genaddress.c

#include "../lightning/external/libwally-core/include/wally_address.h"
#include "../lightning/external/libwally-core/include/wally_bip32.h"
#include "../lightning/external/libwally-core/src/secp256k1/include/secp256k1.h"
#include "../lightning/common/bech32.c"
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/crypto/ripemd160/ripemd160.h>
#include <ccan/str/hex/hex.h>
#include <err.h>
#include <assert.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
	unsigned char *seed;
	size_t seed_len;
	struct ext_key master_extkey, child_extkey, child2_extkey;

	seed_len = hex_data_size(strlen(argv[1]));
	seed = malloc(seed_len);
	if (!hex_decode(argv[1], strlen(argv[1]), seed, seed_len))
		errx(1, "Expected hex");

	/* Generate BIP32 children m/0/0/i */
	if (bip32_key_from_seed(seed, seed_len,
				BIP32_VER_TEST_PRIVATE,
				0, &master_extkey) != WALLY_OK)
		errx(1, "bip32_key_from_seed failed");

	if (bip32_key_from_parent(&master_extkey, 0, BIP32_FLAG_KEY_PRIVATE,
				  &child_extkey) != WALLY_OK)
		errx(1, "bip32_key_from_parent/0 failed");
	if (bip32_key_from_parent(&child_extkey, 0, BIP32_FLAG_KEY_PRIVATE,
				  &child2_extkey) != WALLY_OK)
		errx(1, "bip32_key_from_parent/0/0 failed");

	for (uint32_t i = 0; i < 10; i++) {
		secp256k1_pubkey pubkey;
		char *wif;
		struct ripemd160 r160;
		unsigned char key[33];
		struct sha256 s256;
		char swaddr[73 + strlen("bcrt")];
		struct ext_key ext;
		unsigned char priv_key[32];
		char privkey_hex[65];
		char pubkey_hex[67];

		if (bip32_key_from_parent(&child2_extkey, i,
					  BIP32_FLAG_KEY_PRIVATE, &ext)
		    != WALLY_OK)
			errx(1, "bip32_key_from_parent/0/0/%u failed", i);

		/* libwally says: The private key with prefix byte 0. */
		memcpy(priv_key, ext.priv_key+1, sizeof(priv_key));

		if (!hex_encode(priv_key, sizeof(priv_key),
				privkey_hex, sizeof(privkey_hex)))
			errx(1, "Cannot hex-encode privkey");
		if (wally_wif_from_bytes(priv_key, sizeof(priv_key), 0xef,
					 WALLY_WIF_FLAG_COMPRESSED,
					 &wif) != WALLY_OK)
			errx(1, "Cannot encode privkey seed/0/0/%u", i);

		if (secp256k1_ec_pubkey_create(wally_get_secp_context(),
					       &pubkey, priv_key) != 1)
			errx(1, "Cannot derive pubkey");

		size_t outlen = 33;
		if (!secp256k1_ec_pubkey_serialize(wally_get_secp_context(),
						   key, &outlen, &pubkey,
						   SECP256K1_EC_COMPRESSED))
			errx(1, "Cannot serialize pubkey");

		if (!hex_encode(key, outlen, pubkey_hex, sizeof(pubkey_hex)))
			errx(1, "Cannot hex-encode pubkey");
		
		printf("pubkey 0/0/%u: %s\n", i, pubkey_hex);
		printf("privkey 0/0/%u: %s\n", i, privkey_hex);
		printf("WIF 0/0/%u: %s\n", i, wif);

		assert(outlen == 33);
		sha256(&s256, key, sizeof(key));
		ripemd160(&r160, s256.u.u8, sizeof(s256.u.u8));

		if (segwit_addr_encode(swaddr, "bcrt", 0, r160.u.u8, sizeof(r160.u.u8)) != 1)
			errx(1, "Cannot make segwit address");	
		printf("P2WPKH 0/0/%u: %s\n\n", i, swaddr);
	}
	return 0;
}