Class: Bitcoin::Script

Inherits:
Object
  • Object
show all
Defined in:
lib/bitcoin/script.rb

Defined Under Namespace

Classes: ScriptOpcodeError

Constant Summary collapse

OP_0 =
0
OP_FALSE =
0
OP_1 =
81
OP_TRUE =
81
OP_2 =
0x52
OP_3 =
0x53
OP_4 =
0x54
OP_5 =
0x55
OP_6 =
0x56
OP_7 =
0x57
OP_8 =
0x58
OP_9 =
0x59
OP_10 =
0x5a
OP_11 =
0x5b
OP_12 =
0x5c
OP_13 =
0x5d
OP_14 =
0x5e
OP_15 =
0x5f
OP_16 =
0x60
OP_PUSHDATA0 =
0
OP_PUSHDATA1 =
76
OP_PUSHDATA2 =
77
OP_PUSHDATA4 =
78
OP_PUSHDATA_INVALID =

0xEE

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OP_NOP =
97
OP_DUP =
118
OP_HASH160 =
169
OP_EQUAL =
135
OP_VERIFY =
105
OP_EQUALVERIFY =
136
OP_CHECKSIG =
172
OP_CHECKSIGVERIFY =
173
OP_CHECKMULTISIG =
174
OP_CHECKMULTISIGVERIFY =
175
OP_TOALTSTACK =
107
OP_FROMALTSTACK =
108
OP_TUCK =
125
OP_SWAP =
124
OP_BOOLAND =
154
OP_ADD =
147
OP_SUB =
148
OP_GREATERTHANOREQUAL =
162
OP_DROP =
117
OP_HASH256 =
170
OP_SHA256 =
168
OP_SHA1 =
167
OP_RIPEMD160 =
166
OP_NOP1 =
176
OP_NOP2 =
177
OP_NOP3 =
178
OP_NOP4 =
179
OP_NOP5 =
180
OP_NOP6 =
181
OP_NOP7 =
182
OP_NOP8 =
183
OP_NOP9 =
184
OP_NOP10 =
185
OP_CODESEPARATOR =
171
OP_MIN =
163
OP_MAX =
164
OP_2OVER =
112
OP_2ROT =
113
OP_2SWAP =
114
OP_IFDUP =
115
OP_DEPTH =
116
OP_1NEGATE =
79
OP_WITHIN =
165
OP_NUMEQUAL =
156
OP_NUMEQUALVERIFY =
157
OP_LESSTHAN =
159
OP_LESSTHANOREQUAL =
161
OP_GREATERTHAN =
160
OP_NOT =
145
OP_0NOTEQUAL =
146
OP_ABS =
144
OP_1ADD =
139
OP_1SUB =
140
OP_NEGATE =
143
OP_BOOLOR =
155
OP_NUMNOTEQUAL =
158
OP_RETURN =
106
OP_OVER =
120
OP_IF =
99
OP_NOTIF =
100
OP_ELSE =
103
OP_ENDIF =
104
OP_PICK =
121
OP_SIZE =
130
OP_VER =
98
OP_ROLL =
122
OP_ROT =
123
OP_2DROP =
109
OP_2DUP =
110
OP_3DUP =
111
OP_NIP =
119
OP_CAT =
126
OP_SUBSTR =
127
OP_LEFT =
128
OP_RIGHT =
129
OP_INVERT =
131
OP_AND =
132
OP_OR =
133
OP_XOR =
134
OP_2MUL =
141
OP_2DIV =
142
OP_MUL =
149
OP_DIV =
150
OP_MOD =
151
OP_LSHIFT =
152
OP_RSHIFT =
153
OP_INVALIDOPCODE =
0xff
OPCODES =
Hash[*constants.grep(/^OP_/).map{|i| [const_get(i), i.to_s] }.flatten]
OPCODES_ALIAS =
{
  "OP_TRUE"  => OP_1,
  "OP_FALSE" => OP_0,
  "OP_EVAL" => OP_NOP1,
  "OP_CHECKHASHVERIFY" => OP_NOP2,
}
DISABLED_OPCODES =
[
  OP_CAT, OP_SUBSTR, OP_LEFT, OP_RIGHT, OP_INVERT,
  OP_AND, OP_OR, OP_XOR, OP_2MUL, OP_2DIV, OP_MUL,
  OP_DIV, OP_MOD, OP_LSHIFT, OP_RSHIFT
]
OP_2_16 =
(82..96).to_a
OPCODES_PARSE_BINARY =
{}
OPCODES_PARSE_STRING =
{}
SIGHASH_TYPE =
{
  all: 1,
  none: 2,
  single: 3,
  forkid: 64,
  anyonecanpay: 128
}.freeze
OPCODES_METHOD =
Hash[*instance_methods.grep(/^op_/).map{|m|
  [ (OPCODES.find{|k,v| v == m.to_s.upcase }.first rescue nil), m ]
}.flatten]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input_script, previous_output_script = nil) ⇒ Script

create a new script. bytes is typically input_script + output_script


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# File 'lib/bitcoin/script.rb', line 165

def initialize(input_script, previous_output_script=nil)
  @raw_byte_sizes = [input_script.bytesize, previous_output_script ? previous_output_script.bytesize : 0]
  @input_script, @previous_output_script = input_script, previous_output_script
  @parse_invalid = nil
  @inner_p2sh = nil
  @script_codeseparator_index = nil

  @raw = if @previous_output_script
           @input_script + [ Bitcoin::Script::OP_CODESEPARATOR ].pack("C") + @previous_output_script
         else
           @input_script
         end

  @chunks = parse(@input_script)

  if previous_output_script
    @script_codeseparator_index = @chunks.size
    @chunks << Bitcoin::Script::OP_CODESEPARATOR
    @chunks += parse(@previous_output_script)
  end

  @stack, @stack_alt, @exec_stack = [], [], []
  @last_codeseparator_index = 0
  @do_exec = true
end

Instance Attribute Details

#chunksObject (readonly)

Returns the value of attribute chunks


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

def chunks
  @chunks
end

#debugObject (readonly)

Returns the value of attribute debug


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

def debug
  @debug
end

#rawObject (readonly)

Returns the value of attribute raw


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

def raw
  @raw
end

#stackObject (readonly)

Returns the value of attribute stack


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

def stack
  @stack
end

Class Method Details

.add_sig_to_multisig_script_sig(sig, script_sig, hash_type = SIGHASH_TYPE[:all]) ⇒ Object

take a multisig script sig (or p2sh multisig script sig) and add another signature to it after the OP_0. Used to sign a tx by multiple parties. Signatures must be in the same order as the pubkeys in the output script being redeemed.


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# File 'lib/bitcoin/script.rb', line 881

def self.add_sig_to_multisig_script_sig(sig, script_sig, hash_type = SIGHASH_TYPE[:all])
  signature = sig + [hash_type].pack("C*")
  offset = script_sig.empty? ? 0 : 1
  script_sig.insert(offset, pack_pushdata(signature))
end

.binary_from_string(script_string) ⇒ Object

raw script binary of a string representation


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# File 'lib/bitcoin/script.rb', line 404

def self.binary_from_string(script_string)
  buf = ""
  script_string.split(" ").each{|i|
    i = if opcode = OPCODES_PARSE_STRING[i]
      opcode
    else
      case i
      when /OP_PUSHDATA/             # skip
      when /OP_(.+)$/;               raise ScriptOpcodeError, "#{i} not defined!"
      when /\(opcode\-(\d+)\)/;      $1.to_i
      when "(opcode";                # skip  # fix invalid opcode parsing
      when /^(\d+)\)/;               $1.to_i # fix invalid opcode parsing
      when /(\d+):(\d+):(.+)?/
        pushdata, len, data = $1.to_i, $2.to_i, $3
        pack_pushdata_align(pushdata, len, [data].pack("H*"))
      else
        data = [i].pack("H*")
        pack_pushdata(data)
      end
    end

    buf << if i.is_a?(Bitcoin::Integer)
             i < 256 ? [i].pack("C") : [OpenSSL::BN.new(i.to_s,10).to_hex].pack("H*")
           else
             i
           end if i
  }
  buf
end

.check_pubkey_encoding?(pubkey, opts = {}) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1548

def self.check_pubkey_encoding?(pubkey, opts={})
  return false if opts[:verify_strictenc] && !is_compressed_or_uncompressed_pub_key?(pubkey)
  true
end

