Renamed packge to "pyflo-lib" so we can upload to PyPI

Co-Authored-By: Sai Raj <39055732+sairajzero@users.noreply.github.com>

.gitignore

@@ -3,4 +3,6 @@ build/
 dist/
 .github/
 pybtc.egg-info/
-
+pyflo.egg-info/
+pyflo_lib.egg-info/
+*.pyc

README.md

@@ -1,8 +1,6 @@
 ## Python bitcoin library modified for FLO
 
-
 ### Installation
-
 To install pyflo, 
 
     $ git clone https://github.com/ranchimall/pyflo
@@ -20,10 +18,10 @@ To install pyflo,
 Every message sent to the Blockchain is in hash format, and not in plain string. So we convert the message we are signing into a SHA256 hash before. 
 
 ```
->>> import pybtc
+>>> import pyflo
 
 # ADDRESS GENERATION 
->>> a = pybtc.Address(address_type="P2PKH")
+>>> a = pyflo.Address(address_type="P2PKH")
 >>> a.address
 'FTP7LL7QjhgKfqYX1pis18bCqEpZaGSRzZ'
 >>> a.private_key.wif
@@ -34,13 +32,13 @@ Every message sent to the Blockchain is in hash format, and not in plain string.
 '033c30b269e2d5df229f3f0ce294b19c4f0a3a8d12280415ce41e7bd3784a619c4'
 
 # CONVERT MESSAGE INTO SHA-256 HASH 
->>> pybtc.sha256(b'vivek'.hex())
+>>> pyflo.sha256(b'vivek'.hex())
 b'\xa3\xdas\x97e\x01\x81,\xd7\xb8!\xa2\x0b\xfb\t\xaf\nj\x89\x1eA\x9c\xdf\xb7a\xfb\x19\xa9,\x91BB'
->>> pybtc.sha256(b'vivek'.hex()).hex()
+>>> pyflo.sha256(b'vivek'.hex()).hex()
 'a3da73976501812cd7b821a20bfb09af0a6a891e419cdfb761fb19a92c914242'
 >>> msg = b'vivek'.hex()
->>> msg_hash_hex = sha256(msg).hex()
->>> msg_hash_bytes = sha256(msg)
+>>> msg_hash_hex = pyflo.sha256(msg).hex()
+>>> msg_hash_bytes = pyflo.sha256(msg)
 >>> msg
 '766976656b'
 >>> msg_hash_hex
@@ -49,10 +47,120 @@ b'\xa3\xdas\x97e\x01\x81,\xd7\xb8!\xa2\x0b\xfb\t\xaf\nj\x89\x1eA\x9c\xdf\xb7a\xf
 b'\xa3\xdas\x97e\x01\x81,\xd7\xb8!\xa2\x0b\xfb\t\xaf\nj\x89\x1eA\x9c\xdf\xb7a\xfb\x19\xa9,\x91BB'
 
 # SIGN AND VERIFY THE MESSAGE 
->>> sig_msg_hex = pybtc.sign_message(msg_hash_hex, a.private_key.wif)
->>> pybtc.verify_signature(sig_msg_hex, a.public_key.hex, msg_hash_hex)
+>>> sig_msg_hex = pyflo.sign_message(msg_hash_hex, a.private_key.wif)
+>>> pyflo.verify_signature(sig_msg_hex, a.public_key.hex, msg_hash_hex)
 True
+
+# SIGN AND VERIFY MESSAGE IN STANDARD OPERATION
+>> pyflo.sign_message_standard_ops('vivek', a.private_key.wif)
+'3045022039747449a6fbac008d04d763a3a62f2261d1c5a35ee6a21a8354d8757d27593802210085a4d4b9886de6d06c3563c97160c8d70f492ce56f9e00dbcd7276004369402e'
+>> sig_msg_hex = pyflo.sign_message_standard_ops('vivek', a.private_key.wif)
+
+# To verify the above signature, run the following in the console of any Standard Ops app 
+>> sign_msg_hex = '3045022039747449a6fbac008d04d763a3a62f2261d1c5a35ee6a21a8354d8757d27593802210085a4d4b9886de6d06c3563c97160c8d70f492ce56f9e00dbcd7276004369402e'
+>> a.public_key.hex = '033c30b269e2d5df229f3f0ce294b19c4f0a3a8d12280415ce41e7bd3784a619c4'
+>> floCrypto.verifySign('vivek', sig_msg_hex, a.public_key.hex) 
+true
+
 ```
 
+The **sign_message_standard_ops** function verifies with [RanchiMall standard operations](https://github.com/ranchimall/Standard_Operations).
+Things to note:
+The function now takes 2 parameters -
 
+1. Message in string ( not hex-encoded string)
+2. Private key in wif (not bytes etc.)
+The hex parameter has been removed as we are always returning hex in standard ops
 
+New libraries used - hashlib
+The elliptical curve folder, holds the code taken from starkbank ecdsa (MIT License)
+no other additional dependencies
+
+The signature generated with **sign_message_standard_ops** cannot be verified using purely Pyflo. Users can use the following API to verify signatures 
+
+** Python **
+``` 
+import requests
+
+url = 'https://flo-sign-validator.duckdns.org'
+myobj = {'floID': floID,
+            'pubKey': pubKey,
+            'message': message,
+            'sign': sign}
+
+x = requests.post(url, json = myobj)
+print(x.text)
+
+```
+
+** JavaScript **
+``` 
+fetch("https://flo-sign-validator.duckdns.org", {
+  method: "POST",
+  body: JSON.stringify({
+    floID: floID,
+    pubKey: pubKey,
+    message: message,
+    sign: sign
+  }),
+  headers: {
+    "Content-type": "application/json; charset=UTF-8",
+  },
+})
+  .then(function (response) {
+    return response.json();
+  })
+  .then(function (data) {
+    console.log(data);
+  })
+  .catch((error) => console.error("Error:", error));
+
+```
+
+** PHP **
+```
+            function callAPI($method, $url, $data){
+            $curl = curl_init();
+            switch ($method){
+                case "POST":
+                    curl_setopt($curl, CURLOPT_POST, 1);
+                    if ($data)
+                        curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
+                    break;
+                case "PUT":
+                    curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT");
+                    if ($data)
+                        curl_setopt($curl, CURLOPT_POSTFIELDS, $data);                              
+                    break;
+                default:
+                    if ($data)
+                        $url = sprintf("%s?%s", $url, http_build_query($data));
+            }
+            // OPTIONS:
+            curl_setopt($curl, CURLOPT_URL, $url);
+            curl_setopt($curl, CURLOPT_HTTPHEADER, array(
+                'APIKEY: 111111111111111111111',
+                'Content-Type: application/json',
+            ));
+            curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
+            curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
+            // EXECUTE:
+            $result = curl_exec($curl);
+            curl_close($curl);
+            return $result;
+            }
+            
+            $floID = $_POST['floID'];
+            $pubKey = $_POST['floPubKey'];
+            $message = $_POST['message'];
+            $signDataWithFlo = $_POST['signDataWithFlo'];
+    
+    
+            $data_array =  array( "floID"        => $floID, "pubKey" => $pubKey, "message" => $message, "sign" => $signDataWithFlo  );
+            $make_call = callAPI('POST', 'https://flo-sign-validator.duckdns.org', json_encode($data_array));
+            $response = json_decode($make_call, true);
+            
+            print_r($response);
+
+```
+            

