sbtools: add option to force sb dump

In the case of encrypted SB files without any key match, it is
still possible to dump the section headers. The force option
allows one to do so. It also allows to dump unencrypted sections
of encrypted files if there are some.

Change-Id: I36280230679ac5903f9c451c68c276f5c6959536

1 files changed, 27 insertions, 4 deletions

diff --git a/utils/imxtools/sbtools/sb.c b/utils/imxtools/sbtools/sb.c
index 9b97509..78f98b5 100644
--- a/utils/imxtools/sbtools/sb.c
+++ b/utils/imxtools/sbtools/sb.c
@@ -503,7 +503,7 @@ static struct sb_section_t *read_section(bool data_sec, uint32_t id, byte *buf,
         printf(OFF, "%s", indent);
         uint8_t checksum = instruction_checksum(hdr);
         if(checksum != hdr->checksum)
-            fatal(SB_CHECKSUM_ERROR, "Bad instruction checksum");
+            fatal(SB_CHECKSUM_ERROR, "Bad instruction checksum\n");
         if(hdr->flags != 0)
         {
             printf(GREY, "[");
@@ -788,7 +788,8 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
         printf(BLUE, "Encryption keys\n");
         for(int i = 0; i < g_nr_keys; i++)
         {
-            printf(RED, "  Key %d: ", i);
+            printf(RED, "  Key %d\n", i),
+            printf(GREEN, "    Key: ");
             printf(YELLOW, "");
             print_key(&g_key_array[i], true);
             printf(GREEN, "    CBC-MAC: ");
@@ -859,7 +860,12 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
         free(cbcmacs);
 
         if(!valid_key)
-            fatal(SB_NO_VALID_KEY, "No valid key found\n");
+        {
+            if(g_force)
+                printf(GREY, "  No valid key found\n");
+            else
+                fatal(SB_NO_VALID_KEY, "No valid key found\n");
+        }
 
         if(getenv("SB_REAL_KEY") != 0)
         {
@@ -868,6 +874,12 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
             if(!parse_key(&env, &k) || *env)
                 fatal(SB_ERROR, "Invalid SB_REAL_KEY\n");
             memcpy(real_key, k.u.key, 16);
+            /* assume the key is valid */
+            if(valid_key)
+                printf(GREY, "  Overriding real key\n");
+            else
+                printf(GREY, "  Assuming real key is ok\n");
+            valid_key = true;
         }
 
         printf(RED, "  Summary:\n");
@@ -916,6 +928,13 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
             if(encrypted)
                 printf(RED, " (Encrypted)");
             printf(OFF, "\n");
+
+            /* skip it if we cannot decrypt it */
+            if(encrypted && !valid_key)
+            {
+                printf(GREY, "  Skipping section content (no valid key)\n");
+                continue;
+            }
             
             /* save it */
             byte *sec = xmalloc(size);
@@ -939,7 +958,7 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
             free(sec);
         }
     }
-    else
+    else if(valid_key)
     {
         /* advanced raw mode */
         printf(BLUE, "Commands\n");
@@ -1041,6 +1060,10 @@ struct sb_file_t *sb_read_memory(void *_buf, size_t filesize, bool raw_mode, voi
             }
         }
     }
+    else
+    {
+        printf(GREY, "Cannot read content in raw mode without a valid key\n");
+    }
     
     /* final signature */
     printf(BLUE, "Final signature:\n");