Port MASTG-TEST-0015 to v2 (by @guardsquare)

[nmsa]

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This PR closes #2948.

[cpholguera]

I like how you split them and I agree with the mapping to "MASWE-0012: Insecure or Wrong Usage of Cryptographic Key". So we can have 2 tests here at least:

1. For asymmetric keys is the key pair being used for multiple activities (e.g. signatures vs encryption)

• key purpose (can be read from the properties of the key)

2. For symmetric keys, are those being used for multiple business purposes? (hard to automate)

• the typical "key reuse case", right? Dangerous especially for ECB if I'm not mistaken.
• Can we test by collecting all uses of the same key with Frida and inspecting the reversed code? e.g. The observation can contains all the uses of each key with backtraces to know the locations. In the evaluation we'd suggest to reverse engineer those places and try to determine the "business purpose".

See https://crypto.stackexchange.com/questions/33751/aes-key-reuse-and-guessing-the-key

(Ideally we'd find another source from NIST for example)

The reuse of the key is not a problem as long as you have chosen a mode of operation that is appropriate for your application (and of course, if you have used it properly). This is because the mode of operation will "pre-mix" your clear text data in a way that, even before encryption, two identical block of data you feed to the actual AES algorithm will never be identical (or at least, not more often than by random chance).

[nmsa]

Addressed your comments according to what we discussed live yesterday.