/* Very simplistic gateway:

* - Doesn't do payment protocol.

* - Has race when it's killed.

* - Puts private key on cmdline.

*

* You'll need to have a running 'bitcoind -testnet -txindex -server'

* (if you've run the bitcoind in testnet mode before without -txindex,

* you'll need to run bitcoind -testnet -txindex -reindex).

*/

#include "hex.h"

#include "json.h"

#include "pettycoin_dir.h"

#include "protocol.h"

#include <ccan/build_assert/build_assert.h>

#include <ccan/err/err.h>

#include <ccan/htable/htable_type.h>

#include <ccan/noerr/noerr.h>

#include <ccan/opt/opt.h>

#include <ccan/read_write_all/read_write_all.h>

#include <ccan/tal/grab_file/grab_file.h>

#include <ccan/tal/str/str.h>

#include <errno.h>

#include <fcntl.h>

#include <openssl/ec.h>

#include <openssl/err.h>

#include <openssl/obj_mac.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <unistd.h>

/* Whee, we're on testnet, who cares? */

#define REQUIRED_CONFIRMATIONS 1

static const struct protocol_double_sha *

keyof(const struct protocol_double_sha *elem)

{

return elem;

}

static size_t thash_sha(const struct protocol_double_sha *key)

{

size_t ret;

memcpy(&ret, key, sizeof(ret));

return ret;

}

static bool thash_eq(const struct protocol_double_sha *a,

const struct protocol_double_sha *key)

{

return memcmp(a, key, sizeof(*a)) == 0;

}

HTABLE_DEFINE_TYPE(struct protocol_double_sha, keyof, thash_sha, thash_eq,

thash);

/* Import gateway key:

(eg generated by dumpprivkey mxxEy4ryr3R3f3EXXGKd2w8z4sWnsZMcb9)

importprivkey cSJqHe7RU9rZDDnHxgb39vvYxttNM83JsMkJ1EeYNPtuckGd4Qej rescan=false

Put it in account "gateway":

setaccount mxxEy4ryr3R3f3EXXGKd2w8z4sWnsZMcb9 gateway

Get transactions:

listsinceblock [blockhash] [target-confirmations]

{

"transactions" : [

{

"account" : "testing",

"address" : "mxxEy4ryr3R3f3EXXGKd2w8z4sWnsZMcb9",

"category" : "receive",

"amount" : 10.00000000,

"confirmations" : 137,

"blockhash" : "0000000000d11ab706ffce64cb29f54a1d51ba93de3df6c9c645a514e6424d47",

"blockindex" : 1,

"blocktime" : 1384856232,

"txid" : "3e92a4eb30abe2fc99e7c3ae6b908614bea321ced1eae20261d9f6285763a2b4",

"time" : 1384856232,

"timereceived" : 1384856942

}

],

"lastblock" : "0000000000de8cd3feedc9909cad8e2bf071daa02eafefc41f4c396a048b218e"

}

getrawtransaction 3e92a4eb30abe2fc99e7c3ae6b908614bea321ced1eae20261d9f6285763a2b4

0100000001362ba4199d822ed6bc5a44885f85f0053a1ebd2582da59b1e7980f666478a3b2010000006b483045022100ffb3a0d23e76b88b137153578ce39ff24b3b0a74970457a88bdf94365f9403f102206a321767d1448e8df2cd79a12706ffd00d784a7223cfbbd53ad16e720567e7410121033d04604f326951ea0f78b8b6d043dd1cff7777bcc01171df776a20011accb9a7ffffffff02802feeec010000001976a91434a0a7ba1c9d03225cdd7151c8d97fa925b610ae88ac00ca9a3b000000001976a914bf42747a54fa333f398e0046c005b6e6eeb1e45088ac00000000

decoderawtransaction 0100000001362ba4199d822ed6bc5a44885f85f0053a1ebd2582da59b1e7980f666478a3b2010000006b483045022100ffb3a0d23e76b88b137153578ce39ff24b3b0a74970457a88bdf94365f9403f102206a321767d1448e8df2cd79a12706ffd00d784a7223cfbbd53ad16e720567e7410121033d04604f326951ea0f78b8b6d043dd1cff7777bcc01171df776a20011accb9a7ffffffff02802feeec010000001976a91434a0a7ba1c9d03225cdd7151c8d97fa925b610ae88ac00ca9a3b000000001976a914bf42747a54fa333f398e0046c005b6e6eeb1e45088ac00000000

