u-boot: fit: add support to decrypt fit with aes

This commit add to u-boot the support to decrypt
fit image encrypted with aes. The FIT image contains
the key name and the IV name. Then u-boot look for
the key and IV in his device tree and decrypt images
before moving to the next stage.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/common/image-fit.c b/common/image-fit.c
index 6b50ceba1a..f3bb00c98a 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -948,6 +948,31 @@ int fit_image_get_data_size(const void *fit, int noffset, int *data_size)
 }
 
 /**
+ * Get 'data-size-unciphered' property from a given image node.
+ *
+ * @fit: pointer to the FIT image header
+ * @noffset: component image node offset
+ * @data_size: holds the data-size property
+ *
+ * returns:
+ *     0, on success
+ *     -ENOENT if the property could not be found
+ */
+int fit_image_get_data_size_unciphered(const void *fit, int noffset,
+				       size_t *data_size)
+{
+	const fdt32_t *val;
+
+	val = fdt_getprop(fit, noffset, "data-size-unciphered", NULL);
+	if (!val)
+		return -ENOENT;
+
+	*data_size = (size_t)fdt32_to_cpu(*val);
+
+	return 0;
+}
+
+/**
  * fit_image_get_data_and_size - get data and its size including
  *				 both embedded and external data
  * @fit: pointer to the FIT format image header
@@ -1381,6 +1406,32 @@ int fit_all_image_verify(const void *fit)
 	return 1;
 }
 
+#ifdef CONFIG_FIT_CIPHER
+static int fit_image_uncipher(const void *fit, int image_noffset,
+			      void **data, size_t *size)
+{
+	int cipher_noffset, ret;
+	void *dst;
+	size_t size_dst;
+
+	cipher_noffset = fdt_subnode_offset(fit, image_noffset,
+					    FIT_CIPHER_NODENAME);
+	if (cipher_noffset < 0)
+		return 0;
+
+	ret = fit_image_decrypt_data(fit, image_noffset, cipher_noffset,
+				     *data, *size, &dst, &size_dst);
+	if (ret)
+		goto out;
+
+	*data = dst;
+	*size = size_dst;
+
+ out:
+	return ret;
+}
+#endif /* CONFIG_FIT_CIPHER */
+
 /**
  * fit_image_check_os - check whether image node is of a given os type
  * @fit: pointer to the FIT format image header
@@ -1981,6 +2032,18 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 		return -ENOENT;
 	}
 
+#ifdef CONFIG_FIT_CIPHER
+	/* Decrypt data before uncompress/move */
+	if (IMAGE_ENABLE_DECRYPT) {
+		puts("   Decrypting Data ... ");
+		if (fit_image_uncipher(fit, noffset, &buf, &size)) {
+			puts("Error\n");
+			return -EACCES;
+		}
+		puts("OK\n");
+	}
+#endif
+
 #if !defined(USE_HOSTCC) && defined(CONFIG_FIT_IMAGE_POST_PROCESS)
 	/* perform any post-processing on the image data */
 	board_fit_image_post_process(&buf, &size);