.check_signature_encoding?(sig, opts = {}) ⇒ Boolean

Loosely matches CheckSignatureEncoding()

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1567

def self.check_signature_encoding?(sig, opts={})
  return true  if sig.bytesize == 0
  return false if (opts[:verify_dersig] || opts[:verify_low_s] || opts[:verify_strictenc]) and !is_der_signature?(sig)
  return false if opts[:verify_low_s] && !is_low_der_signature?(sig)

  if opts[:verify_strictenc]
    return false unless is_defined_hashtype_signature?(sig)

    hash_type = sig.unpack('C*')[-1]
    uses_forkid = (hash_type&SIGHASH_TYPE[:forkid]) != 0
    return false if opts[:fork_id] && !uses_forkid
    return false if !opts[:fork_id] && uses_forkid
  end

  true
end

.compare_big_endian(c1, c2) ⇒ Object

Compares two arrays of bytes


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# File 'lib/bitcoin/script.rb', line 1620

def self.compare_big_endian(c1, c2)
  c1, c2 = c1.dup, c2.dup # Clone the arrays

  while c1.size > c2.size
    return 1 if c1.shift > 0
  end

  while c2.size > c1.size
    return -1 if c2.shift > 0
  end

  c1.size.times{|idx| return c1[idx] - c2[idx] if c1[idx] != c2[idx] }
  0
end

.decode_OP_N(opcode) ⇒ Object

Converts OP_0,1,2,…,16 into 0, 1, 2, …, 16. Returns nil for other opcodes.


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# File 'lib/bitcoin/script.rb', line 979

def self.decode_OP_N(opcode)
  if opcode == OP_0
    return 0
  end
  if opcode.is_a?(Bitcoin::Integer) && opcode >= OP_1 && opcode <= OP_16
    return opcode - (OP_1 - 1);
  else
    nil
  end
end

.drop_signatures(script_pubkey, drop_signatures) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 518

def self.drop_signatures(script_pubkey, drop_signatures)
  script = new(script_pubkey).to_string.split(" ").delete_if{|c| drop_signatures.include?(c) }.join(" ")
  script_pubkey = binary_from_string(script)
end

.from_string(input_script, previous_output_script = nil) ⇒ Object

script object of a string representation


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

def self.from_string(input_script, previous_output_script=nil)
  if previous_output_script
    new(binary_from_string(input_script), binary_from_string(previous_output_script))
  else
    new(binary_from_string(input_script))
  end
end

.is_compressed_or_uncompressed_pub_key?(pubkey) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1553

def self.is_compressed_or_uncompressed_pub_key?(pubkey)
  return false if pubkey.bytesize < 33 # "Non-canonical public key: too short"
  case pubkey[0]
  when "\x04"
    return false if pubkey.bytesize != 65 # "Non-canonical public key: invalid length for uncompressed key"
  when "\x02", "\x03"
    return false if pubkey.bytesize != 33 # "Non-canonical public key: invalid length for compressed key"
  else
    return false # "Non-canonical public key: compressed nor uncompressed"
  end
  true
end

.is_defined_hashtype_signature?(sig) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1656

def self.is_defined_hashtype_signature?(sig)
  return false if sig.empty?

  s = sig.unpack("C*")
  hash_type = s[-1] & (~(SIGHASH_TYPE[:anyonecanpay] | SIGHASH_TYPE[:forkid]))
  return false if hash_type < SIGHASH_TYPE[:all]   ||  hash_type > SIGHASH_TYPE[:single] # Non-canonical signature: unknown hashtype byte

  true
end

.is_der_signature?(sig) ⇒ Boolean

Loosely correlates with IsDERSignature() from interpreter.cpp

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1585

def self.is_der_signature?(sig)
  return false if sig.bytesize < 9 # Non-canonical signature: too short
  return false if sig.bytesize > 73 # Non-canonical signature: too long

  s = sig.unpack("C*")

  return false if s[0] != 0x30 # Non-canonical signature: wrong type
  return false if s[1] != s.size-3 # Non-canonical signature: wrong length marker

  length_r = s[3]
  return false if (5 + length_r) >= s.size # Non-canonical signature: S length misplaced
  length_s = s[5+length_r]
  return false if (length_r + length_s + 7) != s.size # Non-canonical signature: R+S length mismatch

  return false if s[2] != 0x02 # Non-canonical signature: R value type mismatch

  return false if length_r == 0 # Non-canonical signature: R length is zero

  r_val = s.slice(4, length_r)
  return false if r_val[0] & 0x80 != 0 # Non-canonical signature: R value negative

  return false if length_r > 1 && (r_val[0] == 0x00) && !(r_val[1] & 0x80 != 0) # Non-canonical signature: R value excessively padded

  s_val = s.slice(6 + length_r, length_s)
  return false if s[6 + length_r - 2] != 0x02 # Non-canonical signature: S value type mismatch

  return false if length_s == 0 # Non-canonical signature: S length is zero
  return false if (s_val[0] & 0x80) != 0 # Non-canonical signature: S value negative

  return false if length_s > 1 && (s_val[0] == 0x00) && !(s_val[1] & 0x80) # Non-canonical signature: S value excessively padded

  true
end

.is_low_der_signature?(sig) ⇒ Boolean

Loosely correlates with IsLowDERSignature() from interpreter.cpp

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 1636

def self.is_low_der_signature?(sig)
  s = sig.unpack("C*")

  length_r = s[3]
  length_s = s[5+length_r]
  s_val = s.slice(6 + length_r, length_s)

  # If the S value is above the order of the curve divided by two, its
  # complement modulo the order could have been used instead, which is
  # one byte shorter when encoded correctly.
  max_mod_half_order = [
    0x7f,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
    0x5d,0x57,0x6e,0x73,0x57,0xa4,0x50,0x1d,
    0xdf,0xe9,0x2f,0x46,0x68,0x1b,0x20,0xa0]

  compare_big_endian(s_val, [0]) > 0 &&
    compare_big_endian(s_val, max_mod_half_order) <= 0
end

.pack_pushdata(data) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 356

def self.pack_pushdata(data)
  size = data.bytesize

  if data.bitcoin_pushdata
    size = data.bitcoin_pushdata_length
    pack_pushdata_align(data.bitcoin_pushdata, size, data)
  else
    head = if size < OP_PUSHDATA1
             [size].pack("C")
           elsif size <= 0xff
             [OP_PUSHDATA1, size].pack("CC")
           elsif size <= 0xffff
             [OP_PUSHDATA2, size].pack("Cv")
           #elsif size <= 0xffffffff
           else
             [OP_PUSHDATA4, size].pack("CV")
           end
    head + data
  end
end

.pack_pushdata_align(pushdata, len, data) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 377

def self.pack_pushdata_align(pushdata, len, data)
  case pushdata
  when OP_PUSHDATA1
    [OP_PUSHDATA1, len].pack("CC") + data
  when OP_PUSHDATA2
    [OP_PUSHDATA2, len].pack("Cv") + data
  when OP_PUSHDATA4
    [OP_PUSHDATA4, len].pack("CV") + data
  when OP_PUSHDATA_INVALID
    data
  else # OP_PUSHDATA0
    [len].pack("C") + data
  end
end

.sort_p2sh_multisig_signatures(script_sig, sig_hash) ⇒ Object

Sort signatures in the given script_sig according to the order of pubkeys in the redeem script. Also needs the sig_hash to match signatures to pubkeys.


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# File 'lib/bitcoin/script.rb', line 896

def self.sort_p2sh_multisig_signatures script_sig, sig_hash
  script = new(script_sig)
  redeem_script = new(script.chunks[-1])
  pubkeys = redeem_script.get_multisig_pubkeys

  # find the pubkey for each signature by trying to verify it
  sigs = Hash[script.chunks[1...-1].map.with_index do |sig, idx|
    pubkey = pubkeys.map {|key|
      Bitcoin::Key.new(nil, key.hth).verify(sig_hash, sig) ? key : nil }.compact.first
    raise "Key for signature ##{idx} not found in redeem script!"  unless pubkey
    [pubkey, sig]
  end]

  [OP_0].pack("C*") + pubkeys.map {|k| sigs[k] ? pack_pushdata(sigs[k]) : nil }.join +
    pack_pushdata(redeem_script.raw)
end

.to_address_script(address) ⇒ Object

generate hash160 or p2sh output script, depending on the type of the given address. see #to_hash160_script and #to_p2sh_script.


