From f4569740492c4255d546d5129b45c08e509cc8a1 Mon Sep 17 00:00:00 2001
From: Arthur Chan <arthur.chan@adalogics.com>
Date: Mon, 9 Nov 2026 04:30:54 +0000
Subject: [PATCH] OSS-Fuzz: Add new fuzzer/dict/corpus/scripts targets datetime
 processing

Signed-off-by: Arthur Chan <arthur.chan@adalogics.com>
---
 Makefile                 |   5 ++++-
 corp-datetime/date_0     | Bin 0 -> 12 bytes
 corp-datetime/date_1     | Bin 0 -> 12 bytes
 corp-datetime/date_2     | Bin 0 -> 12 bytes
 corp-datetime/date_3     | Bin 0 -> 12 bytes
 corp-datetime/datetime_0 |   1 +
 corp-datetime/datetime_1 |   1 +
 corp-datetime/datetime_2 |   1 +
 corp-datetime/datetime_3 |   1 +
 corp-datetime/datetime_4 |   1 +
 corp-datetime/datetime_5 |   1 +
 corp-datetime/datetime_6 |   1 +
 corp-datetime/datetime_7 |   1 +
 corp-datetime/time_0     |   1 +
 corp-datetime/time_1     |   1 +
 corp-datetime/time_2     |   1 +
 corp-datetime/time_3     |   1 +
 corp-datetime/time_4     |   1 +
 corp-datetime/time_5     |   1 +
 corp-datetime/time_6     |   1 +
 corp-datetime/time_7     |   1 +
 corp-datetime/time_8     |   1 +
 datetime.py              |  45 +++++++++++++++++++++++++++++++++++++++
 fuzz_targets.txt         |   1 +
 fuzzer-datetime.dict     |  33 ++++++++++++++++++++++++++++
 25 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 corp-datetime/date_0
 create mode 100644 corp-datetime/date_1
 create mode 100644 corp-datetime/date_2
 create mode 100644 corp-datetime/date_3
 create mode 100644 corp-datetime/datetime_0
 create mode 100644 corp-datetime/datetime_1
 create mode 100644 corp-datetime/datetime_2
 create mode 100644 corp-datetime/datetime_3
 create mode 100644 corp-datetime/datetime_4
 create mode 100644 corp-datetime/datetime_5
 create mode 100644 corp-datetime/datetime_6
 create mode 100644 corp-datetime/datetime_7
 create mode 100644 corp-datetime/time_0
 create mode 100644 corp-datetime/time_1
 create mode 100644 corp-datetime/time_2
 create mode 100644 corp-datetime/time_3
 create mode 100644 corp-datetime/time_4
 create mode 100644 corp-datetime/time_5
 create mode 100644 corp-datetime/time_6
 create mode 100644 corp-datetime/time_7
 create mode 100644 corp-datetime/time_8
 create mode 100644 datetime.py
 create mode 100644 fuzzer-datetime.dict

diff --git a/Makefile b/Makefile
index 01df3e8..9623816 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-all: fuzzer-binascii fuzzer-html fuzzer-email fuzzer-httpclient fuzzer-json fuzzer-difflib fuzzer-csv fuzzer-decode fuzzer-ast fuzzer-tarfile fuzzer-tarfile-hypothesis fuzzer-zipfile fuzzer-zipfile-hypothesis fuzzer-re fuzzer-configparser fuzzer-tomllib fuzzer-plistlib fuzzer-xml fuzzer-zoneinfo
+all: fuzzer-binascii fuzzer-html fuzzer-email fuzzer-httpclient fuzzer-json fuzzer-difflib fuzzer-csv fuzzer-decode fuzzer-ast fuzzer-tarfile fuzzer-tarfile-hypothesis fuzzer-zipfile fuzzer-zipfile-hypothesis fuzzer-re fuzzer-configparser fuzzer-tomllib fuzzer-plistlib fuzzer-xml fuzzer-zoneinfo fuzzer-datetime
 
 PYTHON_CONFIG_PATH=$(CPYTHON_INSTALL_PATH)/bin/python3-config
 CXXFLAGS += $(shell $(PYTHON_CONFIG_PATH) --cflags)
@@ -42,3 +42,6 @@ fuzzer-xml:
 	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"xml.py\"" -ldl $(LDFLAGS) -o fuzzer-xml
 fuzzer-zoneinfo:
 	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"zoneinfo.py\"" -ldl $(LDFLAGS) -o fuzzer-zoneinfo
+
+fuzzer-datetime:
+	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"datetime.py\"" -ldl $(LDFLAGS) -o fuzzer-datetime
diff --git a/corp-datetime/date_0 b/corp-datetime/date_0
new file mode 100644
index 0000000000000000000000000000000000000000..8ace41233710041fcfd6727f5d6e4ac3de3055c6
GIT binary patch
literal 12
TcmZQzH8L<V(KRsCH8ceP3c~^K

