The value we initialize a CHOICE's `element` enum field to, prior to
decoding the CHOICE value, needs be one that does not cause
`asn1_free()` to do anything since we've not done anything yet either.
Should always run AFL before pushing changes to the ASN.1 compiler or
template interpreter!
Still fuzzing. There are crashers in the _asn1_print() path, though
right now they cannot affect anything else in Heimdal other than
asn1_print, since that's the only thing calling it yet.
For now we just add new types that can auto-decode through open types
in CSRs, but we leave the originals as they were to avoid having to
update lib/hx509/req.c for now.
Our asn1_print, like OpenSSL's, just knows how to parse and dump DER.
Ours can attempt to decode OCTET STRING and IMPLICIT-tagged constructed
values as DER, which is very useful.
But _now_ it's even better. Now it knows about all types exported from
all ASN.1 modules in `lib/asn1/` in Heimdal, and if told to print as
some type, it will use the new printing interface to print JSON-like
representations of values:
```
$ ./asn1_print /tmp/t490/ek2.crt Certificate |
jq '.tbsCertificate.extensions[3]._extnValue[]._values'
[
{
"_type": "TPMSpecification",
"family": "2.0",
"level": "0",
"revision": "138"
}
]
[
{
"_type": "TPMSecurityAssertions",
"version": "0",
"fieldUpgradable": true,
"ekGenerationType": "655617",
"ekGenerationLocation": "655616",
"ekCertificateGenerationLocation": "655616",
"ccInfo": {
"_type": "CommonCriteriaMeasures",
"version": "3.1",
"assurancelevel": "4",
"evaluationStatus": "2",
"plus": true,
"strengthOfFunction": null,
"profileOid": null,
"profileUri": null,
"targetOid": null,
"targetUri": null
},
"fipsLevel": {
"_type": "FIPSLevel",
"version": "140-2",
"level": "2",
"plus": false
},
"iso9000Certified": false,
"iso9000Uri": null
}
]
```
Status:
- And it works!
- We have an extensive test based on decoding a rich EK certficate.
This test exercises all of:
- decoding
- encoding with and without decoded open types
- copying of decoded values with decoded open types
- freeing of decoded values with decoded open types
Valgrind finds no memory errors.
- Added a manual page for the compiler.
- rfc2459.asn1 now has all three primary PKIX types that we care about
defined as in RFC5912, with IOS constraints and parameterization:
- `Extension` (embeds open type in an `OCTET STRING`)
- `OtherName` (embeds open type in an `ANY`-like type)
- `SingleAttribute` (embeds open type in an `ANY`-like type)
- `AttributeSet` (embeds open type in a `SET OF ANY`-like type)
All of these use OIDs as the open type type ID field, but integer
open type type ID fields are also supported (and needed, for
Kerberos).
That will cover every typed hole pattern in all our ASN.1 modules.
With this we'll be able to automatically and recursively decode
through all subject DN attributes even when the subject DN is a
directoryName SAN, and subjectDirectoryAttributes, and all
extensions, and all SANs, and all authorization-data elements, and
PA-data, and...
We're not really using `SingleAttribute` and `AttributeSet` yet
because various changes are needed in `lib/hx509` for that.
- `asn1_compile` builds and recognizes the subset of X.681/682/683 that
we need for, and now use in, rfc2459.asn1. It builds the necessary
AST, generates the correct C types, and generates templating for
object sets and open types!
- See READMEs for details.
- Codegen backend not tested; I won't make it implement automatic open
type handling, but it should at least not crash by substituting
`heim_any` for open types not embedded in `OCTET STRING`.
- We're _really_ starting to have problems with the ITU-T ASN.1
grammar and our version of it...
Type names have to start with upper-case, value names with
lower-case, but it's not enough to disambiguate.
The fact the we've allowed value and type names to violate their
respective start-with case rules is causing us trouble now that we're
adding grammar from X.681/682/683, and we're going to have to undo
that.
In preparation for that I'm capitalizing the `heim_any` and
`heim_any_set` types, and doing some additional cleanup, which
requires changes to other parts of Heimdal (all in this same commit
for now).
Problems we have because of this:
- We cannot IMPORT values into modules because we have no idea if a
symbol being imported refers to a value or a type because the only
clue we would have is the symbol's name, so we assume IMPORTed
symbols are for types.
This means we can't import OIDs, for example, which is super
annoying.
One thing we might be able to do here is mark imported symbols as
being of an undetermined-but-not-undefined type, then coerce the
symbol's type the first time it's used in a context where its type
is inferred as type, value, object, object set, or class. (Though
since we don't generate C symbols for objects or classes, we won't
be able to import them, especially since we need to know them at
compile time and cannot defer their handling to link- or
run-time.)
- The `NULL` type name, and the `NULL` value name now cause two
reduce/reduce conflicts via the `FieldSetting` production.
- Various shift/reduce conflicts involving `NULL` values in
non-top-level contexts (in constraints, for example).
- Currently I have a bug where to disambiguate the grammar I have a
CLASS_IDENTIFIER token that is all caps, while TYPE_IDENTIFIER must
start with a capital but not be all caps, but this breaks Kerberos
since all its types are all capitalized -- oof!
To fix this I made it so class names have to be all caps and
start with an underscore (ick).
TBD:
- Check all the XXX comments and address them
- Apply this treatment to Kerberos! Automatic handling of authz-data
sounds useful :)
- Apply this treatment to PKCS#10 (CSRs) and other ASN.1 modules too.
- Replace various bits of code in `lib/hx509/` with uses of this
feature.
- Add JER.
- Enhance `hxtool` and `asn1_print`.
Getting there!
This is a much better and more complete implementation of POSIX RTLD
functions than what we had. In particular this gets us a more complete
`dladdr()` implementation.
This adds enough support for SET { ... } types to the template backend
to allow the X.690 sample test to be run with the template backend.
Limitations:
- For DER encoding, the SET { ... } members must be manually sorted by
the module author.
- Decoding of out-of-order encodings (BER) is not supported at this
time.
These shortcomings will be addressed later.
Note that because we don't parse IMPORTed modules at this time, we can't
sort SET { ... } members at compile time if any of them out an
outer-most tag that the compiler cannot see without learning to parse
IMPORTed modules.
The regular ASN.1 compiler does NOT sort SET { ... } types' members by
tag, though it should. It cannot because if a field is of an untagged
imported type, then the compiler won't know the field's tag because the
compiler does not read and parse IMPORTed modules. At least the regular
ASN.1 compiler does handle out-of-order encodings on decode.
The template ASN.1 compiler did not even support SET { ... } types at
all. With this commit the template ASN.1 compiler does, but still it
does not sort members on encode, and it does not decode out-of-
[definition-]order encodings.
A proper fix to these issues will require run-time sorting of SET
members on encode. An even better fix will require making the compiler
able to read and parse more than one module in one run, that way it can
know all the things about IMPORTed types that it currently leaves to
run-time.
