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

238
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]
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, anyonecanpay: 128 }
OPCODES_METHOD = 

      
    

  




  
Instance Attribute Summary collapse

  




  
    

      Class Method Summary
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      Instance Method Summary
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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 158

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

  @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

    
      
      
      

  

  
    #chunks  ⇒ Object  (readonly)
  

  

  




  

    

Returns the value of attribute chunks.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 155

def chunks
  @chunks
end


    		
  





    
      
      
      

  

  
    #debug  ⇒ Object  (readonly)
  

  

  




  

    

Returns the value of attribute debug.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 155

def debug
  @debug
end


    		
  





    
      
      
      

  

  
    #raw  ⇒ Object  (readonly)
  

  

  




  

    

Returns the value of attribute raw.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 155

def raw
  @raw
end


    		
  





    
      
      
      

  

  
    #stack  ⇒ Object  (readonly)
  

  

  




  

    

Returns the value of attribute stack.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 155

def stack
  @stack
end


    		
  





    
  



  

    
Class Method Details


    
      

  

  
    .add_sig_to_multisig_script_sig(sig, script_sig, hash_type = )  ⇒ 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 839

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 380

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?(Fixnum)
             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:


    
  
    
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        (Boolean)
      
      
      
    
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# File 'lib/bitcoin/script.rb', line 1502

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:


    
  
    
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        (Boolean)
      
      
      
    
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# File 'lib/bitcoin/script.rb', line 1521

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)
  return false if opts[:verify_strictenc] && !is_defined_hashtype_signature?(sig)
  true
end


    		
  





    
      

  

  
    .compare_big_endian(c1, c2)  ⇒ Object 
  

  

  




  

    

Compares two arrays of bytes



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1565

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 937

def self.decode_OP_N(opcode)
  if opcode == OP_0
    return 0
  end
  if opcode.is_a?(Fixnum) && 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 494

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 369

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 
  

  

  




  

    

  





  

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        (Boolean)
      
      
      
    
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# File 'lib/bitcoin/script.rb', line 1507

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:


    
  
    
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        (Boolean)
      
      
      
    
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# File 'lib/bitcoin/script.rb', line 1601

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

  s = sig.unpack("C*")
  hash_type = s[-1] & (~(SIGHASH_TYPE[:anyonecanpay]))
  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:


    
  
    
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        (Boolean)
      
      
      
    
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# File 'lib/bitcoin/script.rb', line 1530

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 1581

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 332

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 353

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 854

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 764

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)
  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 732

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 775

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 828

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 788

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 814

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 848

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 740

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 726

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


    		
  





    
      

  

  
    .to_pubkey_script_sig(signature, pubkey, hash_type = )  ⇒ 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 797

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 821

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 748

def self.to_witness_hash160_script(hash160)
  return nil  unless hash160
  #  witness ver  length  hash160
  [ ["00",         "14",  hash160].join ].pack("H*")
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 756

def self.to_witness_p2sh_script(p2sh)
  return nil  unless p2sh
  #  witness ver  length  sha256
  [ [ "00",        "20",   p2sh].join].pack("H*")
end


    		
  





    
  


  

    
Instance Method Details


    
      

  

  
    #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 313

def append_opcode(opcode)
  raise "Opcode should be a Fixnum" if !opcode.is_a?(Fixnum)
  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 326

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 1333

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 1355

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 1346

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 608

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 1383

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_count  ⇒ Object 
  

  

  




  

    
      


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

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


    		
  





    
      

  

  
    #get_address  ⇒ Object 
  

  

  




  

    

get single address, or first for multisig script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 719

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


    		
  





    
      

  

  
    #get_addresses  ⇒ Object 
  

  

  




  

    

get all addresses this script corresponds to (if possible)



  





  



  

    
      


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

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?
  []
end


    		
  





    
      

  

  
    #get_hash160  ⇒ Object 
  

  

  




  

    

get the hash160 for this hash160 or pubkey script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 671

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_address  ⇒ Object 
  

  

  




  

    

get the hash160 address for this hash160 script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 680

def get_hash160_address
  Bitcoin.hash160_to_address(get_hash160)
end


    		
  





