NAME
Bitcoin::Crypto::PSBT - Partially Signed Bitcoin Transactions
SYNOPSIS
use Bitcoin::Crypto qw(btc_psbt);
# import PSBT from a serialized form
my $psbt = btc_psbt->from_serialized([base64 => $psbt_string]);
# dump in readable format
print $psbt->dump;
# get a single PSBT field
my $field = $psbt->get_field('PSBT_GLOBAL_TX_VERSION');
# get decoded field key and value
my $key = $field->key;
my $value = $field->value;
# get all PSBT fields of a given type
my @fields = $psbt->get_all_fields('PSBT_GLOBAL_PROPRIETARY');DESCRIPTION
This is a class implementing the PSBT format as described in BIP174 and BIP370. It currently supports versions 0 and 2 of the spec. It allows serialization, deserialization, validation and access to PSBT fields. It currently does not support the roles defined by the PSBT documents, so all the operations on PSBTs (like adding inputs or creating a final transaction out of it) must be done manually.
PSBT consists of a number of maps: one global, one for each transaction input and one for each transaction output. Each map holds a number of fields. Each field has a value and can optionally have extra key data.
INTERFACE
Attributes
maps
Not assignable in the constructor
An array reference of PSBT internal maps - objects of class Bitcoin::Crypto::PSBT::Map. It should seldom be handled manually - use "get_field", "get_all_fields" and "add_field" to access fields of specific map.
Methods
new
$psbt = $class->new(%args)This is a standard Moo constructor, which can be used to create the object.
Returns class instance.
version
$version = $object->version()Returns the version of the PSBT (0 or 2).
input_count
$int = $object->input_count()Returns the number of inputs the PSBT defines.
output_count
$int = $object->output_count()Returns the number of outputs the PSBT defines.
get_field
$field = $object->get_field($field_type_name, $map_index = undef, $key = undef)Tries to get a field of $field_type_name as defined in BIP174, for example PSBT_GLOBAL_UNSIGNED_TX. If the field is from input or output maps, it also requires $map_index to be passed (0-based index of the input or output). Optional $key (a bytestring) can be provided if this PSBT field defines keys.
Returns an instance of Bitcoin::Crypto::PSBT::Field, which you can use to access key and value data.
If there isn't exactly one field with this type in the map, it will throw an exception. This allows you to write the following without checking the return value of the function:
my $output_index_0 = $object->get_field('PSBT_IN_OUTPUT_INDEX', 0)->value;See "get_all_fields" for a variant which does not check the field count.
get_all_fields
@fields = $object->get_all_fields($field_type_name, $map_index = undef, $key = undef)Same as "get_field", but will return all the fields of given type from a given map. It may be used if the field exists, or to get multiple fields with different key data.
The return value is a list (not an array), so using it in scalar context will get the last found field (as opposed to a field count).
add_field
$object = $object->add_field(%field_data)
$object = $object->add_field($field_object, $map_index = undef)Adds a new field to the PSBT. It can be run either with %field_data (a hash arguments for the "new" in Bitcoin::Crypto::PSBT::Field) or with $field_object (constructed Bitcoin::Crypto::PSBT::Field) and $map_index.
If passing %field_data hash, it can contain an additional index key to represent $map_index. The field will be constructed and added to the map. Adding the index to a map triggers its validations, so it must be complete enough to pass them. For this reason, sometimes it could be more preferable to construct and fill the field by hand before adding it to the PSBT.
Note that a field cannot be used in more than one map at a time.
list_fields
@list = $object->list_fields()This method lists all fields present in the PSBT. It returns a list of array references, each array reference has two elements: field type and map index. These are the same elements that are needed in "get_all_fields" calls, so you may use this data to loop through PSBT fields.
check
$object = $object->check()Checks the internal state of PSBT fields and throws an exception if it is invalid. Returns the object itself.
to_serialized
$serialized = $object->to_serialized()Serializes a PSBT into a bytestring. "check" is called automatically before serializing.
from_serialized
$object = $class->from_serialized($data)Deserializes the bytestring $data into a PSBT object. "check" is called automatically after deserializing.
dump
$text = $object->dump()Returns a readable description of all the maps in the PSBT.
FIELD REFERENCE
Just for reference, here is a list of all PSBT fields which are currently supported by this module. This list is auto-generated from "key_data" in Bitcoin::Crypto::PSBT::FieldType and Bitcoin::Crypto::PSBT::FieldType/value_data (which contain short strings with description of field content).
For a list of PSBT fields, see BIP174.
