drbg_functest.c

// Copyright lowRISC contributors (OpenTitan project).
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
 
#include "sw/device/lib/base/status.h"
#include "sw/device/lib/crypto/drivers/entropy.h"
#include "sw/device/lib/crypto/include/drbg.h"
#include "sw/device/lib/runtime/log.h"
#include "sw/device/lib/testing/randomness_quality.h"
#include "sw/device/lib/testing/test_framework/check.h"
#include "sw/device/lib/testing/test_framework/ottf_main.h"
 
#include "hw/top_earlgrey/sw/autogen/top_earlgrey.h"
 
#define MODULE_ID MAKE_MODULE_ID('t', 's', 't')
 
OTTF_DEFINE_TEST_CONFIG();
 
static const uint32_t kTestSeed[12] = {
    0x73bec010, 0x9262474c, 0x16a30f76, 0x531b51de, 0x2ee494e5, 0xdfec9db3,
    0xcb7a879d, 0x5600419c, 0xca79b0b0, 0xdda33b5c, 0xa468649e, 0xdf5d73fa};
// Note that the word order in the expected output is reversed compared to the
// NIST reference.
static const uint32_t kExpOutput[16] = {
    0xd1c07cd9, 0x5af8a7f1, 0x1012c84c, 0xe48bb8cb, 0x87189e99, 0xd40fccb1,
    0x771c619b, 0xdf82ab22, 0x80b1dc2f, 0x2581f391, 0x64f7ac0c, 0x510494b3,
    0xa43c41b7, 0xdb17514c, 0x87b107ae, 0x793e01c5,
};
static const otcrypto_const_byte_buf_t kEmptyBuffer = {
    .data = NULL,
    .len = 0,
};
 
static status_t kat_test(void) {
  otcrypto_const_byte_buf_t entropy = {
      .data = (const unsigned char *)kTestSeed,
      .len = sizeof(kTestSeed),
  };
 
  // Instantiate DRBG.
  TRY(otcrypto_drbg_manual_instantiate(entropy, /*perso_string=*/kEmptyBuffer));
 
  uint32_t actual_output_words[ARRAYSIZE(kExpOutput)];
  otcrypto_word32_buf_t actual_output = {
      .data = actual_output_words,
      .len = ARRAYSIZE(actual_output_words),
  };
 
  // Generate output twice.
  LOG_INFO("Generating...");
  TRY(otcrypto_drbg_manual_generate(/*additional_input=*/kEmptyBuffer,
                                    actual_output));
  LOG_INFO("Generating again...");
  TRY(otcrypto_drbg_manual_generate(/*additional_input=*/kEmptyBuffer,
                                    actual_output));
 
  // Compare second result to expected output.
  TRY_CHECK_ARRAYS_EQ(kExpOutput, actual_output_words, ARRAYSIZE(kExpOutput));
  TRY_CHECK_ARRAYS_EQ(kExpOutput, kExpOutput, 0);
 
  return OK_STATUS();
}
 
static status_t random_test(void) {
  // Instantiate DRBG.
  TRY(otcrypto_drbg_instantiate(/*perso_string=*/kEmptyBuffer));
 
  // Generate a relatively large amount of output data.
  uint32_t output_data[1024];
  otcrypto_word32_buf_t output = {
      .data = output_data,
      .len = ARRAYSIZE(output_data),
  };
  TRY(otcrypto_drbg_generate(/*additional_input=*/kEmptyBuffer, output));
 
  // Run a basic randomness-quality check on the output.
  return randomness_quality_monobit_test(
      (unsigned char *)output_data, sizeof(output_data),
      kRandomnessQualitySignificanceOnePercent);
}
 
bool test_main(void) {
  status_t result = OK_STATUS();
 
  // Initialize the entropy complex.
  CHECK_STATUS_OK(entropy_complex_init());
  CHECK_STATUS_OK(entropy_complex_check());
 
  EXECUTE_TEST(result, kat_test);
  EXECUTE_TEST(result, random_test);
  return status_ok(result);
}