libansilove

commit 40ecff56b1af844cf0a9a1893afe3ed1354d2784
parent 3c3083487455d5ee5d6af5e4a20f315e14ed2b02
Author: Frederic Cambus <fred@statdns.com>
Date:   Wed, 12 Dec 2018 15:04:40 +0100

Add format validation checks for the XBin loader

Diffstat:
M
TODO
 | 
2
--
M
src/loaders/xbin.c
 | 
7
+++++++

2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/TODO b/TODO
@@ -3,8 +3,6 @@
 - Parse ANSI in two pass, like we do for Tundra, to avoid storing temporary
   data and save memory?
 - Use OpenBSD style(9) for function prototypes and declarations?
-- Be more resilient with corrupt files, especially ADF / IDF / XBIN files
-  with malformed headers
 - Fix rendering bugs in the PabloDraw 24-bit ANSI sequences handling
 - Fuzz with AFL, especially for non ANSI formats
 - Allow enabling DOS aspect ratio + retina at the same time
diff --git a/src/loaders/xbin.c b/src/loaders/xbin.c
@@ -20,6 +20,8 @@
 #include "fonts.h"
 #include "output.h"
 
+#define XBIN_HEADER_LENGTH 11 /* 4 + 1 + 2 + 2 + 1 + 1 */
+
 int
 ansilove_xbin(struct ansilove_ctx *ctx, struct ansilove_options *options)
 {
@@ -30,6 +32,11 @@ ansilove_xbin(struct ansilove_ctx *ctx, struct ansilove_options *options)
 		return -1;
 	}
 
+	if (ctx->length < XBIN_HEADER_LENGTH) {
+		ctx->error = ANSILOVE_FORMAT_ERROR;
+		return -1;
+	}
+
 	const uint8_t *font_data;
 	uint8_t *font_data_xbin = NULL;