mkimage: fit: add support to encrypt image with aes

This commit add the support of encrypting image with aes
in mkimage. To enable the ciphering, a node cipher with
a reference to a key and IV (Initialization Vector) must
be added to the its file. Then mkimage add the encrypted
image to the FIT and add the key and IV to the u-boot
device tree.

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

common/image-cipher.c

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Softathome
+ */
+
+#ifdef USE_HOSTCC
+#include "mkimage.h"
+#include <time.h>
+#else
+#include <common.h>
+#include <malloc.h>
+DECLARE_GLOBAL_DATA_PTR;
+#endif /* !USE_HOSTCC*/
+#include <image.h>
+#include <uboot_aes.h>
+#include <u-boot/aes.h>
+
+struct cipher_algo cipher_algos[] = {
+	{
+		.name = "aes128",
+		.key_len = AES128_KEY_LENGTH,
+		.iv_len  = AES_BLOCK_LENGTH,
+#if IMAGE_ENABLE_ENCRYPT
+		.calculate_type = EVP_aes_128_cbc,
+#endif
+		.encrypt = image_aes_encrypt,
+		.add_cipher_data = image_aes_add_cipher_data
+	},
+	{
+		.name = "aes192",
+		.key_len = AES192_KEY_LENGTH,
+		.iv_len  = AES_BLOCK_LENGTH,
+#if IMAGE_ENABLE_ENCRYPT
+		.calculate_type = EVP_aes_192_cbc,
+#endif
+		.encrypt = image_aes_encrypt,
+		.add_cipher_data = image_aes_add_cipher_data
+	},
+	{
+		.name = "aes256",
+		.key_len = AES256_KEY_LENGTH,
+		.iv_len  = AES_BLOCK_LENGTH,
+#if IMAGE_ENABLE_ENCRYPT
+		.calculate_type = EVP_aes_256_cbc,
+#endif
+		.encrypt = image_aes_encrypt,
+		.add_cipher_data = image_aes_add_cipher_data
+	}
+};
+
+struct cipher_algo *image_get_cipher_algo(const char *full_name)
+{
+	int i;
+	const char *name;
+
+	for (i = 0; i < ARRAY_SIZE(cipher_algos); i++) {
+		name = cipher_algos[i].name;
+		if (!strncmp(name, full_name, strlen(name)))
+			return &cipher_algos[i];
+	}
+
+	return NULL;
+}