Sign EVM Messages

import java.util.List;
import xyz.dynamic.waas.ServerKeyShare;
import xyz.dynamic.waas.core.types.WalletProperties;
import xyz.dynamic.waas.evm.DynamicEvmWalletClient;
import xyz.dynamic.waas.opts.SignMessageOpts;

// Load the metadata + shares you persisted at creation time.
WalletProperties walletProperties = WalletProperties.fromJson(
    redis.get("wallet:" + accountAddress)
);
List<ServerKeyShare> externalServerKeyShares = ServerKeyShare.fromJsonList(
    vault.read("wallet:" + accountAddress + "/shares")
);

String signature = client.signMessage(SignMessageOpts.builder()
    .message("Hello, World!".getBytes(java.nio.charset.StandardCharsets.UTF_8))
    .walletProperties(walletProperties)
    .externalServerKeyShares(externalServerKeyShares)
    .build()
).join();

System.out.println("Signature: " + signature);

boolean ok = DynamicEvmWalletClient.verifyMessageSignature(
    walletProperties.accountAddress(),
    "Hello, World!".getBytes(java.nio.charset.StandardCharsets.UTF_8),
    signature
);
assert ok : "signature does not match accountAddress";

String nonce   = String.valueOf(System.currentTimeMillis());
String message = "Sign this message to authenticate: " + nonce;

String signature = client.signMessage(SignMessageOpts.builder()
    .message(message.getBytes(java.nio.charset.StandardCharsets.UTF_8))
    .walletProperties(walletProperties)
    .externalServerKeyShares(externalServerKeyShares)
    .build()
).join();

String payloadJson = "{\"userId\":123,\"action\":\"transfer\",\"amount\":\"100\"}";

String signature = client.signMessage(SignMessageOpts.builder()
    .message(payloadJson.getBytes(java.nio.charset.StandardCharsets.UTF_8))
    .walletProperties(walletProperties)
    .externalServerKeyShares(externalServerKeyShares)
    .build()
).join();