add Auth Encrypted WIF feature

Created by: Tortue95

src/auth.py

 from tools import *
+import nacl.encoding
+import nacl.signing
+import nacl.hash
+import scrypt
+import pyaes
 import getpass
 import os
 
@@ -24,7 +29,8 @@ def generate_auth_file(c):
     seed = auth_method(c)
     with open(file, "w") as f:
         f.write(seed)
-    print("Authfile generated for the public key: ", get_publickey_from_seed(seed))
+    print("Authfile generated for the public key: ",
+          get_publickey_from_seed(seed))
 
 
 def auth_by_auth_file(c):
@@ -56,6 +62,7 @@ def auth_by_seed():
 def auth_by_scrypt(c):
     salt = input("Please enter your Scrypt Salt (Secret identifier): ")
     password = getpass.getpass("Please enter your Scrypt password (masked): ")
+        
     if c.contains_definitions('n') and c.contains_definitions('r') and c.contains_definitions('p'):
         n, r, p = c.get_definition('n'), c.get_definition('r'), c.get_definition('p')
         if n.isnumeric() and r.isnumeric() and p.isnumeric():
@@ -75,6 +82,120 @@ def auth_by_scrypt(c):
 
 
 def auth_by_wif():
-    wif = input("Please enter your WIF address: ")
-    seed = get_seed_from_wif(wif)
-    return seed
+    wif = input("Please enter your WIF or Encrypted WIF address: ")
+
+    regex = re.compile('^[1-9A-HJ-NP-Za-km-z]*$')
+    if not re.search(regex, wif):
+        print("Error: the format of WIF is invalid")
+        exit(1)
+
+    wif_bytes = b58_decode(wif)
+    fi = wif_bytes[0:1]
+
+    if fi == b'\x01':
+        return get_seed_from_wifv1(wif)
+    elif fi == b'\x02':
+        password = getpass.getpass("Please enter the " +
+                                   "password of WIF (masked): ")
+        return get_seed_from_ewifv1(wif, password)
+
+    print("Error: the format of WIF is invalid or unknown")
+    exit(1)
+
+
+def get_seed_from_scrypt(salt, password, N=4096, r=16, p=1):
+    seed = scrypt.hash(password, salt, N, r, p, 32)
+    seedhex = nacl.encoding.HexEncoder.encode(seed).decode("utf-8")
+    return seedhex
+
+
+def get_seed_from_wifv1(wif):
+    regex = re.compile('^[1-9A-HJ-NP-Za-km-z]*$')
+    if not re.search(regex, wif):
+        print("Error: the format of WIF is invalid")
+        exit(1)
+
+    wif_bytes = b58_decode(wif)
+    if len(wif_bytes) != 35:
+        print("Error: the size of WIF is invalid")
+        exit(1)
+
+    checksum_from_wif = wif_bytes[-2:]
+    fi = wif_bytes[0:1]
+    seed = wif_bytes[1:-2]
+    seed_fi = wif_bytes[0:-2]
+
+    if fi != b'\x01':
+        print("Error: It's not a WIF format")
+        exit(1)
+
+    # checksum control
+    checksum = nacl.hash.sha256(
+                    nacl.hash.sha256(seed_fi, nacl.encoding.RawEncoder),
+                    nacl.encoding.RawEncoder)[0:2]
+    if checksum_from_wif != checksum:
+        print("Error: bad checksum of the WIF")
+        exit(1)
+
+    seedhex = nacl.encoding.HexEncoder.encode(seed).decode("utf-8")
+    return seedhex
+
+
+def get_seed_from_ewifv1(ewif, password):
+    regex = re.compile('^[1-9A-HJ-NP-Za-km-z]*$')
+    if not re.search(regex, ewif):
+        print("Error: the format of EWIF is invalid")
+        exit(1)
+
+    wif_bytes = b58_decode(ewif)
+    if len(wif_bytes) != 39:
+        print("Error: the size of EWIF is invalid")
+        exit(1)
+
+    wif_no_checksum = wif_bytes[0:-2]
+    checksum_from_ewif = wif_bytes[-2:]
+    fi = wif_bytes[0:1]
+    salt = wif_bytes[1:5]
+    encryptedhalf1 = wif_bytes[5:21]
+    encryptedhalf2 = wif_bytes[21:37]
+
+    if fi != b'\x02':
+        print("Error: It's not a EWIF format")
+        exit(1)
+
+    # Checksum Control
+    checksum = nacl.hash.sha256(
+                   nacl.hash.sha256(wif_no_checksum, nacl.encoding.RawEncoder),
+                   nacl.encoding.RawEncoder)[0:2]
+    if checksum_from_ewif != checksum:
+        print("Error: bad checksum of EWIF address")
+        exit(1)
+
+    # SCRYPT
+    password = password.encode("utf-8")
+    scrypt_seed = scrypt.hash(password, salt, 16384, 8, 8, 64)
+    derivedhalf1 = scrypt_seed[0:32]
+    derivedhalf2 = scrypt_seed[32:64]
+
+    # AES
+    aes = pyaes.AESModeOfOperationECB(derivedhalf2)
+    decryptedhalf1 = aes.decrypt(encryptedhalf1)
+    decryptedhalf2 = aes.decrypt(encryptedhalf2)
+
+    # XOR
+    seed1 = xor_bytes(decryptedhalf1, derivedhalf1[0:16])
+    seed2 = xor_bytes(decryptedhalf2, derivedhalf1[16:32])
+    seed = seed1+seed2
+    seedhex = nacl.encoding.HexEncoder.encode(seed).decode("utf-8")
+
+    # Password Control
+    salt_from_seed = nacl.hash.sha256(
+                        nacl.hash.sha256(
+                            b58_decode(get_publickey_from_seed(seedhex)),
+                            nacl.encoding.RawEncoder),
+                        nacl.encoding.RawEncoder)[0:4]
+    if salt_from_seed != salt:
+        print("Error: bad Password of EWIF address")
+        exit(1)
+
+    return seedhex