From a35e324d9245835abb07166910ffc9ec9d690038 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20R=C3=BChsen?= <tim.ruehsen@gmx.de>
Date: Sat, 5 Jan 2019 21:10:04 +0100
Subject: [PATCH] Add libidn2_register_fuzzer and corpora

---
 fuzz/Makefile.am               |  4 +-
 fuzz/libidn2_register_fuzzer.c | 68 ++++++++++++++++++++++++++++++++++
 lib/context.c                  | 24 ++++++++----
 3 files changed, 87 insertions(+), 9 deletions(-)
 create mode 100644 fuzz/libidn2_register_fuzzer.c

diff --git a/fuzz/Makefile.am b/fuzz/Makefile.am
index bc55d30..6f6d7c8 100644
--- a/fuzz/Makefile.am
+++ b/fuzz/Makefile.am
@@ -6,12 +6,14 @@ LDADD = ../lib/libidn2.la ../gl/libgnu.la $(LTLIBUNISTRING)
 
 IDN_TESTS = \
  libidn2_to_ascii_8z_fuzzer$(EXEEXT) \
- libidn2_to_unicode_8z8z_fuzzer$(EXEEXT)
+ libidn2_to_unicode_8z8z_fuzzer$(EXEEXT) \
+ libidn2_register_fuzzer$(EXEEXT)
 
 check_PROGRAMS = $(IDN_TESTS)
 
 libidn2_to_ascii_8z_fuzzer_SOURCES = libidn2_to_ascii_8z_fuzzer.c main.c fuzzer.h
 libidn2_to_unicode_8z8z_fuzzer_SOURCES = libidn2_to_unicode_8z8z_fuzzer.c main.c fuzzer.h
+libidn2_register_fuzzer_SOURCES = libidn2_register_fuzzer.c main.c fuzzer.h
 
 dist-hook:
 	find . -name '*.options' -exec cp -v '{}' $(distdir) ';'
diff --git a/fuzz/libidn2_register_fuzzer.c b/fuzz/libidn2_register_fuzzer.c
new file mode 100644
index 0000000..7164a93
--- /dev/null
+++ b/fuzz/libidn2_register_fuzzer.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright(c) 2019 Tim Ruehsen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * This file is part of libidn2.
+ */
+
+#include <config.h>
+
+#include <assert.h> /* assert */
+#include <stdlib.h> /* malloc, free */
+#include <string.h> /* memcpy */
+
+#include "idn2.h"
+#include "fuzzer.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+	char *ulabel, *alabel;
+	char *out;
+
+	if (size > 1024)
+		return 0;
+
+	ulabel = (char *) malloc(size + 1);
+	assert(ulabel != NULL);
+
+	/* 0 terminate */
+	memcpy(ulabel, data, size);
+	ulabel[size] = 0;
+
+	if (idn2_register_ul(ulabel, NULL, &out, 0) == IDNA_SUCCESS)
+		idn2_free(out);
+
+	free(ulabel);
+
+	alabel = (char *) malloc(size + 4 + 1);
+	assert(alabel != NULL);
+
+	/* 0 terminate */
+	memcpy(alabel, "xn--", 4);
+	memcpy(alabel + 4, data, size);
+	alabel[size] = 0;
+
+	if (idn2_register_ul(NULL, alabel, &out, 0) == IDNA_SUCCESS)
+		idn2_free(out);
+
+	free(alabel);
+
+	return 0;
+}
diff --git a/lib/context.c b/lib/context.c
index 991ec9f..1ee9ba3 100644
--- a/lib/context.c
+++ b/lib/context.c
@@ -29,11 +29,8 @@
 #include <config.h>
 
 #include "idn2.h"
-
 #include "tables.h"
-
 #include <unictype.h>		/* uc_combining_class, UC_CCC_VR */
-
 #include "context.h"
 
 int
@@ -115,6 +112,17 @@ _idn2_contextj_rule (const uint32_t * label, size_t llen, size_t pos)
   return IDN2_CONTEXTJ_NO_RULE;
 }
 
+static inline const char *
+_uc_script_name (ucs4_t uc)
+{
+  const uc_script_t *ucs = uc_script(uc);
+
+  if (!ucs)
+    return "";
+
+  return ucs->name;
+}
+
 int
 _idn2_contexto_rule (const uint32_t * label, size_t llen, size_t pos)
 {
@@ -140,7 +148,7 @@ _idn2_contexto_rule (const uint32_t * label, size_t llen, size_t pos)
       /* GREEK LOWER NUMERAL SIGN (KERAIA) */
       if (pos == llen - 1)
 	return IDN2_CONTEXTO;
-      if (strcmp (uc_script (label[pos + 1])->name, "Greek") == 0)
+      if (strcmp (_uc_script_name (label[pos + 1]), "Greek") == 0)
 	return IDN2_OK;
       return IDN2_CONTEXTO;
       break;
@@ -151,7 +159,7 @@ _idn2_contexto_rule (const uint32_t * label, size_t llen, size_t pos)
       /* HEBREW PUNCTUATION GERSHAYIM */
       if (pos == 0)
 	return IDN2_CONTEXTO;
-      if (strcmp (uc_script (label[pos - 1])->name, "Hebrew") == 0)
+      if (strcmp (_uc_script_name (label[pos - 1]), "Hebrew") == 0)
 	return IDN2_OK;
       return IDN2_CONTEXTO;
       break;
@@ -202,9 +210,9 @@ _idn2_contexto_rule (const uint32_t * label, size_t llen, size_t pos)
 	bool script_ok = false;
 
 	for (i = 0; !script_ok && i < llen; i++)
-	  if (strcmp (uc_script (label[i])->name, "Hiragana") == 0
-	      || strcmp (uc_script (label[i])->name, "Katakana") == 0
-	      || strcmp (uc_script (label[i])->name, "Han") == 0)
+	  if (strcmp (_uc_script_name (label[i]), "Hiragana") == 0
+	      || strcmp (_uc_script_name (label[i]), "Katakana") == 0
+	      || strcmp (_uc_script_name (label[i]), "Han") == 0)
 	    script_ok = true;
 
 	if (script_ok)
-- 
2.19.1

