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Initial checkin for prng_reseed, author name change
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Signed-off-by: Varunkumar Trivedi <[email protected]>
Signed-off-by: Varunkumar Trivedi <[email protected]>
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github-gcontributor committed Sep 20, 2024
1 parent 7fad7db commit b62a3ec
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30 changes: 30 additions & 0 deletions sw/device/tests/BUILD
Original file line number Diff line number Diff line change
Expand Up @@ -6279,3 +6279,33 @@ opentitan_test(
"//sw/device/lib/testing/test_framework:ottf_utils",
],
)


opentitan_test(
name = "aes_force_prng_reseed_test",
srcs = ["aes_force_prng_reseed_test.c"],
verilator = verilator_params(
timeout = "long",
),
exec_env = dicts.add(
{
"//hw/top_earlgrey:sim_verilator": None,
"//hw/top_earlgrey:fpga_cw340_sival": None,
},
),
deps = [
"//hw/ip/aes:model",
"//hw/top_earlgrey/sw/autogen:top_earlgrey",
"//sw/device/lib/base:memory",
"//sw/device/lib/base:mmio",
"//sw/device/lib/dif:aes",
"//sw/device/lib/dif:edn",
"//sw/device/lib/runtime:log",
"//sw/device/lib/testing:aes_testutils",
"//sw/device/lib/testing/test_framework:ottf_main",
"//sw/device/lib/dif:entropy_src",
"//sw/device/lib/testing:entropy_testutils",
"//sw/device/sca/lib:simple_serial",
],
)

274 changes: 274 additions & 0 deletions sw/device/tests/aes_force_prng_reseed_test.c
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@@ -0,0 +1,274 @@
// 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/bitfield.h"
#include "sw/device/lib/base/mmio.h"
#include "sw/device/lib/base/multibits.h"
#include "sw/device/lib/dif/dif_aes.h"
#include "sw/device/lib/dif/dif_csrng.h"
#include "sw/device/lib/dif/dif_csrng_shared.h"
#include "sw/device/lib/dif/dif_edn.h"
#include "sw/device/lib/dif/dif_entropy_src.h"
#include "sw/device/lib/runtime/hart.h"
#include "sw/device/lib/runtime/log.h"
#include "sw/device/lib/testing/aes_testutils.h"
#include "sw/device/lib/testing/csrng_testutils.h"
#include "sw/device/lib/testing/entropy_testutils.h"
#include "sw/device/lib/testing/test_framework/check.h"
#include "sw/device/lib/testing/test_framework/ottf_main.h"
#include "sw/device/sca/lib/simple_serial.h"

#include "hw/top_earlgrey/sw/autogen/top_earlgrey.h"

OTTF_DEFINE_TEST_CONFIG();

enum {
kTestTimeout = 1000 * 1000, // Timeout for waiting for AES operations
};

static dif_aes_t aes;
static dif_edn_t edn0, edn1;
static dif_csrng_t csrng;
static dif_entropy_src_t entropy_src;

// Function to fetch and log CSRNG internal state
static void log_csrng_internal_state(const dif_csrng_t *csrng) {
dif_csrng_internal_state_t csrng_state;
dif_csrng_internal_state_id_t instance_id = kCsrngInternalStateIdSw;

CHECK_DIF_OK(dif_csrng_get_internal_state(csrng, instance_id, &csrng_state));

LOG_INFO("CSRNG internal state: 0x%x", csrng_state);
}

void monitor_entropy_sources(void) {
// EDN status monitoring
bool edn_status0, edn_status1;
CHECK_DIF_OK(dif_edn_get_status(&edn0, kDifEdnStatusReady, &edn_status0));
CHECK_DIF_OK(dif_edn_get_status(&edn1, kDifEdnStatusReady, &edn_status1));
LOG_INFO("EDN0 status: 0x%x", edn_status0);
LOG_INFO("EDN1 status: 0x%x", edn_status1);
}

// Function to check the status of EDN
static void monitor_edn_status(const dif_edn_t *edn0, const dif_edn_t *edn1) {
bool edn_status0, edn_status1;

// Check EDN0 status using kDifEdnStatusReady flag
CHECK_DIF_OK(dif_edn_get_status(edn0, kDifEdnStatusReady, &edn_status0));
LOG_INFO("EDN0 status (Ready): 0x%x", edn_status0);

// Check EDN1 status using kDifEdnStatusReady flag
CHECK_DIF_OK(dif_edn_get_status(edn1, kDifEdnStatusReady, &edn_status1));
LOG_INFO("EDN1 status (Ready): 0x%x", edn_status1);
}

