Class: CiBlockIo::Key

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(privkey = nil, compressed = true) ⇒ Key

Returns a new instance of Key.


178
179
180
181
182
183
184
185
186
# File 'lib/ci_block_io.rb', line 178

def initialize(privkey = nil, compressed = true)
  # the privkey must be in hex if at all provided

  @group = ECDSA::Group::Secp256k1
  @private_key = privkey.to_i(16) || 1 + SecureRandom.random_number(group.order - 1)
  @public_key = @group.generator.multiply_by_scalar(@private_key)
  @compressed = compressed

end

Class Method Details

.from_passphrase(passphrase) ⇒ Object

Raises:

  • (Exception)

218
219
220
221
222
223
224
225
226
227
228
# File 'lib/ci_block_io.rb', line 218

def self.from_passphrase(passphrase)
  # create a private+public key pair from a given passphrase
  # think of this as your brain wallet. be very sure to use a sufficiently long passphrase
  # if you don't want a passphrase, just use Key.new and it will generate a random key for you

  raise Exception.new('Must provide passphrase at least 8 characters long.') if passphrase.nil? or passphrase.length < 8

  hashed_key = Helper.sha256([passphrase].pack("H*")) # must pass bytes to sha256

  return Key.new(hashed_key)
end

.from_wif(wif) ⇒ Object


230
231
232
233
234
235
236
237
238
239
240
241
# File 'lib/ci_block_io.rb', line 230

def self.from_wif(wif)
  # returns a new key extracted from the Wallet Import Format provided
  # TODO check against checksum

  hexkey = Helper.decode_base58(wif)
  actual_key = hexkey[2...66]

  compressed = hexkey[2..hexkey.length].length-8 > 64 and hexkey[2..hexkey.length][64...66] == '01'

  return Key.new(actual_key, compressed)

end

Instance Method Details

#deterministicGenerateK(data, privkey, group = ECDSA::Group::Secp256k1) ⇒ Object


249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
# File 'lib/ci_block_io.rb', line 249

def deterministicGenerateK(data, privkey, group = ECDSA::Group::Secp256k1)
  # returns a deterministic K  -- RFC6979

  hash = data.bytes.to_a

  x = [privkey.to_s(16)].pack("H*").bytes.to_a

  k = []
  32.times { k.insert(0, 0) }

  v = []
  32.times { v.insert(0, 1) }

  # step D
  k = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), [].concat(v).concat([0]).concat(x).concat(hash).pack("C*")).bytes.to_a

  # step E
  v = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), v.pack("C*")).bytes.to_a

  #  puts "E: " + v.pack("C*").unpack("H*")[0]

  # step F
  k = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), [].concat(v).concat([1]).concat(x).concat(hash).pack("C*")).bytes.to_a

  # step G
  v = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), v.pack("C*")).bytes.to_a

  # step H2b (Step H1/H2a ignored)
  v = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), v.pack("C*")).bytes.to_a

  h2b = v.pack("C*").unpack("H*")[0]
  tNum = h2b.to_i(16)

  # step H3
  while (!isPositive(tNum) or tNum >= group.order) do
    # k = crypto.HmacSHA256(Buffer.concat([v, new Buffer([0])]), k)
    k = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), [].concat(v).concat([0]).pack("C*")).bytes.to_a

    # v = crypto.HmacSHA256(v, k)
    v = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), k.pack("C*"), v.pack("C*")).bytes.to_a

    # T = BigInteger.fromBuffer(v)
    tNum = v.pack("C*").unpack("H*")[0].to_i(16)
  end

  return tNum
end

#isPositive(i) ⇒ Object


243
244
245
246
247
# File 'lib/ci_block_io.rb', line 243

def isPositive(i)
  sig = "!+-"[i <=> 0]

  return sig.eql?("+")
end

#private_keyObject


188
189
190
191
# File 'lib/ci_block_io.rb', line 188

def private_key
  # returns private key in hex form
  return @private_key.to_s(16)
end

#public_keyObject


193
194
195
196
197
# File 'lib/ci_block_io.rb', line 193

def public_key
  # returns the compressed form of the public key to save network fees (shorter scripts)

  return ECDSA::Format::PointOctetString.encode(@public_key, compression: @compressed).unpack("H*")[0]
end

#sign(data) ⇒ Object


199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
# File 'lib/ci_block_io.rb', line 199

def sign(data)
  # signed the given hexadecimal string

  nonce = deterministicGenerateK([data].pack("H*"), @private_key) # RFC6979

  signature = ECDSA.sign(@group, @private_key, data.to_i(16), nonce)

  # BIP0062 -- use lower S values only
  r, s = signature.components

  over_two = @group.order >> 1 # half of what it was                     
  s = @group.order - s if (s > over_two)

  signature = ECDSA::Signature.new(r, s)

  # DER encode this, and return it in hex form
  return ECDSA::Format::SignatureDerString.encode(signature).unpack("H*")[0]
end