Add new configuration keyword "RehashBl"

This feature is needed in case an image is updated at later stage
after bootimage has been created.

How to use:
  Add keyword "RehashBl" to configuration file, for example, update.cfg:
    RehashBl;

  Invoke cbootimage to re-calculate bootloader aes hash, for example, for
  bootimage bootloader.bin:
    $ cbootimage -s tegra210 --update update.cfg bootloader.bin bootloader.bin-resigned

  Where bootloader.bin-resigned is the resigned bootimage bootloader.bin

Signed-off-by: Jimmy Zhang <jimmzhang@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

7 files changed, 105 insertions, 0 deletions

diff --git a/samples/update.cfg b/samples/update.cfg
new file mode 100644
index 0000000..c5c741b
--- /dev/null
+++ b/samples/update.cfg
@@ -0,0 +1 @@
+RehashBl;
diff --git a/src/crypto.c b/src/crypto.c
index 039be0a..5438a53 100644
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -326,3 +326,37 @@ reverse_byte_order(
 	if (size % 2)
 		out[size / 2] = in[size / 2];
 }
+
+int
+sign_bl(build_image_context *context,
+	u_int8_t *bootloader,
+	u_int32_t length,
+	u_int32_t image_instance)
+{
+	int e = 0;
+	u_int8_t  *hash_buffer;
+	u_int32_t  hash_size;
+
+	g_soc_config->get_value(token_hash_size,
+			&hash_size, context->bct);
+
+	hash_buffer = calloc(1, hash_size);
+	if (hash_buffer == NULL)
+		return -ENOMEM;
+
+	/* Encrypt and compute hash */
+	if ((e = sign_data_block(bootloader,
+			length,
+			hash_buffer)) != 0)
+		goto fail;
+
+	if ((e = g_soc_config->setbl_param(image_instance,
+				token_bl_crypto_hash,
+				(u_int32_t*)hash_buffer,
+				context->bct)) != 0)
+		goto fail;
+
+ fail:
+	free(hash_buffer);
+	return e;
+}
diff --git a/src/crypto.h b/src/crypto.h
index f56b67d..3cd73f2 100644
--- a/src/crypto.h
+++ b/src/crypto.h
@@ -49,4 +49,11 @@ reverse_byte_order(
 	u_int8_t *out,
 	const u_int8_t *in,
 	const u_int32_t size);
+
+int
+sign_bl(build_image_context *context,
+	u_int8_t *bootloader,
+	u_int32_t length,
+	u_int32_t image_instance);
+
 #endif /* #ifndef INCLUDED_CRYPTO_H */
diff --git a/src/data_layout.c b/src/data_layout.c
index 0826092..5d3fe10 100644
--- a/src/data_layout.c
+++ b/src/data_layout.c
@@ -1065,3 +1065,54 @@ int get_bct_size_from_image(build_image_context *context)
 	context->bct = 0;
 	return bct_size;
 }
+
+int resign_bl(build_image_context *context)
+{
+	int ret;
+	u_int8_t  *buffer, *image;
+	u_int32_t  image_instance = 0;	/* support only one instance */
+	u_int32_t  image_actual_size; /* In bytes */
+	u_int32_t  bl_length;
+	u_int32_t  pages_in_image;
+	u_int32_t  blk_size, page_size, current_blk, current_page;
+	u_int32_t  offset;
+
+	/* read in bl from image */
+	g_soc_config->get_value(token_block_size, &blk_size, context->bct);
+	g_soc_config->get_value(token_page_size, &page_size, context->bct);
+
+	GET_BL_FIELD(image_instance, start_blk, &current_blk);
+	GET_BL_FIELD(image_instance, start_page,  &current_page);
+	GET_BL_FIELD(image_instance, length,  &bl_length);
+
+	offset = current_blk * blk_size +
+			current_page * page_size;
+
+	if (read_from_image(context->input_image_filename,
+				offset, bl_length,
+				&image, &image_actual_size, file_type_bin)) {
+		printf("Error reading image file %s.\n",
+				context->input_image_filename);
+		return -ENOMEM;
+	}
+
+	pages_in_image = ICEIL(image_actual_size, page_size);
+
+	/* Create a local copy of the bl */
+	if ((buffer = malloc(pages_in_image * page_size)) == NULL) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	memset(buffer, 0, pages_in_image * page_size);
+	memcpy(buffer, image, image_actual_size);
+
+	insert_padding(buffer, image_actual_size);
+
+	/* sign bl */
+	ret = sign_bl(context, buffer, image_actual_size, image_instance);
+	free (buffer);
+ fail:
+	free (image);
+	return ret;
+}
diff --git a/src/data_layout.h b/src/data_layout.h
index c6e53e6..0e6e41f 100644
--- a/src/data_layout.h
+++ b/src/data_layout.h
@@ -64,4 +64,6 @@ get_bct_size_from_image(build_image_context *context);
 int
 begin_update(build_image_context *context);
 
+int
+resign_bl(build_image_context *context);
 #endif /* #ifndef INCLUDED_DATA_LAYOUT_H */
diff --git a/src/parse.c b/src/parse.c
index 667895c..6f37dad 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -80,6 +80,8 @@ static int
 parse_dev_param(build_image_context *context, parse_token token, char *rest);
 static int
 parse_sdram_param(build_image_context *context, parse_token token, char *rest);
+static int
+parse_sign_bl(build_image_context *context, parse_token token, char *rest);
 
 static int process_statement(build_image_context *context,
 				char *str,
@@ -121,6 +123,7 @@ static parse_item s_top_level_items[] = {
 	{ "RsaKeyModulusFile=", token_rsa_key_modulus,	parse_rsa_param },
 	{ "RsaPssSigBlFile=",   token_rsa_pss_sig_bl,	parse_rsa_param },
 	{ "RsaPssSigBctFile=",  token_rsa_pss_sig_bct,	parse_rsa_param },
+	{ "RehashBl",       token_sign_bl,		parse_sign_bl },
 	{ NULL, 0, NULL } /* Must be last */
 };
 
@@ -689,6 +692,12 @@ parse_bct_file(build_image_context *context, parse_token token, char *rest)
 	return 0;
 }
 
+static int
+parse_sign_bl(build_image_context *context, parse_token token, char *rest)
+{
+	return resign_bl(context);
+}
+
 static char *
 parse_end_state(char *str, char *uname, int chars_remaining)
 {
diff --git a/src/parse.h b/src/parse.h
index f2e28b3..191742c 100644
--- a/src/parse.h
+++ b/src/parse.h
@@ -117,6 +117,7 @@ typedef enum
 	token_rsa_key_modulus,
 	token_rsa_pss_sig_bl,
 	token_rsa_pss_sig_bct,
+	token_sign_bl,
 
 	token_nand_clock_divider,
 	token_nand_nand_timing,