feat(esptool_py): Add esptool to components

components/esptool_py/esptool/pyaes/util.py

@@ -0,0 +1,60 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2014 Richard Moore
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+# Why to_bufferable?
+# Python 3 is very different from Python 2.x when it comes to strings of text
+# and strings of bytes; in Python 3, strings of bytes do not exist, instead to
+# represent arbitrary binary data, we must use the "bytes" object. This method
+# ensures the object behaves as we need it to.
+
+def to_bufferable(binary):
+    return binary
+
+def _get_byte(c):
+    return ord(c)
+
+try:
+    xrange
+except:
+
+    def to_bufferable(binary):
+        if isinstance(binary, bytes):
+            return binary
+        return bytes(ord(b) for b in binary)
+
+    def _get_byte(c):
+        return c
+
+def append_PKCS7_padding(data):
+    pad = 16 - (len(data) % 16)
+    return data + to_bufferable(chr(pad) * pad)
+
+def strip_PKCS7_padding(data):
+    if len(data) % 16 != 0:
+        raise ValueError("invalid length")
+
+    pad = _get_byte(data[-1])
+
+    if pad > 16:
+        raise ValueError("invalid padding byte")
+
+    return data[:-pad]