[ci] Automatic comparison of traces

This PR adds a new CI job to automatically compare a generated
trace to a golden reference trace. This helps to quickly
identify CI issues.

Signed-off-by: Pascal Nasahl <[email protected]>

ci/azure-pipelines.yml

@@ -28,3 +28,11 @@ jobs:
   - publish: ./ci/ci_projects/opentitan_simple_aes_data/
     artifact: traces
     displayName: "Upload traces"
+  - bash: |
+      pushd ci
+      ./ci_check_aes_traces.sh
+      popd
+    displayName: "Capture & check static AES traces"
+  - publish: ./ci/tmp/
+    artifact: traces
+    displayName: "Upload traces AES."

ci/ci_capture_aes_cw310.yaml

@@ -25,6 +25,6 @@ capture:
   project_name: ci_projects/opentitan_simple_aes
   waverunner_ip: 192.168.1.228
 plot_capture:
-  show: False
-  num_traces: 100
-  trace_image_filename: null
+  show: True
+  num_traces: 2
+  trace_image_filename: ci_projects/sample_traces_aes.html

ci/ci_check_aes_traces.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+# Simple script to test AES captures
+# Create results folder.
+mkdir -p tmp
+
+# AES
+MODE="aes"
+BOARD=cw310
+declare -A aes_test_list
+aes_test_list["aes-static"]=2
+
+ARGS="--force-program-bitstream"
+for test in ${!aes_test_list[@]}; do
+  echo Testing ${test} on CW310 - `date`
+  NUM_TRACES=${aes_test_list[${test}]}
+  ../cw/capture.py --cfg-file ci_capture_aes_cw310.yaml capture ${test} \
+      --num-traces ${NUM_TRACES} ${ARGS} &>> "tmp/test_capture.log"
+
+  mv ./ci_projects/sample_traces_${MODE}.html tmp/${test}_traces.html
+  ARGS=""
+done

cw/capture.py

@@ -210,6 +210,43 @@ def capture_end(cfg):
         plot_results(cfg["plot_capture"], cfg["capture"]["project_name"])
 
 
+def capture_aes_static(ot):
+    """A generator for capturing AES traces for fixed key and test.
+
+    Args:
+      ot: Initialized OpenTitan target.
+    """
+    key = bytearray([0x81, 0x1E, 0x37, 0x31, 0xB0, 0x12, 0x0A, 0x78,
+                     0x42, 0x78, 0x1E, 0x22, 0xB2, 0x5C, 0xDD, 0xF9])
+    text = bytearray([0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
+                      0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA])
+
+    tqdm.write(f'Fixed key: {binascii.b2a_hex(bytes(key))}')
+
+    while True:
+        cipher = AES.new(bytes(key), AES.MODE_ECB)
+        ret = cw.capture_trace(ot.scope, ot.target, text, key, ack=False, as_int=True)
+        if not ret:
+            raise RuntimeError('Capture failed.')
+        expected = binascii.b2a_hex(cipher.encrypt(bytes(text)))
+        got = binascii.b2a_hex(ret.textout)
+        if got != expected:
+            raise RuntimeError(f'Bad ciphertext: {got} != {expected}.')
+        yield ret
+
+
+@app_capture.command()
+def aes_static(ctx: typer.Context,
+               force_program_bitstream: bool = opt_force_program_bitstream,
+               num_traces: int = opt_num_traces,
+               plot_traces: int = opt_plot_traces):
+    """Capture AES traces from a target that runs the `aes_serial` program."""
+    capture_init(ctx, force_program_bitstream, num_traces, plot_traces)
+    capture_loop(capture_aes_static(ctx.obj.ot), ctx.obj.ot,
+                 ctx.obj.cfg["capture"], ctx.obj.cfg["device"])
+    capture_end(ctx.obj.cfg)
+
+
 def capture_aes_random(ot, ktp):
     """A generator for capturing AES traces.
     Fixed key, Random texts.