[Silabs] Port platform specific Multi-Chip OTA work (#34440)

* Pull request #1836: Cherry multi ota

Merge in WMN_TOOLS/matter from cherry-multi-ota to silabs_slc_1.3

Squashed commit of the following:

commit 4320bb46571658bc44fb82345348265def394991
Author: Michael Rupp <michael.rupp@silabs.com>
Date:   Fri May 10 14:26:07 2024 -0400

    remove some unwanted diffs in provision files

commit be160931dc600de7e7ead378b70d6a43c3945e46
Author: Michael Rupp <michael.rupp@silabs.com>
Date:   Fri May 10 14:24:25 2024 -0400

    revert changes to generator.project.mak

commit 14b6605887166e6d5284a61feb2bf407d850bdcf
Author: Michael Rupp <michael.rupp@silabs.com>
Date:   Fri May 10 13:06:12 2024 -0400

    revert NVM key changes and script changes

... and 8 more commits

* Restyled by whitespace

* Restyled by clang-format

* Restyled by gn

* Restyled by autopep8

* remove unused libs caught by linter

* update doctree with new readmes

* rerun CI, cirque failing for unknown reasons

* fix include guards in provision examples

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <commits@restyled.io>

docs/tools/index.md

@@ -49,6 +49,8 @@ Source files for these tools are located at `scripts/tools`.
 :maxdepth: 1
 
