Class: BTC::Script

Inherits:
Object
  • Object
show all
Includes:
Opcodes
Defined in:
lib/btcruby/script/script.rb

Constant Summary

Constants included from Opcodes

Opcodes::OPCODE_NAME_TO_VALUE, Opcodes::OPCODE_VALUE_TO_NAME, Opcodes::OP_0, Opcodes::OP_0NOTEQUAL, Opcodes::OP_1, Opcodes::OP_10, Opcodes::OP_11, Opcodes::OP_12, Opcodes::OP_13, Opcodes::OP_14, Opcodes::OP_15, Opcodes::OP_16, Opcodes::OP_1ADD, Opcodes::OP_1NEGATE, Opcodes::OP_1SUB, Opcodes::OP_2, Opcodes::OP_2DIV, Opcodes::OP_2DROP, Opcodes::OP_2DUP, Opcodes::OP_2MUL, Opcodes::OP_2OVER, Opcodes::OP_2ROT, Opcodes::OP_2SWAP, Opcodes::OP_3, Opcodes::OP_3DUP, Opcodes::OP_4, Opcodes::OP_5, Opcodes::OP_6, Opcodes::OP_7, Opcodes::OP_8, Opcodes::OP_9, Opcodes::OP_ABS, Opcodes::OP_ADD, Opcodes::OP_AND, Opcodes::OP_BOOLAND, Opcodes::OP_BOOLOR, Opcodes::OP_CAT, Opcodes::OP_CHECKLOCKTIMEVERIFY, Opcodes::OP_CHECKMULTISIG, Opcodes::OP_CHECKMULTISIGVERIFY, Opcodes::OP_CHECKSIG, Opcodes::OP_CHECKSIGVERIFY, Opcodes::OP_CODESEPARATOR, Opcodes::OP_DEPTH, Opcodes::OP_DIV, Opcodes::OP_DROP, Opcodes::OP_DUP, Opcodes::OP_ELSE, Opcodes::OP_ENDIF, Opcodes::OP_EQUAL, Opcodes::OP_EQUALVERIFY, Opcodes::OP_FALSE, Opcodes::OP_FROMALTSTACK, Opcodes::OP_GREATERTHAN, Opcodes::OP_GREATERTHANOREQUAL, Opcodes::OP_HASH160, Opcodes::OP_HASH256, Opcodes::OP_IF, Opcodes::OP_IFDUP, Opcodes::OP_INVALIDOPCODE, Opcodes::OP_INVERT, Opcodes::OP_LEFT, Opcodes::OP_LESSTHAN, Opcodes::OP_LESSTHANOREQUAL, Opcodes::OP_LSHIFT, Opcodes::OP_MAX, Opcodes::OP_MIN, Opcodes::OP_MOD, Opcodes::OP_MUL, Opcodes::OP_NEGATE, Opcodes::OP_NIP, Opcodes::OP_NOP, Opcodes::OP_NOP1, Opcodes::OP_NOP10, Opcodes::OP_NOP2, Opcodes::OP_NOP3, Opcodes::OP_NOP4, Opcodes::OP_NOP5, Opcodes::OP_NOP6, Opcodes::OP_NOP7, Opcodes::OP_NOP8, Opcodes::OP_NOP9, Opcodes::OP_NOT, Opcodes::OP_NOTIF, Opcodes::OP_NUMEQUAL, Opcodes::OP_NUMEQUALVERIFY, Opcodes::OP_NUMNOTEQUAL, Opcodes::OP_OR, Opcodes::OP_OVER, Opcodes::OP_PICK, Opcodes::OP_PUSHDATA1, Opcodes::OP_PUSHDATA2, Opcodes::OP_PUSHDATA4, Opcodes::OP_RESERVED, Opcodes::OP_RESERVED1, Opcodes::OP_RESERVED2, Opcodes::OP_RETURN, Opcodes::OP_RIGHT, Opcodes::OP_RIPEMD160, Opcodes::OP_ROLL, Opcodes::OP_ROT, Opcodes::OP_RSHIFT, Opcodes::OP_SHA1, Opcodes::OP_SHA256, Opcodes::OP_SIZE, Opcodes::OP_SUB, Opcodes::OP_SUBSTR, Opcodes::OP_SWAP, Opcodes::OP_TOALTSTACK, Opcodes::OP_TRUE, Opcodes::OP_TUCK, Opcodes::OP_VER, Opcodes::OP_VERIF, Opcodes::OP_VERIFY, Opcodes::OP_VERNOTIF, Opcodes::OP_WITHIN, Opcodes::OP_XOR

