From 0c43e25e4bd81b9f30e3103380d32c876f728edf Mon Sep 17 00:00:00 2001
From: TJ <hacker@iam.tj>
Date: Fri, 8 Apr 2016 12:17:21 +0100
Subject: [PATCH] Add CRC32 calculation for headers and image payloads

---
 firmware_header_dump.c | 46 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/firmware_header_dump.c b/firmware_header_dump.c
index 0594376..5e1f99e 100644
--- a/firmware_header_dump.c
+++ b/firmware_header_dump.c
@@ -84,7 +84,7 @@ unsigned int crc32(const unsigned char *data, ssize_t len, unsigned int crc)
 int
 main(int argc, char **argv)
 {
-  unsigned int arg, crc;
+  unsigned int arg, crc_header, crc_payload;
   char *filename = NULL;
   int fd, fd_mode;
   unsigned char *buffer = NULL;
@@ -132,9 +132,12 @@ main(int argc, char **argv)
      unsigned int offset = 0;
      unsigned int count = 0;
      unsigned int next = 1;
+     void *payload = NULL;
 
      while (next) {
        unsigned long len = 0;
+       crc_header = crc_payload = 0xffffffff;
+
        if (count) // switch struct type after initial file header
          header_len = sizeof(IMAGE_TAG);
 
@@ -159,11 +162,28 @@ main(int argc, char **argv)
          } else {
            next = *(unsigned char *)(pimage->imageNext);
            len = atol(pimage->imageLen);
+           offset += sizeof(IMAGE_TAG);
          }
 
-         if (!count) {
-           printf("Image Offset:  0x%08x\n", 0x20000);
+         crc_header = crc32(buffer, header_len - (count ? CRC_LEN : TOKEN_LEN), crc_header);
+
+         // read payload and calculate CRC32
+         lseek(fd, offset, SEEK_SET);
+         if ( (payload = heap_and_reap(NULL, len, 1)) != NULL) {
+           if ( (qty = read(fd, payload, len)) < len) {
+             fprintf(stderr, "skipping CRC calculation: only able to read %ld of %ld bytes\n", qty, len);
+           } else {
+             crc_payload = crc32(payload, len, crc_payload);
+
+             heap_and_reap(payload, 0, 0);
+           }
+         } else {
+           close(fd);
+           pr_error_exit(0, "unable to allocate memory (%ld bytes)\n", len);
+         }
 
+         if (!count) {
+           printf("Image Offset:  0x%08x\n", offset);
            printf("%04lx Tag Version: %s\n"
                   "%04lx Signature 1: %s\n"
                   "%04lx Signature 2: %s\n"
@@ -182,7 +202,9 @@ main(int argc, char **argv)
                   "%04lx Internal Version: %s\n"
                   "%04lx Image Next: %u\n"
                   "%04lx Image Validation Token: 0x%08x\n"
-                  "%04lx Tag Validation Token: 0x%08x\n"
+                  "%04lx Tag Validation Token:   0x%08x\n"
+                  "     Calculated Image CRC32: 0x%08x\n"
+                  "     Calculated Tag   CRC32: 0x%08x\n"
                   "\n",
                   offsetof(struct _FILE_TAG, tagVersion), pfile->tagVersion,
                   offsetof(struct _FILE_TAG, signiture_1), pfile->signiture_1,
@@ -202,27 +224,35 @@ main(int argc, char **argv)
                   offsetof(struct _FILE_TAG, internalversion), pfile->internalversion,
                   offsetof(struct _FILE_TAG, imageNext), next,
                   offsetof(struct _FILE_TAG, imageValidationToken), ntohl( *((unsigned int *)(pfile->imageValidationToken)) ),
-                  offsetof(struct _FILE_TAG, tagValidationToken), ntohl( *((unsigned int *)(pfile->tagValidationToken)) )
+                  offsetof(struct _FILE_TAG, tagValidationToken), ntohl( *((unsigned int *)(pfile->tagValidationToken)) ),
+                  crc_payload,
+                  crc_header
            );
 
          } else {
-           printf("Image Offset:  0x%08lx\n", offset + sizeof(IMAGE_TAG));
+           printf("Image Offset:  0x%08x\n", offset);
            printf("%04lx Image Next: %u\n"
                   "%04lx Image Type: %s (%lu)\n"
                   "%04lx Image Signature: %u\n"
                   "%04lx Image Len: %s (0x%08lx)\n"
                   "%04lx Image Validation Token: 0x%08x\n"
-                  "%04lx Tag Validation Token: 0x%08x\n"
+                  "%04lx Tag Validation Token:   0x%08x\n"
+                  "     Calculated Image CRC32: 0x%08x\n"
+                  "     Calculated Tag CRC32:   0x%08x\n"
                   "\n",
                   offsetof(struct _IMAGE_TAG, imageNext), next,
                   offsetof(struct _IMAGE_TAG, imageType), image_type[atol(pimage->imageType)], atol(pimage->imageType),
                   offsetof(struct _IMAGE_TAG, imageSignature), (unsigned int)*pimage->imageSignature,
                   offsetof(struct _IMAGE_TAG, imageLen), pimage->imageLen, len,
                   offsetof(struct _IMAGE_TAG, imageValidationToken), ntohl( *((unsigned int *)(pimage->imageValidationToken)) ),
-                  offsetof(struct _IMAGE_TAG, tagValidationToken), ntohl( *((unsigned int *)(pimage->tagValidationToken)) )
+                  offsetof(struct _IMAGE_TAG, tagValidationToken), ntohl( *((unsigned int *)(pimage->tagValidationToken)) ),
+                  crc_payload,
+                  crc_header
            );
          }
 
+
+         // next seek point will be end of current payload
          offset += len;
 
          heap_and_reap(buffer, 0, 0);
-- 
2.17.1