From 166232b6f32f5ac4c1b56ac1e5cfdd5155200a05 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kittywhiskers@users.noreply.github.com>
Date: Mon, 28 Feb 2022 00:40:56 +0530
Subject: [PATCH] merge bitcoin#17291: Add fuzzing harness for ISO-8601 related
 functions

---
 doc/fuzzing.md                  |  2 +-
 src/Makefile.test.include       |  7 +++++++
 src/test/fuzz/parse_iso8601.cpp | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 src/test/fuzz/parse_iso8601.cpp

diff --git a/doc/fuzzing.md b/doc/fuzzing.md
index 1d515339fc..81b67dc5d2 100644
--- a/doc/fuzzing.md
+++ b/doc/fuzzing.md
@@ -102,7 +102,7 @@ libFuzzer is needed (all found in the `compiler-rt` runtime libraries package).
 To build all fuzz targets with libFuzzer, run
 
 ```
-./configure --disable-ccache --enable-fuzz --with-sanitizers=fuzzer,address CC=clang CXX=clang++
+./configure --disable-ccache --enable-fuzz --with-sanitizers=fuzzer,address,undefined CC=clang CXX=clang++
 make
 ```
 
diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index aaa5b65d64..65199e2329 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -35,6 +35,7 @@ FUZZ_TARGETS = \
   test/fuzz/messageheader_deserialize \
   test/fuzz/netaddr_deserialize \
   test/fuzz/out_point_deserialize \
+  test/fuzz/parse_iso8601 \
   test/fuzz/partial_merkle_tree_deserialize \
   test/fuzz/partially_signed_transaction_deserialize \
   test/fuzz/prefilled_transaction_deserialize \
@@ -321,6 +322,12 @@ test_fuzz_netaddr_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_netaddr_deserialize_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
 test_fuzz_netaddr_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)
 
+test_fuzz_parse_iso8601_SOURCES = $(FUZZ_SUITE) test/fuzz/parse_iso8601.cpp
+test_fuzz_parse_iso8601_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_parse_iso8601_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_parse_iso8601_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
+test_fuzz_parse_iso8601_LDADD = $(FUZZ_SUITE_LD_COMMON)
+
 test_fuzz_script_SOURCES = $(FUZZ_SUITE) test/fuzz/script.cpp
 test_fuzz_script_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 test_fuzz_script_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
diff --git a/src/test/fuzz/parse_iso8601.cpp b/src/test/fuzz/parse_iso8601.cpp
new file mode 100644
index 0000000000..c86f8a853e
--- /dev/null
+++ b/src/test/fuzz/parse_iso8601.cpp
@@ -0,0 +1,32 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <util/time.h>
+
+#include <cassert>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+
+    const int64_t random_time = fuzzed_data_provider.ConsumeIntegral<int64_t>();
+    const std::string random_string = fuzzed_data_provider.ConsumeRemainingBytesAsString();
+
+    const std::string iso8601_datetime = FormatISO8601DateTime(random_time);
+    const int64_t parsed_time_1 = ParseISO8601DateTime(iso8601_datetime);
+    if (random_time >= 0) {
+        assert(parsed_time_1 >= 0);
+        if (iso8601_datetime.length() == 20) {
+            assert(parsed_time_1 == random_time);
+        }
+    }
+
+    const int64_t parsed_time_2 = ParseISO8601DateTime(random_string);
+    assert(parsed_time_2 >= 0);
+}