Script Functions

int wally_scriptpubkey_get_type(const unsigned char *bytes, size_t bytes_len, size_t *written)

Determine the type of a scriptPubkey script.

Parameters:

• bytes – Bytes of the scriptPubkey.

• bytes_len – Length of bytes in bytes.

• written – Destination for the script type, one of the Script type constants.

Returns:

See Error Codes

int wally_scriptpubkey_p2pkh_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a P2PKH scriptPubkey.

Parameters:

• bytes – Bytes to create a scriptPubkey for.

• bytes_len – The length of bytes in bytes. If WALLY_SCRIPT_HASH160 is given in flags, bytes is a public key to hash160 before creating the P2PKH, and bytes_len must be EC_PUBLIC_KEY_LEN or EC_PUBLIC_KEY_UNCOMPRESSED_LEN. Otherwise, bytes_len must be HASH160_LEN and bytes must contain the hash160 to use.

• flags – WALLY_SCRIPT_HASH160 or 0.

• bytes_out – Destination for the resulting scriptPubkey.

• len – Size of bytes_out. Passing WALLY_SCRIPTPUBKEY_P2PKH_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_scriptsig_p2pkh_from_sig(const unsigned char *pub_key, size_t pub_key_len, const unsigned char *sig, size_t sig_len, uint32_t sighash, unsigned char *bytes_out, size_t len, size_t *written)

Create a P2PKH scriptSig from a pubkey and compact signature.

This function creates the scriptSig by converting sig to DER encoding, appending the given sighash, then calling wally_scriptsig_p2pkh_from_der.

Parameters:

• pub_key – The public key to create a scriptSig with.

• pub_key_len – Length of pub_key in bytes. Must be EC_PUBLIC_KEY_LEN or EC_PUBLIC_KEY_UNCOMPRESSED_LEN.

• sig – The compact signature to create a scriptSig with.

• sig_len – The length of sig in bytes. Must be EC_SIGNATURE_LEN.

• sighash – WALLY_SIGHASH_ flags specifying the type of signature desired.

• bytes_out – Destination for the resulting scriptSig.

• len – The length of bytes_out in bytes.

• len – Size of bytes_out. Passing WALLY_SCRIPTSIG_P2PKH_MAX_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_witness_p2wpkh_from_sig(const unsigned char *pub_key, size_t pub_key_len, const unsigned char *sig, size_t sig_len, uint32_t sighash, struct wally_tx_witness_stack **witness)

Create a P2WPKH witness from a pubkey and compact signature.

Parameters:

• pub_key – The public key to create a witness with.

• pub_key_len – Length of pub_key in bytes. Must be EC_PUBLIC_KEY_LEN or EC_PUBLIC_KEY_UNCOMPRESSED_LEN.

• sig – The compact signature to create a witness with.

• sig_len – The length of sig in bytes. Must be EC_SIGNATURE_LEN.

• sighash – WALLY_SIGHASH_ flags specifying the type of signature desired.

• witness – Destination for the newly created witness.

Returns:

See Error Codes

int wally_scriptsig_p2pkh_from_der(const unsigned char *pub_key, size_t pub_key_len, const unsigned char *sig, size_t sig_len, unsigned char *bytes_out, size_t len, size_t *written)

Create a P2PKH scriptSig from a pubkey and DER signature plus sighash.

Parameters:

• pub_key – The public key to create a scriptSig with.

• pub_key_len – Length of pub_key in bytes. Must be EC_PUBLIC_KEY_LEN EC_PUBLIC_KEY_UNCOMPRESSED_LEN.

• sig – The DER encoded signature to create a scriptSig, with the sighash byte appended to it.

• sig_len – The length of sig in bytes.

• bytes_out – Destination for the resulting scriptSig.

• len – Size of bytes_out. Passing WALLY_SCRIPTSIG_P2PKH_MAX_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_witness_p2wpkh_from_der(const unsigned char *pub_key, size_t pub_key_len, const unsigned char *sig, size_t sig_len, struct wally_tx_witness_stack **witness)

Create a P2WPKH witness from a pubkey and DER signature plus sighash.

Parameters:

• pub_key – The public key to create a witness with.

