boot: Rename boot_enc_decrypt to boot_decrypt_key

[de-nordic]

All of boot_enc_ function follow the same pattern where they take encryption context as the first parameter, and the boot_enc_decrypt stands out here as it does not work around the encryption context, but is rather single-part decryption function only used for decrypting of the image encryption key.

[utzig]

I think this is arguably worse; as part of the encrypted images "api" all functions have names that start with boot_enc_, and you are breaking this "standard" naming. Either it should be called boot_enc_decrypt_key, which I don't see a reason for either, or you want to reuse it for something else, in which case it's better to just rename as part of the new use PR.

[de-nordic]

I think this is arguably worse; as part of the encrypted images "api" all functions have names that start with boot_enc_, and you are breaking this "standard" naming. Either it should be called boot_enc_decrypt_key, which I don't see a reason for either, or you want to reuse it for something else, in which case it's better to just rename as part of the new use PR.

Putting api and standard in quotes seems to mock them rather then making them an argument in discussion.

Worse? Nah. All except this one function take enc_key_data objects. That one function is completely independent from encryption context setup by all the other functions and completely setups, decrypts, and drops encryption context within its body.

And the standard somehow names the encryption function boot_encrypt, even though it is one taking the context, and yet stands out in naming.

For me pattern was clear: everything boot_enc_ operates around enc_key.

I do not want to make everything in one PR and I am not going to reuse boot_decrypt, actually I have to implement boot_enc_decrypt and boot_enc_encrypt , and various others encryption/decryption only functions, as the PSA, which I am using, uses different set of functions for decryption/encryption, which also includes the process setup.

[nvlsianpu]

I'm fine with the change which makes the function name descriptive.

I do not want to make everything in one PR and I am not going to reuse boot_decrypt, actually I have to implement boot_enc_decrypt and boot_enc_encrypt...

Yes - this will fit to the pattern.

[de-nordic]

I have marked it as DNM, because while reworking boot_enc_load I am now considering making both boot_enc_load and boot_decrypt_key part of boot_status API.

[de-nordic]

I have marked it as DNM, because while reworking boot_enc_load I am now considering making both boot_enc_load and boot_decrypt_key part of boot_status API.

Nope, not the good idea. But the boot_enc_load is gone.

[nvlsianpu]

@d3zd3z, @utzig last call. This is just mcuboot internal function rename l I'm going to merge this PR.

[utzig]

Putting api and standard in quotes seems to mock them rather then making them an argument in discussion.

If it's an API to you, then it's an API. I wrote it so there would be no point in mocking! You need to write "boot_enc_encrypt", that's all that you had to say, it's fine.

@d3zd3z, @utzig last call. This is just mcuboot internal function rename l I'm going to merge this PR.

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