pybtc/__init__.py

@@ -1,10 +0,0 @@
-from pybtc.constants import *
-from pybtc.opcodes import *
-from pybtc.consensus import *
-from pybtc.functions import *
-
-
-from .transaction import *
-from .block import *
-from .address import *
-from .wallet import *

pyflo/__init__.py

@@ -0,0 +1,10 @@
+from pyflo.constants import *
+from pyflo.opcodes import *
+from pyflo.consensus import *
+from pyflo.functions import *
+
+
+from .transaction import *
+from .block import *
+from .address import *
+from .wallet import *

pyflo/address.py

@@ -1,10 +1,10 @@
-from pybtc.constants import *
-from pybtc.opcodes import *
-from pybtc.functions.tools import bytes_from_hex, int_to_var_int
-from pybtc.functions.script import op_push_data, decode_script
-from pybtc.functions.hash import hash160, sha256
-from pybtc.functions.address import  hash_to_address, public_key_to_p2sh_p2wpkh_script
-from pybtc.functions.key import (create_private_key,
+from pyflo.constants import *
+from pyflo.opcodes import *
+from pyflo.functions.tools import bytes_from_hex, int_to_var_int
+from pyflo.functions.script import op_push_data, decode_script
+from pyflo.functions.hash import hash160, sha256
+from pyflo.functions.address import  hash_to_address, public_key_to_p2sh_p2wpkh_script
+from pyflo.functions.key import (create_private_key,
                                  private_key_to_wif,
                                  is_wif_valid,
                                  wif_to_private_key,

pyflo/block.py

@@ -1,9 +1,9 @@
 from struct import unpack, pack
 from io import BytesIO
-from pybtc.functions.block import bits_to_target, target_to_difficulty
-from pybtc.functions.hash import double_sha256
-from pybtc.functions.tools import var_int_to_int, read_var_int, var_int_len, rh2s
-from pybtc.transaction import Transaction
+from pyflo.functions.block import bits_to_target, target_to_difficulty
+from pyflo.functions.hash import double_sha256
+from pyflo.functions.tools import var_int_to_int, read_var_int, var_int_len, rh2s
+from pyflo.transaction import Transaction
 
 
 class Block(dict):

pyflo/constants.py

@@ -14,7 +14,7 @@ ECDSA_SEC256K1_ORDER = 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8
 
 MAINNET_ADDRESS_BYTE_PREFIX = b'\x23'
 TESTNET_ADDRESS_BYTE_PREFIX = b'\x73'
-MAINNET_SCRIPT_ADDRESS_BYTE_PREFIX = b'\x05'
+MAINNET_SCRIPT_ADDRESS_BYTE_PREFIX = b'\x5e'
 TESTNET_SCRIPT_ADDRESS_BYTE_PREFIX = b'\xc4'
 MAINNET_SEGWIT_ADDRESS_BYTE_PREFIX = b'\x03\x03\x00\x02\x03'
 TESTNET_SEGWIT_ADDRESS_BYTE_PREFIX = b'\x03\x03\x00\x14\x02'
@@ -22,7 +22,8 @@ TESTNET_SEGWIT_ADDRESS_BYTE_PREFIX = b'\x03\x03\x00\x14\x02'
 MAINNET_ADDRESS_PREFIX = 'F'
 TESTNET_ADDRESS_PREFIX = 'o'
 TESTNET_ADDRESS_PREFIX_2 = 'o'
-MAINNET_SCRIPT_ADDRESS_PREFIX = '3'
+MAINNET_SCRIPT_ADDRESS_PREFIX = 'e'
+MAINNET_SCRIPT_ADDRESS_PREFIX_2 = 'f'
 TESTNET_SCRIPT_ADDRESS_PREFIX = '2'
 
 MAINNET_PRIVATE_KEY_UNCOMPRESSED_PREFIX = '5'
@@ -35,6 +36,7 @@ ADDRESS_PREFIX_LIST = (MAINNET_ADDRESS_PREFIX,
                        TESTNET_ADDRESS_PREFIX,
                        TESTNET_ADDRESS_PREFIX_2,
                        MAINNET_SCRIPT_ADDRESS_PREFIX,
+                       MAINNET_SCRIPT_ADDRESS_PREFIX_2,
                        TESTNET_SCRIPT_ADDRESS_PREFIX)
 
 PRIVATE_KEY_PREFIX_LIST = (MAINNET_PRIVATE_KEY_UNCOMPRESSED_PREFIX,

pyflo/ellipticcurve/__init__.py

@@ -0,0 +1,6 @@
+from .utils.compatibility import *
+from .privateKey import PrivateKey
+from .publicKey import PublicKey
+from .signature import Signature
+from .utils.file import File
+from .ecdsa import Ecdsa

pyflo/ellipticcurve/curve.py

@@ -0,0 +1,79 @@
+#
+# Elliptic Curve Equation
+#
+# y^2 = x^3 + A*x + B (mod P)
+#
+from .point import Point
+
+
+class CurveFp:
+
+    def __init__(self, A, B, P, N, Gx, Gy, name, oid, nistName=None):
+        self.A = A
+        self.B = B
+        self.P = P
+        self.N = N
+        self.G = Point(Gx, Gy)
+        self.name = name
+        self.nistName = nistName
+        self.oid = oid  # ASN.1 Object Identifier
+
+    def contains(self, p):
+        """
+        Verify if the point `p` is on the curve
+
+        :param p: Point p = Point(x, y)
+        :return: boolean
+        """
+        if not 0 <= p.x <= self.P - 1:
+            return False
+        if not 0 <= p.y <= self.P - 1:
+            return False
+        if (p.y**2 - (p.x**3 + self.A * p.x + self.B)) % self.P != 0:
+            return False
+        return True
+
+    def length(self):
+        return (1 + len("%x" % self.N)) // 2
+
+
+secp256k1 = CurveFp(
+    name="secp256k1",
+    A=0x0000000000000000000000000000000000000000000000000000000000000000,
+    B=0x0000000000000000000000000000000000000000000000000000000000000007,
+    P=0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f,
+    N=0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141,
+    Gx=0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,
+    Gy=0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8,
+    oid=[1, 3, 132, 0, 10]
+)
+
+prime256v1 = CurveFp(
+    name="prime256v1",
+    nistName="P-256",
+    A=0xffffffff00000001000000000000000000000000fffffffffffffffffffffffc,
+    B=0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b,
+    P=0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff,
+    N=0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551,
+    Gx=0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296,
+    Gy=0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5,
+    oid=[1, 2, 840, 10045, 3, 1, 7],
+)
+
+p256 = prime256v1
+
+supportedCurves = [
+    secp256k1,
+    prime256v1,
+]
+
+_curvesByOid = {tuple(curve.oid): curve for curve in supportedCurves}
+
+
+def getCurveByOid(oid):
+    if oid not in _curvesByOid:
+        raise Exception("Unknown curve with oid {oid}; The following are registered: {names}".format(
+            oid=".".join([str(number) for number in oid]),
+            names=", ".join([curve.name for curve in supportedCurves]),
+        ))
+    return _curvesByOid[oid]

