libfwupdplugin: Allow getting images by checksum value

libfwupdplugin/fu-firmware-image.c

@@ -284,6 +284,45 @@ fu_firmware_image_get_bytes (FuFirmwareImage *self)
 	return g_bytes_ref (priv->bytes);
 }
 
+/**
+ * fu_firmware_image_get_checksum:
+ * @self: a #FuPlugin
+ * @csum_kind: a #GChecksumType, e.g. %G_CHECKSUM_SHA256
+ * @error: A #GError, or %NULL
+ *
+ * Returns a checksum of the data.
+ *
+ * Returns: (transfer full): a checksum string, or %NULL if the checksum is not available
+ *
+ * Since: 1.5.5
+ **/
+gchar *
+fu_firmware_image_get_checksum (FuFirmwareImage *self,
+				GChecksumType csum_kind,
+				GError **error)
+{
+	FuFirmwareImagePrivate *priv = GET_PRIVATE (self);
+	FuFirmwareImageClass *klass = FU_FIRMWARE_IMAGE_GET_CLASS (self);
+
+	g_return_val_if_fail (FU_IS_FIRMWARE_IMAGE (self), NULL);
+	g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+	/* subclassed */
+	if (klass->get_checksum != NULL)
+		return klass->get_checksum (self, csum_kind, error);
+
+	/* internal data */
+	if (priv->bytes == NULL) {
+		g_set_error (error,
+			     FWUPD_ERROR,
+			     FWUPD_ERROR_NOT_FOUND,
+			     "no bytes found in firmware bytes %s",
+			     priv->id);
+		return NULL;
+	}
+	return g_compute_checksum_for_bytes (csum_kind, priv->bytes);
+}
+
 /**
  * fu_firmware_image_parse:
  * @self: A #FuFirmwareImage

libfwupdplugin/fu-firmware-image.h

@@ -31,8 +31,12 @@ struct _FuFirmwareImageClass
 						 XbNode			*n,
 						 GError			**error)
 						 G_GNUC_WARN_UNUSED_RESULT;
+	gchar			*(*get_checksum)(FuFirmwareImage	*self,
+						 GChecksumType		 csum_kind,
+						 GError			**error)
+						 G_GNUC_WARN_UNUSED_RESULT;
 	/*< private >*/
-	gpointer		 padding[27];
+	gpointer		 padding[26];
 };
 
 #define FU_FIRMWARE_IMAGE_ID_PAYLOAD		"payload"
@@ -63,6 +67,9 @@ void		 fu_firmware_image_set_idx	(FuFirmwareImage	*self,
 GBytes		*fu_firmware_image_get_bytes	(FuFirmwareImage	*self);
 void		 fu_firmware_image_set_bytes	(FuFirmwareImage	*self,
 						 GBytes			*bytes);
+gchar		*fu_firmware_image_get_checksum	(FuFirmwareImage	*self,
+						 GChecksumType		 csum_kind,
+						 GError			**error);
 gboolean	 fu_firmware_image_parse	(FuFirmwareImage	*self,
 						 GBytes			*fw,
 						 FwupdInstallFlags	 flags,

libfwupdplugin/fu-firmware.c

@@ -671,6 +671,51 @@ fu_firmware_get_image_by_idx (FuFirmware *self, guint64 idx, GError **error)
 	return NULL;
 }
 
+/**
+ * fu_firmware_get_image_by_checksum:
+ * @self: a #FuPlugin
+ * @checksum: checksum string of any format
+ * @error: A #GError, or %NULL
+ *
+ * Gets the firmware image using the image checksum. The checksum type is guessed
+ * based on the length of the input string.
+ *
+ * Returns: (transfer full): a #FuFirmwareImage, or %NULL if the image is not found
+ *
+ * Since: 1.5.5
+ **/
+FuFirmwareImage *
+fu_firmware_get_image_by_checksum (FuFirmware *self,
+				   const gchar *checksum,
+				   GError **error)
+{
+	FuFirmwarePrivate *priv = GET_PRIVATE (self);
+	GChecksumType csum_kind;
+
+	g_return_val_if_fail (FU_IS_FIRMWARE (self), NULL);
+	g_return_val_if_fail (checksum != NULL, NULL);
+	g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+	csum_kind = fwupd_checksum_guess_kind (checksum);
+	for (guint i = 0; i < priv->images->len; i++) {
+		FuFirmwareImage *img = g_ptr_array_index (priv->images, i);
+		g_autofree gchar *checksum_tmp = NULL;
+
+		/* if this expensive then the subclassed FuFirmwareImage can
+		 * cache the result as required */
+		checksum_tmp = fu_firmware_image_get_checksum (img, csum_kind, error);
+		if (checksum_tmp == NULL)
+			return NULL;
+		if (g_strcmp0 (checksum_tmp, checksum) == 0)
+			return g_object_ref (img);
+	}
+	g_set_error (error,
+		     FWUPD_ERROR,
+		     FWUPD_ERROR_NOT_FOUND,
+		     "no image with checksum %s found in firmware", checksum);
+	return NULL;
+}
+
 /**
  * fu_firmware_get_image_by_idx_bytes:
  * @self: a #FuPlugin

libfwupdplugin/fu-firmware.h

@@ -128,6 +128,9 @@ FuFirmwareImage *fu_firmware_get_image_by_idx		(FuFirmware	*self,
 GBytes		*fu_firmware_get_image_by_idx_bytes	(FuFirmware	*self,
 							 guint64	 idx,
 							 GError		**error);
+FuFirmwareImage	*fu_firmware_get_image_by_checksum	(FuFirmware	*self,
+							 const gchar	*checksum,
+							 GError		**error);
 FuFirmwareImage	*fu_firmware_get_image_default		(FuFirmware	*self,
 							 GError		**error);
 GBytes		*fu_firmware_get_image_default_bytes	(FuFirmware	*self,

libfwupdplugin/fwupdplugin.map

@@ -703,5 +703,7 @@ LIBFWUPDPLUGIN_1.5.4 {
 LIBFWUPDPLUGIN_1.5.5 {
   global:
     fu_device_retry_full;
+    fu_firmware_get_image_by_checksum;
+    fu_firmware_image_get_checksum;
   local: *;
 } LIBFWUPDPLUGIN_1.5.4;