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authorPádraig Brady <P@draigBrady.com>2011-09-16 11:47:35 +0100
committerPádraig Brady <P@draigBrady.com>2011-09-16 19:09:26 +0100
commit7da844cc86e1209acbe820771b0e9a35fd89da3b (patch)
tree38035a065326d41abd6535306ff4aca7273d8c3a /src
parentb98e41cc74016d5f6b2f70847c126e737193a36b (diff)
downloadcoreutils-7da844cc86e1209acbe820771b0e9a35fd89da3b.tar.xz
md5sum: handle BSD reversed format checksums
* src/md5sum.c (split_3): Detect and handle BSD reversed format checksums. * tests/misc/md5sum-bsd: Add a new test. * tests/Makefile.am: Reference new test. * NEWS: Mention the improvement Suggested by Rimas Kudelis.
Diffstat (limited to 'src')
-rw-r--r--src/md5sum.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/src/md5sum.c b/src/md5sum.c
index ff9538a28..9de34a5e8 100644
--- a/src/md5sum.c
+++ b/src/md5sum.c
@@ -99,7 +99,7 @@
not include any newline character at the end of a line. */
#define MIN_DIGEST_LINE_LENGTH \
(DIGEST_HEX_BYTES /* length of hexadecimal message digest */ \
- + 2 /* blank and binary indicator */ \
+ + 1 /* blank */ \
+ 1 /* minimum filename length */ )
/* True if any of the files read were the standard input. */
@@ -126,6 +126,9 @@ static bool quiet = false;
improperly formatted. */
static bool strict = false;
+/* Whether a BSD reversed format checksum is detected. */
+static int bsd_reversed = -1;
+
/* For long options that have no equivalent short option, use a
non-character as a pseudo short option, starting with CHAR_MAX + 1. */
enum
@@ -307,9 +310,24 @@ split_3 (char *s, size_t s_len,
s[i++] = '\0';
- if (s[i] != ' ' && s[i] != '*')
- return false;
- *binary = (s[i++] == '*');
+ /* If "bsd reversed" format detected. */
+ if ((s_len - i == 1) || (s[i] != ' ' && s[i] != '*'))
+ {
+ /* Don't allow mixing bsd and standard formats,
+ to minimize security issues with attackers
+ renaming files with leading spaces.
+ This assumes that with bsd format checksums
+ that the first file name does not have
+ a leading ' ' or '*'. */
+ if (bsd_reversed == 0)
+ return false;
+ bsd_reversed = 1;
+ }
+ else if (bsd_reversed != 1)
+ {
+ bsd_reversed = 0;
+ *binary = (s[i++] == '*');
+ }
/* All characters between the type indicator and end of line are
significant -- that includes leading and trailing white space. */