pyflo/ellipticcurve/ecdsa.py

@@ -0,0 +1,46 @@
+from hashlib import sha256
+from .signature import Signature
+from .math import Math
+from .utils.integer import RandomInteger
+from .utils.binary import numberFromByteString
+from .utils.compatibility import *
+
+
+class Ecdsa:
+
+    @classmethod
+    def sign(cls, message, privateKey, hashfunc=sha256):
+        byteMessage = hashfunc(toBytes(message)).digest()
+        numberMessage = numberFromByteString(byteMessage)
+        curve = privateKey.curve
+
+        r, s, randSignPoint = 0, 0, None
+        while r == 0 or s == 0:
+            randNum = RandomInteger.between(1, curve.N - 1)
+            randSignPoint = Math.multiply(curve.G, n=randNum, A=curve.A, P=curve.P, N=curve.N)
+            r = randSignPoint.x % curve.N
+            s = ((numberMessage + r * privateKey.secret) * (Math.inv(randNum, curve.N))) % curve.N
+        recoveryId = randSignPoint.y & 1
+        if randSignPoint.y > curve.N:
+            recoveryId += 2
+
+        return Signature(r=r, s=s, recoveryId=recoveryId)
+
+    @classmethod
+    def verify(cls, message, signature, publicKey, hashfunc=sha256):
+        byteMessage = hashfunc(toBytes(message)).digest()
+        numberMessage = numberFromByteString(byteMessage)
+        curve = publicKey.curve
+        r = signature.r
+        s = signature.s
+        if not 1 <= r <= curve.N - 1:
+            return False
+        if not 1 <= s <= curve.N - 1:
+            return False
+        inv = Math.inv(s, curve.N)
+        u1 = Math.multiply(curve.G, n=(numberMessage * inv) % curve.N, N=curve.N, A=curve.A, P=curve.P)
+        u2 = Math.multiply(publicKey.point, n=(r * inv) % curve.N, N=curve.N, A=curve.A, P=curve.P)
+        v = Math.add(u1, u2, A=curve.A, P=curve.P)
+        if v.isAtInfinity():
+            return False
+        return v.x % curve.N == r

pyflo/ellipticcurve/math.py

@@ -0,0 +1,177 @@
+from .point import Point
+
+
+class Math:
+
+    @classmethod
+    def multiply(cls, p, n, N, A, P):
+        """
+        Fast way to multily point and scalar in elliptic curves
+
+        :param p: First Point to mutiply
+        :param n: Scalar to mutiply
+        :param N: Order of the elliptic curve
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :param A: Coefficient of the first-order term of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point that represents the sum of First and Second Point
+        """
+        return cls._fromJacobian(
+            cls._jacobianMultiply(cls._toJacobian(p), n, N, A, P), P
+        )
+
+    @classmethod
+    def add(cls, p, q, A, P):
+        """
+        Fast way to add two points in elliptic curves
+
+        :param p: First Point you want to add
+        :param q: Second Point you want to add
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :param A: Coefficient of the first-order term of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point that represents the sum of First and Second Point
+        """
+        return cls._fromJacobian(
+            cls._jacobianAdd(cls._toJacobian(p), cls._toJacobian(q), A, P), P,
+        )
+
+    @classmethod
+    def inv(cls, x, n):
+        """
+        Extended Euclidean Algorithm. It's the 'division' in elliptic curves
+
+        :param x: Divisor
+        :param n: Mod for division
+        :return: Value representing the division
+        """
+        if x == 0:
+            return 0
+
+        lm = 1
+        hm = 0
+        low = x % n
+        high = n
+
+        while low > 1:
+            r = high // low
+            nm = hm - lm * r
+            nw = high - low * r
+            high = low
+            hm = lm
+            low = nw
+            lm = nm
+
+        return lm % n
+
+    @classmethod
+    def _toJacobian(cls, p):
+        """
+        Convert point to Jacobian coordinates
+
+        :param p: First Point you want to add
+        :return: Point in Jacobian coordinates
+        """
+        return Point(p.x, p.y, 1)
+
+    @classmethod
+    def _fromJacobian(cls, p, P):
+        """
+        Convert point back from Jacobian coordinates
+
+        :param p: First Point you want to add
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point in default coordinates
+        """
+        z = cls.inv(p.z, P)
+        x = (p.x * z ** 2) % P
+        y = (p.y * z ** 3) % P
+
+        return Point(x, y, 0)
+
+    @classmethod
+    def _jacobianDouble(cls, p, A, P):
+        """
+        Double a point in elliptic curves
+
+        :param p: Point you want to double
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :param A: Coefficient of the first-order term of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point that represents the sum of First and Second Point
+        """
+        if p.y == 0:
+            return Point(0, 0, 0)
+
+        ysq = (p.y ** 2) % P
+        S = (4 * p.x * ysq) % P
+        M = (3 * p.x ** 2 + A * p.z ** 4) % P
+        nx = (M**2 - 2 * S) % P
+        ny = (M * (S - nx) - 8 * ysq ** 2) % P
+        nz = (2 * p.y * p.z) % P
+
+        return Point(nx, ny, nz)
+
+    @classmethod
+    def _jacobianAdd(cls, p, q, A, P):
+        """
+        Add two points in elliptic curves
+
+        :param p: First Point you want to add
+        :param q: Second Point you want to add
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :param A: Coefficient of the first-order term of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point that represents the sum of First and Second Point
+        """
+        if p.y == 0:
+            return q
+        if q.y == 0:
+            return p
+
+        U1 = (p.x * q.z ** 2) % P
+        U2 = (q.x * p.z ** 2) % P
+        S1 = (p.y * q.z ** 3) % P
+        S2 = (q.y * p.z ** 3) % P
+
+        if U1 == U2:
+            if S1 != S2:
+                return Point(0, 0, 1)
+            return cls._jacobianDouble(p, A, P)
+
+        H = U2 - U1
+        R = S2 - S1
+        H2 = (H * H) % P
+        H3 = (H * H2) % P
+        U1H2 = (U1 * H2) % P
+        nx = (R ** 2 - H3 - 2 * U1H2) % P
+        ny = (R * (U1H2 - nx) - S1 * H3) % P
+        nz = (H * p.z * q.z) % P
+
+        return Point(nx, ny, nz)
+
+    @classmethod
+    def _jacobianMultiply(cls, p, n, N, A, P):
+        """
+        Multily point and scalar in elliptic curves
+
+        :param p: First Point to mutiply
+        :param n: Scalar to mutiply
+        :param N: Order of the elliptic curve
+        :param P: Prime number in the module of the equation Y^2 = X^3 + A*X + B (mod p)
+        :param A: Coefficient of the first-order term of the equation Y^2 = X^3 + A*X + B (mod p)
+        :return: Point that represents the sum of First and Second Point
+        """
+        if p.y == 0 or n == 0:
+            return Point(0, 0, 1)
+
+        if n == 1:
+            return p
+
+        if n < 0 or n >= N:
+            return cls._jacobianMultiply(p, n % N, N, A, P)
+
+        if (n % 2) == 0:
+            return cls._jacobianDouble(
+                cls._jacobianMultiply(p, n // 2, N, A, P), A, P
+            )
+
+        return cls._jacobianAdd(
+            cls._jacobianDouble(cls._jacobianMultiply(p, n // 2, N, A, P), A, P), p, A, P
+        )

