Add fuzzer for binascii module

Makefile

@@ -1,8 +1,8 @@
-all : 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-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-binascii
 
 PYTHON_CONFIG_PATH=$(CPYTHON_INSTALL_PATH)/bin/python3-config
 CXXFLAGS += $(shell $(PYTHON_CONFIG_PATH) --cflags)
-LDFLAGS += -rdynamic $(shell $(PYTHON_CONFIG_PATH) --ldflags --embed)
+LDFLAGS += -rdynamic $(shell $(PYTHON_CONFIG_PATH) --ldflags --embed) $(CPYTHON_MODLIBS) -Wl,--allow-multiple-definition
 
 fuzzer-html:
 	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"html.py\"" -ldl $(LDFLAGS) -o fuzzer-html
@@ -40,3 +40,6 @@ 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-binascii:
+	clang++ $(CXXFLAGS) $(LIB_FUZZING_ENGINE) -std=c++17 fuzzer.cpp -DPYTHON_HARNESS_PATH="\"binascii.py\"" -ldl $(LDFLAGS) -o fuzzer-binascii

binascii.py

@@ -0,0 +1,95 @@
+from fuzzeddataprovider import FuzzedDataProvider
+import binascii
+
+# Top-level operation constants for FuzzerRunOne
+OP_DECODE = 0
+OP_ENCODE = 1
+OP_CHECKSUM = 2
+OP_ROUNDTRIP = 3
+
+# Decode/encode sub-operation constants
+CODEC_BASE64_STRICT = 0
+CODEC_HEX = 1
+CODEC_UU = 2
+CODEC_QP = 3
+CODEC_BASE64 = 4
+CODEC_BASE64_ALT = 5
+
+
+def op_decode(fdp):
+    which = fdp.ConsumeIntInRange(CODEC_BASE64_STRICT, CODEC_BASE64_ALT)
+    strict = fdp.ConsumeBool()
+    data = fdp.ConsumeBytes(fdp.remaining_bytes())
+    if which == CODEC_BASE64_STRICT:
+        if strict:
+            binascii.a2b_base64(data, strict_mode=True)
+        else:
+            binascii.a2b_base64(data)
+    elif which == CODEC_HEX:
+        binascii.a2b_hex(data)
+    elif which == CODEC_UU:
+        binascii.a2b_uu(data)
+    elif which == CODEC_QP:
+        binascii.a2b_qp(data)
+    elif which == CODEC_BASE64:
+        binascii.a2b_base64(data)
+    elif which == CODEC_BASE64_ALT:
+        binascii.a2b_base64(data)
+
+
+def op_encode(fdp):
+    which = fdp.ConsumeIntInRange(CODEC_BASE64_STRICT, CODEC_BASE64_ALT)
+    newline = fdp.ConsumeBool()
+    data = fdp.ConsumeBytes(fdp.ConsumeIntInRange(0, 10000))
+    if not data:
+        return
+    if which == CODEC_BASE64_STRICT:
+        binascii.b2a_base64(data, newline=newline)
+    elif which == CODEC_HEX:
+        binascii.b2a_hex(data)
+    elif which == CODEC_UU:
+        uu_data = fdp.ConsumeBytes(fdp.ConsumeIntInRange(0, 45))
+        binascii.b2a_uu(uu_data)
+    elif which == CODEC_QP:
+        binascii.b2a_qp(data)
+    elif which == CODEC_BASE64:
+        binascii.b2a_base64(data)
+    elif which == CODEC_BASE64_ALT:
+        binascii.b2a_base64(data)
+
+
+def op_checksum(fdp):
+    use_crc32 = fdp.ConsumeBool()
+    data = fdp.ConsumeBytes(fdp.remaining_bytes())
+    if use_crc32:
+        binascii.crc32(data)
+    else:
+        binascii.crc_hqx(data, 0)
+
+
+def op_roundtrip(fdp):
+    data = fdp.ConsumeBytes(fdp.remaining_bytes())
+    hexed = binascii.hexlify(data)
+    binascii.unhexlify(hexed)
+
+
+# Fuzzes the binascii module's C implementation (Modules/binascii.c).
+# Exercises binary-to-ASCII and ASCII-to-binary conversions for base64,
+# hex, UU-encoding, and quoted-printable codecs. Also tests CRC32,
+# CRC-HQX checksums, and hexlify/unhexlify roundtrips.
+def FuzzerRunOne(FuzzerInput):
+    if len(FuzzerInput) < 1 or len(FuzzerInput) > 0x100000:
+        return
+    fdp = FuzzedDataProvider(FuzzerInput)
+    op = fdp.ConsumeIntInRange(OP_DECODE, OP_ROUNDTRIP)
+    try:
+        if op == OP_DECODE:
+            op_decode(fdp)
+        elif op == OP_ENCODE:
+            op_encode(fdp)
+        elif op == OP_CHECKSUM:
+            op_checksum(fdp)
+        else:
+            op_roundtrip(fdp)
+    except Exception:
+        pass

fuzz_targets.txt

@@ -1,4 +1,5 @@
 ast ast.py
+binascii binascii.py
 configparser configparser.py
 csv csv.py
 decode decode.py