py3: remove py2/3 branches

Remove `if-else`s with a condition like `sys.version_info >= (3, 0)`.

capa/features/__init__.py

@@ -27,10 +27,7 @@ VALID_ARCH = (ARCH_X32, ARCH_X64)
 
 
 def bytes_to_str(b):
-    if sys.version_info[0] >= 3:
-        return str(codecs.encode(b, "hex").decode("utf-8"))
-    else:
-        return codecs.encode(b, "hex")
+    return str(codecs.encode(b, "hex").decode("utf-8"))
 
 
 def hex_string(h):

capa/features/extractors/helpers.py

@@ -16,10 +16,7 @@ MIN_STACKSTRING_LEN = 8
 
 
 def xor_static(data, i):
-    if sys.version_info >= (3, 0):
-        return bytes(c ^ i for c in data)
-    else:
-        return "".join(chr(ord(c) ^ i) for c in data)
+    return bytes(c ^ i for c in data)
 
 
 def is_aw_function(symbol):

capa/features/extractors/ida/__init__.py

@@ -34,10 +34,7 @@ def add_ea_int_cast(o):
     this bit of skullduggery lets use cast viv-utils objects as ints.
     the correct way of doing this is to update viv-utils (or subclass the objects here).
     """
-    if sys.version_info[0] >= 3:
-        setattr(o, "__int__", types.MethodType(get_ea, o))
-    else:
-        setattr(o, "__int__", types.MethodType(get_ea, o, type(o)))
+    setattr(o, "__int__", types.MethodType(get_ea, o))
     return o
 
 

capa/features/extractors/ida/basicblock.py

@@ -39,18 +39,11 @@ def get_printable_len(op):
         raise ValueError("Unhandled operand data type 0x%x." % op.dtype)
 
     def is_printable_ascii(chars):
-        if sys.version_info[0] >= 3:
-            return all(c < 127 and chr(c) in string.printable for c in chars)
-        else:
-            return all(ord(c) < 127 and c in string.printable for c in chars)
+        return all(c < 127 and chr(c) in string.printable for c in chars)
 
     def is_printable_utf16le(chars):
-        if sys.version_info[0] >= 3:
-            if all(c == 0x00 for c in chars[1::2]):
-                return is_printable_ascii(chars[::2])
-        else:
-            if all(c == "\x00" for c in chars[1::2]):
-                return is_printable_ascii(chars[::2])
+        if all(c == 0x00 for c in chars[1::2]):
+            return is_printable_ascii(chars[::2])
 
     if is_printable_ascii(chars):
         return idaapi.get_dtype_size(op.dtype)

capa/features/extractors/ida/helpers.py

@@ -23,11 +23,7 @@ def find_byte_sequence(start, end, seq):
         end: max virtual address
         seq: bytes to search e.g. b"\x01\x03"
     """
-    if sys.version_info[0] >= 3:
-        seq = " ".join(["%02x" % b for b in seq])
-    else:
-        seq = " ".join(["%02x" % ord(b) for b in seq])
-
+    seq = " ".join(["%02x" % b for b in seq])
     while True:
         ea = idaapi.find_binary(start, end, seq, 0, idaapi.SEARCH_DOWN)
         if ea == idaapi.BADADDR:

capa/features/freeze.py

@@ -264,15 +264,14 @@ def main(argv=None):
     parser.add_argument(
         "-f", "--format", choices=[f[0] for f in formats], default="auto", help="Select sample format, %s" % format_help
     )
-    if sys.version_info >= (3, 0):
-        parser.add_argument(
-            "-b",
-            "--backend",
-            type=str,
-            help="select the backend to use",
-            choices=(capa.main.BACKEND_VIV, capa.main.BACKEND_SMDA),
-            default=capa.main.BACKEND_VIV,
-        )
+    parser.add_argument(
+        "-b",
+        "--backend",
+        type=str,
+        help="select the backend to use",
+        choices=(capa.main.BACKEND_VIV, capa.main.BACKEND_SMDA),
+        default=capa.main.BACKEND_VIV,
+    )
     args = parser.parse_args(args=argv)
 
     if args.quiet:
@@ -285,8 +284,7 @@ def main(argv=None):
         logging.basicConfig(level=logging.INFO)
         logging.getLogger().setLevel(logging.INFO)
 
-    backend = args.backend if sys.version_info > (3, 0) else capa.main.BACKEND_VIV
-    extractor = capa.main.get_extractor(args.sample, args.format, backend)
+    extractor = capa.main.get_extractor(args.sample, args.format, args.backend)
     with open(args.output, "wb") as f:
         f.write(dump(extractor))
 

capa/ida/plugin/item.py

@@ -328,14 +328,10 @@ class CapaExplorerByteViewItem(CapaExplorerFeatureItem):
         """
         byte_snap = idaapi.get_bytes(location, 32)
 
