defmodule BitcoinLib.Script.Opcodes.Crypto.Sha1 do
@moduledoc """
Based on https://en.bitcoin.it/wiki/Script
Word OP_SHA1
Opcode 161
Hex 0xa7
Input in
Output hash
The input is hashed using SHA-1.
"""
@behaviour BitcoinLib.Script.Opcode
defstruct []
alias BitcoinLib.Crypto
alias BitcoinLib.Script.Opcodes.Crypto.Sha1
@type t :: Sha1
@value 0xA7
@doc """
Returns 0xa7
## Examples
iex> BitcoinLib.Script.Opcodes.Crypto.Sha1.v()
0xa7
"""
@spec v() :: 0xA7
def v do
@value
end
@doc """
Returns <<0xa7>>
## Examples
iex> BitcoinLib.Script.Opcodes.Crypto.Sha1.encode()
<<0xa7>>
"""
@spec encode() :: <<_::8>>
def encode() do
<<@value::8>>
end
@doc """
The input is hashed using SHA-1.
## Examples
iex> pub_key = <<0x0218fb7aff2c6cb9c25b7cd9aa0b9bdd712e5617f07cb0c96bdda0b44c25a5d25f::264>>
...> %BitcoinLib.Script.Opcodes.Crypto.Sha1{}
...> |> BitcoinLib.Script.Opcodes.Crypto.Sha1.execute([pub_key, 3])
{:ok, [<<0x148bdd3eb072846d9828b2042e8391e4f6614ad2::160>>, 3]}
"""
@spec execute(Sha1.t(), [<<_::264>> | list()]) :: {:ok, [<<_::160>> | list()]}
def execute(_opcode, []), do: {:error, "trying to execute OP_SHA1 on an empty stack"}
def execute(_opcode, [first_element | remaining]) do
hash = Crypto.sha1(first_element)
{:ok, [hash | remaining]}
end
end