bigchaindb-driver: [handcraft tx] The browser (or proxy) sent a request that this server could not understand.

Both @mgrand (java) and @zballs (go) encountered the same error meanwhile trying to implement code to generate valid transaction payloads.

Key Pair Generation

BigchainDB relies on the Python cryptoconditions library to generate keypairs, which in turn relies on libsodium (via PyNacl) and base58.

It is important to note that the base58 library must be an implementation compatible with what is used by the bitcoin network, but not including the check (for example, the server uses b58encode() rather than b58encode_check()). An example Java implementation that should be compatible is available here.

The payload reported by @mgrand is:

{
    "version": 1,
    "transaction": {
        "asset": {
            "data": null,
            "divisible": false,
            "refillable": false,
            "updatable": false,
            "id": "50965943-3070-41d6-a7be-a44727933476"
        },
        "metadata": {
            "data": {
                "bogosity": 43
            },
            "id": "316f0ef9-4566-48c8-9b9c-0db09329ea2c"
        },
        "conditions": [
            {
                "amount": 1,
                "cid": 0,
                "owners_after": [
                    "QDui4QA6QKMpMRpJQxm8QMM3m4ty2oY3HcgUq5hx3bixdHYbLBnJMZysqYd91Lr1"
                ],
                "condition": {
                    "uri": "cc:4:20:MC0wCAYDK2VkCgEBAyEAErZADsVxHrIG4zs0ghg0hMvGeqRUv00e5DF_2CRtg4Y:96",
                    "details": {
                        "bitmask": 32,
                        "public_key": "QDui4QA6QKMpMRpJQxm8QMM3m4ty2oY3HcgUq5hx3bixdHYbLBnJMZysqYd91Lr1",
                        "signature": null,
                        "type": "fulfillment",
                        "type_id": 4
                    }
                }
            }
        ],
        "fulfillments": [
            {
                "signature": "449ZhWnCjKuMjJ87SPJeuTTeMGub6c6wUnYwcUGT1xKfTB9AJaAVCzETcnpcDH6ob1ZbwuY8To5BXYdXpGJ9fW8L",
                "public_key": "QDui4QA6QKMpMRpJQxm8QMM3m4ty2oY3HcgUq5hx3bixdHYbLBnJMZysqYd91Lr1",
                "type_id": 4,
                "bitmask": 32,
                "type": "fulfillment"
            }
        ],
        "operation": "CREATE"
    },
    "id": "c80a202d95620166611b6755fa1b94a032505df36c1ab4a123ce5675b50b38b8"
}