    
      

  

  
    #get_keys_provided  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 876

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


    		
  





    
      

  

  
    #get_multisig_addresses  ⇒ Object 
  

  

  




  

    

get the pubkey addresses for this multisig script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 690

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_pubkeys  ⇒ Object 
  

  

  




  

    

get the public keys for this multisig script



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #get_op_return_data  ⇒ Object 
  

  

  




  

    

get the data possibly included in an OP_RETURN script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 704

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_address  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 699

def get_p2sh_address
  Bitcoin.hash160_to_p2sh_address(get_hash160)
end


    		
  





    
      

  

  
    #get_pubkey  ⇒ Object 
  

  

  




  

    

get the public key for this pubkey script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 660

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


    		
  





    
      

  

  
    #get_pubkey_address  ⇒ Object 
  

  

  




  

    

get the pubkey address for this pubkey script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 666

def get_pubkey_address
  Bitcoin.pubkey_to_address(get_pubkey)
end


    		
  





    
      

  

  
    #get_signatures_required  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 871

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 518

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 519

def inner_p2sh?; @inner_p2sh; end


    		
  





    
      

  

  
    #inner_p2sh_script  ⇒ Object 
  

  

  




  

    

get the inner p2sh script



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 522

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


    		
  





    
      

  

  
    #invalid  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 490

def invalid
  @script_invalid = true; nil
end


    		
  





    
      

  

  
    #invalid?  ⇒ Boolean 
  

  

  




  

    

  





  

Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
    
    • 
  





  

    
      


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# File 'lib/bitcoin/script.rb', line 410

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 565

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 573

def is_multisig?
  return false  if @chunks.size < 4 || !@chunks[-2].is_a?(Fixnum)
  @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 579

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 533

def is_pay_to_script_hash?
  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 558

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 599

def is_push_only?(script_data=nil)
  check_pushes(push_only=true, canonical_only=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 553

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(witness_v0_keyhash or witness_v0_scripthash)



  





  

Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
    
    • 
  





  

    
      


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# File 'lib/bitcoin/script.rb', line 584

def is_witness?
  is_witness_v0_keyhash? || is_witness_v0_scripthash?
end


    		
  





    
      

  

  
    #is_witness_v0_keyhash?  ⇒ Boolean 
  

  

  




  

    

is this a witness pubkey script



  





  

Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
    
    • 
  





  

    
      


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# File 'lib/bitcoin/script.rb', line 589

def is_witness_v0_keyhash?
  @chunks.length == 2 &&@chunks[0] == 0 && @chunks[1].is_a?(String) && @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 594

def is_witness_v0_scripthash?
  @chunks.length == 2 &&@chunks[0] == 0 && @chunks[1].is_a?(String) && @chunks[1].bytesize == 32
end


    		
  





    
      

  

  
    #op_0  ⇒ Object 
  

  

  




  

    

An empty array of bytes is pushed onto the stack.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1144

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


    		
  





    
      

  

  
    #op_0notequal  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 1075

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


    		
  





    
      

  

  
    #op_1  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1149

def op_1
  @stack << 1
end


    		
  





    
      

  

  
    #op_1add  ⇒ Object 
  

  

  




  

    

1 is added to the input.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1099

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


    		
  





    
      

  

  
    #op_1negate  ⇒ Object 
  

  

  




  

    

The number -1 is pushed onto the stack.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1184

def op_1negate
  @stack << -1
end


    		
  





    
      

  

  
    #op_1sub  ⇒ Object 
  

  

  




  

    

1 is subtracted from the input.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1105

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


    		
  





    
      

  

  
    #op_2div  ⇒ Object 
  

  

  




  

    

The input is divided by 2. Currently disabled.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1087

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


    		
  





    
      

  

  
    #op_2drop  ⇒ Object 
  

  

  




  

    

Removes the top two stack items.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1289

def op_2drop
  @stack.pop(2)
end


    		
  





    
      

  

  
    #op_2dup  ⇒ Object 
  

  

  




  

    

Duplicates the top two stack items.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1294

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


    		
  





    
      

  

  
    #op_2mul  ⇒ Object 
  

  

  




  

    

The input is multiplied by 2. Currently disabled.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1093

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


    		
  





    
      

  

  
    #op_2over  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_2rot  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1264

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


    		
  





    
      

  

  
    #op_2swap  ⇒ Object 
  

  

  




  

    

Swaps the top two pairs of items.



