Class: Bitcoin::PSBT::Tx

Inherits:
Object
  • Object
show all
Includes:
HexConverter
Defined in:
lib/bitcoin/psbt/tx.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from HexConverter

#to_hex

Constructor Details

#initialize(tx = nil) ⇒ Tx

Returns a new instance of Tx.



39
40
41
42
43
44
45
46
 
# File 'lib/bitcoin/psbt/tx.rb', line 39

def initialize(tx = nil)
  @tx = tx
  @xpubs = []
  @inputs = tx ? tx.in.map{Input.new}: []
  @outputs = tx ? tx.out.map{Output.new}: []
  @proprietaries = []
  @unknowns = {}
end

Instance Attribute Details

#inputs ⇒ Object (readonly)

Returns the value of attribute inputs.



33
34
35
 
# File 'lib/bitcoin/psbt/tx.rb', line 33

def inputs
  @inputs
end

#outputs ⇒ Object (readonly)

Returns the value of attribute outputs.



34
35
36
 
# File 'lib/bitcoin/psbt/tx.rb', line 34

def outputs
  @outputs
end

#proprietaries ⇒ Object

Returns the value of attribute proprietaries.



35
36
37
 
# File 'lib/bitcoin/psbt/tx.rb', line 35

def proprietaries
  @proprietaries
end

#tx ⇒ Object

Returns the value of attribute tx.



31
32
33
 
# File 'lib/bitcoin/psbt/tx.rb', line 31

def tx
  @tx
end

#unknowns ⇒ Object

Returns the value of attribute unknowns.



36
37
38
 
# File 'lib/bitcoin/psbt/tx.rb', line 36

def unknowns
  @unknowns
end

#version_number ⇒ Object

Returns the value of attribute version_number.



37
38
39
 
# File 'lib/bitcoin/psbt/tx.rb', line 37

def version_number
  @version_number
end

#xpubs ⇒ Object

Returns the value of attribute xpubs.



32
33
34
 
# File 'lib/bitcoin/psbt/tx.rb', line 32

def xpubs
  @xpubs
end

Class Method Details

.parse_from_base64(base64) ⇒ Bitcoin::PartiallySignedTx

parse Partially Signed Bitcoin Transaction data with Base64 format.

Parameters:

  • base64 (String) —

    a Partially Signed Bitcoin Transaction data with Base64 format.

Returns:

  • (Bitcoin::PartiallySignedTx) 


51
52
53
 
# File 'lib/bitcoin/psbt/tx.rb', line 51

def self.parse_from_base64(base64)
  self.parse_from_payload(Base64.decode64(base64))
end

.parse_from_payload(payload) ⇒ Bitcoin::PartiallySignedTx

parse Partially Signed Bitcoin Transaction data.

Parameters:

  • payload (String) —

    a Partially Signed Bitcoin Transaction data with binary format.

Returns:

  • (Bitcoin::PartiallySignedTx)

Raises:

  • (ArgumentError) 


58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
 
# File 'lib/bitcoin/psbt/tx.rb', line 58

def self.parse_from_payload(payload)
  buf = StringIO.new(payload)
  raise ArgumentError, 'Invalid PSBT magic bytes.' unless buf.read(4).unpack1('N') == PSBT_MAGIC_BYTES
  raise ArgumentError, 'Invalid PSBT separator.' unless buf.read(1).bth.to_i(16) == 0xff
  partial_tx = self.new
  found_sep = false
  # read global data.
  until buf.eof?
    key_len = Bitcoin.unpack_var_int_from_io(buf)
    if key_len == 0
      found_sep = true
      break
    end
    key_start = buf.pos
    key_type = Bitcoin.unpack_var_int_from_io(buf)
    key = buf.read(key_len - (buf.pos - key_start))
    value = buf.read(Bitcoin.unpack_var_int_from_io(buf))