• pub_key_len – Length of pub_key in bytes. Must be EC_PUBLIC_KEY_LEN EC_PUBLIC_KEY_UNCOMPRESSED_LEN.

• sig – The DER encoded signature to create a witness, with the sighash byte appended to it.

• sig_len – The length of sig in bytes.

• witness – Destination for the newly created witness.

Returns:

See Error Codes

int wally_witness_p2tr_from_sig(const unsigned char *sig, size_t sig_len, struct wally_tx_witness_stack **witness)

Create a P2TR keyspend witness from a BIP340 signature plus optional sighash.

Parameters:

• sig – The BIP340-encoded keyspend signature, including a sighash byte for non WALLY_SIGHASH_DEFAULT sighashes.

• sig_len – The length of sig in bytes. Must be 64 or 65.

• witness – Destination for the newly created witness.

Returns:

See Error Codes

int wally_scriptpubkey_op_return_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create an OP_RETURN scriptPubkey.

Parameters:

• bytes – Bytes to create a scriptPubkey for.

• bytes_len – Length of bytes in bytes. Must be less than or equal to WALLY_MAX_OP_RETURN_LEN.

• flags – Currently unused, must be 0.

• bytes_out – Destination for the resulting scriptPubkey.

• len – Size of bytes_out. Passing WALLY_SCRIPTPUBKEY_OP_RETURN_MAX_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_scriptpubkey_p2sh_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a P2SH scriptPubkey.

Parameters:

• bytes – Bytes to create a scriptPubkey for. If WALLY_SCRIPT_HASH160 is given, bytes is a redeem script to hash160 before creating the P2SH. Otherwise, bytes_len must be HASH160_LEN and bytes must contain the hash160 to use.

• bytes_len – Length of bytes in bytes.

• flags – WALLY_SCRIPT_HASH160 or 0.

• bytes_out – Destination for the resulting scriptPubkey.

• len – Size of bytes_out. Passing WALLY_SCRIPTPUBKEY_P2SH_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_scriptpubkey_multisig_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t threshold, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a multisig scriptPubkey.

Parameters:

• bytes – Compressed public keys to create a scriptPubkey from.

• bytes_len – Length of bytes in bytes. Must be a multiple of EC_PUBLIC_KEY_LEN.

• threshold – The number of signatures that must match to satisfy the script.

• flags – Must be WALLY_SCRIPT_MULTISIG_SORTED for BIP67 sorting or 0.

• bytes_out – Destination for the resulting scriptPubkey.

• len – The length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Note

A maximum of 15 keys are allowed to be passed.

Returns:

See Variable Length Output Buffers

int wally_scriptsig_multisig_from_bytes(const unsigned char *script, size_t script_len, const unsigned char *bytes, size_t bytes_len, const uint32_t *sighash, size_t sighash_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a multisig scriptSig.

Parameters:

• script – The redeem script this scriptSig provides signatures for.

• script_len – The length of script in bytes.

• bytes – Compact signatures to place in the scriptSig.

• bytes_len – Length of bytes in bytes. Must be a multiple of EC_SIGNATURE_LEN.

• sighash – WALLY_SIGHASH_ flags for each signature in bytes.

• sighash_len – The number of sighash flags in sighash.

• flags – Must be zero.

• bytes_out – Destination for the resulting scriptSig.

• len – The length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_witness_multisig_from_bytes(const unsigned char *script, size_t script_len, const unsigned char *bytes, size_t bytes_len, const uint32_t *sighash, size_t sighash_len, uint32_t flags, struct wally_tx_witness_stack **witness)

Create a multisig scriptWitness.

Parameters:

• script – The witness script this scriptWitness provides signatures for.

• script_len – The length of script in bytes.

• bytes – Compact signatures to place in the scriptWitness.

• bytes_len – Length of bytes in bytes. Must be a multiple of EC_SIGNATURE_LEN.

• sighash – WALLY_SIGHASH_ flags for each signature in bytes.

• sighash_len – The number of sighash flags in sighash.

• flags – Must be zero.

• witness – Destination for newly allocated witness.