{

"txid" : "3e92a4eb30abe2fc99e7c3ae6b908614bea321ced1eae20261d9f6285763a2b4",

"version" : 1,

"locktime" : 0,

"vin" : [

{

"txid" : "b2a37864660f98e7b159da8225bd1e3a05f0855f88445abcd62e829d19a42b36",

"vout" : 1,

"scriptSig" : {

"asm" : "3045022100ffb3a0d23e76b88b137153578ce39ff24b3b0a74970457a88bdf94365f9403f102206a321767d1448e8df2cd79a12706ffd00d784a7223cfbbd53ad16e720567e74101 033d04604f326951ea0f78b8b6d043dd1cff7777bcc01171df776a20011accb9a7",

"hex" : "483045022100ffb3a0d23e76b88b137153578ce39ff24b3b0a74970457a88bdf94365f9403f102206a321767d1448e8df2cd79a12706ffd00d784a7223cfbbd53ad16e720567e7410121033d04604f326951ea0f78b8b6d043dd1cff7777bcc01171df776a20011accb9a7"

},

"sequence" : 4294967295

}

],

"vout" : [

{

"value" : 82.70000000,

"n" : 0,

"scriptPubKey" : {

"asm" : "OP_DUP OP_HASH160 34a0a7ba1c9d03225cdd7151c8d97fa925b610ae OP_EQUALVERIFY OP_CHECKSIG",

"hex" : "76a91434a0a7ba1c9d03225cdd7151c8d97fa925b610ae88ac",

"reqSigs" : 1,

"type" : "pubkeyhash",

"addresses" : [

"mkKDtYgXqH23PPEGrSGuiUdiJjTKgRUoBR"

]

}

},

{

"value" : 10.00000000,

"n" : 1,

"scriptPubKey" : {

"asm" : "OP_DUP OP_HASH160 bf42747a54fa333f398e0046c005b6e6eeb1e450 OP_EQUALVERIFY OP_CHECKSIG",

"hex" : "76a914bf42747a54fa333f398e0046c005b6e6eeb1e45088ac",

"reqSigs" : 1,

"type" : "pubkeyhash",

"addresses" : [

"mxxEy4ryr3R3f3EXXGKd2w8z4sWnsZMcb9"

]

}

}

]

}

*/

static bool get_lock(int fd)

{

struct flock fl;

int ret;

fl.l_type = F_WRLCK;

fl.l_whence = SEEK_SET;

fl.l_start = 0;

fl.l_len = 0;

/* Note: non-blocking! */

do {

ret = fcntl(fd, F_SETLK, &fl);

} while (ret == -1 && errno == EINTR);

return ret == 0;

}

/* gateway-txs file contains the transactions we've already injected. */

static int read_gateway_txs(struct thash *thash)

{

struct protocol_double_sha *sha;

struct stat st;

int fd, i, num;

fd = open("gateway-txs", O_RDWR);

if (fd < 0)

err(1, "Opening gateway file");

if (!get_lock(fd))

err(1, "Locking gateway file");

if (fstat(fd, &st) == -1)

err(1, "Statting gateway file");

if (st.st_size % sizeof(*sha))

errx(1, "Gateway file invalid size %llu",

(long long)st.st_size);

num = st.st_size / sizeof(*sha);

sha = tal_arr(NULL, struct protocol_double_sha, num);

if (read(fd, sha, st.st_size) != st.st_size)

err(1, "Reading gateway file");

for (i = 0; i < num; i++)

thash_add(thash, sha + i);

return fd;

}

/* arg* may be null */

static char *ask_process(const tal_t *ctx,

const char *arg5)

{

char *output;

int fds[2], status;

if (pipe(fds) != 0)

return NULL;

switch (fork()) {

case -1:

return NULL;

case 0:

close(fds[0]);

dup2(fds[1], STDOUT_FILENO);

execlp(name, name, arg1, arg2, arg3, arg4, arg5, NULL);

exit(errno);

}

close(fds[1]);

output = grab_fd(ctx, fds[0]);

close_noerr(fds[0]);

wait(&status);

if (!WIFEXITED(status)) {

output = tal_free(output);

errno = EINTR;

} else if (WEXITSTATUS(status)) {

output = tal_free(output);

errno = WEXITSTATUS(status);

}

return output;

}

static char *ask_bitcoind(const tal_t *ctx,

const char *opt3)

{

return ask_process(ctx, "bitcoind", "-testnet", req, opt1, opt2, opt3);

}

static jsmntok_t *json_bitcoind(const tal_t *ctx, const char **output,

const char *opt3)

