[capture] Enable uJSON for OTBN

This commit enables communication with the OTBN SCA code over uJSON.

The device code is located in lowRISC/opentitan#22190.

Signed-off-by: Pascal Nasahl <nasahlpa@lowrisc.org>

Author: nasahlpa

.github/workflows/fpga.yml

@@ -148,6 +148,65 @@ jobs:
           name: traces_sha3_random_cw310_ujson
           path: ./ci/projects/sha3_sca_random_cw310_ujson.html
 
+  otbn_sca_capture_cw310:
+    name: Capture OTBN SCA traces (CW310)
+    runs-on: [ubuntu-22.04-fpga, cw310]
+    timeout-minutes: 30
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          lfs: true
+
+      - name: Install python dependencies
+        run: |
+          python3 -m pip install --user -r python-requirements.txt
+          mkdir -p ci/projects
+
+      - name: Capture OTBN Vertical Keygen traces (simpleserial)
+        working-directory: ci
+        run: |
+          ../capture/capture_otbn.py -c cfg/ci_otbn_sca_vertical_keygen_cw310_simpleserial.yaml -p projects/otbn_sca_vertical_keygen_cw310_simpleserial
+
+      - name: Upload OTBN Vertical Keygen traces (simpleserial)
+        uses: actions/upload-artifact@v4
+        with:
+          name: traces_otbn_sca_vertical_keygen_cw310_simpleserial
+          path: ./ci/projects/otbn_sca_vertical_keygen_cw310_simpleserial.html
+      
+      - name: Capture OTBN Vertical Keygen traces (ujson)
+        working-directory: ci
+        run: |
+          ../capture/capture_otbn.py -c cfg/ci_otbn_sca_vertical_keygen_cw310_ujson.yaml -p projects/otbn_sca_vertical_keygen_cw310_ujson
+
+      - name: Upload OTBN Vertical Keygen traces (ujson)
+        uses: actions/upload-artifact@v4
+        with:
+          name: traces_otbn_sca_vertical_keygen_cw310_ujson
+          path: ./ci/projects/otbn_sca_vertical_keygen_cw310_ujson.html
+
+      - name: Capture OTBN Vertical Modinv traces (simpleserial)
+        working-directory: ci
+        run: |
+          ../capture/capture_otbn.py -c cfg/ci_otbn_sca_vertical_modinv_cw310_simpleserial.yaml -p projects/otbn_sca_vertical_modinv_cw310_simpleserial
+
+      - name: Upload OTBN Vertical Modinv traces (simpleserial)
+        uses: actions/upload-artifact@v4
+        with:
+          name: traces_otbn_sca_vertical_modinv_cw310_simpleserial
+          path: ./ci/projects/otbn_sca_vertical_modinv_cw310_simpleserial.html
+      
+      - name: Capture OTBN Vertical Modinv traces (ujson)
+        working-directory: ci
+        run: |
+          ../capture/capture_otbn.py -c cfg/ci_otbn_sca_vertical_modinv_cw310_ujson.yaml -p projects/otbn_sca_vertical_modinv_cw310_ujson
+
+      - name: Upload OTBN Vertical Modinv traces (ujson)
+        uses: actions/upload-artifact@v4
+        with:
+          name: traces_otbn_sca_vertical_modinv_cw310_ujson
+          path: ./ci/projects/otbn_sca_vertical_modinv_cw310_ujson.html
+
   sca_capture_cw305:
     name: Capture AES SCA traces (CW305)
     runs-on: [ubuntu-22.04-fpga, cw305]

capture/capture_otbn.py

@@ -22,6 +22,7 @@
 
 import util.helpers as helpers
 from target.communication.sca_otbn_commands import OTOTBNVERT
+from target.communication.sca_prng_commands import OTPRNG
 from target.communication.sca_trigger_commands import OTTRIGGER
 from target.targets import Target, TargetConfig
 from util import check_version
@@ -191,39 +192,45 @@ def establish_communication(target, capture_cfg: CaptureConfig):
 
     Returns:
         ot_otbn_vert: The communication interface to the OTBN app.
+        ot_prng: The communication interface to the PRNG SCA application.
         ot_trig: The communication interface to the SCA trigger.
     """
     # Create communication interface to OTBN.
     ot_otbn_vert = OTOTBNVERT(target=target, protocol=capture_cfg.protocol)
 
