Merge pull request #889 from ScilifelabDataCentre/key-derivation

Key derivation

CHANGELOG.md

@@ -1,2 +1,5 @@
 # Data Delivery System Web / API: Changelog
-Please add a _short_ line describing the PR you make, if the PR implements a specific feature or functionality, or refactor. Not needed if you add very small and unnoticable changes.
+Please add a _short_ line describing the PR you make, if the PR implements a specific feature or functionality, or refactor. Not needed if you add very small and unnoticable changes.
+
+## Sprint (2022-02-09 - 2022-02-23)
+* Secure operations that require cryptographic keys are protected for each user with the user's password ([#889](https://github.com/ScilifelabDataCentre/dds_web/pull/889))

dds_web/api/project.py

@@ -240,7 +240,15 @@ def get(self):
         flask.current_app.logger.debug("Getting the private key.")
 
         return flask.jsonify(
-            {"private": obtain_project_private_key(auth.current_user(), project).hex().upper()}
+            {
+                "private": obtain_project_private_key(
+                    user=auth.current_user(),
+                    project=project,
+                    token=dds_web.security.auth.obtain_current_encrypted_token(),
+                )
+                .hex()
+                .upper()
+            }
         )
 
 

dds_web/api/schemas/user_schemas.py

@@ -14,7 +14,7 @@
 from dds_web import auth, db, utils
 from dds_web import errors as ddserr
 from dds_web.database import models
-from dds_web.security.project_user_keys import transfer_invite_private_key_to_user
+from dds_web.security.project_user_keys import verify_and_transfer_invite_to_user
 
 ####################################################################################################
 # SCHEMAS ################################################################################ SCHEMAS #
@@ -196,9 +196,7 @@ def make_user(self, data, **kwargs):
         db.session.add(new_user)
 
         # Verify and transfer invite keys to the new user
-        temporary_key = dds_web.security.auth.verify_invite_key(token)
-        if temporary_key:
-            transfer_invite_private_key_to_user(invite, temporary_key, new_user)
+        if verify_and_transfer_invite_to_user(token, new_user, data.get("password")):
             for project_invite_key in invite.project_invite_keys:
                 project_user_key = models.ProjectUserKeys(
                     project_id=project_invite_key.project_id,
@@ -208,9 +206,6 @@ def make_user(self, data, **kwargs):
                 db.session.add(project_user_key)
                 db.session.delete(project_invite_key)
 
-            # TODO decrypt the user private key using the temp key,
-            #  derive a key from the password and encrypt the user private key with the derived key
-
             flask.session.pop("invite_token", None)
 
             # Delete old invite

dds_web/api/user.py

@@ -122,7 +122,12 @@ def invite_user(args):
                 auth.current_user().unit.invites.append(new_invite)
                 for project in auth.current_user().unit.projects:
                     if project.is_active:
-                        share_project_private_key(auth.current_user(), new_invite, project)
+                        share_project_private_key(
+                            from_user=auth.current_user(),
+                            to_another=new_invite,
+                            from_user_token=dds_web.security.auth.obtain_current_encrypted_token(),
+                            project=project,
+                        )
         else:
             db.session.add(new_invite)
 
@@ -188,7 +193,12 @@ def add_user_to_project(existing_user, project, role):
                     owner=owner,
                 )
             )
-            share_project_private_key(auth.current_user(), existing_user, project)
+            share_project_private_key(
+                from_user=auth.current_user(),
+                to_another=existing_user,
+                from_user_token=dds_web.security.auth.obtain_current_encrypted_token(),
+                project=project,
+            )
 
         try:
             db.session.commit()
@@ -457,7 +467,7 @@ def post(self):
             db.session.commit()
         except sqlalchemy.exc.SQLAlchemyError as err:
             db.session.rollback()
-            raise DatabaseError(message=str(err))
+            raise ddserr.DatabaseError(message=str(err))
         msg = (
             f"The user account {user.username} ({user_email_str}, {user.role}) "
             f" has been {action}d successfully been by {current_user.name} ({current_user.role})."
@@ -542,7 +552,7 @@ def delete_user(user):
             db.session.commit()
         except sqlalchemy.exc.SQLAlchemyError as err:
             db.session.rollback()
-            raise DatabaseError(message=str(err))
+            raise ddserr.DatabaseError(message=str(err))
 
 
 class RemoveUserAssociation(flask_restful.Resource):
@@ -618,7 +628,8 @@ def get(self):
         return {
             "message": "Please take this token to /user/second_factor to authenticate with MFA!",
             "token": encrypted_jwt_token(
-                username=auth.current_user().username, sensitive_content=None
+                username=auth.current_user().username,
+                sensitive_content=flask.request.authorization.get("password"),
             ),
         }
 