{

bool unused;

*output = ask_bitcoind(ctx, req, opt1, opt2, opt3);

if (!*output)

return NULL;

/* It should give us valid, complete JSON. */

return json_parse_input(*output, strlen(*output), &unused);

}

static void setup_gateway(const tal_t *ctx)

{

jsmntok_t *toks;

const char *value;

int fd;

toks = json_bitcoind(ctx, &value, "getaddressesbyaccount", "gateway",

NULL, NULL);

if (!toks || tal_count(toks) == 1)

err(1, "Contacting bitcoind for gateway account");

if (toks[0].type != JSMN_ARRAY)

errx(1, "Unexpected getaddressesbyaccount answer");

if (toks[0].size != 0)

errx(1, "gateway account already exists in bitcoin");

/* FIXME: Generate our own key? */

value = ask_bitcoind(ctx, "getaccountaddress", "gateway", NULL, NULL);

if (!value)

err(1, "Getting account address for gateway");

printf("Gateway address is %s\n", value);

fd = open("gateway-address", O_WRONLY|O_CREAT|O_EXCL, 0600);

if (fd < 0)

err(1, "Creating gateway-address");

/* Skip \n at the end. */

if (!write_all(fd, value, strlen(value)-1))

err(1, "Writing gateway-address");

close(fd);

value = ask_bitcoind(ctx, "dumpprivkey", value, NULL, NULL);

/* Create gateway privkey file */

fd = open("gateway-privkey", O_WRONLY|O_CREAT|O_EXCL, 0600);

if (fd < 0)

err(1, "Creating gateway-privkey");

/* Skip \n at the end. */

if (!write_all(fd, value, strlen(value) - 1))

err(1, "Writing gateway-privkey");

fsync(fd);

close(fd);

/* Create empty gateway-txs file */

fd = open("gateway-txs", O_WRONLY|O_CREAT|O_EXCL, 0600);

if (fd < 0)

err(1, "Creating gateway-txs");

close(fd);

}

/* Tal wrappers for opt. */

static void *opt_allocfn(size_t size)

{

return tal_alloc_(NULL, size, false, TAL_LABEL("opt_allocfn", ""));

}

static void *tal_reallocfn(void *ptr, size_t size)

{

if (!ptr)

return opt_allocfn(size);

tal_resize_(&ptr, 1, size, false);

return ptr;

}

static void tal_freefn(void *ptr)

{

tal_free(ptr);

}

static unsigned int num_of(const char *buffer, const jsmntok_t *tok)

{

unsigned int val;

if (!json_tok_number(buffer, tok, &val))

errx(1, "Invalid number value in '%.*s'",

json_tok_len(tok),

json_tok_contents(buffer, tok));

return val;

}

static const char *get_first_input_addr(const tal_t *ctx,

const char *buffer,

const jsmntok_t *txid)

{

const jsmntok_t *toks, *intxid, *onum, *type, *address;

unsigned int outnum;

const char *delve, *txstr;

/* eg:

getrawtransaction e84b0c87934a146d211fcaa6f1ec187da33e205fb250400cf66620a82a9111a0 1

{

"hex" : "010000000193721eadf1bb2a40498b41ca6be2adaddf4c1780884637fedf05cf37015ac508000000006b4830450221008ce700a0c872af67612e5d5226f1e8bdcb2329549883b8fa02df002409f54c43022029b10a885ca3c5103574f06ab90e6f5a7c9c2cafe6e583f17316c967d678bab4012103c511c82cf0aae4541c026eee5d9f738dc1cb4a2114e20b3f5710a22dc94825ceffffffff02d0f88774030000001976a9144e81b0986efad3643012783f016ec10a9c3d35cd88ac005a6202000000001976a91434f89b68a07bd841bbca98f9b7b1521ce1a3d17688ac00000000",

"txid" : "e84b0c87934a146d211fcaa6f1ec187da33e205fb250400cf66620a82a9111a0",

"version" : 1,

"locktime" : 0,

"vin" : [

{

"txid" : "08c55a0137cf05dffe37468880174cdfadade26bca418b49402abbf1ad1e7293",

"vout" : 0,

"scriptSig" : {

"asm" : "30450221008ce700a0c872af67612e5d5226f1e8bdcb2329549883b8fa02df002409f54c43022029b10a885ca3c5103574f06ab90e6f5a7c9c2cafe6e583f17316c967d678bab401 03c511c82cf0aae4541c026eee5d9f738dc1cb4a2114e20b3f5710a22dc94825ce",

