eth_rpc.h

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/*
 * SPDX-License-Identifier: LGPL-3.0-or-later
 * Copyright (c) 2026 Cryptnox SA
 */
 
#pragma once
 
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
/*
 * Set the RPC URL and the from-address used for nonce queries and
 * ecrecover comparison.  Must be called before any other eth_rpc_* function.
 * from_addr must be a "0x..."-prefixed 40-hex-char string.
 */
void eth_rpc_init(const char *rpc_url, const char *from_addr);
 
/*
 * Optional: set the Infura API secret for HTTP Basic Auth.
 * Pass NULL or empty string to disable.  Must be called before any
 * eth_rpc_* function that makes network requests.
 * The Project ID is used as the username; api_secret is the password.
 */
void eth_rpc_set_auth(const char *project_id, const char *api_secret);
 
/*
 * Connect to a WiFi network and block until an IP is obtained (up to 30 s).
 * Returns true on success.
 */
bool eth_rpc_wifi_connect(const char *ssid, const char *password);
 
/*
 * Fetch the pending transaction count (nonce) for from_addr.
 * Returns true and writes the nonce into *nonce_out on success.
 */
bool eth_rpc_get_nonce(uint64_t *nonce_out);
 
/*
 * Determine the signature parity bit (v = 0 or 1) by calling the ecrecover
 * precompile (address 0x01) via eth_call and matching the recovered address
 * against from_addr.  Returns 0 or 1; defaults to 0 on RPC failure.
 */
uint8_t eth_rpc_ecrecover_parity(const uint8_t hash[32],
                                  const uint8_t r[32],
                                  const uint8_t s[32]);
 
/*
 * Broadcast a raw signed transaction (type-prefixed RLP bytes).
 * On success writes the "0x..."-prefixed tx hash into tx_hash_out and
 * returns true.  tx_hash_out must be at least 68 bytes (2 + 64 + NUL).
 */
bool eth_rpc_send_raw_tx(const uint8_t *tx, size_t tx_len,
                          char *tx_hash_out, size_t tx_hash_max);
 
#ifdef __cplusplus
}
#endif