1 files changed, 38 insertions, 0 deletions

diff --git a/pyecsca/ec/context.py b/pyecsca/ec/context.py
new file mode 100644
index 0000000..a65f461
--- /dev/null
+++ b/pyecsca/ec/context.py
@@ -0,0 +1,38 @@
+from typing import List, Tuple
+
+from .formula import Formula
+from .mod import Mod
+from .point import Point
+
+
+class Context(object):
+    intermediates: List[Tuple[str, Mod]]
+
+    def __init__(self):
+        self.intermediates = []
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        pass
+
+    def execute(self, formula: Formula, *points: Point, **params: Mod) -> Point:
+        coords = {}
+        for i, point in enumerate(points):
+            if point.coordinate_model != formula.coordinate_model:
+                raise ValueError
+            for coord, value in point.coords.items():
+                coords[coord + str(i + 1)] = value
+        locals = {**coords, **params}
+        previous_locals = set(locals.keys())
+        for line in formula.code:
+            exec(compile(line, "", mode="exec"), {}, locals)
+            diff = set(locals.keys()).difference(previous_locals)
+            previous_locals = set(locals.keys())
+            for key in diff:
+                self.intermediates.append((key, locals[key]))
+        resulting = {variable: locals[variable + "3"]
+                     for variable in formula.coordinate_model.variables
+                     if variable + "3" in locals}
+        return Point(formula.coordinate_model, **resulting)