Returns:

See Error Codes

int wally_scriptpubkey_csv_2of2_then_1_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t csv_blocks, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a CSV 2of2 multisig with a single key recovery scriptPubkey.

The resulting output can be spent at any time with both of the two keys given, and by the last (recovery) key alone, csv_blocks after the output confirms.

Parameters:

• bytes – Compressed public keys to create a scriptPubkey from. The second key given will be used as the recovery key.

• bytes_len – Length of bytes in bytes. Must 2 * EC_PUBLIC_KEY_LEN.

• csv_blocks – The number of blocks before the recovery key can be used. Must be between 17 and 65536.

• flags – Must be zero.

• bytes_out – Destination for the resulting scriptPubkey.

• len – The length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_scriptpubkey_csv_2of2_then_1_from_bytes_opt(const unsigned char *bytes, size_t bytes_len, uint32_t csv_blocks, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create an optimised CSV 2of2 multisig with a single key recovery scriptPubkey.

Works like wally_scriptpubkey_csv_2of2_then_1_from_bytes but produces a script that is smaller and compatible with the miniscript expression “and(pk(key_user),or(99@pk(key_service),older(<csv_blocks>)))”.

Returns:

See Variable Length Output Buffers

int wally_scriptpubkey_csv_blocks_from_csv_2of2_then_1(const unsigned char *bytes, size_t bytes_len, uint32_t *value_out)

Get the number of CSV blocks from a CSV 2of2 multisig scriptPubkey.

Returns the number of blocks that must have passed since confirmation of the transaction input before the recovery key alone can be used to spend the input. Can be used with scriptPubkeys generated by either wally_scriptpubkey_csv_2of2_then_1_from_bytes or wally_scriptpubkey_csv_2of2_then_1_from_bytes_opt.

Parameters:

• bytes – The scriptPubkey to fetch the CSV blocks from.

• bytes_len – Length of bytes in bytes.

• value_out – Destination for the resulting number of CSV blocks (between 17 and 65536).

Returns:

See Error Codes

int wally_script_push_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a bitcoin script that pushes data to the stack.

Parameters:

• bytes – Bytes to create a push script for.

• bytes_len – Length of bytes in bytes.

• flags – WALLY_SCRIPT_HASH160 or WALLY_SCRIPT_SHA256 to hash bytes before pushing it.

• bytes_out – Destination for the resulting push script.

• len – The length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_varint_get_length(uint64_t value, size_t *written)

Get the length of an integer serialized to a varint.

Parameters:

• value – The integer value to be find the length of.

• written – Destination for the length of the integer when serialized.

Returns:

See Error Codes

int wally_varint_to_bytes(uint64_t value, unsigned char *bytes_out, size_t len, size_t *written)

Serialize an integer to a buffer as a varint.

Parameters:

• value – The integer value to be serialized.

• bytes_out – Destination for the resulting serialized varint.

• len – The length of bytes_out in bytes. Must be at least wally_varint_get_length(value).

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_varbuff_get_length(const unsigned char *bytes, size_t bytes_len, size_t *written)

Get the length of a buffer serialized to a varbuff (varint size, followed by the buffer).

Parameters:

• bytes – The buffer to get the length of.

• bytes_len – Length of bytes in bytes.

• written – Destination for the length of the buffer when serialized.

Returns:

See Error Codes

int wally_varbuff_to_bytes(const unsigned char *bytes, size_t bytes_len, unsigned char *bytes_out, size_t len, size_t *written)

Serialize a buffer to a varbuff (varint size, followed by the buffer).

Parameters:

• bytes – The buffer to be serialized.

• bytes_len – Length of bytes in bytes.

• bytes_out – Destination for the resulting serialized varbuff.

• len – The length of bytes_out in bytes. Must be at least wally_varbuff_get_length(bytes, bytes_len).

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_witness_program_from_bytes(const unsigned char *bytes, size_t bytes_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a segwit witness program from a script or hash.

Parameters:

• bytes – Script or hash bytes to create a witness program from.

• bytes_len – Length of bytes in bytes. Must be HASH160_LEN or SHA256_LEN if neither WALLY_SCRIPT_HASH160 or WALLY_SCRIPT_SHA256 is given.

