Merge changes from topic "mb/psa-crypto-ecdsa" into integration
* changes:
docs: mark PSA_CRYPTO as an experimental feature
feat(fvp): increase BL1 RW area for PSA_CRYPTO implementation
feat(mbedtls-psa): mbedTLS PSA Crypto with ECDSA
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 654ddc5..347cf20 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -1195,7 +1195,8 @@
The platform will use PSA compliant Crypto APIs during authentication and
image measurement process by enabling this option. It uses APIs defined as
per the `PSA Crypto API specification`_. This feature is only supported if
- using MbedTLS 3.x version. By default it is disabled (``0``).
+ using MbedTLS 3.x version. By default it is disabled (``0``), and this is an
+ experimental feature.
- ``ENABLE_CONSOLE_GETC``: Boolean option to enable `getc()` feature in console
driver(s). By default it is disabled (``0``) because it constitutes an attack
diff --git a/drivers/auth/mbedtls/mbedtls_psa_crypto.c b/drivers/auth/mbedtls/mbedtls_psa_crypto.c
index 2fa8e63..5891acf 100644
--- a/drivers/auth/mbedtls/mbedtls_psa_crypto.c
+++ b/drivers/auth/mbedtls/mbedtls_psa_crypto.c
@@ -28,6 +28,13 @@
#define LIB_NAME "mbed TLS PSA"
+/* Maximum length of R_S pair in the ECDSA signature in bytes */
+#define MAX_ECDSA_R_S_PAIR_LEN 64U
+
+/* Size of ASN.1 length and tag in bytes*/
+#define SIZE_OF_ASN1_LEN 1U
+#define SIZE_OF_ASN1_TAG 1U
+
#if CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \
CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC
/*
@@ -108,6 +115,7 @@
static void construct_psa_key_alg_and_type(mbedtls_pk_type_t pk_alg,
mbedtls_md_type_t md_alg,
+ psa_ecc_family_t psa_ecc_family,
psa_algorithm_t *psa_alg,
psa_key_type_t *psa_key_type)
{
@@ -118,14 +126,173 @@
*psa_alg = PSA_ALG_RSA_PSS(psa_md_alg);
*psa_key_type = PSA_KEY_TYPE_RSA_PUBLIC_KEY;
break;
+ case MBEDTLS_PK_ECDSA:
+ *psa_alg = PSA_ALG_ECDSA(psa_md_alg);
+ *psa_key_type = PSA_KEY_TYPE_ECC_PUBLIC_KEY(psa_ecc_family);
+ break;
default:
*psa_alg = PSA_ALG_NONE;
*psa_key_type = PSA_KEY_TYPE_NONE;
break;
}
+}
+
+
+#if TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA || \
+TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA
+
+/*
+ * This is a helper function to detect padding byte (if the MSB bit of the
+ * first data byte is set to 1, for example 0x80) and on detection, ignore the
+ * padded byte(0x00) and increase the buffer pointer beyond padded byte and
+ * decrease the length of the buffer by 1.
+ *
+ * On Success returns 0, error otherwise.
+ **/
+static inline int ignore_asn1_int_padding_byte(unsigned char **buf_start,
+ size_t *buf_len)
+{
+ unsigned char *local_buf = *buf_start;
+
+ /* Check for negative number */
+ if ((local_buf[0] & 0x80U) != 0U) {
+ return -1;
+ }
+
+ if ((local_buf[0] == 0U) && (local_buf[1] > 0x7FU) &&
+ (*buf_len > 1U)) {
+ *buf_start = &local_buf[1];
+ (*buf_len)--;
+ }
+
+ return 0;
+}
+
+/*
+ * This is a helper function that gets a pointer to the encoded ECDSA publicKey
+ * and its length (as per RFC5280) and returns corresponding decoded publicKey
+ * and its length. As well, it retrieves the family of ECC key in the PSA
+ * format.
+ *
+ * This function returns error(CRYPTO_ERR_SIGNATURE) on ASN.1 parsing failure,
+ * otherwise success(0).
+ **/
+static int get_ecdsa_pkinfo_from_asn1(unsigned char **pk_start,
+ unsigned int *pk_len,
+ psa_ecc_family_t *psa_ecc_family)
+{
+ mbedtls_asn1_buf alg_oid, alg_params;
+ mbedtls_ecp_group_id grp_id;
+ int rc;
+ unsigned char *pk_end;
+ size_t len;
+ size_t curve_bits;
+ unsigned char *pk_ptr = *pk_start;
+
+ pk_end = pk_ptr + *pk_len;
+ rc = mbedtls_asn1_get_tag(&pk_ptr, pk_end, &len,
+ MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ pk_end = pk_ptr + len;
+ rc = mbedtls_asn1_get_alg(&pk_ptr, pk_end, &alg_oid, &alg_params);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ if (alg_params.tag == MBEDTLS_ASN1_OID) {
+ if (mbedtls_oid_get_ec_grp(&alg_params, &grp_id) != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+ *psa_ecc_family = mbedtls_ecc_group_to_psa(grp_id,
+ &curve_bits);
+ } else {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ pk_end = pk_ptr + len - (alg_oid.len + alg_params.len +
+ 2 * (SIZE_OF_ASN1_LEN + SIZE_OF_ASN1_TAG));
+ rc = mbedtls_asn1_get_bitstring_null(&pk_ptr, pk_end, &len);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ *pk_start = pk_ptr;
+ *pk_len = len;
+
+ return rc;
}
/*
+ * Ecdsa-Sig-Value ::= SEQUENCE {
+ * r INTEGER,
+ * s INTEGER
+ * }
+ *
+ * This helper function that gets a pointer to the encoded ECDSA signature and
+ * its length (as per RFC5280) and returns corresponding decoded signature
+ * (R_S pair) and its size.