@@ -633,9 +644,7 @@ def get(self):
 
         token_schemas.TokenSchema().load(args)
 
-        token_claims = dds_web.security.auth.decrypt_and_verify_token_signature(
-            flask.request.headers["Authorization"].split()[1]
-        )
+        token_claims = dds_web.security.auth.obtain_current_encrypted_token_claims()
 
         return {"token": update_token_with_mfa(token_claims)}
 

dds_web/config.py

@@ -64,7 +64,7 @@ class Config(object):
     INVITATION_EXPIRES_IN_HOURS = 7 * 24
 
     # 512MiB; at least 4GiB (0x400000) recommended in production
-    ARGON_MEMORY_COST = os.environ.get("ARGON_MEMORY_COST", 0x80000)
+    ARGON_KD_MEMORY_COST = os.environ.get("ARGON_KD_MEMORY_COST", 0x80000)
 
     SUPERADMIN_USERNAME = os.environ.get("DDS_SUPERADMIN_USERNAME", "superadmin")
     SUPERADMIN_PASSWORD = os.environ.get("DDS_SUPERADMIN_PASSWORD", "password")

dds_web/database/models.py

@@ -357,7 +357,6 @@ class User(flask_login.UserMixin, db.Model):
     hotp_issue_time = db.Column(db.DateTime, unique=False, nullable=True)
     active = db.Column(db.Boolean)
     kd_salt = db.Column(db.LargeBinary(32), default=None)
-    temporary_key = db.Column(db.LargeBinary(32), default=None)
     nonce = db.Column(db.LargeBinary(12), default=None)
     public_key = db.Column(db.LargeBinary(300), default=None)
     private_key = db.Column(db.LargeBinary(300), default=None)
@@ -389,8 +388,6 @@ def __init__(self, **kwargs):
         super(User, self).__init__(**kwargs)
         if not self.hotp_secret:
             self.hotp_secret = os.urandom(20)
-        if not self.public_key or not self.private_key:
-            generate_user_key_pair(self)
 
     def get_id(self):
         """Get user id - in this case username. Used by flask_login."""
@@ -407,7 +404,14 @@ def password(self, plaintext_password):
         """Generate the password hash and save in db."""
         pw_hasher = argon2.PasswordHasher(hash_len=32)
         self._password_hash = pw_hasher.hash(plaintext_password)
-        self.kd_salt = os.urandom(32)
+
+        # User key pair should only be set from here if the password is lost
+        # and all the keys associated with the user should be cleaned up
+        # before setting the password.
+        # This should help the tests for setup as well.
+        if not self.public_key or not self.private_key:
+            self.kd_salt = os.urandom(32)
+            generate_user_key_pair(self, plaintext_password)
 
     def verify_password(self, input_password):
         """Verifies that the specified password matches the encoded password in the database."""

dds_web/development/db_init.py

@@ -17,6 +17,7 @@
     generate_project_key_pair,
     share_project_private_key,
 )
+from dds_web.security.tokens import encrypted_jwt_token
 import dds_web.utils
 
 ####################################################################################################
@@ -154,7 +155,23 @@ def fill_db():
 
     db.session.commit()
 
-    share_project_private_key(unituser_1, researchuser_1, project_1)
-    share_project_private_key(unituser_1, researchuser_2, project_1)
+    unituser_1_token = encrypted_jwt_token(
+        username=unituser_1.username,
+        sensitive_content=password,
+    )
+
+    share_project_private_key(
+        from_user=unituser_1,
+        to_another=researchuser_1,
+        from_user_token=unituser_1_token,
+        project=project_1,
+    )
+
+    share_project_private_key(
+        from_user=unituser_1,
+        to_another=researchuser_2,
+        from_user_token=unituser_1_token,
+        project=project_1,
+    )
 
     db.session.commit()

dds_web/errors.py

@@ -10,14 +10,12 @@
 # Installed
 from werkzeug import exceptions
 import flask
-import dds_web
-import flask_login
 import http
 import json
 import structlog
 
 # Own modules
-from dds_web import actions, auth
+from dds_web import auth
 
 ####################################################################################################
 # LOGGING ################################################################################ LOGGING #
@@ -73,6 +71,50 @@ def __init__(self, encryption_key_char_length):
         general_logger.error(message)
 