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hex: nil, data: nil, op_return: nil, public_keys: nil, signatures_required: nil) ⇒ Script

raw script data in hex



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# File 'lib/btcruby/script/script.rb', line 21

def initialize(hex: nil, # raw script data in hex
               data: nil, # raw script data in binary
               op_return: nil, # binary string for OP_RETURN script (or array of binary string)
               public_keys: nil, signatures_required: nil # multisig
               )
  if data || hex
    data ||= BTC.from_hex(hex)
    data = BTC::Data.ensure_binary_encoding(data)
    @chunks = []
    offset = 0
    while offset < data.bytesize
      chunk = ScriptChunk.with_data(data, offset: offset)
      if !chunk.canonical?
        Diagnostics.current.add_message("BTC::Script: decoded non-canonical chunk at offset #{offset}: #{chunk.to_s}")
      end
      offset += chunk.size
      @chunks << chunk
    end
  elsif op_return
    @chunks = []
    self << OP_RETURN << op_return
  elsif public_keys || signatures_required
    if !public_keys || public_keys.size < 1
      raise ArgumentError, "Public keys must be an array of at least 1 pubkey"
    end
    if !signatures_required || signatures_required < 1
      raise ArgumentError, "Number of required signatures must be greater than zero"
    end
    if signatures_required > public_keys.size
      raise ArgumentError, "Number of required signatures must not exceed number of pubkeys."
    end
    if public_keys.size > 16
      raise ArgumentError, "Maximum number of public keys exceeded (16)"
    end

    n_opcode = Opcode.opcode_for_small_integer(public_keys.size)
    m_opcode = Opcode.opcode_for_small_integer(signatures_required)

    @chunks = []
    self << m_opcode << public_keys << n_opcode << OP_CHECKMULTISIG
  else
    # Empty script
    @chunks = []
  end
end

Instance Attribute Details

#chunks ⇒ Object (readonly)

Returns an array of chunks that constitute the script.



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# File 'lib/btcruby/script/script.rb', line 19

def chunks
  @chunks
end

#data ⇒ Object (readonly)

Serialized binary form of the script (payload)



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# File 'lib/btcruby/script/script.rb', line 6

def data
  @data
end

#multisig_public_keys ⇒ Object (readonly)

List of public keys if it is a multisig script. If it is not a multisig script, returns nil. See also #multisig_script?



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# File 'lib/btcruby/script/script.rb', line 11

def multisig_public_keys
  @multisig_public_keys
end

#multisig_signatures_required ⇒ Object (readonly)

Number of signatures required if it is a multisig script. If it is not a multisig script, returns nil. See also #multisig_script?



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# File 'lib/btcruby/script/script.rb', line 16

def multisig_signatures_required
  @multisig_signatures_required
end

Class Method Details

.encode_pushdata(pushdata, opcode: nil) ⇒ Object

If opcode is nil, then the most compact encoding will be chosen. Returns nil if opcode can’t be used for data, or data is nil or too big.