pyflo/ellipticcurve/point.py

@@ -0,0 +1,14 @@
+
+
+class Point:
+
+    def __init__(self, x=0, y=0, z=0):
+        self.x = x
+        self.y = y
+        self.z = z
+
+    def __str__(self):
+        return "({x}, {y}, {z})".format(x=self.x, y=self.y, z=self.z)
+
+    def isAtInfinity(self):
+        return self.y == 0

pyflo/ellipticcurve/privateKey.py

@@ -0,0 +1,72 @@
+from .math import Math
+from .utils.integer import RandomInteger
+from .utils.pem import getPemContent, createPem
+from .utils.binary import hexFromByteString, byteStringFromHex, intFromHex, base64FromByteString, byteStringFromBase64
+from .utils.der import hexFromInt, parse, encodeConstructed, DerFieldType, encodePrimitive
+from .curve import secp256k1, getCurveByOid
+from .publicKey import PublicKey
+
+
+class PrivateKey:
+
+    def __init__(self, curve=secp256k1, secret=None):
+        self.curve = curve
+        self.secret = secret or RandomInteger.between(1, curve.N - 1)
+
+    def publicKey(self):
+        curve = self.curve
+        publicPoint = Math.multiply(
+            p=curve.G,
+            n=self.secret,
+            N=curve.N,
+            A=curve.A,
+            P=curve.P,
+        )
+        return PublicKey(point=publicPoint, curve=curve)
+
+    def toString(self):
+        return hexFromInt(self.secret)
+
+    def toDer(self):
+        publicKeyString = self.publicKey().toString(encoded=True)
+        hexadecimal = encodeConstructed(
+            encodePrimitive(DerFieldType.integer, 1),
+            encodePrimitive(DerFieldType.octetString, hexFromInt(self.secret)),
+            encodePrimitive(DerFieldType.oidContainer, encodePrimitive(DerFieldType.object, self.curve.oid)),
+            encodePrimitive(DerFieldType.publicKeyPointContainer, encodePrimitive(DerFieldType.bitString, publicKeyString))
+        )
+        return byteStringFromHex(hexadecimal)
+
+    def toPem(self):
+        der = self.toDer()
+        return createPem(content=base64FromByteString(der), template=_pemTemplate)
+
+    @classmethod
+    def fromPem(cls, string):
+        privateKeyPem = getPemContent(pem=string, template=_pemTemplate)
+        return cls.fromDer(byteStringFromBase64(privateKeyPem))
+
+    @classmethod
+    def fromDer(cls, string):
+        hexadecimal = hexFromByteString(string)
+        privateKeyFlag, secretHex, curveData, publicKeyString = parse(hexadecimal)[0]
+        if privateKeyFlag != 1:
+            raise Exception("Private keys should start with a '1' flag, but a '{flag}' was found instead".format(
+                flag=privateKeyFlag
+            ))
+        curve = getCurveByOid(curveData[0])
+        privateKey = cls.fromString(string=secretHex, curve=curve)
+        if privateKey.publicKey().toString(encoded=True) != publicKeyString[0]:
+            raise Exception("The public key described inside the private key file doesn't match the actual public key of the pair")
+        return privateKey
+
+    @classmethod
+    def fromString(cls, string, curve=secp256k1):
+        return PrivateKey(secret=intFromHex(string), curve=curve)
+
+
+_pemTemplate = """
+-----BEGIN EC PRIVATE KEY-----
+{content}
+-----END EC PRIVATE KEY-----
+"""

pyflo/ellipticcurve/publicKey.py

@@ -0,0 +1,88 @@
+from .math import Math
+from .point import Point
+from .curve import secp256k1, getCurveByOid
+from .utils.pem import getPemContent, createPem
+from .utils.der import hexFromInt, parse, DerFieldType, encodeConstructed, encodePrimitive
+from .utils.binary import hexFromByteString, byteStringFromHex, intFromHex, base64FromByteString, byteStringFromBase64
+
+
+class PublicKey:
+
+    def __init__(self, point, curve):
+        self.point = point
+        self.curve = curve
+
+    def toString(self, encoded=False):
+        baseLength = 2 * self.curve.length()
+        xHex = hexFromInt(self.point.x).zfill(baseLength)
+        yHex = hexFromInt(self.point.y).zfill(baseLength)
+        string = xHex + yHex
+        if encoded:
+            return "0004" + string
+        return string
+
+    def toDer(self):
+        hexadecimal = encodeConstructed(
+            encodeConstructed(
+                encodePrimitive(DerFieldType.object, _ecdsaPublicKeyOid),
+                encodePrimitive(DerFieldType.object, self.curve.oid),
+            ),
+            encodePrimitive(DerFieldType.bitString, self.toString(encoded=True)),
+        )
+        return byteStringFromHex(hexadecimal)
+
+    def toPem(self):
+        der = self.toDer()
+        return createPem(content=base64FromByteString(der), template=_pemTemplate)
+
+    @classmethod
+    def fromPem(cls, string):
+        publicKeyPem = getPemContent(pem=string, template=_pemTemplate)
+        return cls.fromDer(byteStringFromBase64(publicKeyPem))
+
+    @classmethod
+    def fromDer(cls, string):
+        hexadecimal = hexFromByteString(string)
+        curveData, pointString = parse(hexadecimal)[0]
+        publicKeyOid, curveOid = curveData
+        if publicKeyOid != _ecdsaPublicKeyOid:
+            raise Exception("The Public Key Object Identifier (OID) should be {ecdsaPublicKeyOid}, but {actualOid} was found instead".format(
+                ecdsaPublicKeyOid=_ecdsaPublicKeyOid,
+                actualOid=publicKeyOid,
+            ))
+        curve = getCurveByOid(curveOid)
+        return cls.fromString(string=pointString, curve=curve)
+
+    @classmethod
+    def fromString(cls, string, curve=secp256k1, validatePoint=True):
+        baseLength = 2 * curve.length()
+        if len(string) > 2 * baseLength and string[:4] == "0004":
+            string = string[4:]
+
+        xs = string[:baseLength]
+        ys = string[baseLength:]
+
+        p = Point(
+            x=intFromHex(xs),
+            y=intFromHex(ys),
+        )
+        publicKey = PublicKey(point=p, curve=curve)
+        if not validatePoint:
+            return publicKey
+        if p.isAtInfinity():
+            raise Exception("Public Key point is at infinity")
+        if not curve.contains(p):
+            raise Exception("Point ({x},{y}) is not valid for curve {name}".format(x=p.x, y=p.y, name=curve.name))
+        if not Math.multiply(p=p, n=curve.N, N=curve.N, A=curve.A, P=curve.P).isAtInfinity():
+            raise Exception("Point ({x},{y}) * {name}.N is not at infinity".format(x=p.x, y=p.y, name=curve.name))
+        return publicKey
+
+
+_ecdsaPublicKeyOid = (1, 2, 840, 10045, 2, 1)
+
+
+_pemTemplate = """
+-----BEGIN PUBLIC KEY-----
+{content}
+-----END PUBLIC KEY-----
+"""

