[settings] Add "base64" setting type

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/settings.c

@@ -39,6 +39,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/uuid.h>
 #include <ipxe/uri.h>
 #include <ipxe/base16.h>
+#include <ipxe/base64.h>
 #include <ipxe/pci.h>
 #include <ipxe/init.h>
 #include <ipxe/version.h>
@@ -2120,6 +2121,46 @@ const struct setting_type setting_type_hexraw __setting_type = {
 	.format = format_hex_raw_setting,
 };
 
+/**
+ * Parse Base64-encoded setting value
+ *
+ * @v type		Setting type
+ * @v value		Formatted setting value
+ * @v buf		Buffer to contain raw value
+ * @v len		Length of buffer
+ * @v size		Integer size, in bytes
+ * @ret len		Length of raw value, or negative error
+ */
+static int parse_base64_setting ( const struct setting_type *type __unused,
+				  const char *value, void *buf, size_t len ) {
+
+	return base64_decode ( value, buf, len );
+}
+
+/**
+ * Format Base64-encoded setting value
+ *
+ * @v type		Setting type
+ * @v raw		Raw setting value
+ * @v raw_len		Length of raw setting value
+ * @v buf		Buffer to contain formatted value
+ * @v len		Length of buffer
+ * @ret len		Length of formatted value, or negative error
+ */
+static int format_base64_setting ( const struct setting_type *type __unused,
+				   const void *raw, size_t raw_len,
+				   char *buf, size_t len ) {
+
+	return base64_encode ( raw, raw_len, buf, len );
+}
+
+/** A Base64-encoded setting */
+const struct setting_type setting_type_base64 __setting_type = {
+	.name = "base64",
+	.parse = parse_base64_setting,
+	.format = format_base64_setting,
+};
+
 /**
  * Format UUID setting value
  *