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_3dup  ⇒ Object 
  

  

  




  

    

Duplicates the top three stack items.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1299

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


    		
  





    
      

  

  
    #op_abs  ⇒ Object 
  

  

  




  

    

The input is made positive.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1081

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


    		
  





    
      

  

  
    #op_add  ⇒ Object 
  

  

  




  

    

a is added to b.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1034

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


    		
  





    
      

  

  
    #op_booland  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1022

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


    		
  





    
      

  

  
    #op_boolor  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1028

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 1443

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)

  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 1486

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 1394

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)

  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 1425

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


    		
  





    
      

  

  
    #op_codeseparator  ⇒ Object 
  

  

  




  

    

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 1378

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


    		
  





    
      

  

  
    #op_depth  ⇒ Object 
  

  

  




  

    

Puts the number of stack items onto the stack.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1189

def op_depth
  @stack << @stack.size
end


    		
  





    
      

  

  
    #op_drop  ⇒ Object 
  

  

  




  

    

Removes the top stack item.



  





  



  

    
      


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

def op_drop
  @stack.pop
end


    		
  





    
      

  

  
    #op_dup  ⇒ Object 
  

  

  




  

    

Duplicates the top stack item.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 967

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


    		
  





    
      

  

  
    #op_else  ⇒ Object 
  

  

  




  

    

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 1243

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


    		
  





    
      

  

  
    #op_endif  ⇒ Object 
  

  

  




  

    

Ends an if/else block.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1249

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


    		
  





    
      

  

  
    #op_equal  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1122

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


    		
  





    
      

  

  
    #op_equalverify  ⇒ Object 
  

  

  




  

    

Same as OP_EQUAL, but runs OP_VERIFY afterward.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1139

def op_equalverify
  op_equal; op_verify
end


    		
  





    
      

  

  
    #op_fromaltstack  ⇒ Object 
  

  

  




  

    

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 1007

def op_fromaltstack
  @stack << @stack_alt.pop
end


    		
  





    
      

  

  
    #op_greaterthan  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1058

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


    		
  





    
      

  

  
    #op_greaterthanorequal  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_hash160  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


984
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# File 'lib/bitcoin/script.rb', line 984

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


    		
  





    
      

  

  
    #op_hash256  ⇒ Object 
  

  

  




  

    

The input is hashed two times with SHA-256.



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_if  ⇒ Object 
  

  

  




  

    

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 1223

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_ifdup  ⇒ Object 
  

  

  




  

    

If the input is true, duplicate it.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1177

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


    		
  





    
      

  

  
    #op_lessthan  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1046

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


    		
  





    
      

  

  
    #op_lessthanorequal  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1052

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


    		
  





    
      

  

  
    #op_max  ⇒ Object 
  

  

  




  

    

Returns the larger of a and b.



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_min  ⇒ Object 
  

  

  




  

    

Returns the smaller of a and b.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1154

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


    		
  





    
      

  

  
    #op_negate  ⇒ Object 
  

  

  




  

    

The sign of the input is flipped.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1111

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


    		
  





    
      

  

  
    #op_nip  ⇒ Object 
  

  

  




  

    

Removes the second-to-top stack item.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1304

def op_nip
  @stack.delete_at(-2)
end


    		
  





    
      

  

  
    #op_nop  ⇒ Object 
  

  

  




  

    

Does nothing



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 954

def op_nop; end


    		
  





    
      

  

  
    #op_nop1  ⇒ Object 
  

  

  




  

    

op_eval: en.bitcoin.it/wiki/BIP_0012



the BIP was never accepted and must be handled as old OP_NOP1




  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1493

def op_nop1; end


    		
  





    
      

  

  
    #op_nop10  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 964

def op_nop10; end


    		
  





    
      

  

  
    #op_nop2  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 956

def op_nop2; end


    		
  





    
      

  

