Finish hf v15 integration

[fbeutin-ledger]

• Add tests for view_tag instruction
• Fix signature test with no view-tag
• Propose fix for view_tag derivation

[j-berman]

the real fix should be in the tests, sending encrypted derivation instead?

Yep, the tests expect derivation to be encrypted with a dummy key 0x55.

Tests are passing on my end with the 2 suggestions.

[j-berman]

In reference to: i < MONERO_SUPPORTED_CLIENT_SIZE + 1

When i == MONERO_SUPPORTED_CLIENT_SIZE, won't behavior be undefined when referencing supported_clients[i]? Seems like it's allowing 1 extra loop

[j-berman]

I think you meant this:

    uint32_t i;
    for (i = 0; i < MONERO_SUPPORTED_CLIENT_SIZE; ++i) {
        // Use strncmp to allow supported version prefixing client version
        unsigned int supported_clients_len = strlen((char*)PIC(supported_clients[i]));
        if (strncmp(PIC(supported_clients[i]), client_version, supported_clients_len) == 0) {
            break;
        }
    }
    if (i == MONERO_SUPPORTED_CLIENT_SIZE) {
        THROW(SW_CLIENT_NOT_SUPPORTED);
    }

[fbeutin-ledger]

Mmmh thanks for catching it, that is indeed a mistake.
I've separated the version check in a dedicated function, this should be better and more clear

[j-berman]

LGTM. Thanks for the changes!

[fbeutin-ledger]

Thanks for the reviews, I've merged the changes on our develop branch