diff -r 753b9fbe18be -r 387b9f7cb0ac src/Pure/General/sha1_samples.ML
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/General/sha1_samples.ML	Mon Aug 26 21:56:08 2013 +0200
@@ -0,0 +1,35 @@
+(*  Title:      Pure/General/sha1_samples.ML
+    Author:     Makarius
+
+Some SHA1 samples found in the wild.
+*)
+
+signature SHA1_SAMPLES =
+sig
+  val test: unit -> unit
+end;
+
+structure SHA1_Samples: SHA1_SAMPLES =
+struct
+
+fun check (msg, key) =
+  let val key' = SHA1.rep (SHA1.digest msg) in
+    if key = key' then ()
+    else
+      raise Fail ("SHA1 library integrity test failed on " ^ quote msg ^ ":\n" ^
+        key ^ " expected, but\n" ^ key' ^ " was found")
+  end;
+
+fun test () =
+  List.app check
+   [("", "da39a3ee5e6b4b0d3255bfef95601890afd80709"),
+    ("a", "86f7e437faa5a7fce15d1ddcb9eaeaea377667b8"),
+    ("abc", "a9993e364706816aba3e25717850c26c9cd0d89d"),
+    ("abcdefghijklmnopqrstuvwxyz", "32d10c7b8cf96570ca04ce37f2a19d84240d3a89"),
+    ("The quick brown fox jumps over the lazy dog", "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12"),
+    (replicate_string 100 "\000", "ed4a77d1b56a118938788fc53037759b6c501e3d"),
+    ("a\000b", "4a3dec2d1f8245280855c42db0ee4239f917fdb8")];
+
+val _ = test ();
+
+end;