The idea of this commit is to separate (de)serialization testing outside
test_api.py and make sure we are testing from_dict/to_dict for all
possible valid data for all classes.
Jussi in his comment here:
https://github.com/theupdateframework/tuf/issues/1391#issuecomment-849390669
proposed using decorators when creating comprehensive testing
for metadata serialization.
The main problems he pointed out is that:
1) there is a lot of code needed to generate the data for each case
2) the test implementation scales badly when you want to add new
cases for your tests, then you would have to add code as well
3) the dictionary format is not visible - we are loading external files
and assuming they are not changed and valid
In this change, I am using a decorator with an argument that complicates
the implementation of the decorator and requires three nested functions,
but the advantages are that we are resolving the above three problems:
1) we don't need new code when adding a new test case
2) a small amount of hardcoded data is required for each new test
3) the dictionaries are all in the test module without the need of
creating new directories and copying data.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Securesystemslib digest() and digest_fileobject()
calls raise sslib specific exceptions that need to be
handled and re-raised as TUF exceptions.
Updated tests in test_api.py accordingly.
Signed-off-by: Teodora Sechkova <tsechkova@vmware.com>
Test unknown signature algorithm/scheme.
Also shorten the incorrect (but syntactically valid) signature a bit.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
Aim to only raise UnsignedMetadataError from verify_signature().
Some of the situations could be things like UnsupportedAlgorithmError
-- where the underlying reason may be a missing dependency -- but it
seems impossible for a client to know whether it's that or whether it
is broken or malicious server side.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
Clarify that we don't semantically validate "Key" instances during
initialization and that this is a responsibility of securesystemslib.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
store signatures in a Dict of keyid to Signature. This ensures
signature uniqueness. Raise in from_dict() if input contains multiple
different signatures for a keyid.
This changes Metadata object API, and makes it slightly different from
the file format: this is justified by making the API safer to use and
easier to validate.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
This is likely not needed by users of the API (as they are interested
in the higher level functionality "verify delegate metadata with
threshold of signatures").
Moving verify to Key makes the API cleaner because including both
"verify myself" and "verify a delegate with threshold" can look awkward
in Metadata, and because the ugly Securesystemslib integration is now
Key class implementation detail (see Key.to_securesystemslib_key()).
Also raise on verify failure instead of returning false: this was found
to confuse API users (and was arguably not a pythonic way to handle it).
* Name the function verify_signature() to make it clear what is being
verified.
* Assume only one signature per keyid exists: see #1422
* Raise only UnsignedMetadataError (when no signatures or verify failure),
the remaining lower level errors will be handled in #1351
* Stop using a "keystore" in tests for the public keys: everything we
need is in metadata already
This changes API, but also should not be something API users want to
call in the future when "verify a delegate with threshold" exists.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
This simplifies life for API users as usually a key needs its
identifier: this is already visible in how update() becomes simpler
in the API.
The downside is that 'from_dict()' now has two arguments (so arguably
the name is not great anymore but it still does _mostly_ the same job
as other from_dicts).
This is an API change, if a minor one.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
This change is relevant to the new metadata class Targets.
In the specification, when describing the Targets metadata file format
and more precisely "TARGETPATH" (or targets containing the actual
target files) it's said:
"It is allowed to have a TARGETS object with no TARGETPATH elements.
This can be used to indicate that no target files are available."
If there is no "TARGETPATH" keys for the dictionary "targets", this
would mean that "Targets.targets" is {}.
Make sure we test for that.
See: https://theupdateframework.github.io/specification/latest/#targetpath
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
We have tests which make sure we can use `Timestamp.update()` and
`Snapshot.update()` with MetaFile instance storing only version
(because length and hashes are optional).
Those tests were created to make sure that we are actually supporting
optional hashes and length when we call `update` for those classes, but
after we changed the `update()` signature to accept `MetaFile` instance
the tests are obsolete.
