Fix bcrypt hashing failure for passwords longer than 72 bytes

Author: ayushthoren

proton/session/srp/util.py

@@ -37,6 +37,8 @@ def bcrypt_b64_encode(s):  # The joy of bcrypt
 
 
 def hash_password_3(hash_class, password, salt, modulus):
+    if len(password) > 72:
+        password = password[:72]
     salt = (salt + b"proton")[:16]
     salt = bcrypt_b64_encode(salt)[:22]
     hashed = bcrypt.hashpw(password, b"$2y$10$" + salt)