Add mpc.peek() for "informational" purposes.

Insert calls pretty much anywhere in your code to inspect values of secure (secret-shared) objects.

mpyc/__init__.py

@@ -29,7 +29,7 @@
 and statistics (securely mimicking Python’s statistics module).
 """
 
-__version__ = '0.10.1'
+__version__ = '0.10.2'
 
 import os
 import sys

mpyc/asyncoro.py

@@ -217,6 +217,9 @@ def _add_callbacks(self, obj):
                 else:
                     self.tally += 1
                     obj.share.add_done_callback(self._decrement)
+            elif isinstance(obj.share, tuple):
+                for x in obj.share:
+                    self._add_callbacks(x)
         elif isinstance(obj, Future) and not obj.done():
             self.tally += 1
             obj.add_done_callback(self._decrement)
@@ -230,6 +233,9 @@ def _get_results(obj):
         if isinstance(obj.share, Future):
             return obj.share.result()
 
+        elif isinstance(obj.share, tuple):
+            return tuple(map(_get_results, obj.share))
+
         return obj.share
 
     if isinstance(obj, Future):
@@ -255,6 +261,9 @@ def gather_shares(rt, *obj):
         if isinstance(obj.share, Future):
             return obj.share
 
+        elif isinstance(obj.share, tuple):
+            return gather_shares(rt, obj.share)
+
         return _AwaitableFuture(obj.share)
 
     if not rt.options.no_async:

mpyc/runtime.py

@@ -210,6 +210,28 @@ def logging(self, enable=None):
         else:
             logging.disable(logging.INFO)
 
+    @asyncoro.mpc_coro
+    async def peek(self, x, label='') -> None:
+        """Peek at the value of secret-shared x,
+        for "informational" and debugging purposes only.
+
+        For secure object x (or list of secure objects compatible with
+        runtime.output()), the value is logged once its computation is done.
+
+        In debug mode, the moment at which the task for the computation of x is
+        scheduled is logged, and the value of this party's secret share of x is
+        logged once the task for the computation of x has completed.
+
+        To facilitate matching of scheduled with completed tasks, an "address"
+        based on the program counter is included as well the given label, if any.
+        """
+        txt = f'Peek at {abs(mpc._program_counter[0]) % (1<<24):#08x}:'
+        if label:
+            txt += f' {label}'
+        logging.debug(f'{txt} Task scheduled')
+        logging.info(f'{txt} Task output {await self.output(x)}')
+        logging.debug(f'{txt} Party {self.pid}\'s share {await self.gather(x)}')
+
     async def start(self):
         """Start the MPyC runtime.
 

tests/test_runtime.py

@@ -25,6 +25,7 @@ def test_secint_array(self):
         a = FF.array([[[-1, 1], [1, -1]]])  # 3D array
         np.assertEqual(mpc.run(mpc.output(mpc.run(mpc.transfer(a, senders=0)))), a)
         c = secint.array(a)
+        mpc.peek(c, label='secint.array')
         a = a.copy()  # NB: needed to pass tests with inplace operations
         self.assertTrue((a == mpc.run(mpc.output(mpc.np_sgn(c)))).all())  # via FF array __eq__
         self.assertTrue((mpc.run(mpc.output(mpc.np_sgn(c))) == a).all())  # via FF array ufunc equal
@@ -251,6 +252,7 @@ def test_secfxp_array(self):
         secfxp = mpc.SecFxp(12)
         a = np.array([[-1.5, 2.5], [4.5, -8.5]])
         c = secfxp.array(a)
+        mpc.peek(c)
 
         np.assertEqual(mpc.run(mpc.output(c + np.array([1, 2]))), a + np.array([1, 2]))
         np.assertEqual(mpc.run(mpc.output(c * np.array([1, 2]))), a * np.array([1, 2]))
@@ -464,6 +466,7 @@ def test_secfld_array(self):
 