// AES key used for the test
static const unsigned char kAesModesKey128[16] = {
0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};

static const unsigned char kAesModesPlainText[16] = {
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
};

static const unsigned char kAesModesCipherTextEcb128[16] = {
0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60,
0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97};

/*
The mask share, used to mask kKey. Note that the masking should not be done
manually. Software is expected to get the key in two shares right from the
beginning.
*/
static const uint8_t kKeyShare1[] = {
0x0f, 0x1f, 0x2f, 0x3F, 0x4f, 0x5f, 0x6f, 0x7f, 0x8f, 0x9f, 0xaf,
0xbf, 0xcf, 0xdf, 0xef, 0xff, 0x0a, 0x1a, 0x2a, 0x3a, 0x4a, 0x5a,
0x6a, 0x7a, 0x8a, 0x9a, 0xaa, 0xba, 0xca, 0xda, 0xea, 0xfa,
};

// Function to print AES blocks key and data
static void aes_print_block(const unsigned char *data, const int num_bytes) {
for (int i = 0; i < num_bytes; i++) {
LOG_INFO("%02x ", data[i]);
}
LOG_INFO("");
}

status_t disable_entropy_complex(void) {
// Use the entropy test utility to stop all EDN0, EDN1, CSRNG, and the Entropy
// Source
TRY(entropy_testutils_stop_all());
LOG_INFO("The entire entropy complex is stopped");
return OK_STATUS();
}

status_t enable_entropy_complex(void) {
// Use the entropy test utility to enable all EDN0, EDN1, CSRNG, and the
// Entropy Source
TRY(entropy_testutils_auto_mode_init());
LOG_INFO("The entire entropy complex is enabled");
return OK_STATUS();
}

status_t execute_test(void) {
// Initialize AES, EDN, CSRNG, and Entropy Source

// Initialize all modules
LOG_INFO("Initializing AES unit.");
CHECK_DIF_OK(
dif_aes_init(mmio_region_from_addr(TOP_EARLGREY_AES_BASE_ADDR), &aes));
CHECK_DIF_OK(dif_aes_reset(&aes));
LOG_INFO("Module initialized: AES");
LOG_INFO("Starting AES PRNG reseed stall test...");
CHECK_DIF_OK(
dif_edn_init(mmio_region_from_addr(TOP_EARLGREY_EDN0_BASE_ADDR), &edn0));
CHECK_DIF_OK(
dif_edn_init(mmio_region_from_addr(TOP_EARLGREY_EDN1_BASE_ADDR), &edn1));
CHECK_DIF_OK(dif_csrng_init(
mmio_region_from_addr(TOP_EARLGREY_CSRNG_BASE_ADDR), &csrng));
CHECK_DIF_OK(dif_entropy_src_init(
mmio_region_from_addr(TOP_EARLGREY_ENTROPY_SRC_BASE_ADDR), &entropy_src));
LOG_INFO("Modules initialized: EDN0, EDN1, CSRNG, Entropy Source");

// Configure AES for ECB mode, 128-bit key, and manual operation
dif_aes_transaction_t transaction = {
.operation = kDifAesOperationEncrypt,
.mode = kDifAesModeEcb,
.key_len = kDifAesKey128,
.key_provider = kDifAesKeySoftwareProvided,
.mask_reseeding = kDifAesReseedPerBlock,
.manual_operation = kDifAesManualOperationManual,
.reseed_on_key_change = true,
.force_masks = false,
.ctrl_aux_lock = false,
};

LOG_INFO(
"AES transaction configured: ECB mode, 128-bit key, manual operation.");

// Disable EDN and CSRNG to simulate stalling
LOG_INFO(
"Disabling entropy complex- EDN0, EDN1, CSRNG, and the Entropy Source "
"...");
disable_entropy_complex();
busy_spin_micros(500);

// Expanding aes_testutils_setup_encryption T1 to T8:
// T: Start of aes_testutils_setup_encryption function steps
// T1: Mask the key. Note that this should not be done manually. Software is
// expected to get the key in two shares right from the beginning.
uint8_t key_share0[sizeof(kAesModesKey128)];
for (int i = 0; i < sizeof(kAesModesKey128); ++i) {
key_share0[i] = kAesModesKey128[i] ^ kKeyShare1[i];
}

// T2: "Convert" key share byte arrays to `dif_aes_key_share_t`.
dif_aes_key_share_t key;
memcpy(key.share0, key_share0, sizeof(key.share0));
memcpy(key.share1, kKeyShare1, sizeof(key.share1));