The reason is that length and hashes can be optional because of the
MetaFile implementation, no the update function itself and we have
other tests validating creating a MetaFie instance without hashes and
length.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Currently, when we call Targets/Snapshot/Timestamp.update() we are
passing all of the necessary values to create MetaFile/Targets File
respectively.
This is not needed, given that one of the reasons we have created
MetaFile and TargetFile is to make the API easier to use.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
In the top-level metadata classes, there are complex attributes such as
"meta" in Targets and Snapshot, "key" and "roles" in Root etc.
We want to represent those complex attributes with a class to allow
easier verification and support for metadata with unrecognized fields.
For more context read ADR 0004 and ADR 0008 in the docs/adr folder.
As written in the spec "targets" in "targets.json" has defined the
"custom" field serving the same purpose as "unrecognized_fields" in the
implementation.
That's why to conform against the spec and support "custom" and allow
"unrecognized_fields" everywhere where it's not sensitive we can define
custom as property which actually access data stored in
unrecognized_fields.
For context read ADR 8 in tuf/docs/adr.
Additionally, after adding the TargetFile class, when we create a
Targets an object we are now calling from dict twice - one for the main
Targets class and one for each of the complex attributes
TargetFile.from_dict() and Delegations.from_dict().
Given that the "from_dict" methods have the side effect of destroying
the given dictionary, we would need to start using deepcopy()
for our tests.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
In the top-level metadata classes, there are complex attributes such as
"meta" in Targets and Snapshot, "key" and "roles" in Root etc.
We want to represent those complex attributes with a class to allow
easier verification and support for metadata with unrecognized fields.
For more context read ADR 0004 and ADR 0008 in the docs/adr folder.
Additionally, after adding the MetaFile class, when we create an object
we are now calling from dict twice - one for the main class (Timestamp,
Snapshot) and one for the pacticular complex attribute -
MetaFile.from_dict(). Given that the "from_dict" methods have the
side effect of destroying the given dictionary, we would need to
start using deepcopy() for our tests.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
NOTE: making consistent_snapshot optional requires using a default value
for the argument in __init__ in Root and thus consistent_snapshot should
be rearranged in the end.
Read more: https://github.com/theupdateframework/tuf/pull/1394#issuecomment-842134961
From chapter 7 in the spec (version 1.0.17)
"Finally, the root metadata should write the Boolean
"consistent_snapshot" attribute at the root level of its keys of
attributes.
If consistent snapshots are not written by the repository,
then the attribute may either be left unspecified or be set to the
False value. Otherwise, it must be set to the True value."
We want to make sure we support repositories
without consistent_snapshot set.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Use either "if X is not None:" or a try-except instead of a "if X:".
I believe Targets.from_dict() was not really broken with previous code
but it looks suspicious and did fail the added test with a strange
exception: I expect the from_dict() methods to mainly fail with
KeyErrors, ValueErrors or AttributeErrors if file format structure
is incorrect.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
A DelegatedRole with paths=[] fails to serialize correctly (paths is not
included in the output json).
Fix the issue, modify tests to notice a regression.
Fixes#1389
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
After the implementation of a Key class representing
the public portion of a key, the method add_key() should
take an argument of type Key, instead of a dictionary.
Test cases are updated accordingly.
Signed-off-by: Teodora Sechkova <tsechkova@vmware.com>
In the top level metadata classes, there are complex attributes such as
"meta" in Targets and Snapshot, "key" and "roles" in Root etc.
We want to represent those complex attributes with a class to allow
easier verification and support for metadata with unrecognized fields.
For more context read ADR 0004 and ADR 0008 in the docs/adr folder.
DelegatedRole shares a couple of fields with the Role class and that's
why it inherits it.
I decided to use a separate Delegations class because I thought it will
make it easier to read, verify and add additional helper functions.
Also, I tried to make sure that I test each level of the delegations
representation for support of storing unrecognized fields.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
We should not do multiple lookups through data structures if one is
enough (here we have extra lookups on both roles and keyids).