    case key_type
    when PSBT_GLOBAL_TYPES[:unsigned_tx]
      raise ArgumentError, 'Invalid global transaction typed key.' unless key_len == 1
      raise ArgumentError, 'Duplicate Key, unsigned tx already provided.' if partial_tx.tx
      partial_tx.tx = Bitcoin::Tx.parse_from_payload(value, non_witness: true, strict: true)
      partial_tx.tx.in.each do |tx_in|
        raise ArgumentError, 'Unsigned tx does not have empty scriptSigs and scriptWitnesses.' if !tx_in.script_sig.empty? || !tx_in.script_witness.empty?
      end
    when PSBT_GLOBAL_TYPES[:xpub]
      raise ArgumentError, 'Size of key was not the expected size for the type global xpub.' unless key.size == Bitcoin::BIP32_EXTKEY_WITH_VERSION_SIZE
      xpub = Bitcoin::ExtPubkey.parse_from_payload(key)
      raise ArgumentError, Errors::Messages::INVALID_PUBLIC_KEY unless xpub.key.fully_valid_pubkey?
      raise ArgumentError, 'Duplicate key, global xpub already provided' if partial_tx.xpubs.any?{|x|x.xpub == xpub}
      info = Bitcoin::PSBT::KeyOriginInfo.parse_from_payload(value)
      raise ArgumentError, "global xpub's depth and the number of indexes not matched." unless xpub.depth == info.key_paths.size
      partial_tx.xpubs << Bitcoin::PSBT::GlobalXpub.new(xpub, info)
    when PSBT_GLOBAL_TYPES[:ver]
      raise ArgumentError, 'Invalid global version typed key.' unless key_len == 1
      raise ArgumentError, 'Duplicate Key, global version already provided.' if partial_tx.version_number
      raise ArgumentError, 'Invalid global version value.' unless value.bytesize == 4
      partial_tx.version_number = value.unpack1('V')
      raise ArgumentError, "An unsupported version was detected." if SUPPORT_VERSION < partial_tx.version_number
    when PSBT_GLOBAL_TYPES[:proprietary]
      proprietary = Proprietary.new(key, value)
      raise ArgumentError, 'Duplicate Key, key for proprietary value already provided.' if partial_tx.proprietaries.any?{|p| p.key == proprietary.key}
      partial_tx.proprietaries << proprietary
    else
      unknown_key = (Bitcoin.pack_var_int(key_type) + key).bth
      raise ArgumentError, 'Duplicate Key, key for unknown value already provided.' if partial_tx.unknowns[unknown_key]
      partial_tx.unknowns[unknown_key] = value
    end
  end

  raise ArgumentError, 'Separator is missing at the end of an output map.' unless found_sep
  raise ArgumentError, 'No unsigned transaction was provided.' unless partial_tx.tx

  # read input data.
  partial_tx.tx.in.each do |tx_in|
    break if buf.eof?
    input = Input.parse_from_buf(buf)
    partial_tx.inputs << input
    if input.non_witness_utxo && input.non_witness_utxo.tx_hash != tx_in.prev_hash
      raise ArgumentError, 'Non-witness UTXO does not match outpoint hash.'
    end
  end

  raise ArgumentError, 'Inputs provided does not match the number of inputs in transaction.' unless partial_tx.inputs.size == partial_tx.tx.in.size

  # read output data.
  partial_tx.tx.outputs.each do
    break if buf.eof?
    output = Output.parse_from_buf(buf)
    break unless output
    partial_tx.outputs << output
  end

  raise ArgumentError, 'Outputs provided does not match the number of outputs in transaction.' unless partial_tx.outputs.size == partial_tx.tx.out.size

  partial_tx
end

Instance Method Details

#extract_tx ⇒ Bitcoin::Tx

extract final tx.

