View Source BitcoinLib.Key.PublicKey (BitcoinLib v0.4.3)

Bitcoin extended public key management module

Link to this section Summary

Functions

Returns a compressed version of an uncompressed public key

Simply calls from_derivation_path and directly returns the public key whatever the outcome.any() Will crash if the index is negative or greater than 0x7FFFFFFF

Derives the nth child of a HD public key

Deserialization of a public key from its xpub version

Deserialization of a public key from its xpub version

Derives a child public key, following a derivation path

Derives an extended public key from an extended private key. Happens to be the same process as for regular keys.

Creates a public key hash

Serialization of a master public key into its xpub version

Serialization of a master public key into its xpub version

Converts the public key to an address of the type specified as the second parameter

Checks a signature against a public key

Link to this section Functions

@spec compress(<<_::520>>) :: <<_::264>>

Returns a compressed version of an uncompressed public key

examples

Examples

iex> <<0x0411DB93E1DCDB8A016B49840F8C53BC1EB68A382E97B1482ECAD7B148A6909A5CB2E0EADDFB84CCF9744464F82E160BFA9B8B64F9D4C03F999B8643F656B412A3::520>> ...> |> BitcoinLib.Key.PublicKey.compress() <<0x0211db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5c::264>>

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derive_child!(public_key, index)

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@spec derive_child!(
  %BitcoinLib.Key.PublicKey{
    chain_code: term(),
    depth: term(),
    fingerprint: term(),
    index: term(),
    key: term(),
    parent_fingerprint: term(),
    uncompressed_key: term()
  },
  integer()
) :: %BitcoinLib.Key.PublicKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term(),
  uncompressed_key: term()
}

Simply calls from_derivation_path and directly returns the public key whatever the outcome.any() Will crash if the index is negative or greater than 0x7FFFFFFF

examples

Examples

iex> public_key = %BitcoinLib.Key.PublicKey{
...>  key: <<0x252C616D91A2488C1FD1F0F172E98F7D1F6E51F8F389B2F8D632A8B490D5F6DA9::264>>,
...>  chain_code: <<0x463223AAC10FB13F291A1BC76BC26003D98DA661CB76DF61E750C139826DEA8B::256>>
...> }
...> index = 0
...> BitcoinLib.Key.PublicKey.derive_child!(public_key, index)
%BitcoinLib.Key.PublicKey{
  key: <<0x30204D3503024160E8303C0042930EA92A9D671DE9AA139C1867353F6B6664E59::264>>,
  chain_code: <<0x05AAE71D7C080474EFAAB01FA79E96F4C6CFE243237780B0DF4BC36106228E31::256>>,
  depth: 1,
  index: 0,
  parent_fingerprint: <<0x18C1259::32>>,
  fingerprint: <<0x9680603F::32>>
}
Link to this function

derive_child(public_key, index)

View Source
@spec derive_child(
  %BitcoinLib.Key.PublicKey{
    chain_code: term(),
    depth: term(),
    fingerprint: term(),
    index: term(),
    key: term(),
    parent_fingerprint: term(),
    uncompressed_key: term()
  },
  integer()
) ::
  {:ok,
   %BitcoinLib.Key.PublicKey{
     chain_code: term(),
     depth: term(),
     fingerprint: term(),
     index: term(),
     key: term(),
     parent_fingerprint: term(),
     uncompressed_key: term()
   }}
  | {:error, binary()}

Derives the nth child of a HD public key

Takes a public key, its chain code and the child's index Returns the child's public key and it's associated chain code

Inspired by https://learnmeabitcoin.com/technical/extended-keys#child-extended-key-derivation

examples

Examples

iex> public_key = %BitcoinLib.Key.PublicKey{
...>  key: <<0x252C616D91A2488C1FD1F0F172E98F7D1F6E51F8F389B2F8D632A8B490D5F6DA9::264>>,
...>  chain_code: <<0x463223AAC10FB13F291A1BC76BC26003D98DA661CB76DF61E750C139826DEA8B::256>>
...> }
...> index = 0
...> BitcoinLib.Key.PublicKey.derive_child(public_key, index)
{
  :ok,
  %BitcoinLib.Key.PublicKey{
    key: <<0x30204D3503024160E8303C0042930EA92A9D671DE9AA139C1867353F6B6664E59::264>>,
    chain_code: <<0x05AAE71D7C080474EFAAB01FA79E96F4C6CFE243237780B0DF4BC36106228E31::256>>,
    depth: 1,
    index: 0,
    parent_fingerprint: <<0x18C1259::32>>,
    fingerprint: <<0x9680603F::32>>
  }
}
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deserialize!(serialized_public_key)

View Source
@spec deserialize!(binary()) :: %BitcoinLib.Key.PublicKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term(),
  uncompressed_key: term()
}

