NAME

Bitcoin::Crypto::Key::Public - Bitcoin public keys

SYNOPSIS

        use Bitcoin::Crypto::Key::Public;

        $pub = Bitcoin::Crypto::Key::Public->from_hex($asn_hex);

        # verify signature (it has to be byte string, see perlpacktut)

        $pub->verify_message(pack("a*", "Hello world"), $sig);

        # getting address from public key (p2wpkh)

        my $address = $pub->get_segwit_address();

DESCRIPTION

This class allows you to create a public key instance.

You can use a public key to:

• verify messages

• create addresses: legacy (p2pkh), compatibility (p2sh(p2wpkh)) and segwit (p2wpkh).

METHODS

from_bytes

        sig: from_bytes($class, $data)

Use this method to create a PublicKey instance from a byte string. Data $data must represent a public key in ASN X9.62 format.

Returns class instance.

new

        sig: new($class, $data)

This works exactly the same as from_bytes

to_bytes

        sig: to_bytes($self)

Does the opposite of from_bytes on a target object

from_hex

        sig: from_hex($class, $hex)

Use this method to create a public key instance from a hexadecimal number. Packs the number and runs it through from_bytes.

Returns class instance.

to_hex

        sig: to_hex($self)

Does the opposite of from_hex on a target object

set_compressed

        sig: set_compressed($self, $val)

Change key's compression state to $val (1/0). This will change the address. If $val is omitted it is set to 1.

Returns current key instance.

set_network

        sig: set_network($self, $val)

Change key's network state to $val. It can be either network name present in Bitcoin::Crypto::Network package or an instance of this class.

Returns current key instance.

verify_message

        sig: verify_message($self, $message, $signature, $algo = "sha256")

Verifies $signature against digest of $message (with $algo digest algorithm) using public key. $algo must be available in Digest package.

Returns boolean.

get_legacy_address

        sig: get_legacy_address($self)

Returns string containing Base58Check encoded public key hash (p2pkh address)

get_compat_address

        sig: get_compat_address($self)

Returns string containing Base58Check encoded script hash containing a witness program for compatibility purposes (p2sh(p2wpkh) address)

get_segwit_address

        sig: get_segwit_address($self)

Returns string containing Bech32 encoded witness program (p2wpkh address)

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:

• KeyCreate - key couldn't be created correctly

• Verify - couldn't verify the message correctly

• NetworkConfig - incomplete or corrupted network configuration

SEE ALSO

Bitcoin::Crypto::Key::Private

Bitcoin::Crypto::Network

Bitcoin::Crypto::Base58

Bitcoin::Crypto::Bech32

cpanm Bitcoin::Crypto

perl -MCPAN -e shell
install Bitcoin::Crypto