 ../scripts/tools/silabs/README
+../scripts/tools/silabs/ota/README
+../scripts/tools/silabs/factory_data_generator/README
 
 ```
 

examples/platform/silabs/provision/ProvisionStorageDefault.cpp

@@ -28,6 +28,9 @@
 #include <platform/silabs/MigrationManager.h>
 #include <platform/silabs/SilabsConfig.h>
 #include <silabs_creds.h>
+#ifdef OTA_ENCRYPTION_ENABLE
+#include <platform/silabs/multi-ota/OtaTlvEncryptionKey.h>
+#endif // OTA_ENCRYPTION_ENABLE
 #ifdef SLI_SI91X_MCU_INTERFACE
 #include <sl_si91x_common_flash_intf.h>
 #else
@@ -659,7 +662,7 @@ CHIP_ERROR Storage::SetOtaTlvEncryptionKey(const ByteSpan & value)
     ReturnErrorOnFailure(key.Import(value.data(), value.size()));
     return SilabsConfig::WriteConfigValue(SilabsConfig::kOtaTlvEncryption_KeyId, key.GetId());
 }
-#endif
+#endif // OTA_ENCRYPTION_ENABLE
 
 /**
  * @brief Reads the test event trigger key from NVM. If the key isn't present, returns default value if defined.

examples/platform/silabs/provision/ProvisionStorageFlash.cpp

@@ -25,6 +25,9 @@
 #include <platform/CHIPDeviceConfig.h>
 #include <platform/silabs/SilabsConfig.h>
 #include <string.h>
+#ifdef OTA_ENCRYPTION_ENABLE
+#include <platform/silabs/multi-ota/OtaTlvEncryptionKey.h>
+#endif // OTA_ENCRYPTION_ENABLE
 
 using namespace chip::Credentials;
 
@@ -708,7 +711,7 @@ CHIP_ERROR Storage::SetOtaTlvEncryptionKey(const ByteSpan & value)
 {
     return CHIP_ERROR_NOT_IMPLEMENTED;
 }
-#endif
+#endif // OTA_ENCRYPTION_ENABLE
 
 CHIP_ERROR Storage::GetTestEventTriggerKey(MutableByteSpan & keySpan)
 {

scripts/tools/silabs/factory_data_generator/README.md

@@ -0,0 +1,56 @@
+# Silabs Factory Data Generator
+
+## Tool implementation
+
+The tool comprises of two files: `default.py`, `custom.py`
+
+### `default.py`
+
+Defines the base `InputArgument` class and its derived classes that will be
+referenced as **default classes**.
+
+`InputArgument` offers an abstract interface in the form of three methods:
+`key()`, `length()`, `encode()`, that will be used to generate the `(K, L, V)`
+tuple through the public `output()` method. Each custom class should implement
+the abstract interface, if its direct parent does not offer a relevant
+implementation.
+
+### `custom.py`
+
+Defines classes for each argument that should generate data in the output binary
+(will be referenced as **custom classes**). Please note that each new class
+should derive from a default class, not from `InputArgument` directly.
+
+### How to add a new argument
+
+Example of defining a new argument class in `custom.py`:
+
+```
+class FooArgument(BarArgument):
+    def __init__(self, arg):
+        super().__init__(arg)
+
+    def key(self):
+        return <unique key identifier>
+
+    def length(self):
+        return <actual length of data>
+
+    def encode(self):
+        return <data as encoded bytes>
+
+    def custom_function(self):
+        pass
+```
+
+where `BarArgument` is one of the **default classes**. Please note that a user
+can define additional methods if needed (e.g. `custom_function`; also see
+`generate_private_key` from `DacPKey` class).
+
+Then use this class in `generate.py` to create a `FooArgument` object from an
+option:
+
+```
+parser.add_argument("--foo", required=True, type=FooArgument,
+                    help="[int | hex] Foo argument.")
+```

scripts/tools/silabs/factory_data_generator/custom.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+#
+#    Copyright (c) 2022 Project CHIP Authors
+#    All rights reserved.
+#
+#    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.
+#
+
+'''This file should contain custom classes derived any class from default.py.
+
+Each class implemented here should describe an input parameter and should
+implement the InputArgument abstract interface, if its base class does not
+already offer an implementation or if there is a need of a custom behavior.
+
+Example of defining a new argument class:
+
+    class FooArgument(IntArgument):
+        def __init__(self, arg):
+            super().__init__(arg)
+
+        def key(self):
+            return <unique key identifier>
+
+        def length(self):
+            return <actual length of data>
+
+        def encode(self):
+            return <data as encoded bytes>
+
+        def custom_function(self):
+            pass
+
+Then use this class in generate.py to create a FooArgument object from an
+option:
+
+    parser.add_argument("--foo", required=True, type=FooArgument,
+                        help="[int | hex] Foo argument.")
+'''
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives.serialization import load_der_private_key
+from default import FileArgument
+
+
+class DacPKey(FileArgument):
+
+    def __init__(self, arg):
+        super().__init__(arg)
+        self.private_key = None
+
+    def key(self):
+        return 1
+
+    def length(self):
+        assert (self.private_key is not None)
+        return len(self.private_key)
+
+    def encode(self):
+        assert (self.private_key is not None)
+        return self.private_key
+
+    def generate_private_key(self, password, use_sss_blob=True):
+        if use_sss_blob:
+            self.private_key = self.val
+        else:
+            keys = load_der_private_key(self.val, password, backend=default_backend())
+            self.private_key = keys.private_numbers().private_value.to_bytes(
+                32, byteorder='big'
+            )
+
+
+class DacCert(FileArgument):
+
+    def __init__(self, arg):
+        super().__init__(arg)
+
+    def key(self):
+        return 2
+
+
+class PaiCert(FileArgument):
+
+    def __init__(self, arg):
+        super().__init__(arg)
+
+    def key(self):
+        return 3
+
+
+class CertDeclaration(FileArgument):
+
+    def __init__(self, arg):
+        super().__init__(arg)
+
+    def key(self):
+        return 4

scripts/tools/silabs/factory_data_generator/default.py

@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+#
+#    Copyright (c) 2022 Project CHIP Authors
+#    All rights reserved.
+#
+#    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.
+#
+'''This file should contain default argument classes.
+
+Base class is InputArgument. It defines the abstract interface to be
+implemented and offers a way to compute a KLV value through output().
+Other classes that derive InputArgument directly will be referenced
+as default classes throughout the docstrings.
+
+The default classes should not be used to instantiate arguments.
+If one wants to add another argument, a custom class should be derived
+from one of the default classes.
+'''
+
+import base64
+import logging
+
+
+class InputArgument:
+    '''Base class for any input argument that will be added to KLV.
+
+    The user will define its arguments as instances of InputArgument
+    by setting the "type" attribute of ArgumentParser add_argument to
+    an instance of a derived class. This means that all derived classes
+    must accept an additional "arg" parameter in the constructor. In the
+    end, the list of arguments will be parsed into objects derived from
+    InputArgument (or default derived classes), which decouples the object
+    creation from its processing.
+
+    Abstract methods:
+        key: Should be overwritten by final classes to return a "magic number".
+        length: Can be overwritten by default classes to specify a default value
+                (e.g. int arguments with a default length value of 4); can also
+                be overwritten by final classes to specify a custom value for a
+                certain argument.
+        encode: Should be overwritten to generate the correct bytes array from
+                its internal value.
+
+    Main usage is to iterate over an iterable entity of InputArguments and call
+    the output() method to generate the (K, L, V) tuple. Note that the output()
+    method should not be implemented, since its a common functionality across
+    all InputArgument classes.
+    '''
+
+    def __init__(self):
+        self.val = None
+
+    def key(self):
+        logging.error("key() should be implemented in derived classes.")
+
+    def length(self):
+        logging.error("length() should be implemented in derived classes.")
+
+    def encode(self):
+        logging.error("encode() should be implemented in derived classes.")
+
+    def output(self):
+        out = (self.key(), self.length(), self.encode())
+        logging.info("'{}' length: {}".format(type(self).__name__, self.length()))
+        return out
+
+
+class IntArgument(InputArgument):
+
+    def __init__(self, arg):
+        super().__init__()
+        self.val = int(arg, 0)
+
+    def length(self):
+        return 4
+
+    def encode(self):
+        return self.val.to_bytes(self.length(), "little")
+
+
+class Base64Argument(InputArgument):
+
+    def __init__(self, arg):
+        super().__init__()
+        self.val = base64.b64decode(arg)
+
+    def length(self):
+        return len(self.encode())
+
+    def encode(self):
+        return base64.b64encode(self.val)
+
+
+class StrArgument(InputArgument):
+
+    def __init__(self, arg):
+        super().__init__()
+        self.val = str(arg)
+
+    def length(self):
+        return len(self.encode())
+
+    def encode(self):
+        return str.encode(self.val)
+
+    def max_length(self):
+        return 32
+
+
+class FileArgument(InputArgument):
+
+    def __init__(self, arg):
+        super().__init__()
+        with open(arg, "rb") as _file:
+            self.val = _file.read()
+
+    def length(self):
+        return len(self.val)
+
+    def encode(self):
+        return self.val

scripts/tools/silabs/ota/README.md

@@ -25,8 +25,7 @@ python3 ./scripts/tools/silabs/ota/ota_multi_image_tool.py create -v 0xDEAD -p 0
 ```
 
