script.c File Reference

#include <btc/script.h>
#include <assert.h>
#include <string.h>
#include "buffer.h"
#include "serialize.h"

Go to the source code of this file.

Functions
btc_bool	btc_script_copy_without_op_codeseperator (const cstring *script_in, cstring *script_out)
btc_script_op *	btc_script_op_new ()
void	btc_script_op_free (btc_script_op *script_op)
void	btc_script_op_free_cb (void *data)
btc_bool	btc_script_get_ops (const cstring *script_in, vector *ops_out)
static btc_bool	btc_script_is_pushdata (enum opcodetype op)
static btc_bool	btc_script_is_op (const btc_script_op *op, enum opcodetype opcode)
static btc_bool	btc_script_is_op_pubkey (const btc_script_op *op)
static btc_bool	btc_script_is_op_pubkeyhash (const btc_script_op *op)
btc_bool	btc_script_is_pubkey (vector *ops)
btc_bool	btc_script_is_pubkeyhash (vector *ops)
btc_bool	btc_script_is_scripthash (vector *ops)
static btc_bool	btc_script_is_op_smallint (const btc_script_op *op)
btc_bool	btc_script_is_multisig (vector *ops)
enum btc_tx_out_type	btc_script_classify (vector *ops)
static enum opcodetype	btc_encode_op_n (int n)
static void	btc_script_append_op (cstring *script_in, enum opcodetype op)
static void	btc_script_append_pushdata (cstring *script_in, unsigned char *data, size_t datalen)
btc_bool	btc_script_build_multisig (cstring *script_in, unsigned int required_signatures, vector *pubkeys_chars)
btc_bool	btc_script_build_p2pkh (cstring *script_in, const uint8_t *hash160)
btc_bool	btc_script_build_p2sh (cstring *script_in, const uint8_t *hash160)

Function Documentation

static enum opcodetype btc_encode_op_n ( int  n )

static

Definition at line 257 of file script.c.

References OP_0, and OP_1.

Referenced by btc_script_build_multisig().

{
    assert(n >= 0 && n <= 16);
    if (n == 0)
        return OP_0;
    return (enum opcodetype)(OP_1+n-1);
}

static void btc_script_append_op ( cstring *  script_in, enum opcodetype  op  )

static

Definition at line 266 of file script.c.

References cstr_append_buf().

Referenced by btc_script_append_pushdata(), btc_script_build_p2pkh(), and btc_script_build_p2sh().

{
    cstr_append_buf(script_in, &op, 1);
}

static void btc_script_append_pushdata ( cstring *  script_in, unsigned char *  data, size_t  datalen  )

static

Definition at line 272 of file script.c.

References btc_script_append_op(), cstr_append_buf(), OP_PUSHDATA1, OP_PUSHDATA2, and OP_PUSHDATA4.

Referenced by btc_script_build_multisig(), btc_script_build_p2pkh(), and btc_script_build_p2sh().

{
    if (datalen < OP_PUSHDATA1)
    {
        cstr_append_buf(script_in, (unsigned char *)&datalen, 1);
    }
    else if (datalen <= 0xff)
    {
        btc_script_append_op(script_in, OP_PUSHDATA1);
        cstr_append_buf(script_in, (unsigned char *)&datalen, 1);
    }
    else if (datalen <= 0xffff)
    {
        btc_script_append_op(script_in, OP_PUSHDATA2);
        uint16_t v = htole16(datalen);
        cstr_append_buf(script_in, &v, sizeof(v));
    }
    else
    {
        btc_script_append_op(script_in, OP_PUSHDATA4);
        uint32_t v = htole32(datalen);
        cstr_append_buf(script_in, &v, sizeof(v));
    }
    cstr_append_buf(script_in, data, datalen);
}

btc_bool btc_script_build_multisig	(	cstring *	script_in,
		unsigned int	required_signatures,
		vector *	pubkeys_chars
	)

Definition at line 298 of file script.c.

References BTC_ECKEY_COMPRESSED_LENGTH, BTC_ECKEY_UNCOMPRESSED_LENGTH, btc_encode_op_n(), btc_script_append_pushdata(), btc_pubkey_::compressed, cstr_append_buf(), cstr_resize(), vector::data, vector::len, OP_CHECKMULTISIG, and btc_pubkey_::pubkey.