Raises:

  • (ArgumentError) 


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# File 'lib/btcruby/script/script.rb', line 513

def self.encode_pushdata(pushdata, opcode: nil)
  raise ArgumentError, "Pushdata is missing" if !pushdata
  if pushdata.bytesize < OP_PUSHDATA1 && opcode == nil
    return BTC::WireFormat.encode_uint8(pushdata.bytesize) + pushdata
  elsif pushdata.bytesize < 0xff && (opcode == nil || opcode == OP_PUSHDATA1)
    return BTC::WireFormat.encode_uint8(OP_PUSHDATA1) +
           BTC::WireFormat.encode_uint8(pushdata.bytesize) +
           pushdata
  elsif pushdata.bytesize < 0xffff && (opcode == nil || opcode == OP_PUSHDATA2)
    return BTC::WireFormat.encode_uint8(OP_PUSHDATA2) +
           BTC::WireFormat.encode_uint16le(pushdata.bytesize) +
           pushdata
  elsif pushdata.bytesize < 0xffffffff && (opcode == nil || opcode == OP_PUSHDATA4)
     return BTC::WireFormat.encode_uint8(OP_PUSHDATA4) +
            BTC::WireFormat.encode_uint32le(pushdata.bytesize) +
            pushdata
  else
    raise ArgumentError, "Invalid opcode or data is too big"
  end
end

.multisig(public_keys: [], signatures_required: 0) ⇒ Object

Initializes a multisignature script “OP_<M> <pubkey1> … <pubkeyN> OP_<N> OP_CHECKMULTISIG” N must be >= M, M and N should be from 1 to 16. If you need a more customized transaction with OP_CHECKMULTISIG, create it using other methods. public_keys is an array of binary strings.



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# File 'lib/btcruby/script/script.rb', line 71

def self.multisig(public_keys: [], signatures_required: 0)
  self.new(public_keys: public_keys, signatures_required: signatures_required)
end

.simulated_compressed_pubkey ⇒ Object

Returns a dummy compressed pubkey (33 bytes).



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# File 'lib/btcruby/script/script.rb', line 375

def self.simulated_compressed_pubkey
  "\x02" + "\xff"*32
end

.simulated_multisig_script(m, n) ⇒ Object

Returns a dummy script that simulates m-of-n multisig script



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# File 'lib/btcruby/script/script.rb', line 380

def self.simulated_multisig_script(m,n)
  self.new <<
    Opcode.opcode_for_small_integer(m) <<
    [simulated_uncompressed_pubkey]*n  << # assuming non-compressed pubkeys to be conservative
    Opcode.opcode_for_small_integer(n) <<
    OP_CHECKMULTISIG
end

.simulated_signature(hashtype: nil) ⇒ Object

Returns a simulated signature with an optional hashtype byte attached



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# File 'lib/btcruby/script/script.rb', line 365

def self.simulated_signature(hashtype: nil)
  "\x30" + "\xff"*71 + (hashtype ? WireFormat.encode_uint8(hashtype) : "")
end

.simulated_uncompressed_pubkey ⇒ Object

Returns a dummy uncompressed pubkey (65 bytes).



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# File 'lib/btcruby/script/script.rb', line 370

def self.simulated_uncompressed_pubkey
  "\x04" + "\xff"*64
end

Instance Method Details

#+(other) ⇒ Object

Returns a new instance with concatenation of two scripts.



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# File 'lib/btcruby/script/script.rb', line 468

def +(other)
  self.dup << other
end

#<<(object) ⇒ Object 



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# File 'lib/btcruby/script/script.rb', line 463

def <<(object)
  append(object)
end

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/btcruby/script/script.rb', line 302

def ==(other)
  return false if other == nil
  self.data == other.data
end

#append(object) ⇒ Object

Appends an opcode (Integer), pushdata (String) or Script and returns self. If Array is passed, this method is recursively called for each element in the array.



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# File 'lib/btcruby/script/script.rb', line 442

def append(object)
  if object.is_a?(BTC::Script)
    append_script(object)
  elsif object.is_a?(BTC::ScriptNumber)
    append_pushdata(object.data)
  elsif object.is_a?(Integer)
    append_opcode(object)
  elsif object.is_a?(String)
    append_pushdata(object.b)
  elsif object.is_a?(Array)
    object.each do |element|
      self << element
    end
  elsif object.is_a?(ScriptChunk)
    @chunks << object
  else
    raise ArgumentError, "Operand must be an integer, a string a BTC::Script instance or an array of any of those."
  end
  return self
end

#append_opcode(opcode) ⇒ Object

Appends a non-pushdata opcode to the script.