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# File 'lib/bitcoin/script.rb', line 803

def self.to_address_script(address)
  hash160 = Bitcoin.hash160_from_address(address)
  case Bitcoin.address_type(address)
  when :hash160; to_hash160_script(hash160)
  when :p2sh;    to_p2sh_script(hash160)
  when :witness_v0_keyhash, :witness_v0_scripthash
    witness_version, witness_program_hex = Bitcoin.decode_segwit_address(address)
    to_witness_script(witness_version, witness_program_hex)
  end
end

.to_hash160_script(hash160) ⇒ Object

generate hash160 tx for given address. returns a raw binary script of the form:

OP_DUP OP_HASH160 <hash160> OP_EQUALVERIFY OP_CHECKSIG

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# File 'lib/bitcoin/script.rb', line 763

def self.to_hash160_script(hash160)
  return nil  unless hash160
  #  DUP   HASH160  length  hash160    EQUALVERIFY  CHECKSIG
  [ ["76", "a9",    "14",   hash160,   "88",        "ac"].join ].pack("H*")
end

.to_multisig_script(m, *pubkeys) ⇒ Object

generate multisig output script for given pubkeys, expecting m signatures. returns a raw binary script of the form:

<m> <pubkey> [<pubkey> ...] <n_pubkeys> OP_CHECKMULTISIG

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# File 'lib/bitcoin/script.rb', line 817

def self.to_multisig_script(m, *pubkeys)
  raise "invalid m-of-n number" unless [m, pubkeys.size].all?{|i| (0..20).include?(i) }
  raise "invalid m-of-n number" if pubkeys.size < m
  pubs = pubkeys.map{|pk| pack_pushdata([pk].pack("H*")) }

  m = m > 16 ?              pack_pushdata([m].pack("C"))              : [80 + m.to_i].pack("C")
  n = pubkeys.size > 16 ?   pack_pushdata([pubkeys.size].pack("C"))   : [80 + pubs.size].pack("C")

  [ m, *pubs, n, [OP_CHECKMULTISIG].pack("C")].join
end

.to_multisig_script_sig(*sigs) ⇒ Object

generate input script sig spending a multisig output script. returns a raw binary script sig of the form:

OP_0 <sig> [<sig> ...]

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# File 'lib/bitcoin/script.rb', line 870

def self.to_multisig_script_sig(*sigs)
  hash_type = sigs.last.is_a?(Numeric) ? sigs.pop : SIGHASH_TYPE[:all]
  partial_script = [OP_0].pack("C*")
  sigs.reverse_each{ |sig| partial_script = add_sig_to_multisig_script_sig(sig, partial_script, hash_type) }
  partial_script
end

.to_op_return_script(data = nil) ⇒ Object

generate OP_RETURN output script with given data. returns a raw binary script of the form:

OP_RETURN <data>

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# File 'lib/bitcoin/script.rb', line 830

def self.to_op_return_script(data = nil)
  buf = [ OP_RETURN ].pack("C")
  return buf unless data
  return buf + pack_pushdata( [data].pack("H*") )
end

.to_p2sh_multisig_script(*args) ⇒ Object

generate p2sh multisig output script for given args. returns the p2sh output script, and the redeem script needed to spend it. see #to_multisig_script for the redeem script, and #to_p2sh_script for the p2sh script.


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# File 'lib/bitcoin/script.rb', line 856

def self.to_p2sh_multisig_script(*args)
  redeem_script = to_multisig_script(*args)
  p2sh_script = to_p2sh_script(Bitcoin.hash160(redeem_script.hth))
  return p2sh_script, redeem_script
end

.to_p2sh_multisig_script_sig(redeem_script, *sigs) ⇒ Object

generate input script sig spending a p2sh-multisig output script. returns a raw binary script sig of the form:

OP_0 <sig> [<sig> ...] <redeem_script>

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# File 'lib/bitcoin/script.rb', line 890

def self.to_p2sh_multisig_script_sig(redeem_script, *sigs)
  to_multisig_script_sig(*sigs.flatten) + pack_pushdata(redeem_script)
end

.to_p2sh_script(p2sh) ⇒ Object

generate p2sh output script for given p2sh hash160. returns a raw binary script of the form:

OP_HASH160 <p2sh> OP_EQUAL

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# File 'lib/bitcoin/script.rb', line 771

def self.to_p2sh_script(p2sh)
  return nil  unless p2sh
  # HASH160  length  hash  EQUAL
  [ ["a9",   "14",   p2sh, "87"].join ].pack("H*")
end

.to_pubkey_script(pubkey) ⇒ Object

generate pubkey tx script for given pubkey. returns a raw binary script of the form:

<pubkey> OP_CHECKSIG

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# File 'lib/bitcoin/script.rb', line 757

def self.to_pubkey_script(pubkey)
  pack_pushdata([pubkey].pack("H*")) + [ OP_CHECKSIG ].pack("C")
end

.to_pubkey_script_sig(signature, pubkey, hash_type = SIGHASH_TYPE[:all]) ⇒ Object

generate input script sig spending a pubkey output with given signature and pubkey. returns a raw binary script sig of the form:

<signature> [<pubkey>]

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# File 'lib/bitcoin/script.rb', line 839

def self.to_pubkey_script_sig(signature, pubkey, hash_type = SIGHASH_TYPE[:all])
  buf = pack_pushdata(signature + [hash_type].pack("C"))
  return buf unless pubkey

  expected_size = case pubkey[0]
                  when "\x04"; 65
                  when "\x02", "\x03"; 33
                  end

  raise "pubkey is not in binary form" if !expected_size || pubkey.bytesize != expected_size

  return buf + pack_pushdata(pubkey)
end

.to_signature_pubkey_script(*a) ⇒ Object

alias for #to_pubkey_script_sig


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# File 'lib/bitcoin/script.rb', line 863

def self.to_signature_pubkey_script(*a)
  to_pubkey_script_sig(*a)
end

.to_witness_hash160_script(hash160) ⇒ Object

generate p2wpkh tx for given address. returns a raw binary script of the form: 0 <hash160>


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# File 'lib/bitcoin/script.rb', line 789

def self.to_witness_hash160_script(hash160)
  return nil  unless hash160
  to_witness_script(0, hash160)
end

.to_witness_p2sh_script(p2sh) ⇒ Object

generate p2wsh output script for given p2sh sha256. returns a raw binary script of the form: 0 <p2sh>


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# File 'lib/bitcoin/script.rb', line 796

def self.to_witness_p2sh_script(p2sh)
  return nil  unless p2sh
  to_witness_script(0, p2sh)
end

.to_witness_script(witness_version, witness_program_hex) ⇒ Object

generate pay-to-witness output script for given witness_version and witness_program. returns a raw binary script of the form: <witness_version> <witness_program>


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# File 'lib/bitcoin/script.rb', line 780

def self.to_witness_script(witness_version, witness_program_hex)
  return nil unless (0..16).include?(witness_version)
  return nil unless witness_program_hex
  version = witness_version != 0 ? 0x50 + witness_version : 0 # 0x50 for OP_1.. codes
  [version].pack('C') + pack_pushdata(witness_program_hex.htb)
end

Instance Method Details

#append_number(number) ⇒ Object

Adds the opcode corresponding to the given number. Returns self.


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# File 'lib/bitcoin/script.rb', line 335

def append_number(number)
  opcode =
    case number
    when -1 then OP_1NEGATE
    when 0 then OP_0
    when 1 then OP_1
    when 2..16 then OP_2 + (16 - number)
    end
  raise "No opcode for number #{number}" if opcode.nil?
  append_opcode(opcode)
end

#append_opcode(opcode) ⇒ Object

Adds opcode (OP_0, OP_1, … OP_CHECKSIG etc.) Returns self.


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# File 'lib/bitcoin/script.rb', line 324

def append_opcode(opcode)
  raise "Opcode should be an integer" if !opcode.is_a?(Bitcoin::Integer)
  if opcode >= OP_0 && opcode <= 0xff
    @chunks << opcode
  else
    raise "Opcode should be within [0x00, 0xff]"
  end
  self
end

#append_pushdata(pushdata_string) ⇒ Object

Adds binary string as pushdata. Pushdata will be encoded in the most compact form (unless the string contains internal info about serialization that's added by Script class) Returns self.