{
    cstr_resize(script_in, 0); //clear script

    if(required_signatures > 16 || pubkeys_chars->len > 16)
        return false;
    enum opcodetype op_req_sig = btc_encode_op_n(required_signatures);
    cstr_append_buf(script_in, &op_req_sig, 1);

    int i;
    for (i = 0; i < (int)pubkeys_chars->len; i++)
    {
        btc_pubkey *pkey = pubkeys_chars->data[i];
        btc_script_append_pushdata(script_in, pkey->pubkey, (pkey->compressed ? BTC_ECKEY_COMPRESSED_LENGTH : BTC_ECKEY_UNCOMPRESSED_LENGTH));
    }

    enum opcodetype op_pub_len = btc_encode_op_n(pubkeys_chars->len);
    cstr_append_buf(script_in, &op_pub_len, 1);

    enum opcodetype op_checkmultisig = OP_CHECKMULTISIG;
    cstr_append_buf(script_in, &op_checkmultisig, 1);

    return true;
}

btc_bool btc_script_build_p2pkh	(	cstring *	script_in,
		const uint8_t *	hash160
	)

Definition at line 323 of file script.c.

References btc_script_append_op(), btc_script_append_pushdata(), cstr_resize(), OP_CHECKSIG, OP_DUP, OP_EQUALVERIFY, and OP_HASH160.

Referenced by btc_tx_add_p2pkh_hash160_out().

{
    cstr_resize(script_in, 0); //clear script

    btc_script_append_op(script_in, OP_DUP);
    btc_script_append_op(script_in, OP_HASH160);


    btc_script_append_pushdata(script_in, hash160, 20);
    btc_script_append_op(script_in, OP_EQUALVERIFY);
    btc_script_append_op(script_in, OP_CHECKSIG);

    return true;
}

btc_bool btc_script_build_p2sh	(	cstring *	script_in,
		const uint8_t *	hash160
	)

Definition at line 338 of file script.c.

References btc_script_append_op(), btc_script_append_pushdata(), cstr_resize(), OP_EQUAL, and OP_HASH160.

Referenced by btc_tx_add_p2sh_hash160_out().

{
    cstr_resize(script_in, 0); //clear script
    btc_script_append_op(script_in, OP_HASH160);
    btc_script_append_pushdata(script_in, hash160, 20);
    btc_script_append_op(script_in, OP_EQUAL);

    return true;
}

enum btc_tx_out_type btc_script_classify

(

vector *

ops

)

Definition at line 243 of file script.c.

References btc_script_is_multisig(), btc_script_is_pubkey(), btc_script_is_pubkeyhash(), btc_script_is_scripthash(), BTC_TX_MULTISIG, BTC_TX_NONSTANDARD, BTC_TX_PUBKEY, BTC_TX_PUBKEYHASH, and BTC_TX_SCRIPTHASH.

{
    if (btc_script_is_pubkeyhash(ops))
        return BTC_TX_PUBKEYHASH;
    if (btc_script_is_scripthash(ops))
        return BTC_TX_SCRIPTHASH;
    if (btc_script_is_pubkey(ops))
        return BTC_TX_PUBKEY;
    if (btc_script_is_multisig(ops))
        return BTC_TX_MULTISIG;

    return BTC_TX_NONSTANDARD;
}

btc_bool btc_script_copy_without_op_codeseperator	(	const cstring *	script_in,
		cstring *	script_out
	)

Definition at line 36 of file script.c.

References cstr_append_buf(), deser_bytes(), deser_skip(), deser_u16(), deser_u32(), const_buffer::len, cstring::len, OP_CODESEPARATOR, OP_PUSHDATA1, OP_PUSHDATA2, OP_PUSHDATA4, const_buffer::p, and cstring::str.

Referenced by btc_tx_sighash().

