tx.c

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/*

 The MIT License (MIT)

 Copyright (c) 2015 Jonas Schnelli

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the "Software"),
 to deal in the Software without restriction, including without limitation
 the rights to use, copy, modify, merge, publish, distribute, sublicense,
 and/or sell copies of the Software, and to permit persons to whom the
 Software is furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included
 in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
 OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 OTHER DEALINGS IN THE SOFTWARE.

*/

#include <stdint.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include "btc/base58.h"
#include "btc/tx.h"

#include "serialize.h"
#include "sha2.h"
#include "utils.h"

void btc_tx_in_free(btc_tx_in* tx_in)
{
    if (!tx_in)
        return;

    memset(&tx_in->prevout.hash, 0, 32);
    tx_in->prevout.n = 0;

    if (tx_in->script_sig) {
        cstr_free(tx_in->script_sig, true);
        tx_in->script_sig = NULL;
    }
}

//callback for vector free function
void btc_tx_in_free_cb(void* data)
{
    if (!data)
        return;

    btc_tx_in* tx_in = data;
    btc_tx_in_free(tx_in);

    memset(tx_in, 0, sizeof(*tx_in));
    free(tx_in);
}


btc_tx_in* btc_tx_in_new()
{
    btc_tx_in* tx_in;
    tx_in = calloc(1, sizeof(*tx_in));
    memset(&tx_in->prevout, 0, sizeof(tx_in->prevout));
    tx_in->sequence = UINT32_MAX;
    return tx_in;
}


void btc_tx_out_free(btc_tx_out* tx_out)
{
    if (!tx_out)
        return;
    tx_out->value = 0;

    if (tx_out->script_pubkey) {
        cstr_free(tx_out->script_pubkey, true);
        tx_out->script_pubkey = NULL;
    }
}


void btc_tx_out_free_cb(void* data)
{
    if (!data)
        return;

    btc_tx_out* tx_out = data;
    btc_tx_out_free(tx_out);

    memset(tx_out, 0, sizeof(*tx_out));
    free(tx_out);
}


btc_tx_out* btc_tx_out_new()
{
    btc_tx_out* tx_out;
    tx_out = calloc(1, sizeof(*tx_out));

    return tx_out;
}


void btc_tx_free(btc_tx* tx)
{
    if (tx->vin)
        vector_free(tx->vin, true);

    if (tx->vout)
        vector_free(tx->vout, true);

    free(tx);
}


btc_tx* btc_tx_new()
{
    btc_tx* tx;
    tx = calloc(1, sizeof(*tx));
    tx->vin = vector_new(8, btc_tx_in_free_cb);
    tx->vout = vector_new(8, btc_tx_out_free_cb);
    tx->version = 1;
    tx->locktime = 0;
    return tx;
}


btc_bool btc_tx_in_deserialize(btc_tx_in* tx_in, struct const_buffer* buf)
{
    deser_u256(tx_in->prevout.hash, buf);
    if (!deser_u32(&tx_in->prevout.n, buf))
        return false;
    if (!deser_varstr(&tx_in->script_sig, buf))
        return false;
    if (!deser_u32(&tx_in->sequence, buf))
        return false;
    return true;
}

btc_bool btc_tx_out_deserialize(btc_tx_out* tx_out, struct const_buffer* buf)
{
    if (!deser_s64(&tx_out->value, buf))
        return false;
    if (!deser_varstr(&tx_out->script_pubkey, buf))
        return false;
    return true;
}

int btc_tx_deserialize(const unsigned char* tx_serialized, size_t inlen, btc_tx* tx)
{
    struct const_buffer buf = {tx_serialized, inlen};

    //tx needs to be initialized
    deser_u32(&tx->version, &buf);
    uint32_t vlen;
    if (!deser_varlen(&vlen, &buf))
        return false;

    unsigned int i;
    for (i = 0; i < vlen; i++) {
        btc_tx_in* tx_in = btc_tx_in_new();

        if (!btc_tx_in_deserialize(tx_in, &buf)) {
            free(tx_in);
        }

        vector_add(tx->vin, tx_in);
    }

    if (!deser_varlen(&vlen, &buf))
        return false;
    for (i = 0; i < vlen; i++) {
        btc_tx_out* tx_out = btc_tx_out_new();

        if (!btc_tx_out_deserialize(tx_out, &buf)) {
            free(tx_out);
        }

        vector_add(tx->vout, tx_out);
    }

    if (!deser_u32(&tx->locktime, &buf))
        return false;