Raises:

  • (ArgumentError) 


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# File 'lib/btcruby/script/script.rb', line 393

def append_opcode(opcode)
  raise ArgumentError, "Invalid opcode value." if opcode > 0xff || opcode < 0
  if opcode > 0 && opcode <= OP_PUSHDATA4
    raise ArgumentError, "Cannot add pushdata opcode without data"
  end
  @chunks << ScriptChunk.new(opcode.chr)
  return self
end

#append_pushdata(data, opcode: nil) ⇒ Object

Appends a pushdata opcode with the most compact encoding. Optional opcode may be equal to OP_PUSHDATA1, OP_PUSHDATA2, or OP_PUSHDATA4. ArgumentError is raised if opcode does not represent a given data length.

Raises:

  • (ArgumentError) 


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# File 'lib/btcruby/script/script.rb', line 405

def append_pushdata(data, opcode: nil)
  raise ArgumentError, "No data provided" if !data
  encoded_pushdata = self.class.encode_pushdata(data, opcode: opcode)
  if !encoded_pushdata
    raise ArgumentError, "Cannot encode pushdata with opcode #{opcode}"
  end
  @chunks << ScriptChunk.new(encoded_pushdata)
  return self
end

#append_script(script) ⇒ Object

Appends script to the current script.

Raises:

  • (ArgumentError) 


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# File 'lib/btcruby/script/script.rb', line 434

def append_script(script)
  raise ArgumentError, "No script is given" if !script
  @chunks += script.chunks
  return self
end

#data_only? ⇒ Boolean

Returns true if the script consists of push data operations only (including OP_<N>). Aka isPushOnly in BitcoinQT. Used in BIP16 (P2SH) implementation.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 267

def data_only?
  # Include PUSHDATA ops and OP_0..OP_16 literals.
  @chunks.each do |chunk|
    return false if !chunk.data_only?
  end
  return true
end

#delete_opcode(opcode) ⇒ Object

Removes all occurences of opcode. Typically it’s OP_CODESEPARATOR.



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# File 'lib/btcruby/script/script.rb', line 416

def delete_opcode(opcode)
  @chunks = @chunks.inject([]) do |list, chunk|
    list << chunk if chunk.opcode != opcode
    list
  end
  return self
end

#delete_pushdata(pushdata) ⇒ Object

Removes all occurences of a given pushdata.



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# File 'lib/btcruby/script/script.rb', line 425

def delete_pushdata(pushdata)
  @chunks = @chunks.inject([]) do |list, chunk|
    list << chunk if chunk.pushdata != pushdata
    list
  end
  return self
end

#detect_multisig ⇒ Object 



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# File 'lib/btcruby/script/script.rb', line 539

def detect_multisig
  # multisig script must have at least 4 ops ("OP_1 <pubkey> OP_1 OP_CHECKMULTISIG")
  return false if @chunks.size < 4
  return false if @chunks.last.opcode != OP_CHECKMULTISIG

  m_chunk = @chunks[0]
  n_chunk = @chunks[-2]
  m_opcode = m_chunk.opcode
  n_opcode = n_chunk.opcode

  m = Opcode.small_integer_from_opcode(m_opcode)
  n = Opcode.small_integer_from_opcode(n_opcode)

  # If m or n is not OP_<int>, but a pushdata with little-endian bignum.
  if !m
    return false if !m_chunk.pushdata?
    m = BTC::BigNumber.new(signed_little_endian: m_chunk.pushdata).integer
  end

  if !n
    return false if !n_chunk.pushdata?
    n = BTC::BigNumber.new(signed_little_endian: n_chunk.pushdata).integer
  end

  return false if m < 1 || n < 1 || m > n

  # We must have correct number of pubkeys in the script. 3 extra ops: OP_<M>, OP_<N> and OP_CHECKMULTISIG
  return false if @chunks.size != (3 + n)

  pubkeys = []
  @chunks[1, n].each do |chunk|
    return false if !chunk.pushdata? || chunk.pushdata.bytesize == 0
    pubkeys << chunk.pushdata
  end