Deserialization of a public key from its xpub version

values from https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#test-vector-1

examples

Examples

iex> "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8"
...> |> BitcoinLib.Key.PublicKey.deserialize!()
%BitcoinLib.Key.PublicKey{
  fingerprint: <<0x3442193E::32>>,
  key: <<0x339A36013301597DAEF41FBE593A02CC513D0B55527EC2DF1050E2E8FF49C85C2::264>>,
  chain_code: <<0x873DFF81C02F525623FD1FE5167EAC3A55A049DE3D314BB42EE227FFED37D508::256>>,
  depth: 0,
  index: 0,
  parent_fingerprint: <<0::32>>
}
Link to this function

deserialize(serialized_public_key)

View Source
@spec deserialize(binary()) ::
  {:ok,
   %BitcoinLib.Key.PublicKey{
     chain_code: term(),
     depth: term(),
     fingerprint: term(),
     index: term(),
     key: term(),
     parent_fingerprint: term(),
     uncompressed_key: term()
   }, :mainnet | :testnet, :bip32 | :bip49 | :bip84}
  | {:error, String.t()}

Deserialization of a public key from its xpub version

values from https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#test-vector-1

examples

Examples

iex> "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8"
...> |> BitcoinLib.Key.PublicKey.deserialize()
{
  :ok,
  %BitcoinLib.Key.PublicKey{
    fingerprint: <<0x3442193E::32>>,
    key: <<0x339A36013301597DAEF41FBE593A02CC513D0B55527EC2DF1050E2E8FF49C85C2::264>>,
    chain_code: <<0x873DFF81C02F525623FD1FE5167EAC3A55A049DE3D314BB42EE227FFED37D508::256>>,
    depth: 0,
    index: 0,
    parent_fingerprint: <<0::32>>
  },
  :mainnet,
  :bip32
}
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from_derivation_path(public_key, derivation_path)

View Source
@spec from_derivation_path(
  %BitcoinLib.Key.PublicKey{
    chain_code: term(),
    depth: term(),
    fingerprint: term(),
    index: term(),
    key: term(),
    parent_fingerprint: term(),
    uncompressed_key: term()
  },
  %BitcoinLib.Key.HD.DerivationPath{
    account: term(),
    address_index: term(),
    change: term(),
    coin_type: term(),
    purpose: term(),
    type: term()
  }
) ::
  {:ok,
   %BitcoinLib.Key.PublicKey{
     chain_code: term(),
     depth: term(),
     fingerprint: term(),
     index: term(),
     key: term(),
     parent_fingerprint: term(),
     uncompressed_key: term()
   }}

Derives a child public key, following a derivation path

examples

Examples

iex> public_key = %BitcoinLib.Key.PublicKey{
...>   key: <<0x252C616D91A2488C1FD1F0F172E98F7D1F6E51F8F389B2F8D632A8B490D5F6DA9::264>>,
...>   chain_code: <<0x463223AAC10FB13F291A1BC76BC26003D98DA661CB76DF61E750C139826DEA8B::256>>
...> }
...> {:ok, derivation_path} = BitcoinLib.Key.HD.DerivationPath.parse("M/44'/0'/0'/0/0")
...> BitcoinLib.Key.PublicKey.from_derivation_path(public_key, derivation_path)
{
  :ok,
  %BitcoinLib.Key.PublicKey{
    key: <<0x29DCAFD0D7D67B13657CC9EE7C8976E141F20F0684BF3FC83CAF068E74186BCDC::264>>,
    chain_code: <<0x162EEE68F7C3823CAF8BD2615A4A33633673CAAB66FF6F338FB0653FC59D462D::256>>,
    depth: 5,
    index: 0,
    parent_fingerprint: <<0xCA2A5281::32>>,
    fingerprint: <<0xAEAAB1AD::32>>
  }
}
Link to this function

from_private_key(private_key)

View Source
@spec from_private_key(%BitcoinLib.Key.PrivateKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term()
}) :: %BitcoinLib.Key.PublicKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term(),
  uncompressed_key: term()
}

Derives an extended public key from an extended private key. Happens to be the same process as for regular keys.

Inspired by https://learnmeabitcoin.com/technical/hd-wallets#master-private-key

examples

Examples

iex> %BitcoinLib.Key.PrivateKey{
...>   key: <<0x081549973BAFBBA825B31BCC402A3C4ED8E3185C2F3A31C75E55F423E9629AA3::264>>,
...>   chain_code: <<0x1D7D2A4C940BE028B945302AD79DD2CE2AFE5ED55E1A2937A5AF57F8401E73DD::256>>
...> }
...> |> BitcoinLib.Key.PublicKey.from_private_key()
%BitcoinLib.Key.PublicKey{
  fingerprint: <<0xED104CB8::32>>,
  key: <<0x0343B337DEC65A47B3362C9620A6E6FF39A1DDFA908ABAB1666C8A30A3F8A7CCCC::264>>,
  uncompressed_key: <<0x0443b337dec65a47b3362c9620a6e6ff39a1ddfa908abab1666c8a30a3f8a7ccccfc24a7914950b6405729a9313cec6ae5bb4a082f92d05ac49df4b6dd8387bfeb::520>>,
  chain_code: <<0x1D7D2A4C940BE028B945302AD79DD2CE2AFE5ED55E1A2937A5AF57F8401E73DD::256>>,
  depth: 0,
  index: 0,
  parent_fingerprint: <<0::32>>
}
@spec hash(%BitcoinLib.Key.PublicKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term(),
  uncompressed_key: term()
}) :: <<_::160>>