• flags – WALLY_SCRIPT_HASH160 or WALLY_SCRIPT_SHA256 to hash the input script before using it. WALLY_SCRIPT_AS_PUSH to generate a push of the generated script as used for the scriptSig in p2sh-p2wpkh and p2sh-p2wsh.

• bytes_out – Destination for the resulting witness program.

• len – Size of bytes_out. Passing WALLY_WITNESSSCRIPT_MAX_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_witness_program_from_bytes_and_version(const unsigned char *bytes, size_t bytes_len, uint32_t version, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a segwit witness program from a script or hash using witness version.

Parameters:

• bytes – Script or hash bytes to create a witness program from.

• bytes_len – Length of bytes in bytes.

• version – Witness version to create a witness program from. Specify a value of 16 or less.

• flags – WALLY_SCRIPT_HASH160 or WALLY_SCRIPT_SHA256 to hash the input script before using it. WALLY_SCRIPT_AS_PUSH to generate a push of the generated script as used for the scriptSig in p2sh-p2wpkh and p2sh-p2wsh.

• bytes_out – Destination for the resulting witness program.

• len – Size of bytes_out. Passing WALLY_WITNESSSCRIPT_MAX_LEN will ensure the buffer is large enough.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_elements_pegout_script_size(size_t genesis_blockhash_len, size_t mainchain_script_len, size_t sub_pubkey_len, size_t whitelistproof_len, size_t *written)

Get the pegout script size.

Parameters:

• genesis_blockhash_len – Length of genesis_blockhash in bytes. Must be SHA256_LEN.

• mainchain_script_len – Length of mainchain_script in bytes.

• sub_pubkey_len – Length of sub_pubkey in bytes. Must be EC_PUBLIC_KEY_LEN.

• whitelistproof_len – The length of whitelistproof in bytes.

• written – Destination for the number of bytes required to hold the pegout script.

Returns:

See Error Codes

int wally_elements_pegout_script_from_bytes(const unsigned char *genesis_blockhash, size_t genesis_blockhash_len, const unsigned char *mainchain_script, size_t mainchain_script_len, const unsigned char *sub_pubkey, size_t sub_pubkey_len, const unsigned char *whitelistproof, size_t whitelistproof_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a pegout script.

Parameters:

• genesis_blockhash – The genesis blockhash of the parent chain.

• genesis_blockhash_len – Length of genesis_blockhash in bytes. Must be SHA256_LEN.

• mainchain_script – The parent chain script.

• mainchain_script_len – Length of mainchain_script in bytes.

• sub_pubkey – The whitelisted public key.

• sub_pubkey_len – Length of sub_pubkey in bytes. Must be EC_PUBLIC_KEY_LEN.

• whitelistproof – The whitelist proof.

• whitelistproof_len – The length of whitelistproof in bytes.

• flags – Must be zero.

• bytes_out – Destination for the resulting pegout script.

• len – The length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

int wally_elements_pegin_contract_script_from_bytes(const unsigned char *redeem_script, size_t redeem_script_len, const unsigned char *script, size_t script_len, uint32_t flags, unsigned char *bytes_out, size_t len, size_t *written)

Create a script for P2CH pegin transactions.

Parameters:

• redeem_script – The federation redeem script.

• redeem_script_len – Length of redeem_script in bytes.

• script – The claim script.

• script_len – Length of script in bytes.

• flags – Must be zero.

• bytes_out – Destination for the resulting script.

• len – Length of bytes_out in bytes.

• written – Destination for the number of bytes written to bytes_out.

Returns:

See Variable Length Output Buffers

Script Constants

Script type constants

WALLY_SCRIPT_TYPE_UNKNOWN

WALLY_SCRIPT_TYPE_OP_RETURN

WALLY_SCRIPT_TYPE_P2PKH

WALLY_SCRIPT_TYPE_P2SH

WALLY_SCRIPT_TYPE_P2WPKH

WALLY_SCRIPT_TYPE_P2WSH

WALLY_SCRIPT_TYPE_MULTISIG

WALLY_SCRIPT_TYPE_P2TR

WALLY_SCRIPT_TYPE_CSV2OF2_1

WALLY_SCRIPT_TYPE_CSV2OF2_1_OPT

WALLY_SCRIPTPUBKEY_P2PKH_LEN

OP_DUP OP_HASH160 [HASH160] OP_EQUALVERIFY OP_CHECKSIG

WALLY_SCRIPTPUBKEY_P2SH_LEN

OP_HASH160 [HASH160] OP_EQUAL

WALLY_SCRIPTPUBKEY_P2WPKH_LEN

OP_0 [HASH160]