Returns:



274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
 
# File 'lib/bitcoin/psbt/tx.rb', line 274

def extract_tx
  extract_tx = Bitcoin::Tx.parse_from_payload(tx.to_payload)
  inputs.each_with_index do |input, index|
    extract_tx.in[index].script_sig = input.final_script_sig if input.final_script_sig
    extract_tx.in[index].script_witness = input.final_script_witness if input.final_script_witness
  end
  # validate signature
  extract_tx.in.each_with_index do |tx_in, index|
    input = inputs[index]
    if input.non_witness_utxo
      utxo = input.non_witness_utxo.out[tx_in.out_point.index]
      raise "input[#{index}]'s signature is invalid.'" unless extract_tx.verify_input_sig(index, utxo.script_pubkey)
    else
      utxo = input.witness_utxo
      raise ArgumentError, "input[#{index}] does not have utxo." unless utxo
      raise "input[#{index}]'s signature is invalid.'" unless extract_tx.verify_input_sig(index, utxo.script_pubkey, amount: utxo.value)
    end
  end
  extract_tx
end

#finalize! ⇒ Bitcoin::PSBT::Tx

finalize tx. TODO This feature is experimental and support only multisig.

Returns:



267
268
269
270
 
# File 'lib/bitcoin/psbt/tx.rb', line 267

def finalize!
  inputs.each {|input|input.finalize!}
  self
end

#input_utxo(index) ⇒ Bitcoin::TxOut

Finds the UTXO for a given input index

Parameters:

  • index (Integer) —

    input_index Index of the input to retrieve the UTXO of

Returns:



146
147
148
149
150
151
152
 
# File 'lib/bitcoin/psbt/tx.rb', line 146

def input_utxo(index)
  input = inputs[index]
  prevout_index = tx.in[index].out_point.index
  return input.non_witness_utxo.out[prevout_index] if input.non_witness_utxo
  return input.witness_utxo if input.witness_utxo
  nil
end

#merge(psbt) ⇒ Bitcoin::PartiallySignedTx

merge two PSBTs to create one PSBT. TODO This feature is experimental.

Parameters:

  • psbt (Bitcoin::PartiallySignedTx) —

    PSBT to be combined which must have same property in PartiallySignedTx.

Returns:

  • (Bitcoin::PartiallySignedTx) —

    combined object.

Raises:

  • (ArgumentError) 


246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
 
# File 'lib/bitcoin/psbt/tx.rb', line 246

def merge(psbt)
  raise ArgumentError, 'The argument psbt must be an instance of Bitcoin::PSBT::Tx.' unless psbt.is_a?(Bitcoin::PSBT::Tx)
  raise ArgumentError, 'The combined transactions are different.' unless tx == psbt.tx
  raise ArgumentError, 'The Partially Signed Input\'s count are different.' unless inputs.size == psbt.inputs.size
  raise ArgumentError, 'The Partially Signed Output\'s count are different.' unless outputs.size == psbt.outputs.size

  combined = Bitcoin::PSBT::Tx.new(tx)
  inputs.each_with_index do |i, index|
    combined.inputs[index] = i.merge(psbt.inputs[index])
  end
  outputs.each_with_index do |o, index|
    combined.outputs[index] = o.merge(psbt.outputs[index])
  end

  combined.unknowns = Hash[unknowns.merge(psbt.unknowns).sort]
  combined
end

#ready_to_sign? ⇒ Boolean

Check whether the signer can sign. Specifically, check the following.

  • If a non-witness UTXO is provided, its hash must match the hash specified in the prevout
  • If a witness UTXO is provided, no non-witness signature may be created
  • If a redeemScript is provided, the scriptPubKey must be for that redeemScript
  • If a witnessScript is provided, the scriptPubKey or the redeemScript must be for that witnessScript

Returns:

  • (Boolean) 


225
226
227
228
 
# File 'lib/bitcoin/psbt/tx.rb', line 225

def ready_to_sign?
  inputs.each.with_index{|psbt_in, index|return false unless psbt_in.ready_to_sign?(input_utxo(index))}
  true
end

#signature_script(index) ⇒ Bitcoin::Script

get signature script of input specified by index

Parameters:

Returns:



233
234
235
236
237
238
239
240
 
# File 'lib/bitcoin/psbt/tx.rb', line 233

def signature_script(index)
  i = inputs[index]
  if i.non_witness_utxo
    i.redeem_script ? i.redeem_script : i.non_witness_utxo.out[tx.in[index].out_point.index].script_pubkey
  else
    i.witness_script ? i.witness_script : i.witness_utxo
  end
end

#to_base64 ⇒ String

generate payload with Base64 format.

