Add to prototype

abac/migrations/0004_encrypteddata.py

@@ -0,0 +1,24 @@
+# Generated by Django 4.2.6 on 2023-10-24 16:16
+
+from django.db import migrations, models
+import django.db.models.deletion
+import uuid
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('abac', '0003_trustedauthority'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EncryptedData',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('x_values', models.TextField()),
+                ('token', models.UUIDField(default=uuid.uuid4, editable=False, unique=True)),
+                ('file', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='abac.file')),
+            ],
+        ),
+    ]

abac/models.py

@@ -1,9 +1,13 @@
-import pickle
-from base64 import b64encode, b64decode
 from django.contrib.auth.models import AbstractUser
 from django.db import models
 from django.utils import timezone
 
+import pickle
+from base64 import b64encode, b64decode
+from random import randint
+from phe import paillier
+from uuid import uuid4
+
 
 class User(AbstractUser):
     pass
@@ -52,7 +56,6 @@ class AttributeType(models.Model):
 
     
 class Attribute(models.Model):
-    
     attribute_type = models.ForeignKey(AttributeType, on_delete=models.CASCADE)
     value = models.CharField(max_length=2048)
 
@@ -81,21 +84,39 @@ class Rule(models.Model):
     write = models.BooleanField(default=False)
     delete = models.BooleanField(default=False)
 
-    def is_satisfied_by(self, user):
-        for rule_attribute in self.ruleattribute_set.all():
-            try:
-                user_attribute = UserAttribute.objects.get(
-                    user=user,
-                    attribute_type=rule_attribute.attribute_type,
-                )
-            except UserAttribute.DoesNotExist:
-                # The user does not have this attribute; the rule is not satisfied.
-                return False
-
-            if not self.attribute_satisfies_rule(user_attribute, rule_attribute):
-                return False
+    def is_satisfied_by(self, user)->(bool, int, int):
+        x = randint(0,1000)
+        y = randint(0,1000)
+        try:
+            paillier_public_key = paillier.PaillierPublicKey(n=int(user.public_key))
+        except:
+            return False, 0, 0
+        encrypted_sum = paillier_public_key.encrypt(x)
 
-        return True
+        for rule_attribute in self.ruleattribute_set.all():
+            if not rule_attribute.attribute_type.is_private:
+                try:
+                    user_attribute = UserAttribute.objects.get(
+                        user=user,
+                        attribute_type=rule_attribute.attribute_type,
+                    )
+                except UserAttribute.DoesNotExist:
+                    # The user does not have this attribute; the rule is not satisfied.
+                    return False, 0, 0
+                if not self.attribute_satisfies_rule(user_attribute, rule_attribute):
+                    return False, 0, 0
+            else:
+                try:
+                    user_attribute = UserAttribute.objects.get(
+                        user=user,
+                        attribute_type=rule_attribute.attribute_type,
+                    )
+                except UserAttribute.DoesNotExist:
+                    # The user does not have this attribute; the rule is not satisfied.
+                    return False, 0, 0
+                encrypted_attribute_value = paillier.EncryptedNumber(paillier_public_key, int(user_attribute.value))
+                encrypted_sum += (encrypted_attribute_value-int(rule_attribute.value))*y
+        return True, x, encrypted_sum.ciphertext()
     
     def attribute_satisfies_rule(self, user_attribute, rule_attribute):
         operator = rule_attribute.operator
@@ -128,3 +149,9 @@ class RuleAttribute(Attribute):
 class TrustedAuthority(models.Model):
     name = models.CharField(max_length=255)
     public_key = models.TextField()
+
+
+class EncryptedData(models.Model):
+    file = models.ForeignKey(File, on_delete=models.CASCADE)
+    x_values = models.TextField()  # Store the x values as comma-separated
+    token = models.UUIDField(default=uuid4, unique=True, editable=False)

abac/templates/decrypt_and_forward.html

@@ -0,0 +1,77 @@
+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Decrypt and Forward</title>
+    <script src="{% static 'abac/jsbn.js' %}"></script>
+    <script src="{% static 'abac/jsbn2.js' %}"></script>
+    <script src="{% static 'abac/prng4.js' %}"></script>
+    <script src="{% static 'abac/rng.js' %}"></script>
+    <script src="{% static 'abac/paillier.js' %}"></script>
+</head>
+<body>
+    <script>
+
+        function getPrivateKeyFromWebStorage() {
+            // Retrieve and parse the stored private key
+            const storedPrivateKey = localStorage.getItem('privateKey');
+            if (!storedPrivateKey) return null;
+
+            const parsedKey = JSON.parse(storedPrivateKey);
+
+            // Construct the public key from the stored value
+            const n = new BigInteger(localStorage.getItem('publicKey'));
+            const publicKey = new paillier.publicKey(2048, n);
+
+            // Construct the private key
+            const lambda = new BigInteger(parsedKey.lambda);
+            const privateKey = new paillier.privateKey(lambda, publicKey);
+            
+            // Attach the x value
+            privateKey.x = new BigInteger(parsedKey.x);
+
+            return privateKey;
+        }
+
+        // Assuming you have a method to get privateKey from local web storage
+        let privateKey = getPrivateKeyFromWebStorage(); 
+
+        let encryptions = {{ encryptions_as_strings|safe }};
+        let decryptedValues = [];
+            
+        for(let enc of encryptions) {
+            let bigIntEnc = new BigInteger(enc.toString());
+            decryptedValues.push(privateKey.decrypt(bigIntEnc).toString(10));
+        }
+
+        // Forward the decrypted values with a POST request
+        let form = document.createElement("form");
+        form.setAttribute("method", "post");
+        form.setAttribute("action", "{% url 'abac:verify_decryption' %}");
+        
+        let csrfField = document.createElement("input");
+        csrfField.setAttribute("type", "hidden");
+        csrfField.setAttribute("name", "csrfmiddlewaretoken");
+        csrfField.setAttribute("value", "{{ csrf_token }}");
+        form.appendChild(csrfField);
+
+        let tokenField = document.createElement("input");
+        tokenField.setAttribute("type", "hidden");
+        tokenField.setAttribute("name", "token");
+        tokenField.setAttribute("value", "{{ token }}");
+        form.appendChild(tokenField);
+        
+        for(let dec of decryptedValues) {
+            let input = document.createElement("input");
+            input.setAttribute("type", "hidden");
+            input.setAttribute("name", "decryptions");
+            input.setAttribute("value", dec);
+            form.appendChild(input);
+        }
+
+        document.body.appendChild(form);
+        form.submit();
+    </script>
+</body>
+</html>