    return true;
}

void btc_tx_in_serialize(cstring* s, const btc_tx_in* tx_in)
{
    ser_u256(s, tx_in->prevout.hash);
    ser_u32(s, tx_in->prevout.n);
    ser_varstr(s, tx_in->script_sig);
    ser_u32(s, tx_in->sequence);
}

void btc_tx_out_serialize(cstring* s, const btc_tx_out* tx_out)
{
    ser_s64(s, tx_out->value);
    ser_varstr(s, tx_out->script_pubkey);
}

void btc_tx_serialize(cstring* s, const btc_tx* tx)
{
    ser_u32(s, tx->version);

    ser_varlen(s, tx->vin ? tx->vin->len : 0);

    unsigned int i;
    if (tx->vin) {
        for (i = 0; i < tx->vin->len; i++) {
            btc_tx_in* tx_in;

            tx_in = vector_idx(tx->vin, i);
            btc_tx_in_serialize(s, tx_in);
        }
    }

    ser_varlen(s, tx->vout ? tx->vout->len : 0);

    if (tx->vout) {
        for (i = 0; i < tx->vout->len; i++) {
            btc_tx_out* tx_out;

            tx_out = vector_idx(tx->vout, i);
            btc_tx_out_serialize(s, tx_out);
        }
    }

    ser_u32(s, tx->locktime);
}

void btc_tx_hash(const btc_tx* tx, uint8_t *hashout)
{
    cstring *txser = cstr_new_sz(1024);
    btc_tx_serialize(txser, tx);


    sha256_Raw((const uint8_t*)txser->str, txser->len, hashout);
    sha256_Raw(hashout, 32, hashout);
    cstr_free(txser, true);
}


void btc_tx_in_copy(btc_tx_in* dest, const btc_tx_in* src)
{
    memcpy(&dest->prevout, &src->prevout, sizeof(dest->prevout));
    dest->sequence = src->sequence;

    if (!src->script_sig)
        dest->script_sig = NULL;
    else {
        dest->script_sig = cstr_new_sz(src->script_sig->len);
        cstr_append_buf(dest->script_sig,
                        src->script_sig->str,
                        src->script_sig->len);
    }
}


void btc_tx_out_copy(btc_tx_out* dest, const btc_tx_out* src)
{
    dest->value = src->value;

    if (!src->script_pubkey)
        dest->script_pubkey = NULL;
    else {
        dest->script_pubkey = cstr_new_sz(src->script_pubkey->len);
        cstr_append_buf(dest->script_pubkey,
                        src->script_pubkey->str,
                        src->script_pubkey->len);
    }
}


void btc_tx_copy(btc_tx* dest, const btc_tx* src)
{
    dest->version = src->version;
    dest->locktime = src->locktime;

    if (!src->vin)
        dest->vin = NULL;
    else {
        unsigned int i;

        if (dest->vin)
            vector_free(dest->vin, true);

        dest->vin = vector_new(src->vin->len, btc_tx_in_free_cb);

        for (i = 0; i < src->vin->len; i++) {
            btc_tx_in* tx_in_old, *tx_in_new;

            tx_in_old = vector_idx(src->vin, i);
            tx_in_new = malloc(sizeof(*tx_in_new));
            btc_tx_in_copy(tx_in_new, tx_in_old);
            vector_add(dest->vin, tx_in_new);
        }
    }

    if (!src->vout)
        dest->vout = NULL;
    else {
        unsigned int i;

        if (dest->vout)
            vector_free(dest->vout, true);

        dest->vout = vector_new(src->vout->len,
                                btc_tx_out_free_cb);

        for (i = 0; i < src->vout->len; i++) {
            btc_tx_out* tx_out_old, *tx_out_new;

            tx_out_old = vector_idx(src->vout, i);
            tx_out_new = malloc(sizeof(*tx_out_new));
            btc_tx_out_copy(tx_out_new, tx_out_old);
            vector_add(dest->vout, tx_out_new);
        }
    }
}

btc_bool btc_tx_sighash(const btc_tx* tx_to, const cstring* fromPubKey, unsigned int in_num, int hashtype, uint8_t* hash)
{
    if (in_num >= tx_to->vin->len)
        return false;

    btc_bool ret = true;

    btc_tx* tx_tmp = btc_tx_new();
    btc_tx_copy(tx_tmp, tx_to);

    cstring* new_script = cstr_new_sz(fromPubKey->len);
    btc_script_copy_without_op_codeseperator(fromPubKey, new_script);

