Add export_public_key entry point to p256-m driver
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/3rdparty/p256-m/p256-m_driver_entrypoints.c b/3rdparty/p256-m/p256-m_driver_entrypoints.c
index e48b4e8..6131dae 100644
--- a/3rdparty/p256-m/p256-m_driver_entrypoints.c
+++ b/3rdparty/p256-m/p256-m_driver_entrypoints.c
@@ -104,6 +104,40 @@
return PSA_SUCCESS;
}
+psa_status_t p256_transparent_export_public_key(const psa_key_attributes_t *attributes,
+ const uint8_t *key_buffer,
+ size_t key_buffer_size,
+ uint8_t *data,
+ size_t data_size,
+ size_t *data_length)
+{
+ /* Is this the right curve? */
+ size_t bits = psa_get_key_bits(attributes);
+ psa_key_type_t type = psa_get_key_type(attributes);
+ if (bits != 256 || type != PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_SECP_R1)) {
+ return PSA_ERROR_NOT_SUPPORTED;
+ }
+
+ /* Validate input and output sizes */
+ if (key_buffer_size != 32) {
+ return PSA_ERROR_INVALID_ARGUMENT;
+ }
+ if (data_size < 65) {
+ return PSA_ERROR_BUFFER_TOO_SMALL;
+ }
+
+ /* Output public key in the PSA export format */
+ data[0] = 0x04;
+ int ret = p256_public_from_private(data + 1, key_buffer);
+ if (ret != P256_SUCCESS) {
+ /* The only possible error is the private key was invalid */
+ return PSA_ERROR_INVALID_ARGUMENT;
+ }
+ *data_length = 65;
+
+ return PSA_SUCCESS;
+}
+
psa_status_t p256_transparent_generate_key(
const psa_key_attributes_t *attributes,
uint8_t *key_buffer,
diff --git a/3rdparty/p256-m/p256-m_driver_entrypoints.h b/3rdparty/p256-m/p256-m_driver_entrypoints.h
index 6eacbc3..42e51d9 100644
--- a/3rdparty/p256-m/p256-m_driver_entrypoints.h
+++ b/3rdparty/p256-m/p256-m_driver_entrypoints.h
@@ -62,6 +62,33 @@
size_t *key_buffer_length,
size_t *bits);
+/** Export SECP256R1 public key, from the private key.
+ *
+ * \param[in] attributes The attributes of the key to use for the
+ * operation.
+ * \param[in] key_buffer The private key in the export format.
+ * \param[in] key_buffer_size The size of the private key in bytes.
+ * \param[out] data The buffer to contain the public key in
+ * the export format upon successful return.
+ * \param[in] data_size The size of the \p data buffer in bytes.
+ * \param[out] data_length The length written to \p data in bytes.
+ *
+ * \retval #PSA_SUCCESS
+ * Success. Keypair generated and stored in buffer.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ * The input is not supported by this driver (not SECP256R1).
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ * The input is invalid.
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL
+ * \p key_buffer_size is too small.
+ */
+psa_status_t p256_transparent_export_public_key(const psa_key_attributes_t *attributes,
+ const uint8_t *key_buffer,
+ size_t key_buffer_size,
+ uint8_t *data,
+ size_t data_size,
+ size_t *data_length);
+
/** Generate SECP256R1 ECC Key Pair.
* Interface function which calls the p256-m key generation function and
* places it in the key buffer provided by the caller (mbed TLS) in the