[TEMPORARY] library: future changes for mbedtls_pk_get_type

This is a temporary placeholder commit that will be implemented once the
referenced function will be implemented in tf-psa-crypto

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>

Author: valeriosetti

library/ssl_tls.c

@@ -5607,11 +5607,13 @@ void mbedtls_ssl_config_free(mbedtls_ssl_config *conf)
 unsigned char mbedtls_ssl_sig_from_pk(mbedtls_pk_context *pk)
 {
 #if defined(MBEDTLS_RSA_C)
+    /* TODO: replace with mbedtls_pk_get_type() */
     if (mbedtls_pk_can_do(pk, MBEDTLS_PK_RSA)) {
         return MBEDTLS_SSL_SIG_RSA;
     }
 #endif
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ANY_ALLOWED_ENABLED)
+    /* TODO: replace with mbedtls_pk_get_type() */
     if (mbedtls_pk_can_do(pk, MBEDTLS_PK_ECDSA)) {
         return MBEDTLS_SSL_SIG_ECDSA;
     }

library/x509write_crt.c

@@ -408,6 +408,7 @@ int mbedtls_x509write_crt_der(mbedtls_x509write_cert *ctx,
 
     /* There's no direct way of extracting a signature algorithm
      * (represented as an element of mbedtls_pk_type_t) from a PK instance. */
+    /* TODO: replace with mbedtls_pk_get_type() */
     if (mbedtls_pk_can_do(ctx->issuer_key, MBEDTLS_PK_RSA)) {
         pk_alg = MBEDTLS_PK_SIGALG_RSA_PKCS1V15;
     } else if (mbedtls_pk_can_do(ctx->issuer_key, MBEDTLS_PK_ECDSA)) {

library/x509write_csr.c

@@ -218,6 +218,7 @@ static int x509write_csr_der_internal(mbedtls_x509write_csr *ctx,
         return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
     }
 
+    /* TODO: replace with mbedtls_pk_get_type() */
     if (mbedtls_pk_can_do(ctx->key, MBEDTLS_PK_RSA)) {
         pk_alg = MBEDTLS_PK_SIGALG_RSA_PKCS1V15;
     } else if (mbedtls_pk_can_do(ctx->key, MBEDTLS_PK_ECDSA)) {