  
    #op_nop3  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 957

def op_nop3; end


    		
  





    
      

  

  
    #op_nop4  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 958

def op_nop4; end


    		
  





    
      

  

  
    #op_nop5  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 959

def op_nop5; end


    		
  





    
      

  

  
    #op_nop6  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 960

def op_nop6; end


    		
  





    
      

  

  
    #op_nop7  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 961

def op_nop7; end


    		
  





    
      

  

  
    #op_nop8  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 962

def op_nop8; end


    		
  





    
      

  

  
    #op_nop9  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 963

def op_nop9; end


    		
  





    
      

  

  
    #op_not  ⇒ Object 
  

  

  




  

    

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 1070

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


    		
  





    
      

  

  
    #op_notif  ⇒ Object 
  

  

  




  

    

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 1233

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_numequal  ⇒ Object 
  

  

  




  

    

Returns 1 if the numbers are equal, 0 otherwise.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1200

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


    		
  





    
      

  

  
    #op_numequalverify  ⇒ Object 
  

  

  




  

    

Same as OP_NUMEQUAL, but runs OP_VERIFY afterward.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1372

def op_numequalverify
  op_numequal; op_verify
end


    		
  





    
      

  

  
    #op_numnotequal  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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

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


    		
  





    
      

  

  
    #op_over  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1217

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


    		
  





    
      

  

  
    #op_pick  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1255

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_return  ⇒ Object 
  

  

  




  

    

Marks transaction as invalid.



  





  



  

    
      


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

def op_return
  @script_invalid = true; nil
end


    		
  





    
      

  

  
    #op_ripemd160  ⇒ Object 
  

  

  




  

    

The input is hashed using RIPEMD-160.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 990

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


    		
  





    
      

  

  
    #op_roll  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1270

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_rot  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1283

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


    		
  





    
      

  

  
    #op_sha1  ⇒ Object 
  

  

  




  

    

The input is hashed using SHA-1.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 978

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


    		
  





    
      

  

  
    #op_sha256  ⇒ Object 
  

  

  




  

    

The input is hashed using SHA-256.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 972

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


    		
  





    
      

  

  
    #op_size  ⇒ Object 
  

  

  




  

    

Returns the length of the input string.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1309

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_sub  ⇒ Object 
  

  

  




  

    

b is subtracted from a.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1040

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


    		
  





    
      

  

  
    #op_swap  ⇒ Object 
  

  

  




  

    

The top two items on the stack are swapped.



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1017

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


    		
  





    
      

  

  
    #op_toaltstack  ⇒ Object 
  

  

  




  

    

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 1002

def op_toaltstack
  @stack_alt << @stack.pop
end


    		
  





    
      

  

  
    #op_tuck  ⇒ Object 
  

  

  




  

    

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 1012

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


    		
  





    
      

  

  
    #op_ver  ⇒ Object 
  

  

  




  

    

Transaction is invalid unless occuring in an unexecuted OP_IF branch



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1319

def op_ver
  invalid if @do_exec
end


    		
  





    
      

  

  
    #op_verify  ⇒ Object 
  

  

  




  

    

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 1128

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_within  ⇒ Object 
  

  

  




  

    

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



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 1194

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 187

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 502

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 1323

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 1328

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 604

def pushes_are_canonical?(script_data=nil)
  check_pushes(push_only=false, canonical_only=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 415

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 Fixnum
      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)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/bitcoin/script.rb', line 1416

def sighash_subscript(drop_sigs)
  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 888

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?(Fixnum) && 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_p2sh  ⇒ Object 
  

  

  




  

    

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 913

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 Fixnum
      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 301

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 272

def to_binary(chunks=nil)
  (chunks || @chunks).map{|chunk|
    case chunk
    when Fixnum; [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 282

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 250

def to_string(chunks=nil)
  string = ""
  (chunks || @chunks).each.with_index{|i,idx|
    string << " " unless idx == 0
    string << case i
    when Fixnum
      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


    		
  





    
      

  

  
    #type  ⇒ Object 
  

  

  




  

    

get type of this tx



  





  



  

    
      


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# File 'lib/bitcoin/script.rb', line 647

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