[sw/crypto] Clear HMAC ctx struct

At certain points the HMAC ctx struct has to be wiped to avoid
leaking secrets. The sensitive fields need to be overwritten
by randomness and the non-sensitive fields are just zeroized.

Signed-off-by: Hakim Filali <[email protected]>
(cherry picked from commit 7389d6c)

Author: h-filali

sw/device/lib/crypto/drivers/hmac.c

@@ -460,6 +460,9 @@ static status_t oneshot(const uint32_t cfg, const hmac_key_t *key,
   // Check that the block is idle.
   HARDENED_TRY(ensure_idle());
 
+  // Make sure that the entropy complex is configured correctly.
+  HARDENED_TRY(entropy_complex_check());
+
   // Configure the HMAC block.
   abs_mmio_write32(kHmacBaseAddr + HMAC_CFG_REG_OFFSET, cfg);
 
@@ -751,6 +754,9 @@ hardened_bool_t hmac_key_integrity_checksum_check(const hmac_key_t *key) {
 }
 
 status_t hmac_update(hmac_ctx_t *ctx, const uint8_t *data, size_t len) {
+  // Make sure that the entropy complex is configured correctly.
+  HARDENED_TRY(entropy_complex_check());
+
   // If we don't have enough new bytes to fill a block, just update the partial
   // block and return.
   size_t block_bytelen = ctx->msg_block_wordlen * sizeof(uint32_t);
@@ -806,6 +812,9 @@ status_t hmac_update(hmac_ctx_t *ctx, const uint8_t *data, size_t len) {
 }
 
 status_t hmac_final(hmac_ctx_t *ctx, uint32_t *digest) {
+  // Make sure that the entropy complex is configured correctly.
+  HARDENED_TRY(entropy_complex_check());
+
   // Retore context will restore the context and also hit start or continue
   // button as necessary.
   HARDENED_TRY(context_restore(ctx));

sw/device/silicon_creator/manuf/base/BUILD

@@ -64,6 +64,7 @@ opentitan_binary(
         "//sw/device/lib/arch:device",
         "//sw/device/lib/base:abs_mmio",
         "//sw/device/lib/base:macros",
+        "//sw/device/lib/crypto/drivers:entropy",
         "//sw/device/lib/dif:flash_ctrl",
         "//sw/device/lib/dif:lc_ctrl",
         "//sw/device/lib/dif:otp_ctrl",
@@ -102,6 +103,7 @@ opentitan_binary(
         "//hw/top_earlgrey/sw/autogen:top_earlgrey",
         "//sw/device/lib/arch:device",
         "//sw/device/lib/base:macros",
+        "//sw/device/lib/crypto/drivers:entropy",
         "//sw/device/lib/dif:flash_ctrl",
         "//sw/device/lib/dif:gpio",
         "//sw/device/lib/dif:lc_ctrl",
@@ -181,6 +183,7 @@ opentitan_test(
             "//sw/device/lib/arch:device",
             "//sw/device/lib/base:abs_mmio",
             "//sw/device/lib/base:macros",
+            "//sw/device/lib/crypto/drivers:entropy",
             "//sw/device/lib/dif:flash_ctrl",
             "//sw/device/lib/dif:gpio",
             "//sw/device/lib/dif:otp_ctrl",
@@ -236,6 +239,7 @@ cc_library(
     srcs = ["tpm_personalize_ext.c"],
     deps = [
         ":personalize_ext",
+        "//sw/device/lib/crypto/drivers:entropy",
         "//sw/device/lib/dif:flash_ctrl",
         "//sw/device/lib/runtime:print",
         "//sw/device/lib/testing/test_framework:status",

sw/device/silicon_creator/manuf/base/ft_personalize.c

@@ -1196,6 +1196,7 @@ bool test_main(void) {
   pinmux_testutils_init(&pinmux);
   CHECK_STATUS_OK(configure_ate_gpio_indicators());
   CHECK_DIF_OK(dif_gpio_write(&gpio, kGpioPinTestStart, true));
+  CHECK_STATUS_OK(entropy_complex_init());
   ujson_t uj = ujson_ottf_console();
 
