2 files changed, 18 insertions, 2 deletions

diff --git a/regress/unittests/test_helper/fuzz.c b/regress/unittests/test_helper/fuzz.c
index 93cff6969..06fb247ef 100644
--- a/regress/unittests/test_helper/fuzz.c
+++ b/regress/unittests/test_helper/fuzz.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: fuzz.c,v 1.6 2015/01/18 19:50:55 djm Exp $    */
+/*      $OpenBSD: fuzz.c,v 1.7 2015/01/18 19:52:44 djm Exp $    */
 /*
  * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
  *
@@ -378,6 +378,14 @@ fuzz_next(struct fuzz *fuzz)
 }
 
 int
+fuzz_matches_original(struct fuzz *fuzz)
+{
+        if (fuzz_len(fuzz) != fuzz->slen)
+                return 0;
+        return memcmp(fuzz_ptr(fuzz), fuzz->seed, fuzz->slen) == 0;
+}
+
+int
 fuzz_done(struct fuzz *fuzz)
 {
         FUZZ_DBG(("fuzz = %p, strategies = 0x%lx", fuzz,
diff --git a/regress/unittests/test_helper/test_helper.h b/regress/unittests/test_helper/test_helper.h
index 48c888ac3..1d9c66986 100644
--- a/regress/unittests/test_helper/test_helper.h
+++ b/regress/unittests/test_helper/test_helper.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: test_helper.h,v 1.5 2015/01/15 07:36:28 djm Exp $     */
+/*      $OpenBSD: test_helper.h,v 1.6 2015/01/18 19:52:44 djm Exp $     */
 /*
  * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
  *
@@ -283,6 +283,13 @@ void fuzz_cleanup(struct fuzz *fuzz);
 /* Prepare the next fuzz case in the series */
 void fuzz_next(struct fuzz *fuzz);
 
+/*
+ * Check whether this fuzz case is identical to the original
+ * This is slow, but useful if the caller needs to ensure that all tests
+ * generated change the input (e.g. when fuzzing signatures).
+ */
+int fuzz_matches_original(struct fuzz *fuzz);
+
 /* Determine whether the current fuzz sequence is exhausted (nonzero = yes) */
 int fuzz_done(struct fuzz *fuzz);
 
@@ -292,4 +299,5 @@ u_char *fuzz_ptr(struct fuzz *fuzz);
 
 /* Dump the current fuzz case to stderr */
 void fuzz_dump(struct fuzz *fuzz);
+
 #endif /* _TEST_HELPER_H */