+ *
+ * This function returns error(CRYPTO_ERR_SIGNATURE) on ASN.1 parsing failure,
+ * otherwise success(0).
+ **/
+static int get_ecdsa_signature_from_asn1(unsigned char *sig_ptr,
+ size_t *sig_len,
+ unsigned char *r_s_pair)
+{
+ int rc;
+ unsigned char *sig_end;
+ size_t len, r_len, s_len;
+
+ sig_end = sig_ptr + *sig_len;
+ rc = mbedtls_asn1_get_tag(&sig_ptr, sig_end, &len,
+ MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ sig_end = sig_ptr + len;
+ rc = mbedtls_asn1_get_tag(&sig_ptr, sig_end, &r_len,
+ MBEDTLS_ASN1_INTEGER);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ if (ignore_asn1_int_padding_byte(&sig_ptr, &r_len) != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ (void)memcpy((void *)&r_s_pair[0], (const void *)sig_ptr, r_len);
+
+ sig_ptr = sig_ptr + r_len;
+ sig_end = sig_ptr + len - (r_len + (SIZE_OF_ASN1_LEN +
+ SIZE_OF_ASN1_TAG));
+ rc = mbedtls_asn1_get_tag(&sig_ptr, sig_end, &s_len,
+ MBEDTLS_ASN1_INTEGER);
+ if (rc != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ if (ignore_asn1_int_padding_byte(&sig_ptr, &s_len) != 0) {
+ return CRYPTO_ERR_SIGNATURE;
+ }
+
+ (void)memcpy((void *)&r_s_pair[r_len], (const void *)sig_ptr, s_len);
+
+ *sig_len = s_len + r_len;
+
+ return 0;
+}
+#endif /*
+ * TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA || \
+ * TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA
+ **/
+
+/*
* Verify a signature.
*
* Parameters are passed using the DER encoding format following the ASN.1
@@ -143,6 +310,10 @@
int rc;
void *sig_opts = NULL;
unsigned char *p, *end;
+ unsigned char *local_sig_ptr;
+ size_t local_sig_len;
+ psa_ecc_family_t psa_ecc_family = 0U;
+ __unused unsigned char reformatted_sig[MAX_ECDSA_R_S_PAIR_LEN] = {0};
/* construct PSA key algo and type */
psa_status_t status = PSA_SUCCESS;
@@ -174,10 +345,36 @@
rc = CRYPTO_ERR_SIGNATURE;
goto end2;
}
- signature.p = p;
+
+ local_sig_ptr = p;
+ local_sig_len = signature.len;
+
+#if TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA || \
+TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA
+ if (pk_alg == MBEDTLS_PK_ECDSA) {
+ rc = get_ecdsa_signature_from_asn1(local_sig_ptr,
+ &local_sig_len,
+ reformatted_sig);
+ if (rc != 0) {
+ goto end2;
+ }
+
+ local_sig_ptr = reformatted_sig;
+
+ rc = get_ecdsa_pkinfo_from_asn1((unsigned char **)&pk_ptr,
+ &pk_len,
+ &psa_ecc_family);
+ if (rc != 0) {
+ goto end2;
+ }
+ }
+#endif /*
+ * TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA || \
+ * TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA
+ **/
/* Convert this pk_alg and md_alg to PSA key type and key algorithm */
- construct_psa_key_alg_and_type(pk_alg, md_alg,
+ construct_psa_key_alg_and_type(pk_alg, md_alg, psa_ecc_family,
&psa_alg, &psa_key_type);
@@ -208,7 +405,7 @@
*/
status = psa_verify_message(psa_key_id, psa_alg,
data_ptr, data_len,
- signature.p, signature.len);
+ local_sig_ptr, local_sig_len);
if (status != PSA_SUCCESS) {
rc = CRYPTO_ERR_SIGNATURE;
diff --git a/plat/arm/board/fvp/include/platform_def.h b/plat/arm/board/fvp/include/platform_def.h
index 836080a..aad0417 100644
--- a/plat/arm/board/fvp/include/platform_def.h
+++ b/plat/arm/board/fvp/include/platform_def.h
@@ -193,8 +193,10 @@
/*
* PLAT_ARM_MAX_BL1_RW_SIZE is calculated using the current BL1 RW debug size
* plus a little space for growth.
+ * In case of PSA Crypto API, few algorithms like ECDSA needs bigger BL1 RW
+ * area.
*/
-#if TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA
+#if TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA_AND_ECDSA || PSA_CRYPTO
#define PLAT_ARM_MAX_BL1_RW_SIZE UL(0xC000)
#else
#define PLAT_ARM_MAX_BL1_RW_SIZE UL(0xB000)