how can I read a keypair from a json file that contains many objects?

Question

My json file looks like

{
  "keypairs": {
      "keypair1":[12345678],
      "keypair2":[12345678],
      "keypair3":[12345678],
  }
}

where [12345678] is actually the array I copied from the keypair file. How do I read these keypairs again with a rust client? I know there is a solana_sdk::signature::read_keypair_file but that's fore only 1 keypair in a file, and I'm not sure what to give as arguments to read_keypair.

Answer 1

You can get the number array for the desired keypair as a Vec<serde_json::Value> within the JSON file using serde_json and convert it to a Vec<u8> using serde::from_value.

Once you have this, you can provide it to the Keypair::from_bytes function to construct your keypair instance from the raw byte array.

let file = std::fs::File::open(path_to_json).unwrap();
let data: serde_json::Value = serde_json::from_reader(file).unwrap();
let key_bytes: Vec<u8> = serde_json::from_value(
    data.get("keypairs").unwrap().get("keypair1").unwrap().clone()
).unwrap();

let pair = solana_sdk::signature::Keypair::from_bytes(&key_bytes).unwrap();