generate a sensible error message when generating
binary images using very long filenames.

This can happen with Buildroot and Yocto builds.

Signed-off-by: Hugo Cornelis <hugo.cornelis at essensium.com>
---

 tools/image-host.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/tools/image-host.c b/tools/image-host.c
index ca4950312f..3719f36117 100644
--- a/tools/image-host.c
+++ b/tools/image-host.c
@@ -378,6 +378,7 @@ static int fit_image_setup_cipher(struct image_cipher_info *info,
 	char *algo_name;
 	char filename[128];
 	int ret = -1;
+	int snprintf_return;
 
 	if (fit_image_cipher_get_algo(fit, noffset, &algo_name)) {
 		fprintf(stderr, "Can't get algo name for cipher in image '%s'\n",
@@ -414,8 +415,18 @@ static int fit_image_setup_cipher(struct image_cipher_info *info,
 	}
 
 	/* Read the key in the file */
-	snprintf(filename, sizeof(filename), "%s/%s%s",
-		 info->keydir, info->keyname, ".bin");
+	snprintf_return = snprintf(filename, sizeof(filename), "%s/%s%s",
+				   info->keydir, info->keyname, ".bin");
+	if (snprintf_return >= sizeof(filename)) {
+		printf("Can't format the key filename when setting up the cipher: insufficient buffer space\n");
+		ret = -1;
+		goto out;
+	}
+	if (snprintf_return < 0) {
+		printf("Can't format the key filename when setting up the cipher: snprintf error\n");
+		ret = -1;
+		goto out;
+	}
 	info->key = malloc(info->cipher->key_len);
 	if (!info->key) {
 		fprintf(stderr, "Can't allocate memory for key\n");
@@ -436,8 +447,18 @@ static int fit_image_setup_cipher(struct image_cipher_info *info,
 
 	if (info->ivname) {
 		/* Read the IV in the file */
-		snprintf(filename, sizeof(filename), "%s/%s%s",
-			 info->keydir, info->ivname, ".bin");
+		snprintf_return = snprintf(filename, sizeof(filename), "%s/%s%s",
+					   info->keydir, info->ivname, ".bin");
+		if (snprintf_return >= sizeof(filename)) {
+			printf("Can't format the IV filename when setting up the cipher: insufficient buffer space\n");
+			ret = -1;
+			goto out;
+		}
+		if (snprintf_return < 0) {
+			printf("Can't format the IV filename when setting up the cipher: snprintf error\n");
+			ret = -1;
+			goto out;
+		}
 		ret = fit_image_read_data(filename, (unsigned char *)info->iv,
 					  info->cipher->iv_len);
 	} else {
-- 
2.34.1