"hex" : "4830450221008ce700a0c872af67612e5d5226f1e8bdcb2329549883b8fa02df002409f54c43022029b10a885ca3c5103574f06ab90e6f5a7c9c2cafe6e583f17316c967d678bab4012103c511c82cf0aae4541c026eee5d9f738dc1cb4a2114e20b3f5710a22dc94825ce"

},

"sequence" : 4294967295

}

],

"vout" : [

{

"value" : 148.39970000,

"n" : 0,

"scriptPubKey" : {

"asm" : "OP_DUP OP_HASH160 4e81b0986efad3643012783f016ec10a9c3d35cd OP_EQUALVERIFY OP_CHECKSIG",

"hex" : "76a9144e81b0986efad3643012783f016ec10a9c3d35cd88ac",

"reqSigs" : 1,

"type" : "pubkeyhash",

"addresses" : [

"mng4N2LZqin7joL7GAjs4tp8WNNt8GjcYz"

]

}

},

{

"value" : 0.40000000,

"n" : 1,

"scriptPubKey" : {

"asm" : "OP_DUP OP_HASH160 34f89b68a07bd841bbca98f9b7b1521ce1a3d176 OP_EQUALVERIFY OP_CHECKSIG",

"hex" : "76a91434f89b68a07bd841bbca98f9b7b1521ce1a3d17688ac",

"reqSigs" : 1,

"type" : "pubkeyhash",

"addresses" : [

"mkM3FYuYoKFiXS3YL99JdJEdPM5HVGpZTj"

]

}

}

],

"blockhash" : "0000000022a3a02881f56c24bbe7556eef98b1e29267b4015a4fbfc83bab5735",

"confirmations" : 14,

"time" : 1406252550,

"blocktime" : 1406252550

}

*/

txstr = tal_fmt(ctx, "%.*s",

(int)(txid->end - txid->start),

buffer + txid->start);

toks = json_bitcoind(ctx, &buffer,

"getrawtransaction", txstr, "1", NULL);

if (!toks)

err(1, "getrawtransaction of tx %s", txstr);

/* This can happen in if someone aims their block reward at

the gateway. */

intxid = json_delve(buffer, toks, ".vin[0].txid");

onum = json_delve(buffer, toks, ".vin[0].vout");

if (!intxid || !onum)

errx(1, "Missing txid/vout in '%s'", buffer);

/* Get this before we replace buffer. */

outnum = num_of(buffer, onum);

/* Get details of *that* tx. */

txstr = tal_fmt(ctx, "%.*s",

(int)(intxid->end - intxid->start),

buffer + intxid->start);

toks = json_bitcoind(ctx, &buffer,

"getrawtransaction", txstr, "1", NULL);

if (!toks)

err(1, "getrawtransaction of input tx %s", txstr);

/* make sure it's a pubkeyhash */

delve = tal_fmt(ctx, ".vout[%u].scriptPubKey.type", outnum);

type = json_delve(buffer, toks, delve);

if (!type || !json_tok_streq(buffer, type, "pubkeyhash"))

errx(1, "'%s' was not a pubkeyhash in '%s'", delve, buffer);

delve = tal_fmt(ctx, ".vout[%u].scriptPubKey.addresses[0]", outnum);

address = json_delve(buffer, toks, delve);

if (!address)

errx(1, "Can't find %s in '%s'", delve, buffer);

return tal_strndup(ctx, buffer + address->start,

address->end - address->start);

}

/* See "https://en.bitcoin.it/wiki/Proper_Money_Handling_(JSON-RPC)" */

static bool pettycoin_tx(const tal_t *ctx, const char *privkey,

const char *destaddr, const char *amount,

size_t amount_len)

{

char *out, *end, *amountstr, *pettyaddr;

u64 amt;

/* We expect <number>.<number>. */

amt = strtoul(amount, &end, 10) * (u64)100000000;

if (end >= amount + amount_len || *end != '.')

errx(1, "Bad amount '%.*s'", (int)amount_len, amount);

amt += strtoul(end + 1, &end, 10);

if (end != amount + amount_len)

errx(1, "Bad amount '%.*s'", (int)amount_len, amount);

amountstr = tal_fmt(ctx, "%llu", (unsigned long long)amt);

pettyaddr = tal_fmt(ctx, "P-%s", destaddr);

out = ask_process(ctx, "pettycoin-tx", "--no-fee",

"from-gateway", privkey, pettyaddr, amountstr);

if (!out)

return false;

out = ask_process(ctx, "pettycoin-query", "sendrawtransaction",

out, NULL, NULL, NULL);

if (!out)

return false;

printf("Injected gateway tx %s\n", out);

return true;