+    # Create communication interface to OT PRNG.
+    ot_prng = OTPRNG(target=target, protocol=capture_cfg.protocol)
+
     # Create communication interface to SCA trigger.
     ot_trig = OTTRIGGER(target=target, protocol=capture_cfg.protocol)
 
-    return ot_otbn_vert, ot_trig
+    return ot_otbn_vert, ot_prng, ot_trig
 
 
-def configure_cipher(cfg: dict, target, capture_cfg: CaptureConfig,
-                     ot_otbn_vert) -> OTOTBNVERT:
+def configure_cipher(cfg: dict, capture_cfg: CaptureConfig, ot_otbn_vert,
+                     ot_prng) -> OTOTBNVERT:
     """ Configure the OTBN app.
 
     Establish communication with the OTBN keygen app and configure the seed.
 
     Args:
         cfg: The configuration for the current experiment.
-        target: The OT target.
         curve_cfg: The curve config.
         capture_cfg: The configuration of the capture.
         ot_otbn_vert: The communication interface to the OTBN app.
+        ot_prng: The communication interface to the PRNG SCA application.
 
     Returns:
         curve_cfg: The curve configuration values.
     """
+    # Initialize OTBN on the target.
+    ot_otbn_vert.init()
+
     # Seed host's PRNG.
     random.seed(cfg["test"]["batch_prng_seed"])
 
     # Seed the target's PRNGs
-    ot_otbn_vert.write_batch_prng_seed(cfg["test"]["batch_prng_seed"].to_bytes(
-        4, "little"))
+    ot_prng.seed_prng(cfg["test"]["batch_prng_seed"].to_bytes(4, "little"))
 
     # select the otbn app on the device (0 -> keygen, 1 -> modinv)
     ot_otbn_vert.choose_otbn_app(cfg["test"]["app"])
@@ -474,12 +481,7 @@ def check_ciphertext_keygen(ot_otbn_vert: OTOTBNVERT, expected_key,
     """
     # Read the output, unmask the key, and check if it matches
     # expectations.
-    share0 = ot_otbn_vert.read_output(curve_cfg.seed_bytes)
-    share1 = ot_otbn_vert.read_output(curve_cfg.seed_bytes)
-    if share0 is None:
-        raise RuntimeError('Random share0 is none')
-    if share1 is None:
-        raise RuntimeError('Random share1 is none')
+    share0, share1 = ot_otbn_vert.read_seeds(curve_cfg.seed_bytes)
 
     d0 = int.from_bytes(share0, byteorder='little')
     d1 = int.from_bytes(share1, byteorder='little')
@@ -505,8 +507,7 @@ def check_ciphertext_modinv(ot_otbn_vert: OTOTBNVERT, expected_output,
         actual_output: The received output of the modinv operation.
     """
     # Read the output, unmask it, and check if it matches expectations.
-    kalpha_inv = ot_otbn_vert.read_output(curve_cfg.key_bytes)
-    alpha = ot_otbn_vert.read_output(curve_cfg.modinv_mask_bytes)
+    kalpha_inv, alpha = ot_otbn_vert.read_alpha(curve_cfg.key_bytes, curve_cfg.modinv_mask_bytes)
     if kalpha_inv is None:
         raise RuntimeError('kaplpha_inv is none')
     if alpha is None:
@@ -589,8 +590,8 @@ def capture_keygen(cfg: dict, scope: Scope, ot_otbn_vert: OTOTBNVERT,
 
                 # Store trace into database.
                 project.append_trace(wave=waves[0, :],
-                                     plaintext=mask,
-                                     ciphertext=share0 + share1,
+                                     plaintext=bytearray(mask),
+                                     ciphertext=bytearray(share0 + share1),
                                      key=seed_used)
 
             # Memory allocation optimization for CW trace library.
@@ -660,11 +661,11 @@ def capture_modinv(cfg: dict, scope: Scope, ot_otbn_vert: OTOTBNVERT,
 