{
    if (script_in->len == 0)
        return false; /* EOF */

    struct const_buffer buf = {script_in->str, script_in->len};
    unsigned char opcode;
    while (buf.len > 0) {
        if (!deser_bytes(&opcode, &buf, 1))
            goto err_out;

        uint32_t data_len;

        if (opcode == OP_CODESEPARATOR)
            continue;

        else if (opcode == OP_PUSHDATA1) {
            uint8_t v8;
            if (!deser_bytes(&v8, &buf, 1))
                goto err_out;
            data_len = v8;
        } else if (opcode == OP_PUSHDATA2) {
            uint16_t v16;
            if (!deser_u16(&v16, &buf))
                goto err_out;
            data_len = v16;
        } else if (opcode == OP_PUSHDATA4) {
            uint32_t v32;
            if (!deser_u32(&v32, &buf))
                goto err_out;
            data_len = v32;
        } else {
            cstr_append_buf(script_out, &opcode, 1);
            continue;
        }

        cstr_append_buf(script_out, buf.p, data_len);
        if (!deser_skip(&buf, data_len))
            goto err_out;
    }

err_out:
    return false;
}

btc_bool btc_script_get_ops	(	const cstring *	script_in,
		vector *	ops_out
	)

Definition at line 108 of file script.c.

References btc_script_op_free(), btc_script_op_new(), btc_script_op_::data, btc_script_op_::datalen, deser_bytes(), deser_skip(), deser_u16(), deser_u32(), const_buffer::len, cstring::len, btc_script_op_::op, OP_PUSHDATA1, OP_PUSHDATA2, OP_PUSHDATA4, const_buffer::p, cstring::str, and vector_add().

{
    if (script_in->len == 0)
        return false; /* EOF */

    struct const_buffer buf = {script_in->str, script_in->len};
    unsigned char opcode;

    btc_script_op* op = NULL;
    while (buf.len > 0) {
        op = btc_script_op_new();

        if (!deser_bytes(&opcode, &buf, 1))
            goto err_out;

        op->op = opcode;

        uint32_t data_len;

        if (opcode < OP_PUSHDATA1) {
            data_len = opcode;
        } else if (opcode == OP_PUSHDATA1) {
            uint8_t v8;
            if (!deser_bytes(&v8, &buf, 1))
                goto err_out;
            data_len = v8;
        } else if (opcode == OP_PUSHDATA2) {
            uint16_t v16;
            if (!deser_u16(&v16, &buf))
                goto err_out;
            data_len = v16;
        } else if (opcode == OP_PUSHDATA4) {
            uint32_t v32;
            if (!deser_u32(&v32, &buf))
                goto err_out;
            data_len = v32;
        } else {
            vector_add(ops_out, op);
            continue;
        }

        op->data = calloc(1, data_len);
        memcpy(op->data, &buf.p, data_len);
        op->datalen = data_len;

        vector_add(ops_out, op);

        if (!deser_skip(&buf, data_len))
            goto err_out;
    }

    return true;
err_out:
    btc_script_op_free(op);
    return false;
}

btc_bool btc_script_is_multisig

(

vector *

ops

)

Definition at line 227 of file script.c.

References btc_script_is_op(), btc_script_is_op_pubkey(), btc_script_is_op_smallint(), vector::len, OP_CHECKMULTISIG, and vector_idx.

Referenced by btc_script_classify().

{
    if ((ops->len < 3) || (ops->len > (16 + 3)) ||
        !btc_script_is_op_smallint(vector_idx(ops, 0)) ||
        !btc_script_is_op_smallint(vector_idx(ops, ops->len - 2)) ||
        !btc_script_is_op(vector_idx(ops, ops->len - 1), OP_CHECKMULTISIG))
        return false;

    unsigned int i;
    for (i = 1; i < (ops->len - 2); i++)
        if (!btc_script_is_op_pubkey(vector_idx(ops, i)))
            return false;

    return true;
}

static btc_bool btc_script_is_op ( const btc_script_op *  op, enum opcodetype  opcode  )

static

Definition at line 170 of file script.c.

References btc_script_op_::op.

Referenced by btc_script_is_multisig(), btc_script_is_pubkey(), btc_script_is_pubkeyhash(), and btc_script_is_scripthash().

{
    return (op->op == opcode);
}

static btc_bool btc_script_is_op_pubkey ( const btc_script_op *  op )

static

Definition at line 175 of file script.c.

References btc_script_is_pushdata(), btc_script_op_::datalen, and btc_script_op_::op.