pyflo/ellipticcurve/signature.py

@@ -0,0 +1,48 @@
+from .utils.compatibility import *
+from .utils.der import parse, encodeConstructed, encodePrimitive, DerFieldType
+from .utils.binary import hexFromByteString, byteStringFromHex, base64FromByteString, byteStringFromBase64
+
+
+class Signature:
+
+    def __init__(self, r, s, recoveryId=None):
+        self.r = r
+        self.s = s
+        self.recoveryId = recoveryId
+
+    def toDer(self, withRecoveryId=False):
+        hexadecimal = self._toString()
+        encodedSequence = byteStringFromHex(hexadecimal)
+        if not withRecoveryId:
+            return encodedSequence
+        return toBytes(chr(27 + self.recoveryId)) + encodedSequence
+
+    def toBase64(self, withRecoveryId=False):
+        return base64FromByteString(self.toDer(withRecoveryId))
+
+    @classmethod
+    def fromDer(cls, string, recoveryByte=False):
+        recoveryId = None
+        if recoveryByte:
+            recoveryId = string[0] if isinstance(string[0], intTypes) else ord(string[0])
+            recoveryId -= 27
+            string = string[1:]
+
+        hexadecimal = hexFromByteString(string)
+        return cls._fromString(string=hexadecimal, recoveryId=recoveryId)
+
+    @classmethod
+    def fromBase64(cls, string, recoveryByte=False):
+        der = byteStringFromBase64(string)
+        return cls.fromDer(der, recoveryByte)
+
+    def _toString(self):
+        return encodeConstructed(
+            encodePrimitive(DerFieldType.integer, self.r),
+            encodePrimitive(DerFieldType.integer, self.s),
+        )
+
+    @classmethod
+    def _fromString(cls, string, recoveryId=None):
+        r, s = parse(string)[0]
+        return Signature(r=r, s=s, recoveryId=recoveryId)

pyflo/ellipticcurve/utils/binary.py

@@ -0,0 +1,37 @@
+from base64 import b64encode, b64decode
+from .compatibility import safeHexFromBinary, safeBinaryFromHex, toString
+
+
+def hexFromInt(number):
+    hexadecimal = "{0:x}".format(number)
+    if len(hexadecimal) % 2 == 1:
+        hexadecimal = "0" + hexadecimal
+    return hexadecimal
+
+
+def intFromHex(hexadecimal):
+    return int(hexadecimal, 16)
+
+
+def hexFromByteString(byteString):
+    return safeHexFromBinary(byteString)
+
+
+def byteStringFromHex(hexadecimal):
+    return safeBinaryFromHex(hexadecimal)
+
+
+def numberFromByteString(byteString):
+    return intFromHex(hexFromByteString(byteString))
+
+
+def base64FromByteString(byteString):
+    return toString(b64encode(byteString))
+
+
+def byteStringFromBase64(base64String):
+    return b64decode(base64String)
+
+
+def bitsFromHex(hexadecimal):
+    return format(intFromHex(hexadecimal), 'b').zfill(4 * len(hexadecimal))

pyflo/ellipticcurve/utils/compatibility.py

@@ -0,0 +1,40 @@
+from sys import version_info as pyVersion
+from binascii import hexlify, unhexlify
+
+
+if pyVersion.major == 3:
+    # py3 constants and conversion functions
+
+    stringTypes = (str,)
+    intTypes = (int, float)
+
+    def toString(string, encoding="utf-8"):
+        return string.decode(encoding)
+
+    def toBytes(string, encoding="utf-8"):
+        return string.encode(encoding)
+
+    def safeBinaryFromHex(hexadecimal):
+        if len(hexadecimal) % 2 == 1:
+            hexadecimal = "0" + hexadecimal
+        return unhexlify(hexadecimal)
+
+    def safeHexFromBinary(byteString):
+        return toString(hexlify(byteString))
+else:
+    # py2 constants and conversion functions
+
+    stringTypes = (str, unicode)
+    intTypes = (int, float, long)
+
+    def toString(string, encoding="utf-8"):
+        return string
+
+    def toBytes(string, encoding="utf-8"):
+        return string
+
+    def safeBinaryFromHex(hexadecimal):
+        return unhexlify(hexadecimal)
+
+    def safeHexFromBinary(byteString):
+        return hexlify(byteString)

