Revert "Switch to sslcrypto for cryptography tasks (#2338)"

This reverts commit fbc7b6fc4f.

plugins/CryptMessage/CryptMessage.py

@@ -1,21 +1,28 @@
 import hashlib
 import base64
-import sslcrypto
+import binascii
+
+import lib.pybitcointools as btctools
+from util import ThreadPool
 from Crypt import Crypt
 
+ecc_cache = {}
 
-curve = sslcrypto.ecc.get_curve("secp256k1")
-
-
-def eciesEncrypt(data, pubkey, ciphername="aes-256-cbc"):
-    ciphertext, key_e = curve.encrypt(
-        data,
-        base64.b64decode(pubkey),
-        algo=ciphername,
-        derivation="sha512",
-        return_aes_key=True
-    )
-    return key_e, ciphertext
+def eciesEncrypt(data, pubkey, ephemcurve=None, ciphername='aes-256-cbc'):
+    from lib import pyelliptic
+    pubkey_openssl = toOpensslPublickey(base64.b64decode(pubkey))
+    curve, pubkey_x, pubkey_y, i = pyelliptic.ECC._decode_pubkey(pubkey_openssl)
+    if ephemcurve is None:
+        ephemcurve = curve
+    ephem = pyelliptic.ECC(curve=ephemcurve)
+    key = hashlib.sha512(ephem.raw_get_ecdh_key(pubkey_x, pubkey_y)).digest()
+    key_e, key_m = key[:32], key[32:]
+    pubkey = ephem.get_pubkey()
+    iv = pyelliptic.OpenSSL.rand(pyelliptic.OpenSSL.get_cipher(ciphername).get_blocksize())
+    ctx = pyelliptic.Cipher(key_e, iv, 1, ciphername)
+    ciphertext = iv + pubkey + ctx.ciphering(data)
+    mac = pyelliptic.hmac_sha256(key_m, ciphertext)
+    return key_e, ciphertext + mac
 
 
 @Crypt.thread_pool_crypt.wrap
@@ -30,12 +37,38 @@ def eciesDecryptMulti(encrypted_datas, privatekey):
     return texts
 
 
-def eciesDecrypt(ciphertext, privatekey):
-    return curve.decrypt(
-        base64.b64decode(ciphertext),
-        curve.wif_to_private(privatekey),
-        derivation="sha512"
-    )
+def eciesDecrypt(encrypted_data, privatekey):
+    ecc_key = getEcc(privatekey)
+    return ecc_key.decrypt(base64.b64decode(encrypted_data))
 
-def split(ciphertext):
-    return ciphertext[:16], ciphertext[86:-32]
+def split(encrypted):
+    iv = encrypted[0:16]
+    ciphertext = encrypted[16 + 70:-32]
+
+    return iv, ciphertext
+
+
+def getEcc(privatekey=None):
+    from lib import pyelliptic
+    global ecc_cache
+    if privatekey not in ecc_cache:
+        if privatekey:
+            publickey_bin = btctools.encode_pubkey(btctools.privtopub(privatekey), "bin")
+            publickey_openssl = toOpensslPublickey(publickey_bin)
+            privatekey_openssl = toOpensslPrivatekey(privatekey)
+            ecc_cache[privatekey] = pyelliptic.ECC(curve='secp256k1', privkey=privatekey_openssl, pubkey=publickey_openssl)
+        else:
+            ecc_cache[None] = pyelliptic.ECC()
+    return ecc_cache[privatekey]
+
+
+def toOpensslPrivatekey(privatekey):
+    privatekey_bin = btctools.encode_privkey(privatekey, "bin")
+    return b'\x02\xca\x00\x20' + privatekey_bin
+
+
+def toOpensslPublickey(publickey):
+    publickey_bin = btctools.encode_pubkey(publickey, "bin")
+    publickey_bin = publickey_bin[1:]
+    publickey_openssl = b'\x02\xca\x00 ' + publickey_bin[:32] + b'\x00 ' + publickey_bin[32:]
+    return publickey_openssl