TLSSocketWrapper: add method to retrieve certificates from filesystem

Author: facchinm

connectivity/netsocket/include/netsocket/TLSSocketWrapper.h

@@ -116,6 +116,18 @@ class TLSSocketWrapper : public Socket {
      */
     nsapi_error_t set_root_ca_cert(const char *root_ca_pem);
 
+    /** Sets the certification of Root CA.
+     *
+     * @note Must be called before calling connect()
+     *
+     * @param root_ca Path containing Root CA Certificate files in any Mbed TLS-supported format.
+     * @retval NSAPI_ERROR_OK on success.
+     * @retval NSAPI_ERROR_NO_MEMORY in case there is not enough memory to allocate certificate.
+     * @retval NSAPI_ERROR_PARAMETER in case the provided root_ca parameter failed parsing.
+     *
+     */
+    nsapi_error_t set_root_ca_cert_path(const void *root_ca);
+
     /** Sets client certificate, and client private key.
      *
      * @param client_cert Client certification in PEM or DER format.

connectivity/netsocket/source/TLSSocketWrapper.cpp

@@ -121,6 +121,35 @@ nsapi_error_t TLSSocketWrapper::set_root_ca_cert(const char *root_ca_pem)
     return set_root_ca_cert(root_ca_pem, strlen(root_ca_pem) + 1);
 }
 
+nsapi_error_t TLSSocketWrapper::set_root_ca_cert_path(const void *root_ca)
+{
+#if !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_FS_IO)
+    return NSAPI_ERROR_UNSUPPORTED;
+#else
+    mbedtls_x509_crt *crt;
+
+    crt = new (std::nothrow) mbedtls_x509_crt;
+    if (!crt) {
+        return NSAPI_ERROR_NO_MEMORY;
+    }
+
+    mbedtls_x509_crt_init(crt);
+
+    /* Parse CA certification */
+    int ret = mbedtls_x509_crt_parse_path(crt, static_cast<const char *>(root_ca));
+    if (ret < 0) {
+        print_mbedtls_error("mbedtls_x509_crt_parse", ret);
+        mbedtls_x509_crt_free(crt);
+        delete crt;
+        return NSAPI_ERROR_PARAMETER;
+    }
+    set_ca_chain(crt);
+    _cacert_allocated = true;
+    return NSAPI_ERROR_OK;
+#endif
+}
+
+
 nsapi_error_t TLSSocketWrapper::set_client_cert_key(const char *client_cert_pem, const char *client_private_key_pem)
 {
     return set_client_cert_key(client_cert_pem, strlen(client_cert_pem) + 1, client_private_key_pem, strlen(client_private_key_pem) + 1);