auth: Persist the user's registration details

If the registration details pass the validations steps, then persist the
details in the database and respond with details about the newly created user.

* gn3/auth/authentication/users.py: new functions
  * `save_user`: create and persist a new user
  * `set_user_password`: hash and persist the new password for the given user
* gn3/auth/authorisation/views.py: Persist the user details and respond with
  the newly persisted user details.

1 files changed, 25 insertions, 1 deletions

diff --git a/gn3/auth/authentication/users.py b/gn3/auth/authentication/users.py
index 6ec6bca..0cd5852 100644
--- a/gn3/auth/authentication/users.py
+++ b/gn3/auth/authentication/users.py
@@ -1,5 +1,5 @@
 """User-specific code and data structures."""
-from uuid import UUID
+from uuid import UUID, uuid4
 from typing import NamedTuple
 
 import bcrypt
@@ -53,3 +53,27 @@ def valid_login(conn: db.DbConnection, user: User, password: str) -> bool:
         return False
 
     return bcrypt.checkpw(password.encode("utf-8"), row["password"])
+
+def save_user(cursor: db.DbCursor, email: str, name: str) -> User:
+    """
+    Create and persist a user.
+
+    The user creation could be done during a transaction, therefore the function
+    takes a cursor object rather than a connection.
+
+    The newly created and persisted user is then returned.
+    """
+    user_id = uuid4()
+    cursor.execute("INSERT INTO users VALUES (?, ?, ?)",
+                   (str(user_id), email, name))
+    return User(user_id, email, name)
+
+def set_user_password(
+        cursor: db.DbCursor, user: User, password: str) -> Tuple[User, bytes]:
+    """Set the given user's password in the database."""
+    hashed_password = bcrypt.hashpw(password.encode("utf8"), bcrypt.gensalt())
+    cursor.execute(
+        ("INSERT INTO user_credentials VALUES (:user_id, :hash) "
+         "ON CONFLICT (user_id) DO UPDATE SET password=:hash"),
+        {"user_id": str(user.user_id), "hash": hashed_password})
+    return user, hashed_password