diff options
Diffstat (limited to 'src/image/der.c')
| -rw-r--r-- | src/image/der.c | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/src/image/der.c b/src/image/der.c index fa17e5659..9d31c253b 100644 --- a/src/image/der.c +++ b/src/image/der.c @@ -76,8 +76,6 @@ static int der_probe ( struct image *image ) { struct asn1_cursor cursor; uint8_t buf[8]; size_t extra; - size_t total; - int len; int rc; /* Sanity check: no realistic DER image can be smaller than this */ @@ -90,21 +88,16 @@ static int der_probe ( struct image *image ) { copy_from_user ( buf, image->data, 0, sizeof ( buf ) ); extra = ( image->len - sizeof ( buf ) ); - /* Get length of ASN.1 sequence */ - len = asn1_start ( &cursor, ASN1_SEQUENCE, extra ); - if ( len < 0 ) { - rc = len; + /* Check that image begins with an ASN.1 sequence object */ + if ( ( rc = asn1_enter_partial ( &cursor, ASN1_SEQUENCE, + &extra ) ) != 0 ) { DBGC ( image, "DER %s is not valid ASN.1: %s\n", image->name, strerror ( rc ) ); return rc; } - /* Add length of tag and length bytes consumed by asn1_start() */ - total = ( len + ( cursor.data - ( ( void * ) buf ) ) ); - assert ( total <= image->len ); - /* Check that image comprises a single well-formed ASN.1 object */ - if ( total != image->len ) { + if ( extra != ( image->len - sizeof ( buf ) ) ) { DBGC ( image, "DER %s is not single ASN.1\n", image->name ); return -ENOEXEC; } |