literal 0
HcmV?d00001

diff --git a/corp-datetime/date_1 b/corp-datetime/date_1
new file mode 100644
index 0000000000000000000000000000000000000000..032c919709146c06604b2904273842bb29d1901c
GIT binary patch
literal 12
PcmZQzH83zR)CD5|3WNdU

literal 0
HcmV?d00001

diff --git a/corp-datetime/date_2 b/corp-datetime/date_2
new file mode 100644
index 0000000000000000000000000000000000000000..6bcac16374b31799e51204b90b5bf27188c92a30
GIT binary patch
literal 12
RcmZQzwFClPLnB>dLjViD0t)~D

literal 0
HcmV?d00001

diff --git a/corp-datetime/date_3 b/corp-datetime/date_3
new file mode 100644
index 0000000000000000000000000000000000000000..54719f4712541a05726ae3ff0248065055848ea3
GIT binary patch
literal 12
TcmZQzH8L<V(KRsAHL?T%3e5ra

literal 0
HcmV?d00001

diff --git a/corp-datetime/datetime_0 b/corp-datetime/datetime_0
new file mode 100644
index 0000000..ef057ee
--- /dev/null
+++ b/corp-datetime/datetime_0
@@ -0,0 +1 @@
+2024-01-15T10:30
\ No newline at end of file
diff --git a/corp-datetime/datetime_1 b/corp-datetime/datetime_1
new file mode 100644
index 0000000..7d23e84
--- /dev/null
+++ b/corp-datetime/datetime_1
@@ -0,0 +1 @@
+2024-01-15 10:30:00
\ No newline at end of file
diff --git a/corp-datetime/datetime_2 b/corp-datetime/datetime_2
new file mode 100644
index 0000000..e67caaa
--- /dev/null
+++ b/corp-datetime/datetime_2
@@ -0,0 +1 @@
+2024-01-15T10:30:00.123456
\ No newline at end of file
diff --git a/corp-datetime/datetime_3 b/corp-datetime/datetime_3
new file mode 100644
index 0000000..fa07490
--- /dev/null
+++ b/corp-datetime/datetime_3
@@ -0,0 +1 @@
+2024-01-15T10:30:00+01:00
\ No newline at end of file
diff --git a/corp-datetime/datetime_4 b/corp-datetime/datetime_4
new file mode 100644
index 0000000..3aee0de
--- /dev/null
+++ b/corp-datetime/datetime_4
@@ -0,0 +1 @@
+2024-01-15T10:30:00.123456-05:30
\ No newline at end of file
diff --git a/corp-datetime/datetime_5 b/corp-datetime/datetime_5
new file mode 100644
index 0000000..d7091cf
--- /dev/null
+++ b/corp-datetime/datetime_5
@@ -0,0 +1 @@
+0001-01-01T00:00:00
\ No newline at end of file
diff --git a/corp-datetime/datetime_6 b/corp-datetime/datetime_6
new file mode 100644
index 0000000..7cae748
--- /dev/null
+++ b/corp-datetime/datetime_6
@@ -0,0 +1 @@
+9999-12-31T23:59:59.999999+00:00
\ No newline at end of file
diff --git a/corp-datetime/datetime_7 b/corp-datetime/datetime_7
new file mode 100644
index 0000000..bbd0b36
--- /dev/null
+++ b/corp-datetime/datetime_7
@@ -0,0 +1 @@
+2024-06-01T12:00:00.000001+02:00
\ No newline at end of file
diff --git a/corp-datetime/time_0 b/corp-datetime/time_0
new file mode 100644
index 0000000..c75d29d
--- /dev/null
+++ b/corp-datetime/time_0
@@ -0,0 +1 @@
+
10:30
\ No newline at end of file
diff --git a/corp-datetime/time_1 b/corp-datetime/time_1
new file mode 100644
index 0000000..c649057
--- /dev/null
+++ b/corp-datetime/time_1
@@ -0,0 +1 @@
+
10:30:00
\ No newline at end of file
diff --git a/corp-datetime/time_2 b/corp-datetime/time_2
new file mode 100644
index 0000000..348f88e
--- /dev/null
+++ b/corp-datetime/time_2
@@ -0,0 +1 @@
+
10:30:00.123456
\ No newline at end of file
diff --git a/corp-datetime/time_3 b/corp-datetime/time_3
new file mode 100644
index 0000000..5ddcd9e
--- /dev/null
+++ b/corp-datetime/time_3
@@ -0,0 +1 @@
+
10:30:00,5
\ No newline at end of file
diff --git a/corp-datetime/time_4 b/corp-datetime/time_4
new file mode 100644
index 0000000..188833d
--- /dev/null