// T3: Wait for status kDifAesStatusIdle
// Start AES with the given transaction
AES_TESTUTILS_WAIT_FOR_STATUS(&aes, kDifAesStatusIdle, true, kTestTimeout);

// T4: dif_aes_start
CHECK_DIF_OK(dif_aes_start(&aes, &transaction, &key, NULL));

// Trigger PRNG reseed for the first key
CHECK_DIF_OK(dif_aes_trigger(&aes, kDifAesTriggerPrngReseed));

// Generate the second key key2 by slightly modifying the first key to ensure
// difference (adding 1) Declare second key shares (ensure it's a new
// declaration)
uint8_t key2_share0[sizeof(kAesModesKey128)];

// Generate the second key by modifying the first key (to ensure it’s
// different)
for (int i = 0; i < sizeof(kAesModesKey128); ++i) {
key2_share0[i] = (kAesModesKey128[i] ^ kKeyShare1[i]) + 1;
}

// Load the second key
dif_aes_key_share_t key2;
memcpy(key2.share0, key2_share0, sizeof(key2_share0));
memcpy(key2.share1, kKeyShare1, sizeof(key2.share1));

LOG_INFO("Conditionally checking AES status after stopping EDN and CSRNG.");
LOG_INFO("Waiting for AES to stall after PRNG reseed request...");
bool stall = false;
CHECK_DIF_OK(dif_aes_get_status(&aes, kDifAesStatusStall, &stall));

if (stall) {
LOG_INFO("AES encryption has stalled as expected.");
} else {
LOG_ERROR(
"ERROR:AES encryption did not stall as expected after EDN stop! Lets "
"proceed "
"for now to verify further steps...");
}

log_csrng_internal_state(&csrng);
monitor_entropy_sources();

LOG_INFO(
"Enabling entropy complex- EDN0, EDN1, CSRNG, and the Entropy Source "
"...");
enable_entropy_complex();
monitor_edn_status(&edn0, &edn1);

// Trigger PRNG reseed request
LOG_INFO("Triggering PRNG reseed...");
CHECK_DIF_OK(dif_aes_trigger(&aes, kDifAesTriggerPrngReseed));

// T5: "Convert" plain data byte arrays to `dif_aes_data_t`
dif_aes_data_t in_data_plain;
memcpy(in_data_plain.data, kAesModesPlainText, sizeof(in_data_plain.data));

// T6: Wait ofr Status kDifAesStatusIdle
LOG_INFO(
"Now Starting AES encryption process firstly by observing if AES is in "
"Idle state");
AES_TESTUTILS_WAIT_FOR_STATUS(&aes, kDifAesStatusIdle, true, kTestTimeout);

// T7: Wait for Status input DifAesStatusInputReady
LOG_INFO("AES started: ECB encryption, waiting for input ready.");
AES_TESTUTILS_WAIT_FOR_STATUS(&aes, kDifAesStatusInputReady, true,
kTestTimeout);
// T8: Load the plain text to trigger the encryption operation
CHECK_DIF_OK(dif_aes_load_data(&aes, in_data_plain));

// Load the second key into AES (key2)
CHECK_DIF_OK(dif_aes_start(&aes, &transaction, &key2, NULL));

// Trigger AES reseed request, specific for manual operation case
LOG_INFO("AES encryption started.");
CHECK_DIF_OK(dif_aes_trigger(&aes, kDifAesTriggerStart));

busy_spin_micros(500);

// LOG_INFO("Setting EDN to auto mode...");
// TRY(entropy_testutils_auto_mode_init());
//// CHECK_DIF_OK(entropy_testutils_auto_mode_init());
// monitor_edn_status(&edn0, &edn1);

// Read out the produced cipher text.
dif_aes_data_t out_data;
LOG_INFO("AES dif_aes_read_output:");
CHECK_DIF_OK(dif_aes_read_output(&aes, &out_data));

LOG_INFO("Encrypted text:");
aes_print_block((const unsigned char *)out_data.data, 16);

// Finish the ECB encryption transaction.
CHECK_DIF_OK(dif_aes_end(&aes));
LOG_INFO("AES comparison out_data with CipherText:");
CHECK_ARRAYS_EQ((uint8_t *)out_data.data, kAesModesCipherTextEcb128,
sizeof(out_data.data));

return OK_STATUS();
}

bool test_main(void) { return status_ok(execute_test()); }
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