Creates a public key hash

examples

Examples

iex> %BitcoinLib.Key.PublicKey{
...>   key: <<0x02b4632d08485ff1df2db55b9dafd23347d1c47a457072a1e87be26896549a8737::264>>
...> }
...> |> BitcoinLib.Key.PublicKey.hash()
<<0x93ce48570b55c42c2af816aeaba06cfee1224fae::160>>
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serialize!(public_key, network \\ :mainnet, format \\ :bip32)

View Source
@spec serialize!(
  %BitcoinLib.Key.PublicKey{
    chain_code: term(),
    depth: term(),
    fingerprint: term(),
    index: term(),
    key: term(),
    parent_fingerprint: term(),
    uncompressed_key: term()
  },
  :mainnet | :testnet,
  :bip32 | :bip49 | :bip84
) :: binary()

Serialization of a master public key into its xpub version

values from https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#test-vector-1

examples

Examples

iex> %BitcoinLib.Key.PublicKey{
...>   key: <<0x339A36013301597DAEF41FBE593A02CC513D0B55527EC2DF1050E2E8FF49C85C2::264>>,
...>   chain_code: <<0x873DFF81C02F525623FD1FE5167EAC3A55A049DE3D314BB42EE227FFED37D508::256>>,
...>   depth: 0,
...>   index: 0,
...>   parent_fingerprint: <<0::32>>
...> }
...> |> BitcoinLib.Key.PublicKey.serialize!()
"xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8"
Link to this function

serialize(public_key, network \\ :mainnet, format \\ :bip32)

View Source
@spec serialize(
  %BitcoinLib.Key.PublicKey{
    chain_code: term(),
    depth: term(),
    fingerprint: term(),
    index: term(),
    key: term(),
    parent_fingerprint: term(),
    uncompressed_key: term()
  },
  :mainnet | :testnet,
  :bip32 | :bip49 | :bip84
) :: {:ok, binary()} | {:error, binary()}

Serialization of a master public key into its xpub version

values from https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#test-vector-1

examples

Examples

iex> %BitcoinLib.Key.PublicKey{
...>   key: <<0x339A36013301597DAEF41FBE593A02CC513D0B55527EC2DF1050E2E8FF49C85C2::264>>,
...>   chain_code: <<0x873DFF81C02F525623FD1FE5167EAC3A55A049DE3D314BB42EE227FFED37D508::256>>,
...>   depth: 0,
...>   index: 0,
...>   parent_fingerprint: <<0::32>>
...> }
...> |> BitcoinLib.Key.PublicKey.serialize()
{
  :ok,
  "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8"
}
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to_address(public_key, type \\ :p2wpkh, network \\ :mainnet)

View Source

Converts the public key to an address of the type specified as the second parameter

Defaults to bech32 address type

examples

Examples

iex> %BitcoinLib.Key.PublicKey{
...>   key: <<0x3EB181FB7B5CF63D82307188B20828B83008F2D2511E5C6EDCBE171C63DD2CBC1::264>>,
...>   chain_code: <<0x581F15490635CF8CD0AEEF556562F52C60179E0E87E0EA92977E364D949DC2E4::256>>,
...>   depth: 0x5,
...>   index: 0x0
...> }
...> |> BitcoinLib.Key.PublicKey.to_address(:p2pkh)
"1BRjWnoAVg3EASJHex5YeyDWC1zZ4CA5vc"
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validate_signature(signature, message, public_key)

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@spec validate_signature(bitstring(), bitstring(), %BitcoinLib.Key.PublicKey{
  chain_code: term(),
  depth: term(),
  fingerprint: term(),
  index: term(),
  key: term(),
  parent_fingerprint: term(),
  uncompressed_key: term()
}) :: boolean()

Checks a signature against a public key

examples

Examples

iex> message = <<0xf05750d5bd2c2b4bbbd57cb07082ba5aabb41863e33bf2cd187a9adb1443dbc3::256>>
...> public_key = %BitcoinLib.Key.PublicKey{
...>   key: <<0x03f0e5a53db9f85e5b2eecf677925ffe21dd1409bcfe9a0730404053599b0901e5::264>>
...> }
...> <<0x30440220032a1544f599bf29981851e826e8a6f7c036958ba3543cf9778a0756dfc425f6022067eec131c0d73825633c0fddce1abfb14bb26bc9e0d6e9d644a77361f74cb55c::560>>
...> |> BitcoinLib.Key.PublicKey.validate_signature(message, public_key)
true