Boot: Add Python2.7 support for post build steps
These minor changes make Python 3 and Python 2.7 verions supported by
the post build scripts, even integrating them as modules.
Change-Id: I0d7a6d95764db082bbec02b0af01da4cf03fd98d
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
diff --git a/bl2/ext/mcuboot/scripts/imgtool_lib/keys.py b/bl2/ext/mcuboot/scripts/imgtool_lib/keys.py
new file mode 100644
index 0000000..fda3ed6
--- /dev/null
+++ b/bl2/ext/mcuboot/scripts/imgtool_lib/keys.py
@@ -0,0 +1,104 @@
+# Copyright 2017 Linaro Limited
+# Copyright (c) 2017-2018, Arm Limited.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Cryptographic key management for imgtool.
+"""
+
+from __future__ import print_function
+from Crypto.Hash import SHA256
+from Crypto.PublicKey import RSA
+from Crypto.Signature import PKCS1_v1_5, PKCS1_PSS
+import hashlib
+from pyasn1.type import namedtype, univ
+from pyasn1.codec.der.encoder import encode
+
+# By default, we use RSA-PSS (PKCS 2.1). That can be overridden on
+# the command line to support the older (less secure) PKCS1.5
+sign_rsa_pss = True
+
+AUTOGEN_MESSAGE = "/* Autogenerated by imgtool.py, do not edit. */"
+
+class RSAPublicKey(univ.Sequence):
+ componentType = namedtype.NamedTypes(
+ namedtype.NamedType('modulus', univ.Integer()),
+ namedtype.NamedType('publicExponent', univ.Integer()))
+
+class RSA2048():
+ def __init__(self, key):
+ """Construct an RSA2048 key with the given key data"""
+ self.key = key
+
+ @staticmethod
+ def generate():
+ return RSA2048(RSA.generate(2048))
+
+ def export_private(self, path):
+ with open(path, 'wb') as f:
+ f.write(self.key.exportKey('PEM'))
+
+ def get_public_bytes(self):
+ node = RSAPublicKey()
+ node['modulus'] = self.key.n
+ node['publicExponent'] = self.key.e
+ return bytearray(encode(node))
+
+ def emit_c(self):
+ print(AUTOGEN_MESSAGE)
+ print("const unsigned char rsa_pub_key[] = {", end='')
+ encoded = self.get_public_bytes()
+ for count, b in enumerate(encoded):
+ if count % 8 == 0:
+ print("\n\t", end='')
+ else:
+ print(" ", end='')
+ print("0x{:02x},".format(b), end='')
+ print("\n};")
+ print("const unsigned int rsa_pub_key_len = {};".format(len(encoded)))
+
+ def sig_type(self):
+ """Return the type of this signature (as a string)"""
+ if sign_rsa_pss:
+ return "PKCS1_PSS_RSA2048_SHA256"
+ else:
+ return "PKCS15_RSA2048_SHA256"
+
+ def sig_len(self):
+ return 256
+
+ def sig_tlv(self):
+ return "RSA2048"
+
+ def sign(self, payload):
+ converted_payload = bytes(payload)
+ sha = SHA256.new(converted_payload)
+ if sign_rsa_pss:
+ signer = PKCS1_PSS.new(self.key)
+ else:
+ signer = PKCS1_v1_5.new(self.key)
+ signature = signer.sign(sha)
+ assert len(signature) == self.sig_len()
+ return signature
+
+def load(path):
+ with open(path, 'rb') as f:
+ pem = f.read()
+ try:
+ key = RSA.importKey(pem)
+ if key.n.bit_length() != 2048:
+ raise Exception("Unsupported RSA bit length, only 2048 supported")
+ return RSA2048(key)
+ except ValueError:
+ raise Exception("Unsupported RSA key file")