SLIP0013 does not provide worked examples for HD structure

[gary-rowe]

The SLIP0013 reference document should provide an example of the expected values for A, B, C, D for a given set of example URIs and index values. These should include optional values (e.g. is a missing "user" field treated as empty string or null) and so on.

Adding these reference values will make supporting the feature much easier.

Here is some Java code to illustrate:

    // See https://github.com/trezor/python-trezor/blob/ca45019918bc4c54f1ace899a9acf397c8f4d92f/tests/test_msg_signidentity.py#L27 for details
    URI identityUri = URI.create("https://satoshi@bitcoin.org/login");

    List<Integer> addressN = IdentityUtils.buildAddressN(identityUri, 0);

    // m/2147483661/2637750992/2845082444/3761103859/4005495825
    assertThat(addressN.size()).isEqualTo(5);
    // Remove the hardening to see the underlying value
    assertThat(addressN.get(0) & 0x0fffffff).isEqualTo(13); // 2147483661L
    assertThat(addressN.get(1) & 0x0fffffff).isEqualTo(221831888); // 2637750992L
    assertThat(addressN.get(2) & 0x0fffffff).isEqualTo(160727884); // 2845082444L
    assertThat(addressN.get(3) & 0x0fffffff).isEqualTo(3007475); // 3761103859
    assertThat(addressN.get(4) & 0x0fffffff).isEqualTo(247399441); // 4005495825

The derivation of A,B,C,D should also be specified as little endian for the avoidance of doubt.

[prusnak]

Unit test for python-trezor contains these: https://github.com/trezor/python-trezor/blob/master/tests/test_msg_signidentity.py (including the hash and A/B/C/D values). If you want, you can create a pull request to SLIP-0013 so we have it there as well.