Restore internal driver for aead_set_lengths

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/library/psa_crypto_aead.h b/library/psa_crypto_aead.h
index f968c15..e82e1cc 100644
--- a/library/psa_crypto_aead.h
+++ b/library/psa_crypto_aead.h
@@ -267,6 +267,47 @@
     const uint8_t *nonce,
     size_t nonce_length );
 
+/** Declare the lengths of the message and additional data for AEAD.
+ *
+ * \note The signature of this function is that of a PSA driver aead_set_lengths
+ *       entry point. This function behaves as an aead_set_lengths entry point
+ *       as defined in the PSA driver interface specification for transparent
+ *       drivers.
+ *
+ * The PSA core calls this function before calling mbedtls_psa_aead_update_ad()
+ * or mbedtls_psa_aead_update() if the algorithm for the operation requires it.
+ * If the algorithm does not require it, calling this function is optional, but
+ * if this function is called then the implementation must enforce the lengths.
+ *
+ * The PSA core may call this function before or after setting the nonce with
+ * mbedtls_psa_aead_set_nonce().
+ *
+ * - For #PSA_ALG_CCM, calling this function is required.
+ * - For the other AEAD algorithms defined in this specification, calling
+ *   this function is not required.
+ *
+ * If this function returns an error status, the PSA core calls
+ * mbedtls_psa_aead_abort().
+ *
+ * \param[in,out] operation     Active AEAD operation.
+ * \param ad_length             Size of the non-encrypted additional
+ *                              authenticated data in bytes.
+ * \param plaintext_length      Size of the plaintext to encrypt in bytes.
+ *
+ * \retval #PSA_SUCCESS
+ *         Success.
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ *         At least one of the lengths is not acceptable for the chosen
+ *         algorithm.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ *         Algorithm previously set is not supported in this configuration of
+ *         the library.
+ */
+psa_status_t mbedtls_psa_aead_set_lengths(
+    mbedtls_psa_aead_operation_t *operation,
+    size_t ad_length,
+    size_t plaintext_length );
+
 /** Pass additional data to an active AEAD operation.
  *
  *  \note The signature of this function is that of a PSA driver