WALLY_SCRIPTPUBKEY_P2WSH_LEN

OP_0 [SHA256]

WALLY_SCRIPTPUBKEY_P2TR_LEN

OP_1 [X-ONLY-PUBKEY]

WALLY_SCRIPTPUBKEY_OP_RETURN_MAX_LEN

OP_RETURN [80 bytes of data]

WALLY_MAX_OP_RETURN_LEN

WALLY_SCRIPTSIG_P2PKH_MAX_LEN

[SIG+SIGHASH] [PUBKEY]

WALLY_SCRIPTSIG_MAX_LEN

MAX_SCRIPT_ELEMENT_SIZE from core

WALLY_WITNESSSCRIPT_MAX_LEN

(PUSH OF)0 [Up to 40 bytes of data]

WALLY_SCRIPT_VARINT_MAX_SIZE

WALLY_SCRIPT_HASH160

hash160 input bytes before using them

WALLY_SCRIPT_SHA256

sha256 input bytes before using them

WALLY_SCRIPT_AS_PUSH

Return a push of the generated script

WALLY_SCRIPT_MULTISIG_SORTED

Sort public keys (BIP67)

OP_0

OP_FALSE

OP_PUSHDATA1

OP_PUSHDATA2

OP_PUSHDATA4

OP_1NEGATE

OP_RESERVED

OP_1

OP_TRUE

OP_2

OP_3

OP_4

OP_5

OP_6

OP_7

OP_8

OP_9

OP_10

OP_11

OP_12

OP_13

OP_14

OP_15

OP_16

OP_NOP

OP_VER

OP_IF

OP_NOTIF

OP_VERIF

OP_VERNOTIF

OP_ELSE

OP_ENDIF

OP_VERIFY

OP_RETURN

OP_TOALTSTACK

OP_FROMALTSTACK

OP_2DROP

OP_2DUP

OP_3DUP

OP_2OVER

OP_2ROT

OP_2SWAP

OP_IFDUP

OP_DEPTH

OP_DROP

OP_DUP

OP_NIP

OP_OVER

OP_PICK

OP_ROLL

OP_ROT

OP_SWAP

OP_TUCK

OP_CAT

OP_SUBSTR

OP_LEFT

OP_RIGHT

OP_SIZE

OP_INVERT

OP_AND

OP_OR

OP_XOR

OP_EQUAL

OP_EQUALVERIFY

OP_RESERVED1

OP_RESERVED2

OP_1ADD

OP_1SUB

OP_2MUL

OP_2DIV

OP_NEGATE

OP_ABS

OP_NOT

OP_0NOTEQUAL

OP_ADD

OP_SUB

OP_MUL

OP_DIV

OP_MOD

OP_LSHIFT

OP_RSHIFT

OP_BOOLAND

OP_BOOLOR

OP_NUMEQUAL

OP_NUMEQUALVERIFY

OP_NUMNOTEQUAL

OP_LESSTHAN

OP_GREATERTHAN

OP_LESSTHANOREQUAL

OP_GREATERTHANOREQUAL

OP_MIN

OP_MAX

OP_WITHIN

OP_RIPEMD160

OP_SHA1

OP_SHA256

OP_HASH160

OP_HASH256

OP_CODESEPARATOR

OP_CHECKSIG

OP_CHECKSIGVERIFY

OP_CHECKMULTISIG

OP_CHECKMULTISIGVERIFY

OP_NOP1

OP_CHECKLOCKTIMEVERIFY

OP_NOP2

OP_CHECKSEQUENCEVERIFY

OP_NOP3

OP_NOP4

OP_NOP5

OP_NOP6

OP_NOP7

OP_NOP8

OP_NOP9

OP_NOP10

OP_INVALIDOPCODE