  # Now we extracted all pubkeys and verified the numbers.
  @multisig_public_keys = pubkeys
  @multisig_signatures_required = m
  return true
end

#detect_multisig_if_needed ⇒ Object 



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# File 'lib/btcruby/script/script.rb', line 534

def detect_multisig_if_needed
  return if @is_multisig != nil
  @is_multisig = detect_multisig
end

#dropped_prefix_data ⇒ Object

Returns pushdata if script starts with <pushdata> OP_DROP Returns nil if the script starts with some other opcodes or shorter than 2 opcodes.



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# File 'lib/btcruby/script/script.rb', line 248

def dropped_prefix_data
  if @chunks.size >= 2 && @chunks[0].pushdata? && @chunks[1].opcode == OP_DROP
    return @chunks[0].pushdata
  end
  nil
end

#dup ⇒ Object

Complete copy of a script.



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# File 'lib/btcruby/script/script.rb', line 298

def dup
  Script.new(data: self.data)
end

#find_and_delete(subscript) ⇒ Object

Removes chunks matching subscript byte-for-byte and returns a new script instance with subscript removed. So if pushdata items are encoded differently, they won’t match. Consensus-critical code.



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# File 'lib/btcruby/script/script.rb', line 481

def find_and_delete(subscript)
  subscript.is_a?(Script) or raise ArgumentError,"Argument must be an instance of BTC::Script"
  # Replacing [a b a]
  # Script: a b b a b a b a c
  # Result: a b b       b a c
  subscriptsize = subscript.chunks.size
  buf = []
  i = 0
  result = Script.new
  chunks.each do |chunk|
    if chunk == subscript.chunks[i]
      buf << chunk
      i+=1
      if i == subscriptsize # matched the whole subscript
        i = 0
        buf.clear
      end
    else
      i = 0
      result << buf
      result << chunk
    end
  end
  result
end

#inspect ⇒ Object 



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# File 'lib/btcruby/script/script.rb', line 308

def inspect
  %{#<#{self.class.name} #{to_s.inspect} (#{self.data.bytesize} bytes)>}
end

#multisig_script? ⇒ Boolean

Returns true if the script is in form “<M> <pubkey1> … <pubkeyN> <N> OP_CHECKMULTISIG”

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 178

def multisig_script?
  detect_multisig_if_needed
  @is_multisig
end

#op_return_data ⇒ Object

Returns first data chunk if this script is ‘OP_RETURN <data>’. Otherwise returns nil.



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# File 'lib/btcruby/script/script.rb', line 221

def op_return_data
  return nil if !op_return_data_only_script?
  return @chunks[1].pushdata
end

#op_return_data_only_script? ⇒ Boolean

Returns true if this script is of form ‘OP_RETURN <data>’

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 213

def op_return_data_only_script?
  return @chunks.size >= 2 &&
         @chunks[0].opcode == OP_RETURN &&
         @chunks[1..-1].all?{|c| c.pushdata? }
end

#op_return_items ⇒ Object

Returns all data chunks if this script is ‘OP_RETURN <data> [<data>…]’ Most commonly returned array contains one binary string.



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# File 'lib/btcruby/script/script.rb', line 228

def op_return_items
  return nil if !op_return_data_only_script?
  return @chunks[1, @chunks.size-1].map{|c| c.pushdata}
end

#op_return_script? ⇒ Boolean

Returns true if this script’s first opcode is OP_RETURN.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 207

def op_return_script?
  return @chunks.size >= 1 &&
         @chunks[0].opcode == OP_RETURN
end

#open_assets_marker? ⇒ Boolean

Returns true if this script may be a valid OpenAssets marker. Only checks the prefix and minimal length, does not validate the content. Use this method to quickly filter out non-asset transactions.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 236

def open_assets_marker?
  return false if !op_return_data_only_script?
  data = op_return_data
  return false if !data || data.bytesize < 6
  if data[0, AssetMarker::PREFIX_V1.bytesize] == AssetMarker::PREFIX_V1
    return true
  end
  false
end

#p2pk? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 110

def p2pk?
  return public_key_script?
end

#p2pkh? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 130

def p2pkh?
  return public_key_hash_script?
end

#p2sh? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 148

def p2sh?
  return script_hash_script?
end

#p2sh_script ⇒ Object

Wraps the recipient into an output P2SH script (OP_HASH160 <20-byte hash of the recipient> OP_EQUAL).