Returns:

  • (String) —

    a payload with Base64 format.



173
174
175
 
# File 'lib/bitcoin/psbt/tx.rb', line 173

def to_base64
  Base64.strict_encode64(to_payload)
end

#to_file(path) ⇒ Object

Store the PSBT to a file.

Parameters:

  • path (String) —

    File path to store.

Raises:

  • (ArgumentError) 


179
180
181
182
183
184
 
# File 'lib/bitcoin/psbt/tx.rb', line 179

def to_file(path)
  raise ArgumentError, 'The file already exists' if File.exist?(path)
  File.open(path, 'w') do |f|
    f.write(to_payload)
  end
end

#to_h ⇒ Object 



186
187
188
189
190
191
192
193
194
195
196
 
# File 'lib/bitcoin/psbt/tx.rb', line 186

def to_h
  {
    tx: tx.to_h,
    global_xpubs: xpubs.map(&:to_h),
    psbt_version: version,
    proprietary: proprietaries.map(&:to_h),
    unknown: unknowns.map {|k, v| {"#{k}": v}},
    inputs: inputs.map(&:to_h),
    outputs: outputs.map(&:to_h)
  }
end

#to_payload ⇒ String

generate payload.

Returns:

  • (String) —

    a payload with binary format.



156
157
158
159
160
161
162
163
164
165
166
167
168
169
 
# File 'lib/bitcoin/psbt/tx.rb', line 156

def to_payload
  payload = PSBT_MAGIC_BYTES.itb << 0xff.itb

  payload << PSBT.serialize_to_vector(PSBT_GLOBAL_TYPES[:unsigned_tx], value: tx.to_payload)
  payload << xpubs.map(&:to_payload).join
  payload << PSBT.serialize_to_vector(PSBT_GLOBAL_TYPES[:ver], value: [version_number].pack('V')) if version_number
  payload << proprietaries.map(&:to_payload).join
  payload << unknowns.map {|k,v|Bitcoin.pack_var_int(k.htb.bytesize) << k.htb << Bitcoin.pack_var_int(v.bytesize) << v}.join

  payload << PSBT_SEPARATOR.itb
  payload << inputs.map(&:to_payload).join
  payload << outputs.map(&:to_payload).join
  payload
end

#update!(prev_tx, redeem_script: nil, witness_script: nil, hd_key_paths: []) ⇒ Object

update input key-value maps.

Parameters:

  • prev_tx (Bitcoin::Tx) —

    previous tx reference by input.

  • redeem_script (Bitcoin::Script) (defaults to: nil) —

    redeem script to set input.

  • witness_script (Bitcoin::Script) (defaults to: nil) —

    witness script to set input.

  • hd_key_paths (Hash) (defaults to: []) —

    bip 32 hd key paths to set input.



203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
 
# File 'lib/bitcoin/psbt/tx.rb', line 203

def update!(prev_tx, redeem_script: nil, witness_script: nil, hd_key_paths: [])
  prev_hash = prev_tx.tx_hash
  tx.in.each_with_index do|tx_in, i|
    if tx_in.prev_hash == prev_hash
      utxo = prev_tx.out[tx_in.out_point.index]
      raise ArgumentError, 'redeem script does not match utxo.' if redeem_script && !utxo.script_pubkey.include?(redeem_script.to_hash160)
      raise ArgumentError, 'witness script does not match redeem script.' if redeem_script && witness_script && !redeem_script.include?(witness_script.to_sha256)
      inputs[i].witness_utxo = utxo if utxo.script_pubkey.witness_program? || redeem_script&.witness_program?
      inputs[i].non_witness_utxo = prev_tx
      inputs[i].redeem_script = redeem_script if redeem_script
      inputs[i].witness_script = witness_script if witness_script
      inputs[i].hd_key_paths = hd_key_paths.map(&:pubkey).zip(hd_key_paths).to_h
    end
  end
end

#version ⇒ Integer

get PSBT version

Returns:

  • (Integer) —

    PSBT version number



139
140
141
 
# File 'lib/bitcoin/psbt/tx.rb', line 139

def version
  version_number ? version_number : 0
end