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# File 'lib/bitcoin/script.rb', line 350

def append_pushdata(pushdata_string)
  raise "Pushdata should be a string" if !pushdata_string.is_a?(String)
  @chunks << pushdata_string
  self
end

#cast_to_bignum(buf) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1375

def cast_to_bignum(buf)
  return (invalid; 0) unless buf
  case buf
  when Numeric
    invalid if OpenSSL::BN.new(buf.to_s).to_s(0).unpack("N")[0] > 4
    buf
  when String
    invalid if buf.bytesize > 4
    OpenSSL::BN.new([buf.bytesize].pack("N") + buf.reverse, 0).to_i
  else; raise TypeError, 'cast_to_bignum: failed to cast: %s (%s)' % [buf, buf.class]
  end
end

#cast_to_bool(buf) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1397

def cast_to_bool(buf)
  buf = cast_to_string(buf).unpack("C*")
  size = buf.size
  buf.each.with_index{|byte,index|
    if byte != 0
      # Can be negative zero
      if (index == (size-1)) && byte == 0x80
        return false
      else
        return true
      end
    end
  }
  return false
end

#cast_to_string(buf) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1388

def cast_to_string(buf)
  return (invalid; "") unless buf
  case buf
  when Numeric; OpenSSL::BN.new(buf.to_s).to_s(0)[4..-1].reverse
  when String; buf;
  else; raise TypeError, 'cast_to_string: failed to cast: %s (%s)' % [buf, buf.class]
  end
end

#check_pushes(push_only = true, canonical_only = false, buf) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 633

def check_pushes(push_only=true, canonical_only=false, buf)
  program = buf.unpack("C*")
  until program.empty?
    opcode = program.shift
    if opcode > OP_16
      return false if push_only
      next
    end
    if opcode < OP_PUSHDATA1 && opcode > OP_0
      # Could have used an OP_n code, rather than a 1-byte push.
      return false if canonical_only && opcode == 1 && program[0] <= 16
      program.shift(opcode)
    end
    if opcode == OP_PUSHDATA1
      len = program.shift(1)[0]
      # Could have used a normal n-byte push, rather than OP_PUSHDATA1.
      return false if canonical_only && len < OP_PUSHDATA1
      program.shift(len)
    end
    if opcode == OP_PUSHDATA2
      len = program.shift(2).pack("C*").unpack("v")[0]
      # Could have used an OP_PUSHDATA1.
      return false if canonical_only && len <= 0xff
      program.shift(len)
    end
    if opcode == OP_PUSHDATA4
      len = program.shift(4).pack("C*").unpack("V")[0]
      # Could have used an OP_PUSHDATA2.
      return false if canonical_only && len <= 0xffff
      program.shift(len)
    end
  end
  true
rescue
  # catch parsing errors
  false
end

#codehash_script(opcode) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1425

def codehash_script(opcode)
  # CScript scriptCode(pbegincodehash, pend);
  script    = to_string(@chunks[(@codehash_start||0)...@chunks.size-@chunks.reverse.index(opcode)])
  checkhash = Bitcoin.hash160(Bitcoin::Script.binary_from_string(script).unpack("H*")[0])
  [script, checkhash]
end

#codeseparator_countObject


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# File 'lib/bitcoin/script.rb', line 923

def codeseparator_count
  @chunks.select{|c|c == Bitcoin::Script::OP_CODESEPARATOR}.length
end

#get_addressObject

get single address, or first for multisig script


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# File 'lib/bitcoin/script.rb', line 750

def get_address
  addrs = get_addresses
  addrs.is_a?(Array) ? addrs[0] : addrs
end

#get_addressesObject

get all addresses this script corresponds to (if possible)


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# File 'lib/bitcoin/script.rb', line 735

def get_addresses
  return [get_pubkey_address]    if is_pubkey?
  return [get_hash160_address]   if is_hash160?
  return get_multisig_addresses  if is_multisig?
  return [get_p2sh_address]      if is_p2sh?

  if is_witness_v0_keyhash? || is_witness_v0_scripthash?
    program_hex = chunks[1].unpack("H*").first
    return [Bitcoin.encode_segwit_address(0, program_hex)]
  end

  []
end

#get_hash160Object

get the hash160 for this hash160 or pubkey script


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# File 'lib/bitcoin/script.rb', line 696

def get_hash160
  return @chunks[2..-3][0].unpack("H*")[0]  if is_hash160?
  return @chunks[-2].unpack("H*")[0]        if is_p2sh?
  return Bitcoin.hash160(get_pubkey)        if is_pubkey?
  return @chunks[1].unpack("H*")[0]         if is_witness_v0_keyhash?
  return @chunks[1].unpack("H*")[0]         if is_witness_v0_scripthash?
end

#get_hash160_addressObject

get the hash160 address for this hash160 script


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# File 'lib/bitcoin/script.rb', line 705

def get_hash160_address
  Bitcoin.hash160_to_address(get_hash160)
end

#get_keys_providedObject


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# File 'lib/bitcoin/script.rb', line 918

def get_keys_provided
  return false  unless is_multisig?
  @chunks[-2] - 80
end

#get_multisig_addressesObject

get the pubkey addresses for this multisig script


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# File 'lib/bitcoin/script.rb', line 715

def get_multisig_addresses
  get_multisig_pubkeys.map{|pub|
    begin
      Bitcoin::Key.new(nil, pub.unpack("H*")[0]).addr
    rescue OpenSSL::PKey::ECError, OpenSSL::PKey::EC::Point::Error
    end
  }
end

#get_multisig_pubkeysObject

get the public keys for this multisig script


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# File 'lib/bitcoin/script.rb', line 710

def get_multisig_pubkeys
  1.upto(@chunks[-2] - 80).map{|i| @chunks[i] }
end

#get_op_return_dataObject

get the data possibly included in an OP_RETURN script


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# File 'lib/bitcoin/script.rb', line 729

def get_op_return_data
  return nil  unless is_op_return?
  cast_to_string(@chunks[1]).unpack("H*")[0]  if @chunks[1]
end

#get_p2sh_addressObject


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# File 'lib/bitcoin/script.rb', line 724

def get_p2sh_address
  Bitcoin.hash160_to_p2sh_address(get_hash160)
end

#get_pubkeyObject

get the public key for this pubkey script


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# File 'lib/bitcoin/script.rb', line 685

def get_pubkey
  return @chunks[0].unpack("H*")[0] if @chunks.size == 1
  is_pubkey? ? @chunks[0].unpack("H*")[0] : nil
end

#get_pubkey_addressObject

get the pubkey address for this pubkey script


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# File 'lib/bitcoin/script.rb', line 691

def get_pubkey_address
  Bitcoin.pubkey_to_address(get_pubkey)
end

#get_signatures_requiredObject


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# File 'lib/bitcoin/script.rb', line 913

def get_signatures_required
  return false unless is_multisig?
  @chunks[0] - 80
end

#inner_p2sh!(script = nil) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 542

def inner_p2sh!(script=nil); @inner_p2sh = true; @inner_script_code = script; self; end

#inner_p2sh?Boolean

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 543

def inner_p2sh?; @inner_p2sh; end

#inner_p2sh_scriptObject

get the inner p2sh script


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# File 'lib/bitcoin/script.rb', line 546

def inner_p2sh_script
  return nil if @chunks.size < 4
  *rest, script, _, script_hash, _ = @chunks
  script = rest.pop if script == OP_CODESEPARATOR
  script, script_hash = cast_to_string(script), cast_to_string(script_hash)

  return nil unless Bitcoin.hash160(script.unpack("H*")[0]) == script_hash.unpack("H*")[0]
  script
end

#invalidObject


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# File 'lib/bitcoin/script.rb', line 514

def invalid
  @script_invalid = true; nil
end

#invalid?Boolean

Returns:

  • (Boolean)

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

def invalid?
  @script_invalid ||= false
end

#is_hash160?Boolean

is this a hash160 (address) script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 590

def is_hash160?
  return false  if @chunks.size != 5
  (@chunks[0..1] + @chunks[-2..-1]) ==
    [OP_DUP, OP_HASH160, OP_EQUALVERIFY, OP_CHECKSIG] &&
    @chunks[2].is_a?(String) && @chunks[2].bytesize == 20
end

#is_multisig?Boolean

is this a multisig script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 598

def is_multisig?
  return false  if @chunks.size < 4 || !@chunks[-2].is_a?(Bitcoin::Integer)
  @chunks[-1] == OP_CHECKMULTISIG and get_multisig_pubkeys.all?{|c| c.is_a?(String) }
end

#is_op_return?Boolean

is this an op_return script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 604

def is_op_return?
  @chunks[0] == OP_RETURN && @chunks.size <= 2
end

#is_pay_to_script_hash?Boolean Also known as: is_p2sh?

is this a :script_hash (pay-to-script-hash/p2sh) script?