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# File 'lib/btcruby/script/script.rb', line 334

def p2sh_script
  Script.new << OP_HASH160 << BTC.hash160(self.data) << OP_EQUAL
end

#public_key ⇒ Object

Returns a raw public key if this script is public_key_script?



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# File 'lib/btcruby/script/script.rb', line 115

def public_key
  @chunks[0] && @chunks[0].pushdata
end

#public_key_hash ⇒ Object

Returns public key hash if this script is public_key_hash_script?



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# File 'lib/btcruby/script/script.rb', line 135

def public_key_hash
  @chunks[2] && @chunks[2].pushdata
end

#public_key_hash_script? ⇒ Boolean

Returns true if the script is a P2PKH script: “OP_DUP OP_HASH160 <20-byte hash> OP_EQUALVERIFY OP_CHECKSIG”

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 121

def public_key_hash_script?
  return false if @chunks.size != 5
  return @chunks[0].opcode == OP_DUP &&
         @chunks[1].opcode == OP_HASH160 &&
         @chunks[2].size == 21 &&
         @chunks[3].opcode == OP_EQUALVERIFY &&
         @chunks[4].opcode == OP_CHECKSIG
end

#public_key_script? ⇒ Boolean

Returns true if the script is a pay-to-pubkey script: “<pubkey> OP_CHECKSIG”

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 103

def public_key_script?
  return false if @chunks.size != 2
  return @chunks[0].pushdata? &&
         @chunks[0].pushdata.size >= 33 &&
         @chunks[1].opcode == OP_CHECKSIG
end

#script_hash ⇒ Object

Returns p2sh hash if this script is script_hash_script?



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# File 'lib/btcruby/script/script.rb', line 153

def script_hash
  @chunks[1] && @chunks[1].pushdata
end

#script_hash_script? ⇒ Boolean

Returns true if the script is a P2SH script: “OP_HASH160 <20-byte hash> OP_EQUAL”

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 141

def script_hash_script?
  return false if @chunks.size != 3
  return @chunks[0].opcode == OP_HASH160 &&
         @chunks[1].size == 21 &&
         @chunks[2].opcode == OP_EQUAL
end

#simulated_signature_script(strict: true) ⇒ Object

Returns a dummy script matching this script on the input with the same size as an intended signature script. Only a few standard script types are supported. Set strict to false to allow imprecise guess for P2SH script. Returns nil if could not determine a matching script.



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# File 'lib/btcruby/script/script.rb', line 344

def simulated_signature_script(strict: true)
  if public_key_hash_script?
     # assuming non-compressed pubkeys to be conservative
    return Script.new << Script.simulated_signature(hashtype: SIGHASH_ALL) << Script.simulated_uncompressed_pubkey

  elsif public_key_script?
    return Script.new << Script.simulated_signature(hashtype: SIGHASH_ALL)

  elsif script_hash_script? && !strict
    # This is a wild approximation, but works well if most p2sh scripts are 2-of-3 multisig scripts.
    # If you have a very particular smart contract scheme you should not use TransactionBuilder which estimates fees this way.
    return Script.new << OP_0 << [Script.simulated_signature(hashtype: SIGHASH_ALL)]*2 << Script.simulated_multisig_script(2,3).data

  elsif multisig_script?
    return Script.new << OP_0 << [Script.simulated_signature(hashtype: SIGHASH_ALL)]*self.multisig_signatures_required
  else
    return nil
  end
end

#standard? ⇒ Boolean

Returns true if this is a standard script As of September 2014, standard = public_key_hash_script? ||

p2sh_script? ||
standard_multisig_script? ||
public_key_script? ||
standard_op_return_script?

