CLI decode-token: use CBOR diagnostic format instead of pure JSON

[ok300]

Before this PR, decode-token printed the pure JSON representation of a token. For V3 that is straightforward, but for V4 tokens the byte array fields were printed as arrays of numbers (decimal representation of each byte value).

Example output before PR

cargo run -- decode-token cashuBo2F0gqJhaUgA_9SLj17PgGFwgaNhYQFhc3hAYWNjMTI0MzVlN2I4NDg0YzNjZjE4NTAxNDkyMThhZjkwZjcxNmE1MmJmNGE1ZWQzNDdlNDhlY2MxM2Y3NzM4OGFjWCECRFODGd5IXVW-07KaZCvuWHk3WrnnpiDhHki6SCQh88-iYWlIAK0mjE0fWCZhcIKjYWECYXN4QDEzMjNkM2Q0NzA3YTU4YWQyZTIzYWRhNGU5ZjFmNDlmNWE1YjRhYzdiNzA4ZWIwZDYxZjczOGY0ODMwN2U4ZWVhY1ghAjRWqhENhLSsdHrr2Cw7AFrKUL9Ffr1XN6RBT6w659lNo2FhAWFzeEA1NmJjYmNiYjdjYzY0MDZiM2ZhNWQ1N2QyMTc0ZjRlZmY4YjQ0MDJiMTc2OTI2ZDNhNTdkM2MzZGNiYjU5ZDU3YWNYIQJzEpxXGeWZN5qXSmJjY8MzxWyvwObQGr5G1YCCgHicY2FtdWh0dHA6Ly9sb2NhbGhvc3Q6MzMzOGF1Y3NhdA


{
  "m": "http://localhost:3338",
  "u": "sat",
  "t": [
    {
      "i": [
        0,
        255,
        212,
        139,
        143,
        94,
        207,
        128
      ],
      "p": [
        {
          "a": 1,
          "s": "acc12435e7b8484c3cf1850149218af90f716a52bf4a5ed347e48ecc13f77388",
          "c": [
            2,
            68,
            83,
            131,
            25,
            222,
            72,
            93,
            85,
            190,
            211,
            178,
            154,
            100,
            43,
            238,
            88,
            121,
            55,
            90,
            185,
            231,
            166,
            32,
            225,
            30,
            72,
            186,
            72,
            36,
            33,
            243,
            207
          ],
          "d": null
        }
      ]
    },
    {
      "i": [
        0,
        173,
        38,
        140,
        77,
        31,
        88,
        38
      ],
      "p": [
        {
          "a": 2,
          "s": "1323d3d4707a58ad2e23ada4e9f1f49f5a5b4ac7b708eb0d61f738f48307e8ee",
          "c": [
            2,
            52,
            86,
            170,
            17,
            13,
            132,
            180,
            172,
            116,
            122,
            235,
            216,
            44,
            59,
            0,
            90,
            202,
            80,
            191,
            69,
            126,
            189,
            87,
            55,
            164,
            65,
            79,
            172,
            58,
            231,
            217,
            77
          ],
          "d": null
        },
        {
          "a": 1,
          "s": "56bcbcbb7cc6406b3fa5d57d2174f4eff8b4402b176926d3a57d3c3dcbb59d57",
          "c": [
            2,
            115,
            18,
            156,
            87,
            25,
            229,
            153,
            55,
            154,
            151,
            74,
            98,
            99,
            99,
            195,
            51,
            197,
            108,
            175,
            192,
            230,
            208,
            26,
            190,
            70,
            213,
            128,
            130,
            128,
            120,
            156,
            99
          ],
          "d": null
        }
      ]
    }
  ]
}

NUT-00 defines¹ how a TokenV4 JSON should look like. That is essentially the Diagnostic Notation described² in the CBOR spec. There, byte array fields are represented like h'00ad268c4d1f5826', which is an h followed by the hex representation wrapped in single quotes.

This PR updates decode-token in cdk-cli to print the diagnostic notation instead of the pure JSON representation of a token. This brings decoded TokenV4s in line with the format described in NUT-00, especially around how byte array fields should be handled.

Example output after PR

cargo run -- decode-token cashuBo2F0gqJhaUgA_9SLj17PgGFwgaNhYQFhc3hAYWNjMTI0MzVlN2I4NDg0YzNjZjE4NTAxNDkyMThhZjkwZjcxNmE1MmJmNGE1ZWQzNDdlNDhlY2MxM2Y3NzM4OGFjWCECRFODGd5IXVW-07KaZCvuWHk3WrnnpiDhHki6SCQh88-iYWlIAK0mjE0fWCZhcIKjYWECYXN4QDEzMjNkM2Q0NzA3YTU4YWQyZTIzYWRhNGU5ZjFmNDlmNWE1YjRhYzdiNzA4ZWIwZDYxZjczOGY0ODMwN2U4ZWVhY1ghAjRWqhENhLSsdHrr2Cw7AFrKUL9Ffr1XN6RBT6w659lNo2FhAWFzeEA1NmJjYmNiYjdjYzY0MDZiM2ZhNWQ1N2QyMTc0ZjRlZmY4YjQ0MDJiMTc2OTI2ZDNhNTdkM2MzZGNiYjU5ZDU3YWNYIQJzEpxXGeWZN5qXSmJjY8MzxWyvwObQGr5G1YCCgHicY2FtdWh0dHA6Ly9sb2NhbGhvc3Q6MzMzOGF1Y3NhdA


{
    "m": "http://localhost:3338",
    "u": "sat",
    "t": [
        {
            "i": h'00ffd48b8f5ecf80',
            "p": [
                {
                    "a": 1,
                    "s": "acc12435e7b8484c3cf1850149218af90f716a52bf4a5ed347e48ecc13f77388",
                    "c": h'0244538319de485d55bed3b29a642bee5879375ab9e7a620e11e48ba482421f3cf',
                    "d": null,
                },
            ],
        },
        {
            "i": h'00ad268c4d1f5826',
            "p": [
                {
                    "a": 2,
                    "s": "1323d3d4707a58ad2e23ada4e9f1f49f5a5b4ac7b708eb0d61f738f48307e8ee",
                    "c": h'023456aa110d84b4ac747aebd82c3b005aca50bf457ebd5737a4414fac3ae7d94d',
                    "d": null,
                },
                {
                    "a": 1,
                    "s": "56bcbcbb7cc6406b3fa5d57d2174f4eff8b4402b176926d3a57d3c3dcbb59d57",
                    "c": h'0273129c5719e599379a974a626363c333c56cafc0e6d01abe46d5808280789c63',
                    "d": null,
                },
            ],
        },
    ],
}

Footnotes

1. https://github.com/cashubtc/nuts/blob/main/00.md#example-1 ↩

2. https://www.rfc-editor.org/rfc/rfc8949.html#name-diagnostic-notation ↩

[thesimplekid]

Nice, thank you been meaning to do something about this for awhile.

Also appreciate the detailed PR notes.

ACK 5cf0403

[ok300]

🙏