text: # -*- coding: utf-8 -*-
  #
  #    BitcoinLib - Python Cryptocurrency Library
  #    Parameters secp256r1
  #    © 2016 November - 1200 Web Development <http://1200wd.com/>
  #
  #    This program is free software: you can redistribute it and/or modify
  #    it under the terms of the GNU Affero General Public License as
  #    published by the Free Software Foundation, either version 3 of the
  #    License, or (at your option) any later version.
  #
  #    This program is distributed in the hope that it will be useful,
  #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #    GNU Affero General Public License for more details.
  #
  #    You should have received a copy of the GNU Affero General Public License
  #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
  
  import ecdsa
  
  # Parameters secp256r1
  #  from http://www.secg.org/sec2-v2.pdf, par 2.4.2
  secp256r1_p = 0xFFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFF
  secp256r1_n = 0xFFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551
  secp256r1_b = 0x5AC635D8AA3A93E7B3EBBD55769886BC651D06B0CC53B0F63BCE3C3E27D2604B
  secp256r1_a = 0xFFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFC
  secp256r1_Gx = 0x6B17D1F2E12C4247F8BCE6E563A440F277037D812DEB33A0F4A13945D898C296
  secp256r1_Gy = 0x4FE342E2FE1A7F9B8EE7EB4A7C0F9E162BCE33576B315ECECBB6406837BF51F5
  
  secp256r1_curve = ecdsa.ellipticcurve.CurveFp(secp256r1_p, secp256r1_a, secp256r1_b)
  secp256r1_generator = ecdsa.ellipticcurve.Point(secp256r1_curve, secp256r1_Gx, secp256r1_Gy, secp256r1_n)
  