pyflo/ellipticcurve/utils/der.py

@@ -0,0 +1,159 @@
+from datetime import datetime
+from .oid import oidToHex, oidFromHex
+from .binary import hexFromInt, intFromHex, byteStringFromHex, bitsFromHex
+
+
+class DerFieldType:
+
+    integer = "integer"
+    bitString = "bitString"
+    octetString = "octetString"
+    null = "null"
+    object = "object"
+    printableString = "printableString"
+    utcTime = "utcTime"
+    sequence = "sequence"
+    set = "set"
+    oidContainer = "oidContainer"
+    publicKeyPointContainer = "publicKeyPointContainer"
+
+
+_hexTagToType = {
+    "02": DerFieldType.integer,
+    "03": DerFieldType.bitString,
+    "04": DerFieldType.octetString,
+    "05": DerFieldType.null,
+    "06": DerFieldType.object,
+    "13": DerFieldType.printableString,
+    "17": DerFieldType.utcTime,
+    "30": DerFieldType.sequence,
+    "31": DerFieldType.set,
+    "a0": DerFieldType.oidContainer,
+    "a1": DerFieldType.publicKeyPointContainer,
+}
+_typeToHexTag = {v: k for k, v in _hexTagToType.items()}
+
+
+def encodeConstructed(*encodedValues):
+    return encodePrimitive(DerFieldType.sequence, "".join(encodedValues))
+
+
+def encodePrimitive(tagType, value):
+    if tagType == DerFieldType.integer:
+        value = _encodeInteger(value)
+    if tagType == DerFieldType.object:
+        value = oidToHex(value)
+    return "{tag}{size}{value}".format(tag=_typeToHexTag[tagType], size=_generateLengthBytes(value), value=value)
+
+
+def parse(hexadecimal):
+    if not hexadecimal:
+        return []
+    typeByte, hexadecimal = hexadecimal[:2], hexadecimal[2:]
+    length, lengthBytes = _readLengthBytes(hexadecimal)
+    content, hexadecimal = hexadecimal[lengthBytes: lengthBytes + length], hexadecimal[lengthBytes + length:]
+    if len(content) < length:
+        raise Exception("missing bytes in DER parse")
+
+    tagData = _getTagData(typeByte)
+    if tagData["isConstructed"]:
+        content = parse(content)
+
+    valueParser = {
+        DerFieldType.null: _parseNull,
+        DerFieldType.object: _parseOid,
+        DerFieldType.utcTime: _parseTime,
+        DerFieldType.integer: _parseInteger,
+        DerFieldType.printableString: _parseString,
+    }.get(tagData["type"], _parseAny)
+    return [valueParser(content)] + parse(hexadecimal)
+
+
+def _parseAny(hexadecimal):
+    return hexadecimal
+
+
+def _parseOid(hexadecimal):
+    return tuple(oidFromHex(hexadecimal))
+
+
+def _parseTime(hexadecimal):
+    string = _parseString(hexadecimal)
+    return datetime.strptime(string, "%y%m%d%H%M%SZ")
+
+
+def _parseString(hexadecimal):
+    return byteStringFromHex(hexadecimal).decode()
+
+
+def _parseNull(_content):
+    return None
+
+
+def _parseInteger(hexadecimal):
+    integer = intFromHex(hexadecimal)
+    bits = bitsFromHex(hexadecimal[0])
+    if bits[0] == "0":  # negative numbers are encoded using two's complement
+        return integer
+    bitCount = 4 * len(hexadecimal)
+    return integer - (2 ** bitCount)
+
+
+def _encodeInteger(number):
+    hexadecimal = hexFromInt(abs(number))
+    if number < 0:
+        bitCount = 4 * len(hexadecimal)
+        twosComplement = (2 ** bitCount) + number
+        return hexFromInt(twosComplement)
+    bits = bitsFromHex(hexadecimal[0])
+    if bits[0] == "1":  # if first bit was left as 1, number would be parsed as a negative integer with two's complement
+        hexadecimal = "00" + hexadecimal
+    return hexadecimal
+
+
+def _readLengthBytes(hexadecimal):
+    lengthBytes = 2
+    lengthIndicator = intFromHex(hexadecimal[0:lengthBytes])
+    isShortForm = lengthIndicator < 128  # checks if first bit of byte is 1 (a.k.a. short-form)
+    if isShortForm:
+        length = lengthIndicator * 2
+        return length, lengthBytes
+
+    lengthLength = lengthIndicator - 128  # nullifies first bit of byte (only used as long-form flag)
+    if lengthLength == 0:
+        raise Exception("indefinite length encoding located in DER")
+    lengthBytes += 2 * lengthLength
+    length = intFromHex(hexadecimal[2:lengthBytes]) * 2
+    return length, lengthBytes
+
+
+def _generateLengthBytes(hexadecimal):
+    size = len(hexadecimal) // 2
+    length = hexFromInt(size)
+    if size < 128:  # checks if first bit of byte should be 0 (a.k.a. short-form flag)
+        return length.zfill(2)
+    lengthLength = 128 + len(length) // 2  # +128 sets the first bit of the byte as 1 (a.k.a. long-form flag)
+    return hexFromInt(lengthLength) + length
+
+
+def _getTagData(tag):
+    bits = bitsFromHex(tag)
+    bit8, bit7, bit6 = bits[:3]
+
+    tagClass = {
+        "0": {
+            "0": "universal",
+            "1": "application",
+        },
+        "1": {
+            "0": "context-specific",
+            "1": "private",
+        },
+    }[bit8][bit7]
+    isConstructed = bit6 == "1"
+
+    return {
+        "class": tagClass,
+        "isConstructed": isConstructed,
+        "type": _hexTagToType.get(tag),
+    }

pyflo/ellipticcurve/utils/file.py

@@ -0,0 +1,9 @@
+
+
+class File:
+
+    @classmethod
+    def read(cls, path, mode="r"):
+        with open(path, mode) as blob:
+            content = blob.read()
+        return content

pyflo/ellipticcurve/utils/integer.py

@@ -0,0 +1,16 @@
+from random import SystemRandom
+
+
+class RandomInteger:
+
+    @classmethod
+    def between(cls, min, max):
+        """
+        Return integer x in the range: min <= x <= max
+
+        :param min: minimum value of the integer
+        :param max: maximum value of the integer
+        :return:
+        """
+
+        return SystemRandom().randrange(min, max + 1)

pyflo/ellipticcurve/utils/oid.py

@@ -0,0 +1,35 @@
+from .binary import intFromHex, hexFromInt
+
+
+def oidFromHex(hexadecimal):
+    firstByte, remainingBytes = hexadecimal[:2], hexadecimal[2:]
+    firstByteInt = intFromHex(firstByte)
+    oid = [firstByteInt // 40, firstByteInt % 40]
+    oidInt = 0
+    while len(remainingBytes) > 0:
+        byte, remainingBytes = remainingBytes[0:2], remainingBytes[2:]
+        byteInt = intFromHex(byte)
+        if byteInt >= 128:
+            oidInt = (128 * oidInt) + (byteInt - 128)
+            continue
+        oidInt = (128 * oidInt) + byteInt
+        oid.append(oidInt)
+        oidInt = 0
+    return oid
+
+
+def oidToHex(oid):
+    hexadecimal = hexFromInt(40 * oid[0] + oid[1])
+    for number in oid[2:]:
+        hexadecimal += _oidNumberToHex(number)
+    return hexadecimal
+
+
+def _oidNumberToHex(number):
+    hexadecimal = ""
+    endDelta = 0
+    while number > 0:
+        hexadecimal = hexFromInt((number % 128) + endDelta) + hexadecimal
+        number //= 128
+        endDelta = 128
+    return hexadecimal or "00"

pyflo/ellipticcurve/utils/pem.py

@@ -0,0 +1,14 @@
+from re import search
+
+
+def getPemContent(pem, template):
+    pattern = template.format(content="(.*)")
+    return search("".join(pattern.splitlines()), "".join(pem.splitlines())).group(1)
+
+
+def createPem(content, template):
+    lines = [
+        content[start:start + 64]
+        for start in range(0, len(content), 64)
+    ]
+    return template.format(content="\n".join(lines))

pyflo/functions/address.py

@@ -1,9 +1,9 @@
-from pybtc.opcodes import *
-from pybtc.constants import *
+from pyflo.opcodes import *
+from pyflo.constants import *
 
