implemented derived passwords

imports/hashderive.py

@@ -0,0 +1,30 @@
+import hashlib
+
+import binascii
+
+class HashDerivedKey:
+
+    @staticmethod
+    def from_hex(hex_str):
+        return HashDerivedKey(bytes(bytearray.fromhex(hex_str)))
+
+    def __init__(self, master):
+        def ensure_bytes(b):
+            assert isinstance(b, bytes)
+            return b
+        ensure_bytes(master)
+        def derive(seed):
+            ensure_bytes(seed)
+            sha = hashlib.sha256()
+            sha.update(master)
+            sha.update(seed)
+            return sha.digest()
+        hex = lambda b: binascii.hexlify(b).decode("utf-8")
+        self.master = master
+        self.master_hex = lambda: hex(master)
+        self.derive = derive
+        self.derive_hex = lambda seed: hex(derive(seed))
+
+    def derive_metadata(self,seed):
+        key = self.derive(seed)
+        return (key,{"key_seed": binascii.hexlify(seed).decode("utf-8")})