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 557

def is_pay_to_script_hash?
  @inner_p2sh ||= false
  return false if @inner_p2sh
  if @previous_output_script
    chunks = Bitcoin::Script.new(@previous_output_script).chunks
    chunks.size == 3 &&
    chunks[-3] == OP_HASH160 &&
    chunks[-2].is_a?(String) && chunks[-2].bytesize == 20 &&
    chunks[-1] == OP_EQUAL
  else
    @chunks.size >= 3 &&
    @chunks[-3] == OP_HASH160 &&
    @chunks[-2].is_a?(String) && @chunks[-2].bytesize == 20 &&
    @chunks[-1] == OP_EQUAL &&
    # make sure the script_sig matches the p2sh hash from the pk_script (if there is one)
    (@chunks.size > 3 ? pay_to_script_hash(nil, nil, :check) : true)
  end
end

#is_pubkey?Boolean Also known as: is_send_to_ip?

is this a pubkey script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 583

def is_pubkey?
  return false if @chunks.size != 2
  (@chunks[1] == OP_CHECKSIG) && @chunks[0] && (@chunks[0].is_a?(String)) && @chunks[0] != OP_RETURN
end

#is_push_only?(script_data = nil) ⇒ Boolean

Verify the script is only pushing data onto the stack

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 624

def is_push_only?(script_data=nil)
  check_pushes(true, false, (script_data||@input_script))
end

#is_standard?Boolean

check if script is in one of the recognized standard formats

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 578

def is_standard?
  is_pubkey? || is_hash160? || is_multisig? || is_p2sh?  || is_op_return? || is_witness_v0_keyhash? || is_witness_v0_scripthash?
end

#is_witness?Boolean

is this a witness script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 609

def is_witness?
  @chunks.length == 2 && (0..16).include?(@chunks[0]) && @chunks[1].is_a?(String)
end

#is_witness_v0_keyhash?Boolean

is this a witness pubkey script

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 614

def is_witness_v0_keyhash?
  is_witness? && @chunks[0] == 0 && @chunks[1].bytesize == 20
end

#is_witness_v0_scripthash?Boolean

is this a witness script hash

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 619

def is_witness_v0_scripthash?
  is_witness? && @chunks[0] == 0 && @chunks[1].bytesize == 32
end

#op_0Object

An empty array of bytes is pushed onto the stack.


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# File 'lib/bitcoin/script.rb', line 1186

def op_0
  @stack << "" # []
end

#op_0notequalObject


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# File 'lib/bitcoin/script.rb', line 1117

def op_0notequal
  a = pop_int
  @stack << (a != 0 ? 1 : 0)
end

#op_1Object

The number 1 is pushed onto the stack. Same as OP_TRUE


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# File 'lib/bitcoin/script.rb', line 1191

def op_1
  @stack << 1
end

#op_1addObject

1 is added to the input.


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# File 'lib/bitcoin/script.rb', line 1141

def op_1add
  a = pop_int
  @stack << (a + 1)
end

#op_1negateObject

The number -1 is pushed onto the stack.


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# File 'lib/bitcoin/script.rb', line 1226

def op_1negate
  @stack << -1
end

#op_1subObject

1 is subtracted from the input.


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# File 'lib/bitcoin/script.rb', line 1147

def op_1sub
  a = pop_int
  @stack << (a - 1)
end

#op_2divObject

The input is divided by 2. Currently disabled.


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# File 'lib/bitcoin/script.rb', line 1129

def op_2div
  a = pop_int
  @stack << (a >> 1)
end

#op_2dropObject

Removes the top two stack items.


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# File 'lib/bitcoin/script.rb', line 1331

def op_2drop
  @stack.pop(2)
end

#op_2dupObject

Duplicates the top two stack items.


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# File 'lib/bitcoin/script.rb', line 1336

def op_2dup
  @stack.push(*@stack[-2..-1])
end

#op_2mulObject

The input is multiplied by 2. Currently disabled.


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# File 'lib/bitcoin/script.rb', line 1135

def op_2mul
  a = pop_int
  @stack << (a << 1)
end

#op_2overObject

Copies the pair of items two spaces back in the stack to the front.


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# File 'lib/bitcoin/script.rb', line 1206

def op_2over
  @stack << @stack[-4]
  @stack << @stack[-4]
end

#op_2rotObject

The fifth and sixth items back are moved to the top of the stack.


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# File 'lib/bitcoin/script.rb', line 1306

def op_2rot
  return invalid if @stack.size < 6
  @stack[-6..-1] = [ *@stack[-4..-1], *@stack[-6..-5] ]
end

#op_2swapObject

Swaps the top two pairs of items.


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# File 'lib/bitcoin/script.rb', line 1212

def op_2swap
  p1 = @stack.pop(2)
  p2 = @stack.pop(2)
  @stack += p1 += p2
end

#op_3dupObject

Duplicates the top three stack items.


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# File 'lib/bitcoin/script.rb', line 1341

def op_3dup
  @stack.push(*@stack[-3..-1])
end

#op_absObject

The input is made positive.


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# File 'lib/bitcoin/script.rb', line 1123

def op_abs
  a = pop_int
  @stack << a.abs
end

#op_addObject

a is added to b.


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# File 'lib/bitcoin/script.rb', line 1076

def op_add
  a, b = pop_int(2)
  @stack << a + b
end

#op_boolandObject

If both a and b are not 0, the output is 1. Otherwise 0.


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# File 'lib/bitcoin/script.rb', line 1064

def op_booland
  a, b = pop_int(2)
  @stack << (![a,b].any?{|n| n == 0 } ? 1 : 0)
end

#op_boolorObject

If a or b is not 0, the output is 1. Otherwise 0.


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# File 'lib/bitcoin/script.rb', line 1070

def op_boolor
  a, b = pop_int(2)
  @stack << ( (a != 0 || b != 0) ? 1 : 0 )
end

#op_checkmultisig(check_callback, opts = {}) ⇒ Object

do a CHECKMULTISIG operation on the current stack, asking check_callback to do the actual signature verification.

CHECKMULTISIG does a m-of-n signatures verification on scripts of the form:

0 <sig1> <sig2> | 2 <pub1> <pub2> 2 OP_CHECKMULTISIG
0 <sig1> <sig2> | 2 <pub1> <pub2> <pub3> 3 OP_CHECKMULTISIG
0 <sig1> <sig2> <sig3> | 3 <pub1> <pub2> <pub3> 3 OP_CHECKMULTISIG

see en.bitcoin.it/wiki/BIP_0011 for details. see github.com/bitcoin/bitcoin/blob/master/src/script.cpp#L931

TODO: validate signature order TODO: take global opcode count


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# File 'lib/bitcoin/script.rb', line 1494

def op_checkmultisig(check_callback, opts={})
  return invalid if @stack.size < 1
  n_pubkeys = pop_int
  return invalid  unless (0..20).include?(n_pubkeys)
  #return invalid  if (nOpCount += n_pubkeys) > 201
  return invalid if @stack.size < n_pubkeys
  pubkeys = pop_string(n_pubkeys)

  return invalid if @stack.size < 1
  n_sigs = pop_int
  return invalid if n_sigs < 0 || n_sigs > n_pubkeys
  return invalid if @stack.size < n_sigs
  sigs = pop_string(n_sigs)
  drop_sigs = sigs.dup

  # Bitcoin-core removes an extra item from the stack
  @stack.pop

  subscript = sighash_subscript(drop_sigs, opts)

  success = true
  while success && n_sigs > 0
    sig, pub = sigs.pop, pubkeys.pop
    return (@stack << 0) unless Bitcoin::Script.check_pubkey_encoding?(pub, opts)
    return invalid unless Bitcoin::Script.check_signature_encoding?(sig, opts)
    unless sig && sig.size > 0
      success = false
      break
    end
    signature, hash_type = parse_sig(sig)
    if pub.size > 0 && check_callback.call(pub, signature, hash_type, subscript)
      n_sigs -= 1
    else
      sigs << sig
    end
    n_pubkeys -= 1
    success = false if n_sigs > n_pubkeys
  end

  @stack << (success ? 1 : 0)
end

#op_checkmultisigverify(check_callback, opts = {}) ⇒ Object

Same as OP_CHECKMULTISIG, but OP_VERIFY is executed afterward.