-from pybtc.functions.tools import bytes_from_hex
-from pybtc.functions.hash import double_sha256, hash160
-from pybtc.functions.encode import (encode_base58,
+from pyflo.functions.tools import bytes_from_hex
+from pyflo.functions.hash import double_sha256, hash160
+from pyflo.functions.encode import (encode_base58,
                                     rebase_8_to_5,
                                     bech32_polymod,
                                     rebase_5_to_32,
@@ -14,7 +14,7 @@ from pybtc.functions.encode import (encode_base58,
                                     base32charset_upcase)
 
 
-def hash_to_address(address_hash, testnet=False, script_hash=False, witness_version=None):
+def hash_to_address(address_hash, testnet=False, script_hash=False, witness_version=0):
     """
     Get address from public key/script hash. In case PUBKEY, P2PKH, P2PKH public key/script hash is SHA256+RIPEMD160,
     P2WSH script hash is SHA256.
@@ -70,7 +70,7 @@ def hash_to_address(address_hash, testnet=False, script_hash=False, witness_vers
     return "%s1%s" % (hrp, rebase_5_to_32(address_hash + checksum).decode())
 
 
-def public_key_to_address(pubkey, testnet=False, p2sh_p2wpkh=False, witness_version=None):
+def public_key_to_address(pubkey, testnet=False, p2sh_p2wpkh=False, witness_version=0):
     """
     Get address from public key/script hash. In case PUBKEY, P2PKH, P2PKH public key/script hash is SHA256+RIPEMD160,
     P2WSH script hash is SHA256.
@@ -129,7 +129,8 @@ def address_type(address, num=False):
     :return: address type in string or numeric format. 
     """
     if address[0] in (TESTNET_SCRIPT_ADDRESS_PREFIX,
-                      MAINNET_SCRIPT_ADDRESS_PREFIX):
+                      MAINNET_SCRIPT_ADDRESS_PREFIX,
+                      MAINNET_SCRIPT_ADDRESS_PREFIX_2):
         t = 'P2SH'
     elif address[0] in (MAINNET_ADDRESS_PREFIX,
                         TESTNET_ADDRESS_PREFIX,
@@ -155,7 +156,7 @@ def address_net_type(address):
     :param address: address in base58 or bech32 format.
     :return: address network type in string format or None. 
     """
-    if address[0] in (MAINNET_SCRIPT_ADDRESS_PREFIX,
+    if address[0] in (MAINNET_SCRIPT_ADDRESS_PREFIX, MAINNET_SCRIPT_ADDRESS_PREFIX_2,
                       MAINNET_ADDRESS_PREFIX):
         return "mainnet"
     elif address[:2] == MAINNET_SEGWIT_ADDRESS_PREFIX:
@@ -178,7 +179,8 @@ def address_to_script(address, hex=False):
     :return: public key script in HEX or bytes string.
     """
     if address[0] in (TESTNET_SCRIPT_ADDRESS_PREFIX,
-                      MAINNET_SCRIPT_ADDRESS_PREFIX):
+                      MAINNET_SCRIPT_ADDRESS_PREFIX,
+                      MAINNET_SCRIPT_ADDRESS_PREFIX_2):
         s = [OP_HASH160,
              b'\x14',
              address_to_hash(address, hex=False),
@@ -222,6 +224,7 @@ def is_address_valid(address, testnet=False):
         return False
     if address[0] in (MAINNET_ADDRESS_PREFIX,
                       MAINNET_SCRIPT_ADDRESS_PREFIX,
+                      MAINNET_SCRIPT_ADDRESS_PREFIX_2,
                       TESTNET_ADDRESS_PREFIX,
                       TESTNET_ADDRESS_PREFIX_2,
                       TESTNET_SCRIPT_ADDRESS_PREFIX):
@@ -232,7 +235,8 @@ def is_address_valid(address, testnet=False):
                 return False
         else:
             if address[0] not in (MAINNET_ADDRESS_PREFIX,
-                                  MAINNET_SCRIPT_ADDRESS_PREFIX):
+                                  MAINNET_SCRIPT_ADDRESS_PREFIX,
+                                  MAINNET_SCRIPT_ADDRESS_PREFIX_2):
                 return False
         h = decode_base58(address)
         if len(h) != 25:
@@ -275,11 +279,11 @@ def is_address_valid(address, testnet=False):
         if checksum != checksum2:
             return False
         return True
+    else:
+        return False
 
 
 def get_witness_version(address):
     address = address.split("1")[1]
     h = rebase_32_to_5(address)
     return h[0]
-
-

pyflo/functions/bip32.py

@@ -1,11 +1,11 @@
 from struct import pack
 from secp256k1 import ffi, lib
-from pybtc.functions.key import private_to_public_key, private_key_to_wif
-from pybtc.functions.hash import hmac_sha512, double_sha256, hash160
-from pybtc.functions.encode import (encode_base58,
+from pyflo.functions.key import private_to_public_key, private_key_to_wif
+from pyflo.functions.hash import hmac_sha512, double_sha256, hash160
+from pyflo.functions.encode import (encode_base58,
                                     decode_base58_with_checksum,
                                     encode_base58_with_checksum)
-from pybtc.constants import *
+from pyflo.constants import *
 
 
 def create_master_xprivate_key(seed, testnet=False, base58=True, hex=False):

pyflo/functions/bip39_mnemonic.py

@@ -1,8 +1,8 @@
-from pybtc.constants import *
+from pyflo.constants import *
 import time
 import hashlib
-from pybtc.functions.hash import sha256
-from pybtc.functions.tools import int_from_bytes
+from pyflo.functions.hash import sha256
+from pyflo.functions.tools import int_from_bytes
 
 def generate_entropy(strength=256, hex=True):
     """

pyflo/functions/block.py

@@ -1,5 +1,5 @@
-from pybtc.functions.tools import s2rh, bytes_from_hex, int_from_bytes
-from pybtc.functions.hash import double_sha256
+from pyflo.functions.tools import s2rh, bytes_from_hex, int_from_bytes
+from pyflo.functions.hash import double_sha256
 
 def merkle_root(tx_hash_list, hex=True):
     """

pyflo/functions/encode.py

@@ -1,5 +1,5 @@
-from pybtc.functions.hash import double_sha256
-from pybtc.functions.tools import bytes_from_hex
+from pyflo.functions.hash import double_sha256
+from pyflo.functions.tools import bytes_from_hex
 
 b58_digits = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 base32charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"

pyflo/functions/key.py

@@ -2,9 +2,9 @@ from secp256k1 import ffi, lib
 secp256k1_ec_pubkey_create = lib.secp256k1_ec_pubkey_create
 secp256k1_ec_pubkey_serialize = lib.secp256k1_ec_pubkey_serialize
 
