Commit Graph

7 Commits

Author SHA1 Message Date
David Benjamin
bd42603943 Add a convenience function for i2d compatibility wrappers.
An i2d compatibility function is rather long, so add CBB_finish_i2d for
part of it. It takes a CBB as input so only a 'marshal' function is
needed, rather than a 'to_bytes' one.

Also replace the *inp d2i update pattern with a slightly shorter one.

Change-Id: Ibb41059c9532f6a8ce33460890cc1afe26adc97c
Reviewed-on: https://boringssl-review.googlesource.com/6868
Reviewed-by: Adam Langley <agl@google.com>
2016-02-16 19:40:53 +00:00
David Benjamin
375124b162 Parse BER for PKCS#12 more accurately.
CBS_asn1_ber_to_der currently uses heuristics because implicitly-tagged
constructed strings in BER are ambiguous with implicitly-tagged sequences. It's
not possible to convert BER to DER without knowing the schema.

Fortunately, implicitly tagged strings don't appear often so instead split the
job up: CBS_asn1_ber_to_der fixes indefinite-length elements and constructed
strings it can see. Implicitly-tagged strings it leaves uncoverted, but they
will only nest one level down (because BER kindly allows one to nest
constructed strings arbitrarily!).

CBS_get_asn1_implicit_string then performs the final concatenation at parse
time. This isn't much more complex and lets us parse BER more accurately and
also reject a number of mis-encoded values (e.g. constructed INTEGERs are not a
thing) we'd previously let through. The downside is the post-conversion parsing
code must be aware of this limitation of CBS_asn1_ber_to_der. Fortunately,
there's only one implicitly-tagged string in our PKCS#12 code.

(In the category of things that really really don't matter, but I had spare
cycles and the old BER converter is weird.)

Change-Id: Iebdd13b08559fa158b308ef83a5bb07bfdf80ae8
Reviewed-on: https://boringssl-review.googlesource.com/7052
Reviewed-by: Adam Langley <agl@google.com>
2016-02-16 19:32:50 +00:00
Adam Langley
521d4b805a Export |CBS_get_any_ber_asn1_element|.
We have need of it internally.

Change-Id: I564af468728b22245e8eab384ea7018b7e88cc86
Reviewed-on: https://boringssl-review.googlesource.com/5022
Reviewed-by: Matt Braithwaite <mab@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2015-06-05 21:56:42 +00:00
Adam Langley
cc1e3df75c Make CBS_get_any_asn1_element accept only DER.
This change makes |CBS_get_any_asn1_element| only handle DER elements.
Another function, |CBS_get_any_ber_asn1_element| is exposed internally
for the cases where we need to process BER data.

Change-Id: I544141a1a3d7913986352a8fd9a6d00b9f282652
Reviewed-on: https://boringssl-review.googlesource.com/4994
Reviewed-by: Adam Langley <agl@google.com>
2015-06-03 22:08:16 +00:00
David Benjamin
9b04d657be Export CBS_get_any_asn1_element.
Useful for parsing things when you don't know what tag to expect (e.g. a
CHOICE). Also allow its operands to be NULL, so that it can be used to skip
arbitrary elements.

Delete CBS_ASN1_ANY which wasn't doing anything.

Change-Id: I56413e68b4f2e13860ea3e55373d5830713d7e5c
Reviewed-on: https://boringssl-review.googlesource.com/1661
Reviewed-by: Adam Langley <agl@google.com>
2014-08-28 00:45:30 +00:00
Adam Langley
1f3591d4c7 Export CBS_asn1_ber_to_der.
We don't really want to expose this but the bytestring test calls this
function directly and, when linked against a shared library, thus needs
it to be in the dynamic symbol table.

Change-Id: Ife01da36fe142026a6a3e545cff746512b966ee6
2014-08-27 12:36:59 -07:00
Adam Langley
9c01e00c2e Rework support for ASN.1 BER.
Previously, the ASN.1 functions in bytestring were capable of processing
indefinite length elements when the _ber functions were used. That works
well enough for PKCS#3, but NSS goes a bit crazy with BER encoding and
PKCS#12. Rather than complicate the core bytestring functions further,
the BER support is removed from them and moved to a separate function
that converts from BER to DER (if needed).

Change-Id: I2212b28e99bab9fab8c61f80d2012d3e5a3cc2f0
Reviewed-on: https://boringssl-review.googlesource.com/1591
Reviewed-by: Adam Langley <agl@google.com>
2014-08-25 21:38:08 +00:00