    unsigned int i;
    btc_tx_in* tx_in;
    for (i = 0; i < tx_tmp->vin->len; i++) {
        tx_in = vector_idx(tx_tmp->vin, i);
        cstr_resize(tx_in->script_sig, 0);

        if (i == in_num)
            cstr_append_buf(tx_in->script_sig,
                            new_script->str,
                            new_script->len);
    }
    cstr_free(new_script, true);
    /* Blank out some of the outputs */
    if ((hashtype & 0x1f) == SIGHASH_NONE) {
        /* Wildcard payee */
        if (tx_tmp->vout)
            vector_free(tx_tmp->vout, true);

        tx_tmp->vout = vector_new(1, btc_tx_out_free_cb);

        /* Let the others update at will */
        for (i = 0; i < tx_tmp->vin->len; i++) {
            tx_in = vector_idx(tx_tmp->vin, i);
            if (i != in_num)
                tx_in->sequence = 0;
        }
    }

    else if ((hashtype & 0x1f) == SIGHASH_SINGLE) {
        /* Only lock-in the txout payee at same index as txin */
        unsigned int n_out = in_num;
        if (n_out >= tx_tmp->vout->len) {
            //TODO: set error code
            ret = false;
            goto out;
        }

        vector_resize(tx_tmp->vout, n_out + 1);

        for (i = 0; i < n_out; i++) {
            btc_tx_out* tx_out;

            tx_out = vector_idx(tx_tmp->vout, i);
            tx_out->value = -1;
            if (tx_out->script_pubkey) {
                cstr_free(tx_out->script_pubkey, true);
                tx_out->script_pubkey = NULL;
            }
        }

        /* Let the others update at will */
        for (i = 0; i < tx_tmp->vin->len; i++) {
            tx_in = vector_idx(tx_tmp->vin, i);
            if (i != in_num)
                tx_in->sequence = 0;
        }
    }

    /* Blank out other inputs completely;
     not recommended for open transactions */
    if (hashtype & SIGHASH_ANYONECANPAY) {
        if (in_num > 0)
            vector_remove_range(tx_tmp->vin, 0, in_num);
        vector_resize(tx_tmp->vin, 1);
    }

    cstring* s = cstr_new_sz(512);
    btc_tx_serialize(s, tx_tmp);
    char hextest[4096];
    ser_s32(s, hashtype);

    sha256_Raw((const uint8_t*)s->str, s->len, hash);
    sha256_Raw(hash, 32, hash);

    cstr_free(s, true);

out:
    btc_tx_free(tx_tmp);

    return ret;
}


btc_bool btc_tx_add_address_out(btc_tx* tx, const btc_chain* chain, int64_t amount, const char *address)
{

    uint8_t buf[strlen(address)*2];
    int r = btc_base58_decode_check(address, buf, sizeof(buf));
    if (r <= 0)
        return false;

    if (buf[0] == chain->b58prefix_pubkey_address)
    {
        btc_tx_add_p2pkh_hash160_out(tx, amount, &buf[1]);
    }
    else if (buf[0] == chain->b58prefix_script_address)
    {
        btc_tx_add_p2sh_hash160_out(tx, amount, &buf[1]);
    }

    return true;
}


btc_bool btc_tx_add_p2pkh_hash160_out(btc_tx* tx, int64_t amount, uint8_t *hash160)
{
    btc_tx_out* tx_out = btc_tx_out_new();

    tx_out->script_pubkey = cstr_new_sz(1024);
    btc_script_build_p2pkh(tx_out->script_pubkey, hash160);

    tx_out->value = amount;

    vector_add(tx->vout, tx_out);

    return true;
}

btc_bool btc_tx_add_p2sh_hash160_out(btc_tx* tx, int64_t amount, uint8_t *hash160)
{
    btc_tx_out* tx_out = btc_tx_out_new();

    tx_out->script_pubkey = cstr_new_sz(1024);
    btc_script_build_p2sh(tx_out->script_pubkey, hash160);

    tx_out->value = amount;

    vector_add(tx->vout, tx_out);

    return true;
}

btc_bool btc_tx_add_p2pkh_out(btc_tx* tx, int64_t amount, const btc_pubkey *pubkey)
{

    uint8_t hash160[20];
    btc_pubkey_get_hash160(pubkey, hash160);
    return btc_tx_add_p2pkh_hash160_out(tx, amount, hash160);
}