Also in this case raising on missing key seems like the preferable
alternative so even a try-except is not needed.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
As per the specification (v1.0.1) length and hashes fields
in timestamp and snapshot metadata are optional.
We have implement this in the older API
(see https://github.com/theupdateframework/tuf/pull/1031) and we should
implement it in the new API.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Add a use case for the root class to be tested in test_generic_read
and test_read_write_read_compare tests in test_apy.py
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Verify that adding an already existing key to keyid for a particular
role in Root won't create duplicate key.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
In the top level metadata classes, there are complex attributes such as
"meta" in Targets and Snapshot, "key" and "roles" in Root etc.
We want to represent those complex attributes with a class to allow
easier verification and support for metadata with unrecognized fields.
For more context read ADR 0004 and ADR 0008 in the docs/adr folder.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
In the top level metadata classes, there are complex attributes such as
"meta" in Targets and Snapshot, "key" and "roles" in Root etc.
We want to represent those complex attributes with a class to allow
easier verification and support for metadata with unrecognized fields.
For more context read ADR 0004 and ADR 0008 in the docs/adr folder.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
In order to support ADR 0008 we would want to accept unrecognized
fields in all metadata classes.
Input that contains unknown fields in the 'signed' dictionary should
successfully deserialize into a Metadata object, and that object should
successfully serialize with the unknown fields intact.
Also, we should test that we support unrecognized fields when adding
new classes or modifying existing ones to make sure we support
ADR 0008.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
This is essentially short-hand for
JSONDeserializer().deserialize(data)
but seems much easier for the API user so may be worth it.
Metadata.from_file() now uses Metadata.from_bytes() internally.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>
Checks metadata expiration against a reference time (a naive datetime in UTC).
If not provided, checks against the current UTC date and time.
Returns True if expiration time is less than the reference time.
Signed-off-by: Velichka Atanasova <avelichka@vmware.com>
In the securesystemslib pr https://github.com/secure-systems-lab/securesystemslib/pull/319
I added a new Signer interface with the purpose of supporting multiple
signing implementations.
Additionally, I added the SSlibSigner implementation of that interface
which implements the signing operation for rsa, ed25519 and ecdsa
schemes.
With this commit, I integrate the SSlibSigner into the new API in tuf.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
Revert an earlier commit that moved to/from_dict metadata class
model methods to a util module of the serialization sub-package.
We keep to/from_dict methods on the metadata classes because:
- It seems **idiomatic** (see e.g. 3rd-party libaries such as attrs,
pydantic, marshmallow, or built-ins that provide default or
customizable dict representation for higher-level objects).
The idiomatic choice should make usage more intuitive.
- It feels better **structured** when each method is encapsulated
within the corresponding class, which in turn should make
maintaining/modifying/extending the class model easier.
- It allows us to remove function-scope imports (see subsequent
commit).
Caveat:
Now that "the meat" of the sub-packaged JSON serializer is
implemented on the class, it might make it harder to create a
non-dict based serializer by copy-paste-amending the JSON
serializer.
However, the benefits from above seem to outweigh the disadvantage.
See option 5 of ADR0006 for further details (#1270).
Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>
Add tuf.api.serialization.util module with functions to
convert between TUF metadata class model and the corresponding
dictionary representation. These functions replace the
corresponding to/from_dict classmethods.
Configure api/pylintrc to exempt '_type' from protected member
access warning, because the underscore prefix here is only used to
avoid name shadowing.
Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>
Re-raise all errors that happen during de/serialization as custom
De/SerializationError.
Whilelist 'e', which is idiomatic for error, in api/pylintrc, and
inline exempt broad-except, which are okay if re-raised.
Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>
Currently, we are importing the "utils" module in tests/utils
with "import utils".
This could become a problem when there is another module with
the same general name "utils" and could lead to import mistakes.
Signed-off-by: Martin Vrachev <mvrachev@vmware.com>