Referenced by btc_script_is_multisig(), and btc_script_is_pubkey().

{
    if (!btc_script_is_pushdata(op->op))
        return false;
    if (op->datalen < 33 || op->datalen > 120)
        return false;
    return true;
}

static btc_bool btc_script_is_op_pubkeyhash ( const btc_script_op *  op )

static

Definition at line 184 of file script.c.

References btc_script_is_pushdata(), btc_script_op_::datalen, and btc_script_op_::op.

Referenced by btc_script_is_pubkeyhash(), and btc_script_is_scripthash().

{
    if (!btc_script_is_pushdata(op->op))
        return false;
    if (op->datalen != 20)
        return false;
    return true;
}

static btc_bool btc_script_is_op_smallint ( const btc_script_op *  op )

static

Definition at line 221 of file script.c.

References btc_script_op_::op, OP_0, OP_1, and OP_16.

Referenced by btc_script_is_multisig().

{
    return ((op->op == OP_0) ||
            (op->op >= OP_1 && op->op <= OP_16));
}

btc_bool btc_script_is_pubkey

(

vector *

ops

)

Definition at line 194 of file script.c.

References btc_script_is_op(), btc_script_is_op_pubkey(), vector::len, OP_CHECKSIG, and vector_idx.

Referenced by btc_script_classify().

{
    return ((ops->len == 2) &&
            btc_script_is_op(vector_idx(ops, 1), OP_CHECKSIG) &&
            btc_script_is_op_pubkey(vector_idx(ops, 0)));
}

btc_bool btc_script_is_pubkeyhash

(

vector *

ops

)

Definition at line 202 of file script.c.

References btc_script_is_op(), btc_script_is_op_pubkeyhash(), vector::len, OP_CHECKSIG, OP_DUP, OP_EQUALVERIFY, OP_HASH160, and vector_idx.

Referenced by btc_script_classify().

{
    return ((ops->len == 5) &&
            btc_script_is_op(vector_idx(ops, 0), OP_DUP) &&
            btc_script_is_op(vector_idx(ops, 1), OP_HASH160) &&
            btc_script_is_op_pubkeyhash(vector_idx(ops, 2)) &&
            btc_script_is_op(vector_idx(ops, 3), OP_EQUALVERIFY) &&
            btc_script_is_op(vector_idx(ops, 4), OP_CHECKSIG));
}

static btc_bool btc_script_is_pushdata ( enum opcodetype  op )

inlinestatic

Definition at line 165 of file script.c.

References OP_PUSHDATA4.

Referenced by btc_script_is_op_pubkey(), and btc_script_is_op_pubkeyhash().

{
    return (op <= OP_PUSHDATA4);
}

btc_bool btc_script_is_scripthash

(

vector *

ops

)

Definition at line 213 of file script.c.

References btc_script_is_op(), btc_script_is_op_pubkeyhash(), vector::len, OP_EQUAL, OP_HASH160, and vector_idx.

Referenced by btc_script_classify().

{
    return ((ops->len == 3) &&
            btc_script_is_op(vector_idx(ops, 0), OP_HASH160) &&
            btc_script_is_op_pubkeyhash(vector_idx(ops, 1)) &&
            btc_script_is_op(vector_idx(ops, 2), OP_EQUAL));
}

void btc_script_op_free

(

btc_script_op *

script_op

)

Definition at line 90 of file script.c.

References btc_script_op_::data, btc_script_op_::datalen, btc_script_op_::op, and OP_0.

Referenced by btc_script_get_ops(), and btc_script_op_free_cb().

{
    if (script_op->data) {
        free(script_op->data);
        script_op->data = NULL;
    }
    script_op->datalen = 0;
    script_op->op = OP_0;
}

void btc_script_op_free_cb

(

void *

data

)

Definition at line 100 of file script.c.

References btc_script_op_free().

{
    btc_script_op* script_op = data;
    btc_script_op_free(script_op);

    free(script_op);
}

btc_script_op* btc_script_op_new

(

)

Definition at line 81 of file script.c.

Referenced by btc_script_get_ops().

{
    btc_script_op* script_op;
    script_op = calloc(1, sizeof(*script_op));

    return script_op;
}