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# File 'lib/bitcoin/script.rb', line 1537

def op_checkmultisigverify(check_callback, opts={})
  op_checkmultisig(check_callback, opts)
  op_verify
end

#op_checksig(check_callback, opts = {}) ⇒ Object

do a CHECKSIG operation on the current stack, asking check_callback to do the actual signature verification. This is used by Protocol::Tx#verify_input_signature


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# File 'lib/bitcoin/script.rb', line 1436

def op_checksig(check_callback, opts={})
  return invalid if @stack.size < 2
  pubkey = cast_to_string(@stack.pop)
  return (@stack << 0) unless Bitcoin::Script.check_pubkey_encoding?(pubkey, opts)
  drop_sigs      = [ cast_to_string(@stack[-1]) ]

  signature = cast_to_string(@stack.pop)
  return invalid unless Bitcoin::Script.check_signature_encoding?(signature, opts)
  return (@stack << 0) if signature == ""

  sig, hash_type = parse_sig(signature)

  subscript = sighash_subscript(drop_sigs, opts)

  if check_callback == nil # for tests
    @stack << 1
  else # real signature check callback
    @stack <<
      ((check_callback.call(pubkey, sig, hash_type, subscript) == true) ? 1 : 0)
  end
end

#op_checksigverify(check_callback, opts = {}) ⇒ Object

Same as OP_CHECKSIG, but OP_VERIFY is executed afterward.


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# File 'lib/bitcoin/script.rb', line 1476

def op_checksigverify(check_callback, opts={})
  op_checksig(check_callback, opts)
  op_verify
end

#op_codeseparatorObject

All of the signature checking words will only match signatures to the data after the most recently-executed OP_CODESEPARATOR.


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# File 'lib/bitcoin/script.rb', line 1420

def op_codeseparator
  @codehash_start = @chunks.size - @chunks.reverse.index(OP_CODESEPARATOR)
  @last_codeseparator_index = @chunk_last_index
end

#op_depthObject

Puts the number of stack items onto the stack.


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# File 'lib/bitcoin/script.rb', line 1231

def op_depth
  @stack << @stack.size
end

#op_dropObject

Removes the top stack item.


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# File 'lib/bitcoin/script.rb', line 1159

def op_drop
  @stack.pop
end

#op_dupObject

Duplicates the top stack item.


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# File 'lib/bitcoin/script.rb', line 1009

def op_dup
  @stack << (@stack[-1].dup rescue @stack[-1])
end

#op_elseObject

If the preceding OP_IF or OP_NOTIF or OP_ELSE was not executed then these statements are and if the preceding OP_IF or OP_NOTIF or OP_ELSE was executed then these statements are not.


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# File 'lib/bitcoin/script.rb', line 1285

def op_else
  return if @exec_stack.empty?
  @exec_stack[-1] = !@exec_stack[-1]
end

#op_endifObject

Ends an if/else block.


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# File 'lib/bitcoin/script.rb', line 1291

def op_endif
  return if @exec_stack.empty?
  @exec_stack.pop
end

#op_equalObject

Returns 1 if the inputs are exactly equal, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1164

def op_equal
  a, b = pop_string(2)
  @stack << (a == b ? 1 : 0)
end

#op_equalverifyObject

Same as OP_EQUAL, but runs OP_VERIFY afterward.


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# File 'lib/bitcoin/script.rb', line 1181

def op_equalverify
  op_equal; op_verify
end

#op_fromaltstackObject

Puts the input onto the top of the main stack. Removes it from the alt stack.


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# File 'lib/bitcoin/script.rb', line 1049

def op_fromaltstack
  @stack << @stack_alt.pop
end

#op_greaterthanObject

Returns 1 if a is greater than b, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1100

def op_greaterthan
  a, b = pop_int(2)
  @stack << (a > b ? 1 : 0)
end

#op_greaterthanorequalObject

Returns 1 if a is greater than or equal to b, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1106

def op_greaterthanorequal
  a, b = pop_int(2)
  @stack << (a >= b ? 1 : 0)
end

#op_hash160Object

The input is hashed twice: first with SHA-256 and then with RIPEMD-160.


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# File 'lib/bitcoin/script.rb', line 1026

def op_hash160
  buf = pop_string
  @stack << Digest::RMD160.digest(Digest::SHA256.digest(buf))
end

#op_hash256Object

The input is hashed two times with SHA-256.


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# File 'lib/bitcoin/script.rb', line 1038

def op_hash256
  buf = pop_string
  @stack << Digest::SHA256.digest(Digest::SHA256.digest(buf))
end

#op_ifObject

If the top stack value is not 0, the statements are executed. The top stack value is removed.


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# File 'lib/bitcoin/script.rb', line 1265

def op_if
  value = false
  if @do_exec
    (invalid; return) if @stack.size < 1
    value = cast_to_bool(pop_string) == false ? false : true
  end
  @exec_stack << value
end

#op_ifdupObject

If the input is true, duplicate it.


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# File 'lib/bitcoin/script.rb', line 1219

def op_ifdup
  if cast_to_bool(@stack.last) == true
    @stack << @stack.last
  end
end

#op_lessthanObject

Returns 1 if a is less than b, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1088

def op_lessthan
  a, b = pop_int(2)
  @stack << (a < b ? 1 : 0)
end

#op_lessthanorequalObject

Returns 1 if a is less than or equal to b, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1094

def op_lessthanorequal
  a, b = pop_int(2)
  @stack << (a <= b ? 1 : 0)
end

#op_maxObject

Returns the larger of a and b.


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# File 'lib/bitcoin/script.rb', line 1201

def op_max
  @stack << pop_int(2).max
end

#op_minObject

Returns the smaller of a and b.


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# File 'lib/bitcoin/script.rb', line 1196

def op_min
  @stack << pop_int(2).min
end

#op_negateObject

The sign of the input is flipped.


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# File 'lib/bitcoin/script.rb', line 1153

def op_negate
  a = pop_int
  @stack << -a
end

#op_nipObject

Removes the second-to-top stack item.


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# File 'lib/bitcoin/script.rb', line 1346

def op_nip
  @stack.delete_at(-2)
end

#op_nopObject

Does nothing


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# File 'lib/bitcoin/script.rb', line 996

def op_nop; end

#op_nop1Object


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# File 'lib/bitcoin/script.rb', line 997

def op_nop1; end

#op_nop10Object


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# File 'lib/bitcoin/script.rb', line 1006

def op_nop10; end

#op_nop2Object


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# File 'lib/bitcoin/script.rb', line 998

def op_nop2; end

#op_nop3Object


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# File 'lib/bitcoin/script.rb', line 999

def op_nop3; end

#op_nop4Object


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# File 'lib/bitcoin/script.rb', line 1000

def op_nop4; end

#op_nop5Object


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# File 'lib/bitcoin/script.rb', line 1001

def op_nop5; end

#op_nop6Object


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# File 'lib/bitcoin/script.rb', line 1002

def op_nop6; end

#op_nop7Object


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# File 'lib/bitcoin/script.rb', line 1003

def op_nop7; end

#op_nop8Object


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# File 'lib/bitcoin/script.rb', line 1004

def op_nop8; end

#op_nop9Object


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# File 'lib/bitcoin/script.rb', line 1005

def op_nop9; end

#op_notObject

If the input is 0 or 1, it is flipped. Otherwise the output will be 0.


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# File 'lib/bitcoin/script.rb', line 1112

def op_not
  a = pop_int
  @stack << (a == 0 ? 1 : 0)
end

#op_notifObject

If the top stack value is 0, the statements are executed. The top stack value is removed.


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# File 'lib/bitcoin/script.rb', line 1275

def op_notif
  value = false
  if @do_exec
    (invalid; return) if @stack.size < 1
    value = cast_to_bool(pop_string) == false ? true : false
  end
  @exec_stack << value
end

#op_numequalObject

Returns 1 if the numbers are equal, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1242

def op_numequal
  a, b = pop_int(2)
  @stack << (a == b ? 1 : 0)
end

#op_numequalverifyObject

Same as OP_NUMEQUAL, but runs OP_VERIFY afterward.


