Support AES in PKCS5

[gilles-peskine-arm]

The PBES2 tests in test_suite_pkcs5 all rely on DES, which is deprecated. The PKCS5 module does not support AES, but it's cryptographically agile, so it should be easy to add AES support.

The goal of this task is:

• Add the AES-CBC OID from RFC 8018 to the OID module.
• In test_suite_pkcs5, add test cases using AES, equivalent to what we have for DES.

[jethrogb]

It's not just about the test suite, the pkcs5 module just doesn't support PBES2-AES at all right now.

[gilles-peskine-arm]

@jethrogb Good point! Fortunately the PKCS5 module has no direct dependency on DES, so I think adding AES support is as easy as declaring the OID… and adding test cases.

[zvolin]

Hi!
Tried your suggestion by only declaring the OIDs however I ended up debugging some segfault all the yesterday's evening 😅 . Will try to look more into it tho, however I'm not so familiar with the project

[jethrogb]

@zvolin and I were discussing the mbedtls_pkcs5_pbes2 API and it's not clear to us how to use it safely. What are the requirements on the output buffer size and what is the actual size used on return?

[jethrogb]

mbedtls_pkcs5_pbes2 calls mbedtls_cipher_crypt internally. mbedtls_cipher_crypt specifies input and output should be different memory ranges. mbedtls_pkcs5_pbes2 passes these directly from its own arguments data and output. The only MbedTLS-internal use of mbedtls_pkcs5_pbes2 is in pkparse.c where it passes p and buf right after a statement buf = p.

[gilles-peskine-arm]

Requested again: https://lists.trustedfirmware.org/archives/list/mbed-tls@lists.trustedfirmware.org/thread/Z62P3AIHGJ3H4KXI7HXAELNAEQFCWHHM/