added btcpay pairing instructions to readme

readme/generate_btcpay_keys.py

@@ -0,0 +1,47 @@
+from ecdsa import SigningKey, SECP256k1, VerifyingKey
+import binascii
+import hashlib
+
+def sha_digest(hexastring):
+  return hashlib.sha256(binascii.unhexlify(hexastring)).hexdigest()
+
+def base58encode(hexastring):
+  chars = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
+  int_val = int(hexastring, 16)
+  encoded =  encode58("", int_val, chars)
+  return encoded
+
+def encode58(string, int_val, chars):
+  if int_val == 0:
+    return string
+  else:
+    new_val, rem = divmod(int_val, 58) 
+    new_string = (chars[rem]) + string
+    return encode58(new_string, new_val, chars)
+
+sk = SigningKey.generate(curve=SECP256k1)
+pem = sk.to_pem()
+pem = pem.decode("utf-8")
+
+print("")
+print(pem)
+print("")
+
+public_key = SigningKey.from_pem(pem).get_verifying_key().to_string()
+public_key_hex = binascii.hexlify(public_key)
+checksum_int = int(public_key_hex, 16)
+if(checksum_int % 2 == 0):
+  prefix = "02"
+else:
+  prefix = "03"
+public_key_compressed = prefix + public_key_hex[0:64].decode("utf-8")
+hash_of_public_key = sha_digest(public_key_compressed)
+ripe_hash_of_public_key = hashlib.new("ripemd160")
+ripe_hash_of_public_key.update(binascii.unhexlify(hash_of_public_key))
+version_hash = "0F02"+ripe_hash_of_public_key.hexdigest()
+version_checksum = sha_digest(sha_digest(version_hash))[0:8]
+btcpay_sin = base58encode(version_hash+version_checksum)
+
+print("")
+print(btcpay_sin)
+print("")