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# File 'lib/bitcoin/script.rb', line 1414

def op_numequalverify
  op_numequal; op_verify
end

#op_numnotequalObject

Returns 1 if the numbers are not equal, 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1248

def op_numnotequal
  a, b = pop_int(2)
  @stack << (a != b ? 1 : 0)
end

#op_overObject

Copies the second-to-top stack item to the top.


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# File 'lib/bitcoin/script.rb', line 1259

def op_over
  item = @stack[-2]
  @stack << item if item
end

#op_pickObject

The item n back in the stack is copied to the top.


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# File 'lib/bitcoin/script.rb', line 1297

def op_pick
  return invalid if @stack.size < 2
  pos = pop_int
  return invalid if (pos < 0) || (pos >= @stack.size)
  item = @stack[-(pos+1)]
  @stack << item if item
end

#op_returnObject

Marks transaction as invalid.


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# File 'lib/bitcoin/script.rb', line 1254

def op_return
  @script_invalid = true; nil
end

#op_ripemd160Object

The input is hashed using RIPEMD-160.


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# File 'lib/bitcoin/script.rb', line 1032

def op_ripemd160
  buf = pop_string
  @stack << Digest::RMD160.digest(buf)
end

#op_rollObject

The item n back in the stack is moved to the top.


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# File 'lib/bitcoin/script.rb', line 1312

def op_roll
  return invalid if @stack.size < 2
  pos = pop_int
  return invalid if (pos < 0) || (pos >= @stack.size)
  idx = -(pos+1)
  item = @stack[idx]
  if item
    @stack.delete_at(idx)
    @stack << item if item
  end
end

#op_rotObject

The top three items on the stack are rotated to the left.


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# File 'lib/bitcoin/script.rb', line 1325

def op_rot
  return if @stack.size < 3
  @stack[-3..-1] = [ @stack[-2], @stack[-1], @stack[-3] ]
end

#op_sha1Object

The input is hashed using SHA-1.


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# File 'lib/bitcoin/script.rb', line 1020

def op_sha1
  buf = pop_string
  @stack << Digest::SHA1.digest(buf)
end

#op_sha256Object

The input is hashed using SHA-256.


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# File 'lib/bitcoin/script.rb', line 1014

def op_sha256
  buf = pop_string
  @stack << Digest::SHA256.digest(buf)
end

#op_sizeObject

Returns the length of the input string.


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# File 'lib/bitcoin/script.rb', line 1351

def op_size
  item = @stack[-1]
  size = case item
         when String; item.bytesize
         when Numeric; OpenSSL::BN.new(item.to_s).to_mpi.size - 4
         end
  @stack << size
end

#op_subObject

b is subtracted from a.


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# File 'lib/bitcoin/script.rb', line 1082

def op_sub
  a, b = pop_int(2)
  @stack << a - b
end

#op_swapObject

The top two items on the stack are swapped.


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# File 'lib/bitcoin/script.rb', line 1059

def op_swap
  @stack[-2..-1] = @stack[-2..-1].reverse if @stack[-2]
end

#op_toaltstackObject

Puts the input onto the top of the alt stack. Removes it from the main stack.


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# File 'lib/bitcoin/script.rb', line 1044

def op_toaltstack
  @stack_alt << @stack.pop
end

#op_tuckObject

The item at the top of the stack is copied and inserted before the second-to-top item.


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# File 'lib/bitcoin/script.rb', line 1054

def op_tuck
  @stack[-2..-1] = [ @stack[-1], *@stack[-2..-1] ]
end

#op_verObject

Transaction is invalid unless occuring in an unexecuted OP_IF branch


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# File 'lib/bitcoin/script.rb', line 1361

def op_ver
  invalid if @do_exec
end

#op_verifyObject

Marks transaction as invalid if top stack value is not true. True is removed, but false is not.


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# File 'lib/bitcoin/script.rb', line 1170

def op_verify
  res = pop_int
  if cast_to_bool(res) == false
    @stack << res
    @script_invalid = true # raise 'transaction invalid' ?
  else
    @script_invalid = false
  end
end

#op_withinObject

Returns 1 if x is within the specified range (left-inclusive), 0 otherwise.


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# File 'lib/bitcoin/script.rb', line 1236

def op_within
  bn1, bn2, bn3 = pop_int(3)
  @stack << ( (bn2 <= bn1 && bn1 < bn3) ? 1 : 0 )
end

#parse(bytes, offset = 0) ⇒ Object

parse raw script


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# File 'lib/bitcoin/script.rb', line 197

def parse(bytes, offset=0)
  program = bytes.unpack("C*")
  chunks = []
  until program.empty?
    opcode = program.shift

    if (opcode > 0) && (opcode < OP_PUSHDATA1)
      len, tmp = opcode, program[0]
      chunks << program.shift(len).pack("C*")

      # 0x16 = 22 due to OP_2_16 from_string parsing
      if len == 1 && tmp && tmp <= 22
        chunks.last.bitcoin_pushdata = OP_PUSHDATA0
        chunks.last.bitcoin_pushdata_length = len
      else
        raise "invalid OP_PUSHDATA0" if len != chunks.last.bytesize
      end
    elsif (opcode == OP_PUSHDATA1)
      len = program.shift(1)[0]
      chunks << program.shift(len).pack("C*")

      unless len > OP_PUSHDATA1 && len <= 0xff
        chunks.last.bitcoin_pushdata = OP_PUSHDATA1
        chunks.last.bitcoin_pushdata_length = len
      else
        raise "invalid OP_PUSHDATA1" if len != chunks.last.bytesize
      end
    elsif (opcode == OP_PUSHDATA2)
      len = program.shift(2).pack("C*").unpack("v")[0]
      chunks << program.shift(len).pack("C*")

      unless len > 0xff && len <= 0xffff
        chunks.last.bitcoin_pushdata = OP_PUSHDATA2
        chunks.last.bitcoin_pushdata_length = len
      else
        raise "invalid OP_PUSHDATA2" if len != chunks.last.bytesize
      end
    elsif (opcode == OP_PUSHDATA4)
      len = program.shift(4).pack("C*").unpack("V")[0]
      chunks << program.shift(len).pack("C*")

      unless len > 0xffff # && len <= 0xffffffff
        chunks.last.bitcoin_pushdata = OP_PUSHDATA4
        chunks.last.bitcoin_pushdata_length = len
      else
        raise "invalid OP_PUSHDATA4" if len != chunks.last.bytesize
      end
    else
      chunks << opcode
    end
  end
  chunks
rescue => ex
  # bail out! #run returns false but serialization roundtrips still create the right payload.
  chunks.pop if ex.message.include?("invalid OP_PUSHDATA")
  @parse_invalid = true
  c = bytes.unpack("C*").pack("C*")
  c.bitcoin_pushdata = OP_PUSHDATA_INVALID
  c.bitcoin_pushdata_length = c.bytesize
  chunks << c
end

#pay_to_script_hash(block_timestamp, opts, check_callback) ⇒ Object

pay_to_script_hash: en.bitcoin.it/wiki/BIP_0016

<sig> OP_CHECKSIG | OP_HASH160 <script_hash> OP_EQUAL


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# File 'lib/bitcoin/script.rb', line 526

def pay_to_script_hash(block_timestamp, opts, check_callback)
  return false if @chunks.size < 4
  *rest, script, _, script_hash, _ = @chunks
  script = rest.pop if script == OP_CODESEPARATOR
  script, script_hash = cast_to_string(script), cast_to_string(script_hash)

  return false unless Bitcoin.hash160(script.unpack("H*")[0]) == script_hash.unpack("H*")[0]
  return true  if check_callback == :check

  script = self.class.new(to_binary(rest) + script).inner_p2sh!(script)
  result = script.run(block_timestamp, opts, &check_callback)
  @debug = script.debug
  @stack = script.stack # Set the execution stack to match the redeem script, so checks on stack contents at end of script execution validate correctly
  result
end

#pop_int(count = nil) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1365

def pop_int(count=nil)
  return cast_to_bignum(@stack.pop) unless count
  @stack.pop(count).map{|i| cast_to_bignum(i) }
end

