[PATCH 3/4] cmd: mvebu/bubt: Add support for sha512 checksum validation for Armada 3700

["Pali Rohár" <pali@kernel.org>]

Armada 3700 BootROM supports also images with sha512 checksums and
mox-imager tool [1] generates such bootable images. Without sha512 support
U-Boot bubt command just prints error message:

  Error: Unsupported hash_algorithm_id = 64
  Error: Image header verification failed

This patch adds support for sha512 checksum validation for Armada 3700
images. With it bubt prints:

  Image checksum...OK!

[1] - https://gitlab.nic.cz/turris/mox-boot-builder.git

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 cmd/mvebu/Kconfig | 1 +
 cmd/mvebu/bubt.c  | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/cmd/mvebu/Kconfig b/cmd/mvebu/Kconfig
index 39963db82c98..120397d6d4d0 100644
--- a/cmd/mvebu/Kconfig
+++ b/cmd/mvebu/Kconfig
@@ -4,6 +4,7 @@ depends on ARCH_MVEBU
 config CMD_MVEBU_BUBT
 	bool "bubt"
 	select SHA256 if ARMADA_3700
+	select SHA512 if ARMADA_3700
 	help
 	  bubt - Burn a u-boot image to flash
 	  For details about bubt command please see the documentation
diff --git a/cmd/mvebu/bubt.c b/cmd/mvebu/bubt.c
index 2924b1539f32..276069a0efc2 100644
--- a/cmd/mvebu/bubt.c
+++ b/cmd/mvebu/bubt.c
@@ -26,6 +26,7 @@
 #endif
 #include <u-boot/sha1.h>
 #include <u-boot/sha256.h>
+#include <u-boot/sha512.h>
 
 #if defined(CONFIG_ARMADA_8K)
 #define MAIN_HDR_MAGIC		0xB105B002
@@ -566,8 +567,10 @@ static int check_image_header(void)
 	int image_num;
 	u8 hash_160_output[SHA1_SUM_LEN];
 	u8 hash_256_output[SHA256_SUM_LEN];
+	u8 hash_512_output[SHA512_SUM_LEN];
 	sha1_context hash1_text;
 	sha256_context hash256_text;
+	sha512_context hash512_text;
 	u8 *hash_output;
 	u32 hash_algorithm_id;
 	u32 image_size_to_hash;
@@ -637,6 +640,12 @@ static int check_image_header(void)
 			sha256_finish(&hash256_text, hash_256_output);
 			hash_output = hash_256_output;
 			break;
+		case SHA512_SUM_LEN:
+			sha512_starts(&hash512_text);
+			sha512_update(&hash512_text, buff, image_size_to_hash);
+			sha512_finish(&hash512_text, hash_512_output);
+			hash_output = hash_512_output;
+			break;
 		default:
 			printf("Error: Unsupported hash_algorithm_id = %d\n",
 			       hash_algorithm_id);
-- 
2.20.1