         secfld = mpc.SecFld(2**2)
         c = secfld.array(np.array([[-3, 0], [1, 2]]))
+        mpc.peek(c)
         np.assertEqual(mpc.run(mpc.output(mpc.np_to_bits(c))), [[[1, 1], [0, 0]], [[1, 0], [0, 1]]])
         np.assertEqual(mpc.run(mpc.output(mpc.np_from_bits(mpc.np_to_bits(c[1])))), [1, 2])
         c = mpc._np_randoms(secfld, 5)
@@ -681,6 +684,7 @@ def test_secint(self):
         secint = mpc.SecInt()
         a = secint(12)
         b = secint(13)
+        mpc.peek(b)
         self.assertEqual(mpc.run(mpc.output(mpc.input(a, 0))), 12)
         self.assertEqual(mpc.run(mpc.output(mpc.input([a, b], 0))), [12, 13])
         self.assertEqual(mpc.run(mpc.output(-a)), -12)
@@ -911,6 +915,7 @@ def test_secflt(self):
         secflt = mpc.SecFlt()
         a = secflt(1.25)
         b = secflt(2.5)
+        mpc.peek(b)
         self.assertEqual(mpc.run(mpc.output(mpc.input(a, 0))), 1.25)
         self.assertEqual(mpc.run(mpc.output(a + b)), 3.75)
         self.assertEqual(mpc.run(mpc.output(-a + -b)), -3.75)

tests/test_secgroups.py

@@ -8,7 +8,7 @@ class Arithmetic(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        pass
+        mpc.logging(False)
 
     @classmethod
     def tearDownClass(cls):
@@ -22,7 +22,9 @@ def test_Sn(self):
         b = a @ a
         secgrp = mpc.SecGrp(group)
         c = secgrp(a)
+        mpc.peek(c)
         d = a @ c
+        mpc.peek([c, d])
         self.assertEqual(mpc.run(mpc.output(d)), b)
         e = ~c
         f = e @ b
@@ -70,6 +72,7 @@ def test_QR_SG(self):
             self.assertEqual(mpc.run(mpc.output(h)), g2)
 
             a = secgrp(g)
+            mpc.peek([a, a])
             self.assertRaises(TypeError, operator.truediv, 2, a)
             self.assertRaises(TypeError, operator.add, a, a)
             self.assertRaises(TypeError, operator.add, g, a)
@@ -99,6 +102,7 @@ def test_EC(self):
             self.assertEqual(mpc.run(mpc.output(2*secgrp(g))), g^2)
             bp4 = 4*g
             sec_bp4 = 4*secgrp(g) + secgrp.identity
+            mpc.peek([sec_bp4, sec_bp4])
             self.assertEqual(mpc.run(mpc.output(-sec_bp4)), -bp4)
             sec_bp8 = secgrp.repeat(bp4, secfld(2))
             self.assertEqual(mpc.run(mpc.output(sec_bp8)), bp4 + bp4)
@@ -141,6 +145,7 @@ def test_Cl(self):
         secgrp = mpc.SecGrp(group)
         g = group.generator
         a = secgrp(g)^6
+        mpc.peek(a)
         self.assertEqual(mpc.run(mpc.output(a)), g^6)
         self.assertEqual(mpc.run(mpc.output(a * (a^-1))), group.identity)
         m, z = group.encode(5)

tests/test_seclists.py

@@ -6,6 +6,10 @@
 
 class Arithmetic(unittest.TestCase):
 
+    @classmethod
+    def setUpClass(cls):
+        mpc.logging(False)
+
     def test_secfld(self):
         secfld = mpc.SecFld(101)
         s = seclist([], secfld)
@@ -25,6 +29,7 @@ def test_secfld(self):
         s[5] = 9
         del s[2:4]
         self.assertEqual(mpc.run(mpc.output(list(s))), [1, 2, 6, 9])
+        mpc.peek(list(s))
 
         secfld2 = mpc.SecFld()
         self.assertRaises(TypeError, seclist, [secfld(1)], secfld2)