#pop_string(count = nil) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1370

def pop_string(count=nil)
  return cast_to_string(@stack.pop) unless count
  @stack.pop(count).map{|i| cast_to_string(i) }
end

#pushes_are_canonical?(script_data = nil) ⇒ Boolean

Make sure opcodes used to push data match their intended length ranges

Returns:

  • (Boolean)

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# File 'lib/bitcoin/script.rb', line 629

def pushes_are_canonical?(script_data=nil)
  check_pushes(false, true, (script_data||@raw))
end

#run(block_timestamp = Time.now.to_i, opts = {}, &check_callback) ⇒ Object

run the script. check_callback is called for OP_CHECKSIG operations


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# File 'lib/bitcoin/script.rb', line 439

def run(block_timestamp=Time.now.to_i, opts={}, &check_callback)
  return false if @parse_invalid

  #p [to_string, block_timestamp, is_p2sh?]
  @script_invalid = true if @raw_byte_sizes.any?{|size| size > 10_000 }
  @last_codeseparator_index = 0

  if block_timestamp >= 1333238400 # Pay to Script Hash (BIP 0016)
    return pay_to_script_hash(block_timestamp, opts, check_callback)  if is_p2sh?
  end

  @debug = []
  @chunks.each.with_index{|chunk,idx|
    break if invalid?
    @chunk_last_index = idx

    @debug << @stack.map{|i| i.unpack("H*") rescue i}
    @do_exec = @exec_stack.count(false) == 0 ? true : false
    #p [@stack, @do_exec]

    case chunk
    when Bitcoin::Integer
      if DISABLED_OPCODES.include?(chunk)
        @script_invalid = true
        @debug << "DISABLED_#{OPCODES[chunk]}"
        break
      end

      next @debug.pop  unless (@do_exec || (OP_IF <= chunk && chunk <= OP_ENDIF))

      case chunk
      when *OPCODES_METHOD.keys
        m = method( n=OPCODES_METHOD[chunk] )
        @debug << n.to_s.upcase
        # invoke opcode method
        case m.arity
        when 0
          m.call
        when 1
          m.call(check_callback)
        when -2 # One fixed parameter, one optional
          m.call(check_callback, opts)
        else
          puts "Bitcoin::Script: opcode #{name} method parameters invalid"
        end
      when *OP_2_16
        @stack << OP_2_16.index(chunk) + 2
        @debug << "OP_#{chunk-80}"
      else
        name = OPCODES[chunk] || chunk
        puts "Bitcoin::Script: opcode #{name} unkown or not implemented\n#{to_string.inspect}"
        raise "opcode #{name} unkown or not implemented"
      end
    when String
      if @do_exec
        @debug << "PUSH DATA #{chunk.unpack("H*")[0]}"
        @stack << chunk
      else
        @debug.pop
      end
    end
  }
  @debug << @stack.map{|i| i.unpack("H*") rescue i } #if @do_exec

  if @script_invalid
    @stack << 0
    @debug << "INVALID TRANSACTION"
  end

  @debug << "RESULT"
  return false if @stack.empty?
  return false if cast_to_bool(@stack.pop) == false
  true
end

#sighash_subscript(drop_sigs, opts = {}) ⇒ Object


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# File 'lib/bitcoin/script.rb', line 1458

def sighash_subscript(drop_sigs, opts = {})
  if opts[:fork_id]
    drop_sigs.reject! do |signature|
      if signature && signature.size > 0
        _, hash_type = parse_sig(signature)
        (hash_type&SIGHASH_TYPE[:forkid]) != 0
      end
    end
  end

  if inner_p2sh? && @inner_script_code
    ::Bitcoin::Script.new(@inner_script_code).to_binary_without_signatures(drop_sigs)
  else
    to_binary_without_signatures(drop_sigs)
  end
end

#sigops_count_accurate(is_accurate) ⇒ Object

This matches CScript::GetSigOpCount(bool fAccurate) Note: this does not cover P2SH script which is to be unserialized

and checked explicitly when validating blocks.

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# File 'lib/bitcoin/script.rb', line 930

def sigops_count_accurate(is_accurate)
  count = 0
  last_opcode = nil
  @chunks.each do |chunk| # pushdate or opcode
    if chunk == OP_CHECKSIG || chunk == OP_CHECKSIGVERIFY
      count += 1
    elsif chunk == OP_CHECKMULTISIG || chunk == OP_CHECKMULTISIGVERIFY
      # Accurate mode counts exact number of pubkeys required (not signatures, but pubkeys!). Only used in P2SH scripts.
      # Inaccurate mode counts every multisig as 20 signatures.
      if is_accurate && last_opcode && last_opcode.is_a?(Bitcoin::Integer) && last_opcode >= OP_1 && last_opcode <= OP_16
        count += ::Bitcoin::Script.decode_OP_N(last_opcode)
      else
        count += 20
      end
    end
    last_opcode = chunk
  end
  count
end

#sigops_count_for_p2shObject

This method applies to script_sig that is an input for p2sh output. Bitcoind has somewhat special way to return count for invalid input scripts: it returns 0 when the opcode can't be parsed or when it's over OP_16. Also, if the OP_N is used anywhere it's treated as 0-length data. See CScript::GetSigOpCount(const CScript& scriptSig) in bitcoind.


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# File 'lib/bitcoin/script.rb', line 955

def sigops_count_for_p2sh
  # This is a pay-to-script-hash scriptPubKey;
  # get the last item that the scriptSig
  # pushes onto the stack:

  return 0 if @chunks.size == 0

  data = nil
  @chunks.each do |chunk|
    case chunk
    when Bitcoin::Integer
      data = ""
      return 0 if chunk > OP_16
    when String
      data = chunk
    end
  end
  return 0 if data == ""

  ::Bitcoin::Script.new(data).sigops_count_accurate(true)
end

#subscript_codeseparator(separator_index) ⇒ Object

Returns a script that deleted the script before the index specified by separator_index.


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# File 'lib/bitcoin/script.rb', line 312

def subscript_codeseparator(separator_index)
  buf = []
  process_separator_index = 0
  (chunks || @chunks).each{|chunk|
    buf << chunk if process_separator_index == separator_index
    process_separator_index += 1 if chunk == OP_CODESEPARATOR and process_separator_index < separator_index
  }
  to_binary(buf)
end

#to_binary(chunks = nil) ⇒ Object Also known as: to_payload


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

def to_binary(chunks=nil)

  (chunks || @chunks).map{|chunk|
    case chunk
    when Bitcoin::Integer; [chunk].pack("C*")
    when String; self.class.pack_pushdata(chunk)
    end
  }.join
end

#to_binary_without_signatures(drop_signatures, chunks = nil) ⇒ Object


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

def to_binary_without_signatures(drop_signatures, chunks=nil)
  buf = []
  (chunks || @chunks).each.with_index{|chunk,idx|
    if chunk == OP_CODESEPARATOR and idx <= @last_codeseparator_index
      buf.clear
    elsif chunk == OP_CODESEPARATOR
      if idx == @script_codeseparator_index
        break
      else
        # skip
      end
    elsif drop_signatures.none?{|e| e == chunk }
      buf << chunk
    end
  }
  to_binary(buf)
end

#to_string(chunks = nil) ⇒ Object

string representation of the script


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# File 'lib/bitcoin/script.rb', line 260

def to_string(chunks=nil)
  string = ""
  (chunks || @chunks).each.with_index{|i,idx|
    string << " " unless idx == 0
    string << case i
    when Bitcoin::Integer
      if opcode = OPCODES_PARSE_BINARY[i]
        opcode
      else
        "(opcode-#{i})"
      end
    when String
      if i.bitcoin_pushdata
        "#{i.bitcoin_pushdata}:#{i.bitcoin_pushdata_length}:".force_encoding('binary') + i.unpack("H*")[0]
      else
        i.unpack("H*")[0]
      end
    end
  }
  string
end

#typeObject

get type of this tx


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# File 'lib/bitcoin/script.rb', line 672

def type
  if is_hash160?;                 :hash160
  elsif is_pubkey?;               :pubkey
  elsif is_multisig?;             :multisig
  elsif is_p2sh?;                 :p2sh
  elsif is_op_return?;            :op_return
  elsif is_witness_v0_keyhash?;   :witness_v0_keyhash
  elsif is_witness_v0_scripthash?;:witness_v0_scripthash
  else;                           :unknown
  end
end