                 # Store trace into database.
                 project.append_trace(wave=waves[0, :],
-                                     plaintext=k_used,
+                                     plaintext=bytearray(k_used),
                                      ciphertext=bytearray(
                                          actual_output.to_bytes(
                                              curve_cfg.key_bytes, 'little')),
-                                     key=k_used)
+                                     key=bytearray(k_used))
 
             # Memory allocation optimization for CW trace library.
             num_segments_storage = project.optimize_capture(
@@ -729,6 +730,7 @@ def main(argv=None):
         key_len_bytes=cfg["test"]["key_len_bytes"],
         text_len_bytes=cfg["test"]["text_len_bytes"],
         protocol=cfg["target"]["protocol"],
+        port = cfg["target"].get("port"),
         C=bytearray(),
         seed_fixed=bytearray(),
         expected_fixed_key=bytearray(),
@@ -739,10 +741,10 @@ def main(argv=None):
     )
 
     # Open communication with target.
-    ot_otbn_vert, ot_trig = establish_communication(target, capture_cfg)
+    ot_otbn_vert, ot_prng, ot_trig = establish_communication(target, capture_cfg)
 
     # Configure cipher.
-    curve_cfg = configure_cipher(cfg, target, capture_cfg, ot_otbn_vert)
+    curve_cfg = configure_cipher(cfg, capture_cfg, ot_otbn_vert, ot_prng)
 
     # Configure trigger source.
     # 0 for HW, 1 for SW.

capture/configs/otbn_vertical_keygen_sca_cw310.yaml

@@ -2,30 +2,31 @@ target:
   target_type: cw310
   fpga_bitstream: "../objs/lowrisc_systems_chip_earlgrey_cw310_0.1.bit"
   force_program_bitstream: True
-  fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  # fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  fw_bin: ../objs/sca_ujson_fpga_cw310.bin
   # target_clk_mult is a hardcoded value in the bitstream. Do not change.
   target_clk_mult: 0.24
   target_freq: 24000000
   baudrate: 115200
   output_len_bytes: 40
-  protocol: "simpleserial"
-  # protocol: "ujson"
-  # port: "/dev/ttyACM4"
+  # protocol: "simpleserial"
+  protocol: "ujson"
+  port: "/dev/ttyACM4"
   # Trigger source.
   # hw: Precise, hardware-generated trigger - FPGA only.
   # sw: Fully software-controlled trigger.
   trigger: "hw"
 husky:
   sampling_rate: 200000000
-  num_segments: 20
+  num_segments: 1
   num_cycles: 200
   offset_cycles: 0
   scope_gain: 24
   adc_mul: 1
   decimate: 1
 waverunner:
   waverunner_ip: 100.107.71.10
-  num_segments: 20
+  num_segments: 1
   num_samples: 6000
   sample_offset: 0
 capture:

capture/configs/otbn_vertical_modinv_sca_cw310.yaml

@@ -2,19 +2,20 @@ target:
   target_type: cw310
   fpga_bitstream: "../objs/lowrisc_systems_chip_earlgrey_cw310_0.1.bit"
   force_program_bitstream: True
-  fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  # fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  fw_bin: ../objs/sca_ujson_fpga_cw310.bin
   # target_clk_mult is a hardcoded value in the bitstream. Do not change.
   target_clk_mult: 0.24
   target_freq: 24000000
   baudrate: 115200
   output_len_bytes: 40
-  protocol: "simpleserial"
-  # protocol: "ujson"
-  # port: "/dev/ttyACM4"
+  # protocol: "simpleserial"
+  protocol: "ujson"
+  port: "/dev/ttyACM4"
   # Trigger source.
   # hw: Precise, hardware-generated trigger - FPGA only.
   # sw: Fully software-controlled trigger.
-  trigger: "hw"
+  trigger: "sw"
 husky:
   sampling_rate: 200000000
   num_segments: 20