+++ b/corp-datetime/time_4
@@ -0,0 +1 @@
+
00:00
\ No newline at end of file
diff --git a/corp-datetime/time_5 b/corp-datetime/time_5
new file mode 100644
index 0000000..15612f2
--- /dev/null
+++ b/corp-datetime/time_5
@@ -0,0 +1 @@
+
23:59:59.999999
\ No newline at end of file
diff --git a/corp-datetime/time_6 b/corp-datetime/time_6
new file mode 100644
index 0000000..bd8c2a4
--- /dev/null
+++ b/corp-datetime/time_6
@@ -0,0 +1 @@
+
10:30+01:00
\ No newline at end of file
diff --git a/corp-datetime/time_7 b/corp-datetime/time_7
new file mode 100644
index 0000000..e492887
--- /dev/null
+++ b/corp-datetime/time_7
@@ -0,0 +1 @@
+
10:30:00-05:30
\ No newline at end of file
diff --git a/corp-datetime/time_8 b/corp-datetime/time_8
new file mode 100644
index 0000000..dd2c6ce
--- /dev/null
+++ b/corp-datetime/time_8
@@ -0,0 +1 @@
+
10:30:00.123456+01:00:30
\ No newline at end of file
diff --git a/datetime.py b/datetime.py
new file mode 100644
index 0000000..1663b43
--- /dev/null
+++ b/datetime.py
@@ -0,0 +1,45 @@
+"""Fuzz the C ISO-8601 fast parsers and date/time arithmetic.
+
+date, time and datetime fromisoformat() are implemented in C
+(Modules/_datetimemodule.c) and parse attacker-controlled strings.
+Two properties are exercised: isoformat() must round-trip through
+fromisoformat (documented inverse -- a mismatch is a logic bug and
+raises AssertionError), and fuzzed timedelta shifts drive the C
+normalisation and overflow-checking paths. Invalid ISO strings are
+expected and raise ValueError/TypeError; time objects reject +/- with
+TypeError.
+"""
+from datetime import date, datetime, time, timedelta
+
+
+def FuzzerRunOne(FuzzerInput):
+    if len(FuzzerInput) < 3:
+        return
+    op = FuzzerInput[0]
+    amount = FuzzerInput[1]
+    data = FuzzerInput[2:].decode("utf-8", "replace")
+    if op % 3 == 0:
+        parse = date.fromisoformat
+    elif op % 3 == 1:
+        parse = time.fromisoformat
+    else:
+        parse = datetime.fromisoformat
+    try:
+        parsed = parse(data)
+    except (ValueError, TypeError):
+        return
+
+    # Round-trip property: fromisoformat is the documented inverse of
+    # isoformat(), for all three types.
+    reparsed = type(parsed).fromisoformat(parsed.isoformat())
+    if reparsed != parsed:
+        raise AssertionError(
+            "isoformat round-trip mismatch: %r -> %r" % (parsed, parsed.isoformat())
+        )
+
+    delta = timedelta(amount % 30, amount % 60, amount % 1000000)
+    try:
+        parsed + delta
+        parsed - delta
+    except (TypeError, OverflowError):
+        pass
diff --git a/fuzz_targets.txt b/fuzz_targets.txt
index b016889..2f1aea5 100644
--- a/fuzz_targets.txt
+++ b/fuzz_targets.txt
@@ -2,6 +2,7 @@ ast ast.py
 binascii binascii.py
 configparser configparser.py
 csv csv.py
+datetime datetime.py
 decode decode.py
 difflib difflib.py
 email email.py
diff --git a/fuzzer-datetime.dict b/fuzzer-datetime.dict
new file mode 100644
index 0000000..6824d4d
--- /dev/null
+++ b/fuzzer-datetime.dict
@@ -0,0 +1,33 @@
+# ISO-8601 tokens for date/time/datetime.fromisoformat
+"T"
+"Z"
+"z"
+"+01:00"
+"+01:00:30"
+"-05:30"
+"+0000"
+"+01"
+"2024-01-15"
+"2024-01-15T10:30"
+"2024-01-15 10:30:00"
+"10:30"
+"10:30:00"
+"10:30:00.123456"
+"10:30:00,5"
+".123456"
+",123"
+"24:00"
+"00:00"
+"W"
+"-W"
+"2024-W03-1"
+"2024-W03"
+"2024-021"
+"0001-01-01"
+"9999-12-31"
+"23:59:59.999999"
+"+23:59"
+"-23:59"
+"hh"
+"mm"
+"ss"