   // Read the reset reason directly from the RSTMGR.

sw/device/silicon_creator/manuf/base/sram_cp_provision.c

@@ -6,6 +6,7 @@
 
 #include "sw/device/lib/arch/device.h"
 #include "sw/device/lib/base/abs_mmio.h"
+#include "sw/device/lib/crypto/drivers/entropy.h"
 #include "sw/device/lib/dif/dif_flash_ctrl.h"
 #include "sw/device/lib/dif/dif_lc_ctrl.h"
 #include "sw/device/lib/dif/dif_otp_ctrl.h"
@@ -224,6 +225,7 @@ bool test_main(void) {
   CHECK_STATUS_OK(configure_ate_gpio_indicators());
   CHECK_DIF_OK(dif_gpio_write(&gpio, kGpioPinTestStart, true));
   ottf_console_init();
+  CHECK_STATUS_OK(entropy_complex_init());
   ujson_t uj = ujson_ottf_console();
 
   // Extract factory data from flash info page 0.

sw/device/silicon_creator/manuf/base/sram_cp_provision_functest.c

@@ -5,6 +5,7 @@
 #include <stdint.h>
 
 #include "sw/device/lib/arch/device.h"
+#include "sw/device/lib/crypto/drivers/entropy.h"
 #include "sw/device/lib/dif/dif_flash_ctrl.h"
 #include "sw/device/lib/dif/dif_gpio.h"
 #include "sw/device/lib/dif/dif_lc_ctrl.h"
@@ -118,6 +119,7 @@ static status_t prep_flash_info_page_0(manuf_cp_test_data_t *test_data) {
 bool test_main(void) {
   // Initialize peripherals, pinmux, and console.
   CHECK_STATUS_OK(peripheral_handles_init());
+  CHECK_STATUS_OK(entropy_complex_init());
   CHECK_STATUS_OK(configure_ate_gpio_indicators());
   ottf_console_init();
   ujson_t uj = ujson_ottf_console();

sw/device/silicon_creator/manuf/base/sram_ft_individualize.c

@@ -6,6 +6,7 @@
 
 #include "sw/device/lib/arch/device.h"
 #include "sw/device/lib/base/abs_mmio.h"
+#include "sw/device/lib/crypto/drivers/entropy.h"
 #include "sw/device/lib/dif/dif_flash_ctrl.h"
 #include "sw/device/lib/dif/dif_gpio.h"
 #include "sw/device/lib/dif/dif_otp_ctrl.h"
@@ -174,6 +175,7 @@ static status_t provision(ujson_t *uj) {
 
 bool test_main(void) {
   CHECK_STATUS_OK(peripheral_handles_init());
+  CHECK_STATUS_OK(entropy_complex_init());
   CHECK_STATUS_OK(configure_ate_gpio_indicators());
   ujson_t uj;
 #ifndef ATE

sw/device/silicon_creator/manuf/lib/BUILD

@@ -226,6 +226,7 @@ opentitan_test(
         "//hw/ip/otp_ctrl/data:otp_ctrl_c_regs",
         "//hw/top_earlgrey/sw/autogen:top_earlgrey",
         "//sw/device/lib/base:status",
+        "//sw/device/lib/crypto/drivers:entropy",
         "//sw/device/lib/dif:flash_ctrl",
         "//sw/device/lib/dif:otp_ctrl",
         "//sw/device/lib/dif:rstmgr",

sw/device/silicon_creator/manuf/lib/individualize_sw_cfg_functest.c

@@ -3,6 +3,7 @@
 // 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/dif/dif_flash_ctrl.h"
 #include "sw/device/lib/dif/dif_otp_ctrl.h"
 #include "sw/device/lib/dif/dif_rstmgr.h"
@@ -172,6 +173,7 @@ static void sw_reset(void) {
 
 bool test_main(void) {
   CHECK_STATUS_OK(peripheral_handles_init());
+  CHECK_STATUS_OK(entropy_complex_init());
 
   // Provision CREATOR_SW_CFG partition.
   if (!status_ok(manuf_individualize_device_creator_sw_cfg_check(&otp_ctrl))) {