Be more careful examining results of I/O operations.

diff --git a/src/runtime/blowfish.scm b/src/runtime/blowfish.scm
index 4498228634058b5546248fa4afa5b6f736780a15..940e5ee9d449c5645412aa1ee2258b21957e93ad 100644 (file)
--- a/src/runtime/blowfish.scm
+++ b/src/runtime/blowfish.scm
@@ -51,11 +51,13 @@ USA.
      (lambda ()
        (let loop ((m 0))
         (let ((n (read-bytevector! input-buffer input)))
-          (if (not (fix:= 0 n))
+          (if (and n (not (eof-object? n)))
               (let ((m
                      (blowfish-cfb64 input-buffer 0 n output-buffer 0
                                      key init-vector m encrypt?)))
-                (write-bytevector output-buffer output 0 n)
+                (let ((n* (write-bytevector output-buffer output 0 n)))
+                  (if (not (eqv? n n*))
+                      (error "Short write (requested, actual):" n n*)))
                 (loop m))))))
      (lambda ()
        (bytevector-fill! input-buffer 0)
@@ -88,23 +90,28 @@ USA.
        (error:bad-range-argument port 'read-blowfish-file-header))
     (if (= version 1)
        (make-bytevector 8 0)
-       (let ((init-vector (read-bytevector 8 port)))
-         (if (not (fix:= (bytevector-length init-vector) 8))
-             (error "Short read while getting init-vector:" port))
-          init-vector))))
+       (or (%safe-read-bytevector 8 port)
+           (error "Short read while getting init-vector:" port)))))
 
 (define (try-read-blowfish-file-header port)
   (let* ((n (bytevector-length blowfish-file-header-v1))
-        (bv (read-bytevector n port)))
-    (and (not (fix:= (bytevector-length bv) n))
-        (if (bytevector=? bv blowfish-file-header-v1)
+        (bv1 (%safe-read-bytevector n port)))
+    (and bv1
+        (if (bytevector=? bv1 blowfish-file-header-v1)
             1
             (let* ((m (fix:- (bytevector-length blowfish-file-header-v2) n))
-                   (bv2 (read-bytevector m port)))
-              (and (not (fix:= (bytevector-length bv2) m))
-                   (and (bytevector=? (bytevector-append bv bv2)
-                                      blowfish-file-header-v2)
-                        2)))))))
+                   (bv2 (%safe-read-bytevector m port)))
+              (and bv2
+                   (bytevector=? (bytevector-append bv1 bv2)
+                                 blowfish-file-header-v2)
+                   2))))))
+
+(define (%safe-read-bytevector n port)
+  (let ((bv (read-bytevector n port)))
+    (and bv
+        (not (eof-object? bv))
+        (fix:= (bytevector-length bv) n)
+        bv)))
 
 (define (blowfish-file? pathname)
   (call-with-binary-input-file pathname try-read-blowfish-file-header))