Global map
PSBT_GLOBAL_UNSIGNED_TX
Key data: <none>
Value data: Bitcoin::Crypto::Transaction object
PSBT_GLOBAL_XPUB
Key data: Bitcoin::Crypto::Key::ExtPublic object
Value data: Array reference, where the first item is a fingerprint and the second item is Bitcoin::Crypto::DerivationPath
PSBT_GLOBAL_TX_VERSION
Key data: <none>
Value data: 32-bit positive integer value
PSBT_GLOBAL_FALLBACK_LOCKTIME
Key data: <none>
Value data: 32-bit positive integer value
PSBT_GLOBAL_INPUT_COUNT
Key data: <none>
Value data: Positive integer value
PSBT_GLOBAL_OUTPUT_COUNT
Key data: <none>
Value data: Positive integer value
PSBT_GLOBAL_TX_MODIFIABLE
Key data: <none>
Value data: Hash reference with flags: inputs_modifiable, outputs_modifiable, has_sighash_single
Input map
PSBT_IN_NON_WITNESS_UTXO
Key data: <none>
Value data: Bitcoin::Crypto::Transaction object
PSBT_IN_WITNESS_UTXO
Key data: <none>
Value data: Bitcoin::Crypto::Transaction::Output object
PSBT_IN_PARTIAL_SIG
Key data: Bitcoin::Crypto::Key::Public object
Value data: Bytestring value
PSBT_IN_SIGHASH_TYPE
Key data: <none>
Value data: 32-bit positive integer value
PSBT_IN_REDEEM_SCRIPT
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_IN_WITNESS_SCRIPT
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_IN_BIP32_DERIVATION
Key data: Bitcoin::Crypto::Key::Public object
Value data: Array reference, where the first item is a fingerprint and the second item is Bitcoin::Crypto::DerivationPath
PSBT_IN_FINAL_SCRIPTSIG
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_IN_FINAL_SCRIPTWITNESS
Key data: <none>
Value data: Bytestring value
PSBT_IN_POR_COMMITMENT
Key data: <none>
Value data: Bytestring value
PSBT_IN_RIPEMD160
Key data: Bytestring value
Value data: Bytestring value
PSBT_IN_SHA256
Key data: Bytestring value
Value data: Bytestring value
PSBT_IN_HASH160
Key data: Bytestring value
Value data: Bytestring value
PSBT_IN_HASH256
Key data: Bytestring value
Value data: Bytestring value
PSBT_IN_PREVIOUS_TXID
Key data: <none>
Value data: Bytestring value
PSBT_IN_OUTPUT_INDEX
Key data: <none>
Value data: 32-bit positive integer value
PSBT_IN_SEQUENCE
Key data: <none>
Value data: 32-bit positive integer value
PSBT_IN_REQUIRED_TIME_LOCKTIME
Key data: <none>
Value data: 32-bit positive integer value
PSBT_IN_REQUIRED_HEIGHT_LOCKTIME
Key data: <none>
Value data: 32-bit positive integer value
PSBT_IN_TAP_KEY_SIG
Key data: <none>
Value data: Bytestring value
PSBT_IN_TAP_SCRIPT_SIG
Key data: Array reference, where the first item is Bitcoin::Crypto::Key::Public and second element is a leaf hash bytestring
Value data: Bytestring value
PSBT_IN_TAP_LEAF_SCRIPT
Key data: Instance of Bitcoin::Crypto::Transaction::ControlBlock
Value data: Array reference, where the first item is Bitcoin::Crypto::Script and second element is a leaf version number
PSBT_IN_TAP_BIP32_DERIVATION
Key data: Bitcoin::Crypto::Key::Public object
Value data: Array reference, where first item is an array of leaf hashes, second element is a fingerprint and the third element is Bitcoin::Crypto::DerivationPath
PSBT_IN_TAP_INTERNAL_KEY
Key data: <none>
Value data: Bitcoin::Crypto::Key::Public object
PSBT_IN_TAP_MERKLE_ROOT
Key data: <none>
Value data: Bytestring value
Output map
PSBT_OUT_REDEEM_SCRIPT
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_OUT_WITNESS_SCRIPT
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_OUT_BIP32_DERIVATION
Key data: Bitcoin::Crypto::Key::Public object
Value data: Array reference, where the first item is a fingerprint and the second item is Bitcoin::Crypto::DerivationPath
PSBT_OUT_AMOUNT
Key data: <none>
Value data: Math::BigInt object
PSBT_OUT_SCRIPT
Key data: <none>
Value data: Bitcoin::Crypto::Script object
PSBT_OUT_TAP_INTERNAL_KEY
Key data: <none>
Value data: Bitcoin::Crypto::Key::Public object
PSBT_OUT_TAP_TREE
Key data: <none>
Value data: Bitcoin::Crypto::Script::Tree instance
PSBT_OUT_TAP_BIP32_DERIVATION
Key data: Bitcoin::Crypto::Key::Public object
Value data: Array reference, where first item is an array of leaf hashes, second element is a fingerprint and the third element is Bitcoin::Crypto::DerivationPath
EXCEPTIONS
This module throws an instance of Bitcoin::Crypto::Exception if it encounters an error. It can produce the following error types from the Bitcoin::Crypto::Exception namespace:
PSBT - general error with the PSBT