Originally reported as <http://bugs.debian.org/437214>.
Triggered when input has size modulo 64 is 56–63 bytes.
scheme@(guile-user)> (use-modules (md5))
scheme@(guile-user)> (md5 (open-input-string (make-string 60 #\0)))
ERROR: In procedure string-set!:
ERROR: In procedure string-set!: Wrong type argument in position 1 (expecting
string): #f
Entering a new prompt. Type `,bt' for a backtrace or `,q' to continue.
scheme@(guile-user) [1]> ,bt
In /usr/share/guile/site/md5.scm:
349:10 1 (md5-finalize ((values (a . 1732584193) (b . 4023233417) (c .
2562383102) (. #)) # …))
In unknown file:
0 (string-set! #f #f #\200)
Two errors in that section of the file. The first is a simple typo:
context → 'context.
The second required looking up the libgcrypt source (the basis of this
module) to repair. Lines 322–380 of md5.scm are equivalent to lines
288–301 of cipher/md5.c. Attached patch repairs this part of the file
based on the algorithm in libgcrypt.
$ guile -c '(display (make-string 60 #\0))' | md5sum
5b19445b70b493c78f3bc06eb7962315 -
$ guile
[…]
scheme@(guile-user)> (use-modules (md5))
scheme@(guile-user)> (md5 (open-input-string (make-string 60 #\0)))
$1 = "5b19445b70b493c78f3bc06eb7962315"
Regards
>From 47c92db862ce846dbcc5d27843bc9d26b7708d5d Mon Sep 17 00:00:00 2001
From: Daniel Hartwig <mand...@gmail.com>
Date: Sat, 12 Jan 2013 14:34:26 +0800
Subject: [PATCH] md5: fix errors when input size modulo 64 is > 55 bytes
* src/md5.scm (md5-finalize): Fix typos and missing parts of algorithm
based on cipher/md5.c in libgcrypt.
---
src/md5.scm | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/md5.scm b/src/md5.scm
index 571c857..1acc78b 100644
--- a/src/md5.scm
+++ b/src/md5.scm
@@ -347,11 +347,17 @@ referenced C implementation into Scheme.
'data-size)
1)))))
(begin
- (string-set! (assq-ref (assq-ref 'context 'buffer)
+ (string-set! (assq-ref (assq-ref context 'buffer)
'space)
- (assq-ref (assq-ref 'context 'buffer)
+ (assq-ref (assq-ref context 'buffer)
'data-size)
(integer->char #x80))
+ (assq-set! (assq-ref context 'buffer)
+ 'data-size
+ (+ (assq-ref (assq-ref context 'buffer)
+ 'data-size)
+ 1))
+
(while (< (assq-ref (assq-ref context 'buffer)
'data-size)
64)
@@ -360,7 +366,7 @@ referenced C implementation into Scheme.
'space)
(assq-ref (assq-ref context 'buffer)
'data-size)
- 0)
+ #\nul)
(assq-set! (assq-ref context 'buffer)
'data-size
(+ (assq-ref (assq-ref context 'buffer)
--
1.7.10.4
