signMessageFromBase58

Signs a given message (byte vector) using the Ed25519 algorithm with a private key provided in Base58 format. This is used to prove ownership of a wallet (for off-chain authentication) or to sign Solana transactions.

The function first decodes the Base58 key into its raw byte format and then performs the signing operation.

Parameters

Parameter	Type	Description
message	const std::vector<uint8_t>&	The byte vector containing the data to be signed.
privateKeyBase58	const String&	The 64-byte private key, encoded as a Base58 string.
outSignature	uint8_t[64]	An output parameter. This is a byte array where the resulting 64-byte signature will be stored.

Return Value

• bool: Returns true if signing was successful, false if the private key format is invalid.

Example Code (main.cpp)

#include <Arduino.h>
#include "Infratic-lib.h"

// --- Settings ---
const String SOLANA_RPC_URL = "[https://api.devnet.solana.com](https://api.devnet.solana.com)";
const String MY_PRIVATE_KEY_BASE58 = "YOUR_PRIVATE_KEY_BASE58";

Infratic solana(SOLANA_RPC_URL);

void setup() {
    Serial.begin(115200);
    delay(1000);

    Serial.println("\n=== Sign Message (from Base58) Example ===");

    // Message to be signed
    std::string message_str = "This message was signed by Infratic.";
    std::vector<uint8_t> message(message_str.begin(), message_str.end());

    uint8_t signature[64]; // 64-byte buffer for the signature

    if (solana.signMessageFromBase58(message, MY_PRIVATE_KEY_BASE58, signature)) {
        Serial.println("✅ Message signed successfully!");
        Serial.print("   -> Signature (hex): ");
        for (int i = 0; i < 64; i++) {
            if (signature[i] < 16) Serial.print("0");
            Serial.print(signature[i], HEX);
        }
        Serial.println();
    } else {
        Serial.println("❌ Failed to sign message. Check the private key format.");
    }
}

void loop() {
    // Can be left empty
}