}

int main(int argc, char *argv[])

{

tal_t *ctx = tal(NULL, char);

const char *privkey;

char *pettycoin_dir, *rpc_filename;

bool setup = false;

struct thash thash;

int fd;

unsigned int known_txs = 0;

err_set_progname(argv[0]);

opt_set_alloc(opt_allocfn, tal_reallocfn, tal_freefn);

pettycoin_dir_register_opts(ctx, &pettycoin_dir, &rpc_filename);

opt_register_noarg("--help|-h", opt_usage_and_exit,

"", "Show this message");

opt_register_noarg("--version|-V", opt_version_and_exit, VERSION,

"Display version and exit");

opt_register_noarg("--setup", opt_set_bool, &setup,

"Create new gateway key and initialize files");

opt_early_parse(argc, argv, opt_log_stderr_exit);

opt_parse(&argc, argv, opt_log_stderr_exit);

if (argc != 1)

errx(1, "No arguments needed\n%s", opt_usage(argv[0], NULL));

if (chdir(pettycoin_dir) != 0)

err(1, "Entering pettycoin dir '%s'", pettycoin_dir);

if (setup) {

setup_gateway(ctx);

tal_free(ctx);

exit(0);

}

thash_init(&thash);

fd = read_gateway_txs(&thash);

privkey = grab_file(ctx, "gateway-privkey");

if (!privkey)

err(1, "Reading gateway-privkey");

for (;;) {

jsmntok_t *toks;

const jsmntok_t *t, *end;

const char *buffer;

const tal_t *this_ctx = tal(ctx, char);

char *fromstr = tal_fmt(this_ctx, "%u", known_txs);

toks = json_bitcoind(this_ctx, &buffer,

"listtransactions", "gateway",

"999999", fromstr);

if (!toks)

err(1, "Asking bitcoind for transactions");

/* eg:

[

{

"account" : "foo",

"address" : "mkM3FYuYoKFiXS3YL99JdJEdPM5HVGpZTj",

"category" : "receive",

"amount" : 0.40000000,

"confirmations" : 0,

"txid" : "e84b0c87934a146d211fcaa6f1ec187da33e205fb250400cf66620a82a9111a0",

"walletconflicts" : [

],

"time" : 1406249415,

"timereceived" : 1406249415

}

]

*/

if (toks[0].type != JSMN_ARRAY)

errx(1, "Unexpected type from listtransactions!");

end = json_next(&toks[0]);

for (t = toks + 1; t < end; t = json_next(t)) {

const jsmntok_t *val, *amount;

const char *destaddr;

struct protocol_double_sha txid;

if (t->type != JSMN_OBJECT)

errx(1, "Unexpected type in"

" listtransactions array");

/* Not enough confirmations? Stop here. */

val = json_get_member(buffer, t, "confirmations");

if (num_of(buffer, val) < REQUIRED_CONFIRMATIONS)

break;

/* Next time, don't need this tx. */

known_txs++;

val = json_get_member(buffer, t, "txid");

if (!val)

errx(1, "No txid in '%s'", buffer);

if (!from_hex(buffer + val->start,

val->end - val->start, &txid.sha,

sizeof(txid.sha)))

errx(1, "Bad txid '%.*s'",

json_tok_len(val),

json_tok_contents(buffer, val));

/* Do we already know it? */

if (thash_get(&thash, &txid))

continue;

amount = json_get_member(buffer, t, "amount");

if (!amount)

errx(1, "No amount in '%s'", buffer);

/* Get address of first input. */

destaddr = get_first_input_addr(this_ctx, buffer, val);

/* OK, inject new from_gateway tx. */

if (!pettycoin_tx(ctx, privkey, destaddr,

buffer + amount->start,

amount->end - amount->start)) {

err(1, "Pettcoin injection failed for"

" from-gateway %s P-%s %.*s",

privkey, destaddr,

json_tok_len(amount),

json_tok_contents(buffer, amount));

}

/* FIXME: Racy as hell, we should look on the

* pettycoin network to see if we've actually

* done all the transfers. */

if (!write_all(fd, &txid, sizeof(txid)))

err(1, "Writing out txid");

}

/* Clean up. */

tal_free(this_ctx);

/* FIXME: Ask pettycoin about TO_GATEWAY txs. */

/* Poll. We suck. */

sleep(5);

}

}