-from pybtc.constants import *
-from pybtc.functions.encode import encode_base58, decode_base58
-from pybtc.functions.hash import double_sha256
+from pyflo.constants import *
+from pyflo.functions.encode import encode_base58, decode_base58
+from pyflo.functions.hash import double_sha256
 from .bip39_mnemonic import generate_entropy
 
 bytes_from_hex = bytes.fromhex

pyflo/functions/script.py

@@ -1,5 +1,9 @@
 from struct import unpack
-
+import hashlib
+from pyflo.ellipticcurve.privateKey import PrivateKey
+from pyflo.ellipticcurve.signature import Signature
+from pyflo.ellipticcurve.math import Math
+from pyflo.ellipticcurve.utils.integer import RandomInteger
 from secp256k1 import ffi, lib
 secp256k1_ecdsa_signature_parse_der = lib.secp256k1_ecdsa_signature_parse_der
 secp256k1_ec_pubkey_parse = lib.secp256k1_ec_pubkey_parse
@@ -11,13 +15,14 @@ secp256k1_ecdsa_recoverable_signature_parse_compact = lib.secp256k1_ecdsa_recove
 secp256k1_ecdsa_recover = lib.secp256k1_ecdsa_recover
 secp256k1_ec_pubkey_serialize = lib.secp256k1_ec_pubkey_serialize
 
-from pybtc.opcodes import *
-from pybtc.constants import *
+from pyflo.opcodes import *
+from pyflo.constants import *
 
-from pybtc.functions.tools import bytes_from_hex, int_to_bytes, get_stream
-from pybtc.functions.hash import hash160, sha256
-from pybtc.functions.address import hash_to_address
-from pybtc.functions.key import is_wif_valid, wif_to_private_key
+from pyflo.functions.tools import bytes_from_hex, int_to_bytes, get_stream
+from pyflo.functions.hash import hash160, sha256
+from pyflo.functions.address import hash_to_address
+from pyflo.functions.key import is_wif_valid, wif_to_private_key
+import requests, json
 
 
 def public_key_to_pubkey_script(key, hex=True):
@@ -161,9 +166,6 @@ def script_to_address(script, testnet=False):
     return None
 
 
-
-
-
 def decode_script(script, asm=False):
     """
     Decode script to ASM format or to human readable OPCODES string.
@@ -401,10 +403,76 @@ def verify_signature(sig, pub_key, msg):
     return True if result else False
 
 
+def verify_signature_standard_ops(sig, pub_key, msg, floID):
+    """
+    Verify signature for message and given public key
+
+    :param sig: signature in bytes or HEX encoded string.
+    :param pub_key:  public key in bytes or HEX encoded string.
+    :param msg:  message in bytes, string or HEX encoded string.
+    :flo_id: FLO ID in HEX encoded string.
+    :return: boolean.
+    """
+    url = 'https://flo-sign-validator.duckdns.org'
+    post_data = {
+        'floID': floID,
+        'pubKey': pub_key,
+        'message': msg,
+        'sign': sig
+        }
+    signature_verification = requests.post(url, json = post_data)
+    signature_verification = json.loads(signature_verification.text)
+    if signature_verification['success']:
+        return True 
+    else:
+        return False
+
+
+
+def to_base(n, base):
+    if base == 10:
+        return n
+    result = 0
+    counter = 0
+    while n:
+        r = n % base
+        n //= base
+        result += r * 10 ** counter
+        counter += 1
+    return result
+
+# https://raw.githubusercontent.com/starkbank/ecdsa-python/master/ellipticcurve/ecdsa.py
+def modSign(message, privateKey, hashfunc=sha256):
+    # byteMessage = toBytes(message).digest()
+    # byteMessage = hashfunc(toBytes(message)).digest()
+
+    byteMessage = hashlib.sha256(message.encode("utf-8")).hexdigest()
+    # byteMessage = '0x' + byteMessage
+    
+    # byteMessage = script_to_hash("686579", True)
+    numberMessage = int(byteMessage, base=16)
+    numberMessage = to_base(numberMessage, 16)
+    curve = privateKey.curve
+    r, s, randSignPoint = 0, 0, None
+    while r == 0 or s == 0:
+        randNum = RandomInteger.between(1, curve.N - 1)
+        randSignPoint = Math.multiply(
+            curve.G, n=randNum, A=curve.A, P=curve.P, N=curve.N
+        )
+        r = randSignPoint.x % curve.N
+        s = (
+            (numberMessage + r * privateKey.secret) * (Math.inv(randNum, curve.N))
+        ) % curve.N
+    recoveryId = randSignPoint.y & 1
+    if randSignPoint.y > curve.N:
+        recoveryId += 2
+
+    return Signature(r=r, s=s, recoveryId=recoveryId)
+
+
 def sign_message(msg, private_key, hex=True):
     """
     Sign message
-
     :param msg:  message to sign  bytes or HEX encoded string.
     :param private_key:  private key (bytes, hex encoded string or WIF format)
     :param hex:  (optional) If set to True return key in HEX format, by default is True.
@@ -447,6 +515,25 @@ def sign_message(msg, private_key, hex=True):
     return signature.hex() if hex else signature
 
 
+def sign_message_standard_ops(msg, private_key):
+    """
+    Sign message
+
+    :param msg:  message to sign in string.
+    :param private_key:  private key (WIF format)
+    :param hex:  (optional) If set to True return key in HEX format, by default is True.
+    :return:  DER encoded signature in bytes or HEX encoded string.  
+    """
+    if(is_wif_valid(private_key)):
+        hexKey = wif_to_private_key(private_key)
+    else:
+        raise TypeError("Invalid Private_Key, must be in WIF format")
+    pk = PrivateKey.fromString(hexKey)
+    signature = modSign(msg, pk)
+    toDer = int.from_bytes(signature.toDer(), 'big')
+    return hex(toDer)[2:]
+
+
 def public_key_recovery(signature, messsage, rec_id, compressed=True, hex=True):
     if isinstance(signature, str):
         signature = bytes_from_hex(signature)
@@ -551,5 +638,4 @@ def is_valid_signature_encoding(sig):
     # interpreted as a negative number.
     if (len_s > 1) and (sig[len_r + 6] == 0x00) and (not sig[len_r + 7] & 0x80):
         return False
-    return True
-
+    return True