ci/cfg/ci_otbn_sca_vertical_keygen_cw310_simpleserial.yaml

@@ -0,0 +1,44 @@
+target:
+  target_type: cw310
+  fpga_bitstream: "../objs/lowrisc_systems_chip_earlgrey_cw310_0.1.bit"
+  force_program_bitstream: False
+  fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  # target_clk_mult is a hardcoded value in the bitstream. Do not change.
+  target_clk_mult: 0.24
+  target_freq: 24000000
+  baudrate: 115200
+  output_len_bytes: 40
+  protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
+husky:
+  sampling_rate: 200000000
+  num_segments: 1
+  num_cycles: 200
+  offset_cycles: 0
+  scope_gain: 24
+  adc_mul: 1
+  decimate: 1
+capture:
+  scope_select: husky
+  show_plot: True
+  plot_traces: 10
+  num_traces: 100
+  trace_threshold: 10000
+  trace_db: ot_trace_library
+test:
+  batch_prng_seed: 6
+  key_len_bytes: 40
+  text_len_bytes: 40
+  plain_text_len_bytes: 40
+  masks_off: False
+  # Currently, 'p256' is the only supported curve.
+  curve: p256
+  # Select the OTBN app to analyze. Currently available: 'keygen', 'modinv'
+  app: keygen
+  # For app = keygen: There are two fixed-vs-random test types, KEY and SEED
+  # Currently batch-mode capture only works with SEED
+  test_type: SEED
+  batch_mode: False

ci/cfg/ci_otbn_sca_vertical_keygen_cw310_ujson.yaml

@@ -0,0 +1,45 @@
+target:
+  target_type: cw310
+  fpga_bitstream: "../objs/lowrisc_systems_chip_earlgrey_cw310_0.1.bit"
+  force_program_bitstream: False
+  fw_bin: ../objs/sca_ujson_fpga_cw310.bin
+  # target_clk_mult is a hardcoded value in the bitstream. Do not change.
+  target_clk_mult: 0.24
+  target_freq: 24000000
+  baudrate: 115200
+  output_len_bytes: 40
+  protocol: "ujson"
+  port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
+husky:
+  sampling_rate: 200000000
+  num_segments: 1
+  num_cycles: 200
+  offset_cycles: 0
+  scope_gain: 24
+  adc_mul: 1
+  decimate: 1
+capture:
+  scope_select: husky
+  show_plot: True
+  plot_traces: 10
+  num_traces: 100
+  trace_threshold: 10000
+  trace_db: ot_trace_library
+test:
+  batch_prng_seed: 6
+  key_len_bytes: 40
+  text_len_bytes: 40
+  plain_text_len_bytes: 40
+  masks_off: False
+  # Currently, 'p256' is the only supported curve.
+  curve: p256
+  # Select the OTBN app to analyze. Currently available: 'keygen', 'modinv'
+  app: keygen
+  # For app = keygen: There are two fixed-vs-random test types, KEY and SEED
+  # Currently batch-mode capture only works with SEED
+  test_type: SEED
+  batch_mode: False

ci/cfg/ci_otbn_sca_vertical_modinv_cw310_simpleserial.yaml

@@ -0,0 +1,44 @@
+target:
+  target_type: cw310
+  fpga_bitstream: "../objs/lowrisc_systems_chip_earlgrey_cw310_0.1.bit"
+  force_program_bitstream: False
+  fw_bin: "../objs/otbn_vertical_serial_fpga_cw310.bin"
+  # target_clk_mult is a hardcoded value in the bitstream. Do not change.
+  target_clk_mult: 0.24
+  target_freq: 24000000
+  baudrate: 115200
+  output_len_bytes: 40
+  protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "sw"
+husky:
+  sampling_rate: 200000000
+  num_segments: 20
+  num_cycles: 1000
+  offset_cycles: 0
+  scope_gain: 24
+  adc_mul: 1
+  decimate: 1
+capture:
+  scope_select: husky
+  show_plot: True
+  plot_traces: 10
+  num_traces: 100
+  trace_threshold: 10000
+  trace_db: ot_trace_library
+test:
+  batch_prng_seed: 6
+  key_len_bytes: 40
+  text_len_bytes: 40
+  plain_text_len_bytes: 40
+  masks_off: False
+  # Currently, 'p256' is the only supported curve.
+  curve: p256
+  # Select the OTBN app to analyze. Currently available: 'keygen', 'modinv'
+  app: modinv
+  # For app = keygen: There are two fixed-vs-random test types, KEY and SEED
+  # Currently batch-mode capture only works with SEED
+  test_type: SEED
+  batch_mode: False