regfio: Allow ignoring of checksum

In order to get good coverage fuzzing code has to either calculate
checksums correctly or to disable their verification. This change
implements the latter for the "REGF_FILE" structure used by the
"regfio_*" family of functions.

Signed-off-by: Michael Hanselmann <public@hansmi.ch>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Uri Simchoni <uri@samba.org>

diff --git a/source3/registry/regfio.c b/source3/registry/regfio.c
index 4c6271cda7aa603949f59987086511127199ec67..930ac834d1a2921bab673c6ade1904560a048068 100644 (file)
--- a/source3/registry/regfio.c
+++ b/source3/registry/regfio.c
@@ -482,7 +482,7 @@ static bool read_regf_block( REGF_FILE *file )
        
        prs_mem_free( &ps );
        
-       if ( file->checksum !=  checksum ) {
+       if ( file->checksum != checksum && !file->ignore_checksums) {
                DEBUG(0,("read_regf_block: invalid checksum\n" ));
                return False;
        }
@@ -1242,6 +1242,7 @@ out:
        }
        ZERO_STRUCTP( rb );
        rb->fd = -1;
+       rb->ignore_checksums = false;
        
        if ( !(rb->mem_ctx = talloc_init( "regfio_open" )) ) {
                regfio_close( rb );

diff --git a/source3/registry/regfio.h b/source3/registry/regfio.h
index 23a44c9c88aa9372a749589fd7bf9939ade6ba8e..172427f1985798b529d5191122052b7a5db606b8 100644 (file)
--- a/source3/registry/regfio.h
+++ b/source3/registry/regfio.h
@@ -199,6 +199,13 @@ typedef struct {
        
        REGF_SK_REC *sec_desc_list;     /* list of security descriptors referenced by NK records */
 
+       /* Ignore checksums in input data. Used by fuzzing code to allow more
+        * coverage without having to calcuate a valid checksum. The checksums
+        * are merely to detect data corruption and don't provide a security
+        * value.
+        */
+       bool ignore_checksums;
+
        /* unknowns used to simply writing */
        
        uint32_t unknown1;