changeset 40215:88b18d82fa61

crypto/des: Fix undefined behaviour. * lib/des.c (READ_64BIT_DATA): Cast bytes to 'unsigned int', to avoid shift operations on 'int'.
author Bruno Haible <bruno@clisp.org>
date Sat, 09 Mar 2019 22:21:25 +0100
parents 452ab00796c7
children 02ed6264c100
files ChangeLog lib/des.c
diffstat 2 files changed, 15 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog	Sat Mar 09 20:32:25 2019 +0100
+++ b/ChangeLog	Sat Mar 09 22:21:25 2019 +0100
@@ -1,3 +1,9 @@
+2019-03-09  Bruno Haible  <bruno@clisp.org>
+
+	crypto/des: Fix undefined behaviour.
+	* lib/des.c (READ_64BIT_DATA): Cast bytes to 'unsigned int', to avoid
+	shift operations on 'int'.
+
 2019-03-09  Bruno Haible  <bruno@clisp.org>
 
 	Fix undefined behaviour.
--- a/lib/des.c	Sat Mar 09 20:32:25 2019 +0100
+++ b/lib/des.c	Sat Mar 09 22:21:25 2019 +0100
@@ -407,11 +407,17 @@
  * Macros to convert 8 bytes from/to 32bit words.
  */
 #define READ_64BIT_DATA(data, left, right)                                 \
-    left  = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];  \
-    right = (data[4] << 24) | (data[5] << 16) | (data[6] << 8) | data[7];
+    left  = ((uint32_t) data[0] << 24)                                     \
+            | ((uint32_t) data[1] << 16)                                   \
+            | ((uint32_t) data[2] << 8)                                    \
+            | (uint32_t) data[3];                                          \
+    right = ((uint32_t) data[4] << 24)                                     \
+            | ((uint32_t) data[5] << 16)                                   \
+            | ((uint32_t) data[6] << 8)                                    \
+            | (uint32_t) data[7];
 
 #define WRITE_64BIT_DATA(data, left, right)                                \
-    data[0] = (left >> 24) &0xff; data[1] = (left >> 16) &0xff;    \
+    data[0] = (left >> 24) &0xff; data[1] = (left >> 16) &0xff;            \
     data[2] = (left >> 8) &0xff; data[3] = left &0xff;                     \
     data[4] = (right >> 24) &0xff; data[5] = (right >> 16) &0xff;          \
     data[6] = (right >> 8) &0xff; data[7] = right &0xff;