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 85

def standard?
  public_key_hash_script? ||
  script_hash_script? ||
  standard_multisig_script? ||
  public_key_script? ||
  standard_op_return_script?
end

#standard_address(network: nil) ⇒ Object

Returns BTC::PublicKeyAddress or BTC::ScriptHashAddress if the script is a standard output script for these addresses. If the script is something different, returns nil.



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# File 'lib/btcruby/script/script.rb', line 321

def standard_address(network: nil)
  if public_key_hash_script?
    return BTC::PublicKeyAddress.new(hash: @chunks[2].pushdata, network: network)
  elsif script_hash_script?
    return BTC::ScriptHashAddress.new(hash: @chunks[1].pushdata, network: network)
  elsif public_key_script?
    return BTC::PublicKeyAddress.new(hash: BTC.hash160(@chunks[0].pushdata), network: network)
  end
  nil
end

#standard_multisig_script? ⇒ Boolean

Returns true if the script is “OP_<M> <pubkey1> … <pubkeyN> OP_<N> OP_CHECKMULTISIG” where N is up to 15. Scripts with up to 15 signatures are considered standard and relayed quickly, but you are allowed to create more complex ones.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 161

def standard_multisig_script?
  return false if !multisig_script?

  # Check chunks directly so we make sure OP_<N> are used, not pushdata.
  # Bitcoin allows encoding multisig N and M parameters as pushdata
  # (which will be interpreted as a little-endian bignum)
  m_opcode = @chunks[0].opcode
  n_opcode = @chunks[-2].opcode
  if n_opcode >= OP_1 && n_opcode <= OP_15
    if m_opcode >= OP_1 && m_opcode <= n_opcode
      return true
    end
  end
  return false
end

#standard_op_return_script? ⇒ Boolean

Returns true if this script is a ‘OP_RETURN <data>’ script and data size is within 40 bytes.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 201

def standard_op_return_script?
  retun false if !op_return_data_only_script? || @chunks.size != 2
  @chunks[1].pushdata.bytesize <= 40
end

#subscript(*args) ⇒ Object Also known as: []

Same arguments as with Array#[].



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# File 'lib/btcruby/script/script.rb', line 473

def subscript(*args)
  Script.new << chunks[*args]
end

#to_a ⇒ Object

Returns an array of opcodes or pushdata strings. Integers are opcodes, strings are pushdata binary strings. OP_0 is treated as a zero-length pushdata.



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# File 'lib/btcruby/script/script.rb', line 293

def to_a
  @chunks.map{|c| c.pushdata? ? c.pushdata : c.opcode }
end

#to_hex ⇒ Object 



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# File 'lib/btcruby/script/script.rb', line 286

def to_hex
  BTC.to_hex(self.data)
end

#to_s ⇒ Object

Human-readable textual representation of the script (e.g. “OP_DUP OP_HASH160 5a73e920b7836c74f9e740a5bb885e8580557038 OP_EQUALVERIFY OP_CHECKSIG”)



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# File 'lib/btcruby/script/script.rb', line 282

def to_s
  @chunks.map{|c| c.to_s }.join(" ")
end

#versioned_script? ⇒ Boolean

Returns true if this is an output script wrapped in a versioned pushdata for segwit softfork.

Returns:

  • (Boolean) 


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# File 'lib/btcruby/script/script.rb', line 94

def versioned_script?
  return chunks.size == 1 &&
         chunks[0].pushdata? &&
         chunks[0].canonical? &&
         chunks[0].pushdata.bytesize > 2
end

#without_dropped_prefix_data ⇒ Object

If script starts with ‘<pushdata> OP_DROP`, these two opcodes are removed and a new script instance is returned.



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# File 'lib/btcruby/script/script.rb', line 257

def without_dropped_prefix_data
  if dropped_prefix_data
    return Script.new << @chunks[2..-1]
  end
  self
end