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[nrf noup] Support for ed25519 signature verification using ITS #517

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Merged
merged 1 commit into from
Sep 9, 2025
Merged

[nrf noup] Support for ed25519 signature verification using ITS #517

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38 changes: 25 additions & 13 deletions boot/bootutil/src/ed25519_psa.c
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Original file line number Diff line number Diff line change
Expand Up @@ -26,22 +26,35 @@ BOOT_LOG_MODULE_REGISTER(ed25519_psa);
#if defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
/* List of KMU stored key ids available for MCUboot */
#define MAKE_PSA_KMU_KEY_ID(id) PSA_KEY_HANDLE_FROM_CRACEN_KMU_SLOT(CRACEN_KMU_KEY_USAGE_SCHEME_RAW, id)
static psa_key_id_t kmu_key_ids[3] = {
static psa_key_id_t key_ids[] = {
MAKE_PSA_KMU_KEY_ID(226),
MAKE_PSA_KMU_KEY_ID(228),
MAKE_PSA_KMU_KEY_ID(230)
};

#define KEY_SLOTS_COUNT CONFIG_BOOT_SIGNATURE_KMU_SLOTS

#if defined(CONFIG_BOOT_KMU_KEYS_REVOCATION)
#include <bootutil/key_revocation.h>
static psa_key_id_t *validated_with = NULL;
#endif

BUILD_ASSERT(CONFIG_BOOT_SIGNATURE_KMU_SLOTS <= ARRAY_SIZE(kmu_key_ids),
BUILD_ASSERT(CONFIG_BOOT_SIGNATURE_KMU_SLOTS <= ARRAY_SIZE(key_ids),
"Invalid number of KMU slots, up to 3 are supported on nRF54L15");
#endif

#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
static const psa_key_id_t key_ids[] = {
0x40022100,
0x40022101,
0x40022102,
0x40022103
};

#define KEY_SLOTS_COUNT ARRAY_SIZE(key_ids)
#endif

#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
int ED25519_verify(const uint8_t *message, size_t message_len,
const uint8_t signature[EDDSA_SIGNAGURE_LENGTH],
const uint8_t public_key[EDDSA_KEY_LENGTH])
Expand Down Expand Up @@ -102,7 +115,6 @@ int ED25519_verify(const uint8_t *message, size_t message_len,
ARG_UNUSED(public_key);
/* Set to any error */
psa_status_t status = PSA_ERROR_BAD_STATE;
int ret = 0; /* Fail by default */

/* Initialize PSA Crypto */
status = psa_crypto_init();
Expand All @@ -113,24 +125,24 @@ int ED25519_verify(const uint8_t *message, size_t message_len,

status = PSA_ERROR_BAD_STATE;

for (int i = 0; i < CONFIG_BOOT_SIGNATURE_KMU_SLOTS; ++i) {
psa_key_id_t kid = kmu_key_ids[i];
for (int i = 0; i < KEY_SLOTS_COUNT; ++i) {
psa_key_id_t kid = key_ids[i];

status = psa_verify_message(kid, PSA_ALG_PURE_EDDSA, message,
message_len, signature,
EDDSA_SIGNAGURE_LENGTH);
if (status == PSA_SUCCESS) {
ret = 1;
#if defined(CONFIG_BOOT_KMU_KEYS_REVOCATION)
validated_with = kmu_key_ids + i;
validated_with = key_ids + i;
#endif
break;
return 1;
}

BOOT_LOG_ERR("ED25519 signature verification failed %d", status);
}

return ret;
BOOT_LOG_ERR("ED25519 signature verification failed %d", status);

return 0;
}
#if defined(CONFIG_BOOT_KMU_KEYS_REVOCATION)
int exec_revoke(void)
Expand All @@ -149,12 +161,12 @@ int exec_revoke(void)
goto out;
}
for (int i = 0; i < CONFIG_BOOT_SIGNATURE_KMU_SLOTS; i++) {
if ((kmu_key_ids + i) == validated_with) {
if ((key_ids + i) == validated_with) {
break;
}
BOOT_LOG_DBG("Invalidating key ID %d", i);

status = psa_destroy_key(kmu_key_ids[i]);
status = psa_destroy_key(key_ids[i]);
if (status == PSA_SUCCESS) {
BOOT_LOG_DBG("Success on key ID %d", i);
} else {
Expand Down
6 changes: 4 additions & 2 deletions boot/bootutil/src/image_ed25519.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@ extern int ED25519_verify(const uint8_t *message, size_t message_len,

#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if !defined(MCUBOOT_KEY_IMPORT_BYPASS_ASN)
#if !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
/*
* Parse the public key used for signing.
*/
Expand Down Expand Up @@ -78,6 +79,7 @@ bootutil_import_key(uint8_t **cp, uint8_t *end)
}
#endif /* !defined(MCUBOOT_KEY_IMPORT_BYPASS_ASN) */
#endif
#endif

/* Signature verification base function.
* The function takes buffer of specified length and tries to verify
Expand All @@ -93,7 +95,7 @@ bootutil_verify(uint8_t *buf, uint32_t blen,
int rc;
FIH_DECLARE(fih_rc, FIH_FAILURE);
uint8_t *pubkey = NULL;
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
uint8_t *end;
#endif

Expand All @@ -106,7 +108,7 @@ bootutil_verify(uint8_t *buf, uint32_t blen,
goto out;
}

#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
pubkey = (uint8_t *)bootutil_keys[key_id].key;
end = pubkey + *bootutil_keys[key_id].len;

Expand Down
6 changes: 3 additions & 3 deletions boot/bootutil/src/image_validate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -772,13 +772,13 @@ bootutil_img_validate(struct boot_loader_state *state,
case EXPECTED_SIG_TLV:
{
BOOT_LOG_DBG("bootutil_img_validate: EXPECTED_SIG_TLV == %d", EXPECTED_SIG_TLV);
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
/* Ignore this signature if it is out of bounds. */
if (key_id < 0 || key_id >= bootutil_key_cnt) {
key_id = -1;
continue;
}
#endif /* !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) */
#endif /* !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS) */
if (!EXPECTED_SIG_LEN(len) || len > sizeof(buf)) {
rc = -1;
goto out;
Expand Down Expand Up @@ -1022,7 +1022,7 @@ bootutil_img_validate(struct boot_loader_state *state,

if (type == IMAGE_TLV_DECOMP_SIGNATURE) {
/* Ignore this signature if it is out of bounds. */
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU)
#if !defined(CONFIG_BOOT_SIGNATURE_USING_KMU) && !defined(CONFIG_NCS_BOOT_SIGNATURE_USING_ITS)
if (key_id < 0 || key_id >= bootutil_key_cnt) {
key_id = -1;
continue;
Expand Down