 followed by \*_custom options_- and a positional argument (should be last) that
-specifies the output file. Please see the `create_ota_images.sh` for some
-reference commands.
+specifies the output file.
 
 The list of **custom options**:
 
@@ -38,19 +37,17 @@ The list of **custom options**:
 --app-version-str  --> Application version string. Same as above.
 --app-build-date   --> Application build date. Same as above.
 
-# SSBL options
---bl-input-file    --> Path to the SSBL binary.
---bl-version       --> SSBL version.
---bl-version-str   --> SSBL version string.
---bl-build-date    --> SSBL build date.
-
 # Factory data options
 --factory-data     --> If set, enables the generation of factory data.
 --cert_declaration --> Certification Declaration.
 --dac_cert         --> DAC certificate.
 --dac_key          --> DAC private key.
 --pai_cert         --> PAI certificate.
 
+# Encryption options
+--enc_enable       --> Enable ota encryption
+--input_ota_key    --> 16 Byte AES key
+
 # Custom TLV options
 --json             --> Path to a JSON file following ota_payload.schema
 ```
@@ -67,5 +64,5 @@ processing.
 When defining a custom processor, a user is able to also specify the custom
 format of the TLV by creating a JSON file based on the `ota_payload.schema`. The
 tool offers support for describing multiple TLV in the same JSON file. Please
-see the `examples/ota_max_entries_example.json` for a multi-app + SSBL example.
+see the `examples/ota_custom_entries_example.json` for a multi-binary example.
 Option `--json` must be used to specify the path to the JSON file.