OSS-Fuzz: Add new fuzzer/dict/corpus/scripts targets datetime processing

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

corp-datetime/datetime_0

@@ -0,0 +1 @@
+2024-01-15T10:30

corp-datetime/datetime_1

@@ -0,0 +1 @@
+2024-01-15 10:30:00

corp-datetime/datetime_2

@@ -0,0 +1 @@
+2024-01-15T10:30:00.123456

corp-datetime/datetime_3

@@ -0,0 +1 @@
+2024-01-15T10:30:00+01:00

corp-datetime/datetime_4

@@ -0,0 +1 @@
+2024-01-15T10:30:00.123456-05:30

corp-datetime/datetime_5

@@ -0,0 +1 @@
+0001-01-01T00:00:00

corp-datetime/datetime_6

@@ -0,0 +1 @@
+9999-12-31T23:59:59.999999+00:00

corp-datetime/datetime_7

@@ -0,0 +1 @@
+2024-06-01T12:00:00.000001+02:00

corp-datetime/time_0

@@ -0,0 +1 @@
+
10:30

corp-datetime/time_1

@@ -0,0 +1 @@
+
10:30:00

corp-datetime/time_2

@@ -0,0 +1 @@
+
10:30:00.123456

corp-datetime/time_3

@@ -0,0 +1 @@
+
10:30:00,5

corp-datetime/time_4

@@ -0,0 +1 @@
+
00:00

corp-datetime/time_5

@@ -0,0 +1 @@
+
23:59:59.999999

corp-datetime/time_6

@@ -0,0 +1 @@
+
10:30+01:00

corp-datetime/time_7

@@ -0,0 +1 @@
+
10:30:00-05:30

corp-datetime/time_8

@@ -0,0 +1 @@
+
10:30:00.123456+01:00:30

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

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

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"