abac/templates/upload_public_key.html.old

@@ -1,18 +0,0 @@
-{% extends 'base.html' %}
-{% block content %}
-<div class="container mt-5">
-    <div class="row justify-content-center">
-        <div class="col-md-6">
-            <h2>Upload Public Key</h2>
-            <form method="post" class="mt-3">
-                {% csrf_token %}
-                <div class="form-group">
-                    <label for="public_key">Paste your public key here:</label>
-                    <textarea id="public_key" name="public_key" class="form-control" rows="6" required></textarea>
-                </div>
-                <button type="submit" class="btn btn-primary">Upload Public Key</button>
-            </form>
-        </div>
-    </div>
-</div>
-{% endblock %}

abac/urls.py

@@ -19,7 +19,8 @@ from .views import (
     upload_public_key,
     hierarchy_view,
     trusted_authorities,
-    delete_authority
+    delete_authority,
+    verify_decryption
 )
 
 app_name = 'abac'
@@ -42,4 +43,5 @@ urlpatterns = [
     path('visualization/hierarchical', hierarchy_view, name='hierarchy_vis'),
     path('trusted-authorities', trusted_authorities, name="trusted_authorities"),
     path('trusted-authorities/delete/<int:authority_id>/', delete_authority, name='delete_authority'),
+    path('verify_decryption', verify_decryption, name='verify_decryption')
 ]

abac/views.py

@@ -7,6 +7,7 @@ from django.urls import reverse
 from django.contrib import messages
 from django.core.exceptions import ValidationError
 from django.utils import timezone
+from django.views.decorators.csrf import csrf_exempt
 
 import hashlib
 import json
@@ -17,7 +18,7 @@ from cryptography.hazmat.backends import default_backend
 
 
 from .forms import FileUploadForm, UploadCertificateForm, RuleAttributeForm, TrustedAuthorityForm
-from .models import File, Rule, UserAttribute, RuleAttribute, AttributeType, User, TrustedAuthority
+from .models import File, Rule, UserAttribute, RuleAttribute, AttributeType, User, TrustedAuthority, EncryptedData
     
 
 @login_required
@@ -209,31 +210,67 @@ def get_or_create_attribute_type(name, value, private=False):
 @login_required
 def download_file(request, file_id):
     file = get_object_or_404(File, id=file_id)
-    
     user = request.user
+    allowed, x, enc = check_permission(user, file)
+    if allowed and not x and not enc:
+        return serve_file(file)
+    elif not allowed:    
+        return HttpResponseForbidden('You do not have permission to download this file.')
+    elif enc:
+        encrypted_data = EncryptedData(file=file, x_values=','.join(map(str, x)))
+        encrypted_data.save()
+        context = {
+            'encryptions_as_strings': [str(e) for e in enc],
+            'token': str(encrypted_data.token)
+        }
+        return render(request, 'decrypt_and_forward.html', context)
+
+@login_required
+def verify_decryption(request):
+    if request.method == 'POST':
+        token = request.POST.get('token')
+        decryptions = request.POST.getlist('decryptions')
+        encrypted_data = get_object_or_404(EncryptedData, token=token)
 
-    for rule in file.rule_set.all():
-        if rule.is_satisfied_by(user):
-            return serve_file(file)
+        #Compare decryptions with stored x values TODO: for some reason this didn't work when I tried to make sure the order was preserved
+        x_values = list(map(int, encrypted_data.x_values.split(',')))
+        
+        for decrypted in decryptions:
+            if int(decrypted) in x_values:
+                return serve_file(encrypted_data.file)
+                
+        return HttpResponseForbidden("You don't have the permission to access this file!")
+    return HttpResponseNotAllowed(['POST'])
 
-    return HttpResponseForbidden('You do not have permission to download this file.')
         
 def check_permission(user, file, mode = None):
+    """
+    Method that checks if a user is allowed to perform the operation specified in mode with the file
+    TODO: Implement mode
+
+    """
     if mode:
         pass
     else:
         # a) Check if the user is the owner of the file.
         if user == file.owner:
-            return True
+            return True, [], []
         
         # b) Check if the user is a superuser.
         if user.is_superuser:
-            return True
+            return True, [], []
             
         # c) Check the user's attributes against the file's rules.
+        x = []
+        enc = []
         for rule in file.rule_set.all():
-            if rule.is_satisfied_by(user):
-                return True
+            result, x_i, enc_i = rule.is_satisfied_by(user)
+            if result:
+                x.append(x_i)
+                enc.append(enc_i)
+            else:
+                return False, [], []
+        return True, x, enc
 
 def serve_file(file):
     # Serve the file using FileResponse.