+        details = ""
         if byte_snap:
             byte_snap = codecs.encode(byte_snap, "hex").upper()
-            if sys.version_info >= (3, 0):
-                details = " ".join([byte_snap[i : i + 2].decode() for i in range(0, len(byte_snap), 2)])
-            else:
-                details = " ".join([byte_snap[i : i + 2] for i in range(0, len(byte_snap), 2)])
-        else:
-            details = ""
+            details = " ".join([byte_snap[i : i + 2].decode() for i in range(0, len(byte_snap), 2)])
 
         super(CapaExplorerByteViewItem, self).__init__(parent, display, location=location, details=details)
         self.ida_highlight = idc.get_color(location, idc.CIC_ITEM)

capa/main.py

@@ -288,26 +288,15 @@ def get_workspace(path, format, should_save=True):
     return vw
 
 
-def get_extractor_py2(path, format, disable_progress=False):
-    import capa.features.extractors.viv
-
-    with halo.Halo(text="analyzing program", spinner="simpleDots", stream=sys.stderr, enabled=not disable_progress):
-        vw = get_workspace(path, format, should_save=False)
-
-        try:
-            vw.saveWorkspace()
-        except IOError:
-            # see #168 for discussion around how to handle non-writable directories
-            logger.info("source directory is not writable, won't save intermediate workspace")
-
-    return capa.features.extractors.viv.VivisectFeatureExtractor(vw, path)
-
-
 class UnsupportedRuntimeError(RuntimeError):
     pass
 
 
-def get_extractor_py3(path, format, backend, disable_progress=False):
+def get_extractor(path, format, backend, disable_progress=False):
+    """
+    raises:
+      UnsupportedFormatError:
+    """
     if backend == "smda":
         from smda.SmdaConfig import SmdaConfig
         from smda.Disassembler import Disassembler
@@ -337,17 +326,6 @@ def get_extractor_py3(path, format, backend, disable_progress=False):
         return capa.features.extractors.viv.VivisectFeatureExtractor(vw, path)
 
 
-def get_extractor(path, format, backend, disable_progress=False):
-    """
-    raises:
-      UnsupportedFormatError:
-    """
-    if sys.version_info >= (3, 0):
-        return get_extractor_py3(path, format, backend, disable_progress=disable_progress)
-    else:
-        return get_extractor_py2(path, format, disable_progress=disable_progress)
-
-
 def is_nursery_rule_path(path):
     """
     The nursery is a spot for rules that have not yet been fully polished.
@@ -498,22 +476,11 @@ def install_common_args(parser, wanted=None):
     #
 
     if "sample" in wanted:
-        if sys.version_info >= (3, 0):
-            parser.add_argument(
-                # Python 3 str handles non-ASCII arguments correctly
-                "sample",
-                type=str,
-                help="path to sample to analyze",
-            )
-        else:
-            parser.add_argument(
-                # in #328 we noticed that the sample path is not handled correctly if it contains non-ASCII characters
-                # https://stackoverflow.com/a/22947334/ offers a solution and decoding using getfilesystemencoding works
-                # in our testing, however other sources suggest `sys.stdin.encoding` (https://stackoverflow.com/q/4012571/)
-                "sample",
-                type=lambda s: s.decode(sys.getfilesystemencoding()),
-                help="path to sample to analyze",
-            )
+        parser.add_argument(
+            "sample",
+            type=str,
+            help="path to sample to analyze",
+        )
 
     if "format" in wanted:
         formats = [
@@ -532,15 +499,15 @@ def install_common_args(parser, wanted=None):
             help="select sample format, %s" % format_help,
         )
 
-    if "backend" in wanted and sys.version_info >= (3, 0):
-        parser.add_argument(
-            "-b",
-            "--backend",
-            type=str,
-            help="select the backend to use",
-            choices=(BACKEND_VIV, BACKEND_SMDA),
-            default=BACKEND_VIV,
-        )
+        if "backend" in wanted:
+            parser.add_argument(
+                "-b",
+                "--backend",
+                type=str,
+                help="select the backend to use",
+                choices=(BACKEND_VIV, BACKEND_SMDA),
+                default=BACKEND_VIV,
+            )
 
     if "rules" in wanted:
         parser.add_argument(
@@ -703,8 +670,7 @@ def main(argv=None):
     else:
         format = args.format
         try:
-            backend = args.backend if sys.version_info > (3, 0) else BACKEND_VIV
-            extractor = get_extractor(args.sample, args.format, backend, disable_progress=args.quiet)
+            extractor = get_extractor(args.sample, args.format, args.backend, disable_progress=args.quiet)
         except UnsupportedFormatError:
             logger.error("-" * 80)
             logger.error(" Input file does not appear to be a PE file.")