 
+class TokenMissingError(LoggedHTTPException):
+    """Errors due to missing token."""
+
+    code = http.HTTPStatus.BAD_REQUEST
+
+    def __init__(self, message="Token is missing"):
+        super().__init__(message)
+
+        general_logger.warning(message)
+
+
+class SensitiveContentMissingError(LoggedHTTPException):
+    """Errors due to missing sensitive content in the encrypted token."""
+
+    code = http.HTTPStatus.BAD_REQUEST
+
+    def __init__(self, message="Sensitive content is missing in the encrypted token!"):
+        super().__init__(message)
+
+        general_logger.warning(message)
+
+
+class KeySetupError(LoggedHTTPException):
+    """Errors due to missing keys."""
+
+    code = http.HTTPStatus.INTERNAL_SERVER_ERROR
+
+    def __init__(self, message="Keys are not properly setup!"):
+        super().__init__(message)
+
+        general_logger.warning(message)
+
+
+class KeyOperationError(LoggedHTTPException):
+    """Errors due to issues in key operations."""
+
+    code = http.HTTPStatus.INTERNAL_SERVER_ERROR
+
+    def __init__(self, message="A key cannot be processed!"):
+        super().__init__(message)
+
+        general_logger.warning(message)
+
+
 class AuthenticationError(LoggedHTTPException):
     """Base class for errors due to authentication failure."""
 

dds_web/forms.py

@@ -3,17 +3,14 @@
 # IMPORTS ################################################################################ IMPORTS #
 
 # Standard library
-import re
 
 # Installed
 import flask_wtf
 import flask_login
 import wtforms
-import marshmallow
 
 # Own modules
 from dds_web import utils
-from dds_web.database import models
 
 # FORMS #################################################################################### FORMS #
 

dds_web/security/auth.py

@@ -18,9 +18,8 @@
 
 # Own modules
 from dds_web import basic_auth, auth, mail
-from dds_web.errors import AuthenticationError, AccessDeniedError, InviteError
+from dds_web.errors import AuthenticationError, AccessDeniedError, InviteError, TokenMissingError
 from dds_web.database import models
-from dds_web.security.project_user_keys import verify_invite_temporary_key
 import dds_web.utils
 
 action_logger = structlog.getLogger("actions")
@@ -135,8 +134,11 @@ def matching_email_with_invite(token, email):
     return claims.get("inv") == email
 
 
-def verify_invite_key(token):
-    """Verify token, email, invite and temporary key."""
+def extract_token_invite_key(token):
+    """Verify token, email and invite.
+
+    Return invite and temporary key.
+    """
     claims = __base_verify_token_for_invite(token=token)
 
     # Verify email in token
@@ -149,19 +151,32 @@ def verify_invite_key(token):
     if not invite:
         raise InviteError(message="Invite could not be found!")
 
-    # Verify temporary key from token claims
-    temporary_key = bytes.fromhex(claims.get("sen_con"))
-    if verify_invite_temporary_key(invite=invite, temporary_key=temporary_key):
-        return temporary_key
+    try:
+        return invite, bytes.fromhex(claims.get("sen_con"))
+    except ValueError:
+        raise ValueError("Temporary key is expected be in hexadecimal digits for a byte string.")
+
+
+def obtain_current_encrypted_token():
+    try:
+        return flask.request.headers["Authorization"].split()[1]
+    except KeyError:
+        raise TokenMissingError("Encrypted token is required but missing!")
+
+
+def obtain_current_encrypted_token_claims():
+    token = obtain_current_encrypted_token()
+    if token:
+        return decrypt_and_verify_token_signature(token)
 
 
 @auth.verify_token
 def verify_token(token):
-    """Verify token used in token authencation."""
+    """Verify token used in token authentication."""
     claims = __verify_general_token(token=token)
     user = __user_from_subject(subject=claims.get("sub"))
 
-    return handle_multi_factor_authentication(
+    return __handle_multi_factor_authentication(
         user=user, mfa_auth_time_string=claims.get("mfa_auth_time")
     )
 
@@ -209,7 +224,7 @@ def __user_from_subject(subject):
             return user
 
 
-def handle_multi_factor_authentication(user, mfa_auth_time_string):
+def __handle_multi_factor_authentication(user, mfa_auth_time_string):
     """Verify multifactor authentication time frame."""
     if user:
         if mfa_auth_time_string:
@@ -245,8 +260,10 @@ def send_hotp_email(user):
     return False
 
 
-def extract_encrypted_token_content(token, username):
+def extract_encrypted_token_sensitive_content(token, username):
     """Extract the sensitive content from inside the encrypted token."""
+    if token is None:
+        raise TokenMissingError(message="There is no token to extract sensitive content from.")
     content = decrypt_and_verify_token_signature(token=token)
     if content.get("sub") == username:
         return content.get("sen_con")